/* |
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* Copyright (c) 1996, 2019, Oracle and/or its affiliates. All rights reserved. |
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* DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. |
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* |
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* This code is free software; you can redistribute it and/or modify it |
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* under the terms of the GNU General Public License version 2 only, as |
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* published by the Free Software Foundation. Oracle designates this |
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* particular file as subject to the "Classpath" exception as provided |
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* by Oracle in the LICENSE file that accompanied this code. |
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* |
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* This code is distributed in the hope that it will be useful, but WITHOUT |
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* ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or |
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* FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License |
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* version 2 for more details (a copy is included in the LICENSE file that |
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* accompanied this code). |
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* |
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* You should have received a copy of the GNU General Public License version |
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* 2 along with this work; if not, write to the Free Software Foundation, |
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* Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. |
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* |
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* Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA |
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* or visit www.oracle.com if you need additional information or have any |
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* questions. |
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*/ |
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/* |
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* Portions Copyright IBM Corporation, 2001. All Rights Reserved. |
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*/ |
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package java.math; |
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import static java.math.BigInteger.LONG_MASK; |
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import java.util.Arrays; |
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/** |
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* Immutable, arbitrary-precision signed decimal numbers. A |
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* {@code BigDecimal} consists of an arbitrary precision integer |
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* <i>unscaled value</i> and a 32-bit integer <i>scale</i>. If zero |
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* or positive, the scale is the number of digits to the right of the |
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* decimal point. If negative, the unscaled value of the number is |
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* multiplied by ten to the power of the negation of the scale. The |
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* value of the number represented by the {@code BigDecimal} is |
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* therefore <tt>(unscaledValue × 10<sup>-scale</sup>)</tt>. |
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* |
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* <p>The {@code BigDecimal} class provides operations for |
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* arithmetic, scale manipulation, rounding, comparison, hashing, and |
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* format conversion. The {@link #toString} method provides a |
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* canonical representation of a {@code BigDecimal}. |
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* |
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* <p>The {@code BigDecimal} class gives its user complete control |
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* over rounding behavior. If no rounding mode is specified and the |
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* exact result cannot be represented, an exception is thrown; |
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* otherwise, calculations can be carried out to a chosen precision |
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* and rounding mode by supplying an appropriate {@link MathContext} |
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* object to the operation. In either case, eight <em>rounding |
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* modes</em> are provided for the control of rounding. Using the |
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* integer fields in this class (such as {@link #ROUND_HALF_UP}) to |
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* represent rounding mode is largely obsolete; the enumeration values |
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* of the {@code RoundingMode} {@code enum}, (such as {@link |
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* RoundingMode#HALF_UP}) should be used instead. |
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* |
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* <p>When a {@code MathContext} object is supplied with a precision |
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* setting of 0 (for example, {@link MathContext#UNLIMITED}), |
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* arithmetic operations are exact, as are the arithmetic methods |
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* which take no {@code MathContext} object. (This is the only |
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* behavior that was supported in releases prior to 5.) As a |
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* corollary of computing the exact result, the rounding mode setting |
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* of a {@code MathContext} object with a precision setting of 0 is |
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* not used and thus irrelevant. In the case of divide, the exact |
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* quotient could have an infinitely long decimal expansion; for |
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* example, 1 divided by 3. If the quotient has a nonterminating |
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* decimal expansion and the operation is specified to return an exact |
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* result, an {@code ArithmeticException} is thrown. Otherwise, the |
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* exact result of the division is returned, as done for other |
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* operations. |
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* |
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* <p>When the precision setting is not 0, the rules of |
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* {@code BigDecimal} arithmetic are broadly compatible with selected |
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* modes of operation of the arithmetic defined in ANSI X3.274-1996 |
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* and ANSI X3.274-1996/AM 1-2000 (section 7.4). Unlike those |
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* standards, {@code BigDecimal} includes many rounding modes, which |
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* were mandatory for division in {@code BigDecimal} releases prior |
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* to 5. Any conflicts between these ANSI standards and the |
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* {@code BigDecimal} specification are resolved in favor of |
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* {@code BigDecimal}. |
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* |
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* <p>Since the same numerical value can have different |
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* representations (with different scales), the rules of arithmetic |
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* and rounding must specify both the numerical result and the scale |
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* used in the result's representation. |
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* |
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* |
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* <p>In general the rounding modes and precision setting determine |
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* how operations return results with a limited number of digits when |
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* the exact result has more digits (perhaps infinitely many in the |
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* case of division) than the number of digits returned. |
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* |
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* First, the |
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* total number of digits to return is specified by the |
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* {@code MathContext}'s {@code precision} setting; this determines |
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* the result's <i>precision</i>. The digit count starts from the |
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* leftmost nonzero digit of the exact result. The rounding mode |
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* determines how any discarded trailing digits affect the returned |
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* result. |
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* |
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* <p>For all arithmetic operators , the operation is carried out as |
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* though an exact intermediate result were first calculated and then |
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* rounded to the number of digits specified by the precision setting |
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* (if necessary), using the selected rounding mode. If the exact |
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* result is not returned, some digit positions of the exact result |
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* are discarded. When rounding increases the magnitude of the |
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* returned result, it is possible for a new digit position to be |
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* created by a carry propagating to a leading {@literal "9"} digit. |
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* For example, rounding the value 999.9 to three digits rounding up |
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* would be numerically equal to one thousand, represented as |
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* 100×10<sup>1</sup>. In such cases, the new {@literal "1"} is |
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* the leading digit position of the returned result. |
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* |
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* <p>Besides a logical exact result, each arithmetic operation has a |
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* preferred scale for representing a result. The preferred |
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* scale for each operation is listed in the table below. |
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* |
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* <table border> |
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* <caption><b>Preferred Scales for Results of Arithmetic Operations |
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* </b></caption> |
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* <tr><th>Operation</th><th>Preferred Scale of Result</th></tr> |
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* <tr><td>Add</td><td>max(addend.scale(), augend.scale())</td> |
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* <tr><td>Subtract</td><td>max(minuend.scale(), subtrahend.scale())</td> |
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* <tr><td>Multiply</td><td>multiplier.scale() + multiplicand.scale()</td> |
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* <tr><td>Divide</td><td>dividend.scale() - divisor.scale()</td> |
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* </table> |
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* |
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* These scales are the ones used by the methods which return exact |
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* arithmetic results; except that an exact divide may have to use a |
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* larger scale since the exact result may have more digits. For |
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* example, {@code 1/32} is {@code 0.03125}. |
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* |
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* <p>Before rounding, the scale of the logical exact intermediate |
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* result is the preferred scale for that operation. If the exact |
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* numerical result cannot be represented in {@code precision} |
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* digits, rounding selects the set of digits to return and the scale |
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* of the result is reduced from the scale of the intermediate result |
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* to the least scale which can represent the {@code precision} |
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* digits actually returned. If the exact result can be represented |
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* with at most {@code precision} digits, the representation |
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* of the result with the scale closest to the preferred scale is |
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* returned. In particular, an exactly representable quotient may be |
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* represented in fewer than {@code precision} digits by removing |
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* trailing zeros and decreasing the scale. For example, rounding to |
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* three digits using the {@linkplain RoundingMode#FLOOR floor} |
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* rounding mode, <br> |
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* |
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* {@code 19/100 = 0.19 // integer=19, scale=2} <br> |
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* |
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* but<br> |
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* |
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* {@code 21/110 = 0.190 // integer=190, scale=3} <br> |
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* |
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* <p>Note that for add, subtract, and multiply, the reduction in |
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* scale will equal the number of digit positions of the exact result |
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* which are discarded. If the rounding causes a carry propagation to |
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* create a new high-order digit position, an additional digit of the |
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* result is discarded than when no new digit position is created. |
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* |
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* <p>Other methods may have slightly different rounding semantics. |
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* For example, the result of the {@code pow} method using the |
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* {@linkplain #pow(int, MathContext) specified algorithm} can |
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* occasionally differ from the rounded mathematical result by more |
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* than one unit in the last place, one <i>{@linkplain #ulp() ulp}</i>. |
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* |
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* <p>Two types of operations are provided for manipulating the scale |
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* of a {@code BigDecimal}: scaling/rounding operations and decimal |
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* point motion operations. Scaling/rounding operations ({@link |
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* #setScale setScale} and {@link #round round}) return a |
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* {@code BigDecimal} whose value is approximately (or exactly) equal |
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* to that of the operand, but whose scale or precision is the |
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* specified value; that is, they increase or decrease the precision |
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* of the stored number with minimal effect on its value. Decimal |
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* point motion operations ({@link #movePointLeft movePointLeft} and |
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* {@link #movePointRight movePointRight}) return a |
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* {@code BigDecimal} created from the operand by moving the decimal |
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* point a specified distance in the specified direction. |
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* |
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* <p>For the sake of brevity and clarity, pseudo-code is used |
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* throughout the descriptions of {@code BigDecimal} methods. The |
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* pseudo-code expression {@code (i + j)} is shorthand for "a |
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* {@code BigDecimal} whose value is that of the {@code BigDecimal} |
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* {@code i} added to that of the {@code BigDecimal} |
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* {@code j}." The pseudo-code expression {@code (i == j)} is |
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* shorthand for "{@code true} if and only if the |
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* {@code BigDecimal} {@code i} represents the same value as the |
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* {@code BigDecimal} {@code j}." Other pseudo-code expressions |
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* are interpreted similarly. Square brackets are used to represent |
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* the particular {@code BigInteger} and scale pair defining a |
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* {@code BigDecimal} value; for example [19, 2] is the |
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* {@code BigDecimal} numerically equal to 0.19 having a scale of 2. |
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* |
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* <p>Note: care should be exercised if {@code BigDecimal} objects |
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* are used as keys in a {@link java.util.SortedMap SortedMap} or |
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* elements in a {@link java.util.SortedSet SortedSet} since |
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* {@code BigDecimal}'s <i>natural ordering</i> is <i>inconsistent |
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* with equals</i>. See {@link Comparable}, {@link |
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* java.util.SortedMap} or {@link java.util.SortedSet} for more |
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* information. |
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* |
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* <p>All methods and constructors for this class throw |
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* {@code NullPointerException} when passed a {@code null} object |
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* reference for any input parameter. |
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* |
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* @see BigInteger |
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* @see MathContext |
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* @see RoundingMode |
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* @see java.util.SortedMap |
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* @see java.util.SortedSet |
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* @author Josh Bloch |
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* @author Mike Cowlishaw |
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* @author Joseph D. Darcy |
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* @author Sergey V. Kuksenko |
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*/ |
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public class BigDecimal extends Number implements Comparable<BigDecimal> { |
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/** |
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* The unscaled value of this BigDecimal, as returned by {@link |
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* #unscaledValue}. |
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* |
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* @serial |
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* @see #unscaledValue |
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*/ |
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private final BigInteger intVal; |
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/** |
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* The scale of this BigDecimal, as returned by {@link #scale}. |
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* |
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* @serial |
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* @see #scale |
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*/ |
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private final int scale; // Note: this may have any value, so |
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// calculations must be done in longs |
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/** |
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* The number of decimal digits in this BigDecimal, or 0 if the |
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* number of digits are not known (lookaside information). If |
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* nonzero, the value is guaranteed correct. Use the precision() |
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* method to obtain and set the value if it might be 0. This |
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* field is mutable until set nonzero. |
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* |
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* @since 1.5 |
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*/ |
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private transient int precision; |
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/** |
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* Used to store the canonical string representation, if computed. |
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*/ |
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private transient String stringCache; |
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/** |
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* Sentinel value for {@link #intCompact} indicating the |
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* significand information is only available from {@code intVal}. |
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*/ |
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static final long INFLATED = Long.MIN_VALUE; |
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private static final BigInteger INFLATED_BIGINT = BigInteger.valueOf(INFLATED); |
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/** |
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* If the absolute value of the significand of this BigDecimal is |
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* less than or equal to {@code Long.MAX_VALUE}, the value can be |
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* compactly stored in this field and used in computations. |
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*/ |
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private final transient long intCompact; |
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// All 18-digit base ten strings fit into a long; not all 19-digit |
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// strings will |
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private static final int MAX_COMPACT_DIGITS = 18; |
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/* Appease the serialization gods */ |
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private static final long serialVersionUID = 6108874887143696463L; |
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private static final ThreadLocal<StringBuilderHelper> |
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threadLocalStringBuilderHelper = new ThreadLocal<StringBuilderHelper>() { |
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@Override |
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protected StringBuilderHelper initialValue() { |
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return new StringBuilderHelper(); |
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} |
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}; |
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// Cache of common small BigDecimal values. |
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private static final BigDecimal zeroThroughTen[] = { |
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new BigDecimal(BigInteger.ZERO, 0, 0, 1), |
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new BigDecimal(BigInteger.ONE, 1, 0, 1), |
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new BigDecimal(BigInteger.valueOf(2), 2, 0, 1), |
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new BigDecimal(BigInteger.valueOf(3), 3, 0, 1), |
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new BigDecimal(BigInteger.valueOf(4), 4, 0, 1), |
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new BigDecimal(BigInteger.valueOf(5), 5, 0, 1), |
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new BigDecimal(BigInteger.valueOf(6), 6, 0, 1), |
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new BigDecimal(BigInteger.valueOf(7), 7, 0, 1), |
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new BigDecimal(BigInteger.valueOf(8), 8, 0, 1), |
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new BigDecimal(BigInteger.valueOf(9), 9, 0, 1), |
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new BigDecimal(BigInteger.TEN, 10, 0, 2), |
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}; |
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// Cache of zero scaled by 0 - 15 |
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private static final BigDecimal[] ZERO_SCALED_BY = { |
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zeroThroughTen[0], |
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new BigDecimal(BigInteger.ZERO, 0, 1, 1), |
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new BigDecimal(BigInteger.ZERO, 0, 2, 1), |
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new BigDecimal(BigInteger.ZERO, 0, 3, 1), |
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new BigDecimal(BigInteger.ZERO, 0, 4, 1), |
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new BigDecimal(BigInteger.ZERO, 0, 5, 1), |
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new BigDecimal(BigInteger.ZERO, 0, 6, 1), |
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new BigDecimal(BigInteger.ZERO, 0, 7, 1), |
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new BigDecimal(BigInteger.ZERO, 0, 8, 1), |
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new BigDecimal(BigInteger.ZERO, 0, 9, 1), |
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new BigDecimal(BigInteger.ZERO, 0, 10, 1), |
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new BigDecimal(BigInteger.ZERO, 0, 11, 1), |
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new BigDecimal(BigInteger.ZERO, 0, 12, 1), |
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new BigDecimal(BigInteger.ZERO, 0, 13, 1), |
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new BigDecimal(BigInteger.ZERO, 0, 14, 1), |
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new BigDecimal(BigInteger.ZERO, 0, 15, 1), |
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}; |
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// Half of Long.MIN_VALUE & Long.MAX_VALUE. |
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private static final long HALF_LONG_MAX_VALUE = Long.MAX_VALUE / 2; |
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private static final long HALF_LONG_MIN_VALUE = Long.MIN_VALUE / 2; |
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// Constants |
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/** |
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* The value 0, with a scale of 0. |
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* |
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* @since 1.5 |
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*/ |
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public static final BigDecimal ZERO = |
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zeroThroughTen[0]; |
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/** |
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* The value 1, with a scale of 0. |
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* |
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* @since 1.5 |
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*/ |
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public static final BigDecimal ONE = |
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zeroThroughTen[1]; |
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/** |
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* The value 10, with a scale of 0. |
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* |
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* @since 1.5 |
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*/ |
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public static final BigDecimal TEN = |
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zeroThroughTen[10]; |
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// Constructors |
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/** |
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* Trusted package private constructor. |
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* Trusted simply means if val is INFLATED, intVal could not be null and |
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* if intVal is null, val could not be INFLATED. |
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*/ |
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BigDecimal(BigInteger intVal, long val, int scale, int prec) { |
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this.scale = scale; |
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this.precision = prec; |
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this.intCompact = val; |
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this.intVal = intVal; |
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} |
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/** |
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* Translates a character array representation of a |
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* {@code BigDecimal} into a {@code BigDecimal}, accepting the |
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* same sequence of characters as the {@link #BigDecimal(String)} |
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* constructor, while allowing a sub-array to be specified. |
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* |
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* <p>Note that if the sequence of characters is already available |
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* within a character array, using this constructor is faster than |
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* converting the {@code char} array to string and using the |
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* {@code BigDecimal(String)} constructor . |
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* |
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* @param in {@code char} array that is the source of characters. |
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* @param offset first character in the array to inspect. |
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* @param len number of characters to consider. |
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* @throws NumberFormatException if {@code in} is not a valid |
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* representation of a {@code BigDecimal} or the defined subarray |
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* is not wholly within {@code in}. |
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* @since 1.5 |
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*/ |
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public BigDecimal(char[] in, int offset, int len) { |
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this(in,offset,len,MathContext.UNLIMITED); |
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} |
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/** |
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* Translates a character array representation of a |
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* {@code BigDecimal} into a {@code BigDecimal}, accepting the |
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* same sequence of characters as the {@link #BigDecimal(String)} |
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* constructor, while allowing a sub-array to be specified and |
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* with rounding according to the context settings. |
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* |
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* <p>Note that if the sequence of characters is already available |
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* within a character array, using this constructor is faster than |
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* converting the {@code char} array to string and using the |
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* {@code BigDecimal(String)} constructor . |
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* |
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* @param in {@code char} array that is the source of characters. |
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* @param offset first character in the array to inspect. |
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* @param len number of characters to consider.. |
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* @param mc the context to use. |
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* @throws ArithmeticException if the result is inexact but the |
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* rounding mode is {@code UNNECESSARY}. |
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* @throws NumberFormatException if {@code in} is not a valid |
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* representation of a {@code BigDecimal} or the defined subarray |
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* is not wholly within {@code in}. |
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* @since 1.5 |
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*/ |
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public BigDecimal(char[] in, int offset, int len, MathContext mc) { |
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// protect against huge length, negative values, and integer overflow |
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if ((in.length | len | offset) < 0 || len > in.length - offset) { |
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throw new NumberFormatException |
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("Bad offset or len arguments for char[] input."); |
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} |
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// This is the primary string to BigDecimal constructor; all |
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// incoming strings end up here; it uses explicit (inline) |
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// parsing for speed and generates at most one intermediate |
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// (temporary) object (a char[] array) for non-compact case. |
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// Use locals for all fields values until completion |
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int prec = 0; // record precision value |
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int scl = 0; // record scale value |
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long rs = 0; // the compact value in long |
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BigInteger rb = null; // the inflated value in BigInteger |
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// use array bounds checking to handle too-long, len == 0, |
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// bad offset, etc. |
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try { |
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// handle the sign |
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boolean isneg = false; // assume positive |
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if (in[offset] == '-') { |
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isneg = true; // leading minus means negative |
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offset++; |
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len--; |
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} else if (in[offset] == '+') { // leading + allowed |
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offset++; |
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len--; |
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} |
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// should now be at numeric part of the significand |
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boolean dot = false; // true when there is a '.' |
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long exp = 0; // exponent |
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char c; // current character |
|
boolean isCompact = (len <= MAX_COMPACT_DIGITS); |
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// integer significand array & idx is the index to it. The array |
|
// is ONLY used when we can't use a compact representation. |
|
int idx = 0; |
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if (isCompact) { |
|
// First compact case, we need not to preserve the character |
|
// and we can just compute the value in place. |
|
for (; len > 0; offset++, len--) { |
|
c = in[offset]; |
|
if ((c == '0')) { // have zero |
|
if (prec == 0) |
|
prec = 1; |
|
else if (rs != 0) { |
|
rs *= 10; |
|
++prec; |
|
} // else digit is a redundant leading zero |
|
if (dot) |
|
++scl; |
|
} else if ((c >= '1' && c <= '9')) { // have digit |
|
int digit = c - '0'; |
|
if (prec != 1 || rs != 0) |
|
++prec; // prec unchanged if preceded by 0s |
|
rs = rs * 10 + digit; |
|
if (dot) |
|
++scl; |
|
} else if (c == '.') { // have dot |
|
// have dot |
|
if (dot) // two dots |
|
throw new NumberFormatException(); |
|
dot = true; |
|
} else if (Character.isDigit(c)) { // slow path |
|
int digit = Character.digit(c, 10); |
|
if (digit == 0) { |
|
if (prec == 0) |
|
prec = 1; |
|
else if (rs != 0) { |
|
rs *= 10; |
|
++prec; |
|
} // else digit is a redundant leading zero |
|
} else { |
|
if (prec != 1 || rs != 0) |
|
++prec; // prec unchanged if preceded by 0s |
|
rs = rs * 10 + digit; |
|
} |
|
if (dot) |
|
++scl; |
|
} else if ((c == 'e') || (c == 'E')) { |
|
exp = parseExp(in, offset, len); |
|
// Next test is required for backwards compatibility |
|
if ((int) exp != exp) // overflow |
|
throw new NumberFormatException(); |
|
break; // [saves a test] |
|
} else { |
|
throw new NumberFormatException(); |
|
} |
|
} |
|
if (prec == 0) // no digits found |
|
throw new NumberFormatException(); |
|
// Adjust scale if exp is not zero. |
|
if (exp != 0) { // had significant exponent |
|
scl = adjustScale(scl, exp); |
|
} |
|
rs = isneg ? -rs : rs; |
|
int mcp = mc.precision; |
|
int drop = prec - mcp; // prec has range [1, MAX_INT], mcp has range [0, MAX_INT]; |
|
// therefore, this subtract cannot overflow |
|
if (mcp > 0 && drop > 0) { // do rounding |
|
while (drop > 0) { |
|
scl = checkScaleNonZero((long) scl - drop); |
|
rs = divideAndRound(rs, LONG_TEN_POWERS_TABLE[drop], mc.roundingMode.oldMode); |
|
prec = longDigitLength(rs); |
|
drop = prec - mcp; |
|
} |
|
} |
|
} else { |
|
char coeff[] = new char[len]; |
|
for (; len > 0; offset++, len--) { |
|
c = in[offset]; |
|
// have digit |
|
if ((c >= '0' && c <= '9') || Character.isDigit(c)) { |
|
// First compact case, we need not to preserve the character |
|
// and we can just compute the value in place. |
|
if (c == '0' || Character.digit(c, 10) == 0) { |
|
if (prec == 0) { |
|
coeff[idx] = c; |
|
prec = 1; |
|
} else if (idx != 0) { |
|
coeff[idx++] = c; |
|
++prec; |
|
} // else c must be a redundant leading zero |
|
} else { |
|
if (prec != 1 || idx != 0) |
|
++prec; // prec unchanged if preceded by 0s |
|
coeff[idx++] = c; |
|
} |
|
if (dot) |
|
++scl; |
|
continue; |
|
} |
|
// have dot |
|
if (c == '.') { |
|
// have dot |
|
if (dot) // two dots |
|
throw new NumberFormatException(); |
|
dot = true; |
|
continue; |
|
} |
|
// exponent expected |
|
if ((c != 'e') && (c != 'E')) |
|
throw new NumberFormatException(); |
|
exp = parseExp(in, offset, len); |
|
// Next test is required for backwards compatibility |
|
if ((int) exp != exp) // overflow |
|
throw new NumberFormatException(); |
|
break; // [saves a test] |
|
} |
|
// here when no characters left |
|
if (prec == 0) // no digits found |
|
throw new NumberFormatException(); |
|
// Adjust scale if exp is not zero. |
|
if (exp != 0) { // had significant exponent |
|
scl = adjustScale(scl, exp); |
|
} |
|
// Remove leading zeros from precision (digits count) |
|
rb = new BigInteger(coeff, isneg ? -1 : 1, prec); |
|
rs = compactValFor(rb); |
|
int mcp = mc.precision; |
|
if (mcp > 0 && (prec > mcp)) { |
|
if (rs == INFLATED) { |
|
int drop = prec - mcp; |
|
while (drop > 0) { |
|
scl = checkScaleNonZero((long) scl - drop); |
|
rb = divideAndRoundByTenPow(rb, drop, mc.roundingMode.oldMode); |
|
rs = compactValFor(rb); |
|
if (rs != INFLATED) { |
|
prec = longDigitLength(rs); |
|
break; |
|
} |
|
prec = bigDigitLength(rb); |
|
drop = prec - mcp; |
|
} |
|
} |
|
if (rs != INFLATED) { |
|
int drop = prec - mcp; |
|
while (drop > 0) { |
|
scl = checkScaleNonZero((long) scl - drop); |
|
rs = divideAndRound(rs, LONG_TEN_POWERS_TABLE[drop], mc.roundingMode.oldMode); |
|
prec = longDigitLength(rs); |
|
drop = prec - mcp; |
|
} |
|
rb = null; |
|
} |
|
} |
|
} |
|
} catch (ArrayIndexOutOfBoundsException e) { |
|
throw new NumberFormatException(); |
|
} catch (NegativeArraySizeException e) { |
|
throw new NumberFormatException(); |
|
} |
|
this.scale = scl; |
|
this.precision = prec; |
|
this.intCompact = rs; |
|
this.intVal = rb; |
|
} |
|
private int adjustScale(int scl, long exp) { |
|
long adjustedScale = scl - exp; |
|
if (adjustedScale > Integer.MAX_VALUE || adjustedScale < Integer.MIN_VALUE) |
|
throw new NumberFormatException("Scale out of range."); |
|
scl = (int) adjustedScale; |
|
return scl; |
|
} |
|
/* |
|
* parse exponent |
|
*/ |
|
private static long parseExp(char[] in, int offset, int len){ |
|
long exp = 0; |
|
offset++; |
|
char c = in[offset]; |
|
len--; |
|
boolean negexp = (c == '-'); |
|
// optional sign |
|
if (negexp || c == '+') { |
|
offset++; |
|
c = in[offset]; |
|
len--; |
|
} |
|
if (len <= 0) // no exponent digits |
|
throw new NumberFormatException(); |
|
// skip leading zeros in the exponent |
|
while (len > 10 && (c=='0' || (Character.digit(c, 10) == 0))) { |
|
offset++; |
|
c = in[offset]; |
|
len--; |
|
} |
|
if (len > 10) // too many nonzero exponent digits |
|
throw new NumberFormatException(); |
|
// c now holds first digit of exponent |
|
for (;; len--) { |
|
int v; |
|
if (c >= '0' && c <= '9') { |
|
v = c - '0'; |
|
} else { |
|
v = Character.digit(c, 10); |
|
if (v < 0) // not a digit |
|
throw new NumberFormatException(); |
|
} |
|
exp = exp * 10 + v; |
|
if (len == 1) |
|
break; // that was final character |
|
offset++; |
|
c = in[offset]; |
|
} |
|
if (negexp) // apply sign |
|
exp = -exp; |
|
return exp; |
|
} |
|
/** |
|
* Translates a character array representation of a |
|
* {@code BigDecimal} into a {@code BigDecimal}, accepting the |
|
* same sequence of characters as the {@link #BigDecimal(String)} |
|
* constructor. |
|
* |
|
* <p>Note that if the sequence of characters is already available |
|
* as a character array, using this constructor is faster than |
|
* converting the {@code char} array to string and using the |
|
* {@code BigDecimal(String)} constructor . |
|
* |
|
* @param in {@code char} array that is the source of characters. |
|
* @throws NumberFormatException if {@code in} is not a valid |
|
* representation of a {@code BigDecimal}. |
|
* @since 1.5 |
|
*/ |
|
public BigDecimal(char[] in) { |
|
this(in, 0, in.length); |
|
} |
|
/** |
|
* Translates a character array representation of a |
|
* {@code BigDecimal} into a {@code BigDecimal}, accepting the |
|
* same sequence of characters as the {@link #BigDecimal(String)} |
|
* constructor and with rounding according to the context |
|
* settings. |
|
* |
|
* <p>Note that if the sequence of characters is already available |
|
* as a character array, using this constructor is faster than |
|
* converting the {@code char} array to string and using the |
|
* {@code BigDecimal(String)} constructor . |
|
* |
|
* @param in {@code char} array that is the source of characters. |
|
* @param mc the context to use. |
|
* @throws ArithmeticException if the result is inexact but the |
|
* rounding mode is {@code UNNECESSARY}. |
|
* @throws NumberFormatException if {@code in} is not a valid |
|
* representation of a {@code BigDecimal}. |
|
* @since 1.5 |
|
*/ |
|
public BigDecimal(char[] in, MathContext mc) { |
|
this(in, 0, in.length, mc); |
|
} |
|
/** |
|
* Translates the string representation of a {@code BigDecimal} |
|
* into a {@code BigDecimal}. The string representation consists |
|
* of an optional sign, {@code '+'} (<tt> '\u002B'</tt>) or |
|
* {@code '-'} (<tt>'\u002D'</tt>), followed by a sequence of |
|
* zero or more decimal digits ("the integer"), optionally |
|
* followed by a fraction, optionally followed by an exponent. |
|
* |
|
* <p>The fraction consists of a decimal point followed by zero |
|
* or more decimal digits. The string must contain at least one |
|
* digit in either the integer or the fraction. The number formed |
|
* by the sign, the integer and the fraction is referred to as the |
|
* <i>significand</i>. |
|
* |
|
* <p>The exponent consists of the character {@code 'e'} |
|
* (<tt>'\u0065'</tt>) or {@code 'E'} (<tt>'\u0045'</tt>) |
|
* followed by one or more decimal digits. The value of the |
|
* exponent must lie between -{@link Integer#MAX_VALUE} ({@link |
|
* Integer#MIN_VALUE}+1) and {@link Integer#MAX_VALUE}, inclusive. |
|
* |
|
* <p>More formally, the strings this constructor accepts are |
|
* described by the following grammar: |
|
* <blockquote> |
|
* <dl> |
|
* <dt><i>BigDecimalString:</i> |
|
* <dd><i>Sign<sub>opt</sub> Significand Exponent<sub>opt</sub></i> |
|
* <dt><i>Sign:</i> |
|
* <dd>{@code +} |
|
* <dd>{@code -} |
|
* <dt><i>Significand:</i> |
|
* <dd><i>IntegerPart</i> {@code .} <i>FractionPart<sub>opt</sub></i> |
|
* <dd>{@code .} <i>FractionPart</i> |
|
* <dd><i>IntegerPart</i> |
|
* <dt><i>IntegerPart:</i> |
|
* <dd><i>Digits</i> |
|
* <dt><i>FractionPart:</i> |
|
* <dd><i>Digits</i> |
|
* <dt><i>Exponent:</i> |
|
* <dd><i>ExponentIndicator SignedInteger</i> |
|
* <dt><i>ExponentIndicator:</i> |
|
* <dd>{@code e} |
|
* <dd>{@code E} |
|
* <dt><i>SignedInteger:</i> |
|
* <dd><i>Sign<sub>opt</sub> Digits</i> |
|
* <dt><i>Digits:</i> |
|
* <dd><i>Digit</i> |
|
* <dd><i>Digits Digit</i> |
|
* <dt><i>Digit:</i> |
|
* <dd>any character for which {@link Character#isDigit} |
|
* returns {@code true}, including 0, 1, 2 ... |
|
* </dl> |
|
* </blockquote> |
|
* |
|
* <p>The scale of the returned {@code BigDecimal} will be the |
|
* number of digits in the fraction, or zero if the string |
|
* contains no decimal point, subject to adjustment for any |
|
* exponent; if the string contains an exponent, the exponent is |
|
* subtracted from the scale. The value of the resulting scale |
|
* must lie between {@code Integer.MIN_VALUE} and |
|
* {@code Integer.MAX_VALUE}, inclusive. |
|
* |
|
* <p>The character-to-digit mapping is provided by {@link |
|
* java.lang.Character#digit} set to convert to radix 10. The |
|
* String may not contain any extraneous characters (whitespace, |
|
* for example). |
|
* |
|
* <p><b>Examples:</b><br> |
|
* The value of the returned {@code BigDecimal} is equal to |
|
* <i>significand</i> × 10<sup> <i>exponent</i></sup>. |
|
* For each string on the left, the resulting representation |
|
* [{@code BigInteger}, {@code scale}] is shown on the right. |
|
* <pre> |
|
* "0" [0,0] |
|
* "0.00" [0,2] |
|
* "123" [123,0] |
|
* "-123" [-123,0] |
|
* "1.23E3" [123,-1] |
|
* "1.23E+3" [123,-1] |
|
* "12.3E+7" [123,-6] |
|
* "12.0" [120,1] |
|
* "12.3" [123,1] |
|
* "0.00123" [123,5] |
|
* "-1.23E-12" [-123,14] |
|
* "1234.5E-4" [12345,5] |
|
* "0E+7" [0,-7] |
|
* "-0" [0,0] |
|
* </pre> |
|
* |
|
* <p>Note: For values other than {@code float} and |
|
* {@code double} NaN and ±Infinity, this constructor is |
|
* compatible with the values returned by {@link Float#toString} |
|
* and {@link Double#toString}. This is generally the preferred |
|
* way to convert a {@code float} or {@code double} into a |
|
* BigDecimal, as it doesn't suffer from the unpredictability of |
|
* the {@link #BigDecimal(double)} constructor. |
|
* |
|
* @param val String representation of {@code BigDecimal}. |
|
* |
|
* @throws NumberFormatException if {@code val} is not a valid |
|
* representation of a {@code BigDecimal}. |
|
*/ |
|
public BigDecimal(String val) { |
|
this(val.toCharArray(), 0, val.length()); |
|
} |
|
/** |
|
* Translates the string representation of a {@code BigDecimal} |
|
* into a {@code BigDecimal}, accepting the same strings as the |
|
* {@link #BigDecimal(String)} constructor, with rounding |
|
* according to the context settings. |
|
* |
|
* @param val string representation of a {@code BigDecimal}. |
|
* @param mc the context to use. |
|
* @throws ArithmeticException if the result is inexact but the |
|
* rounding mode is {@code UNNECESSARY}. |
|
* @throws NumberFormatException if {@code val} is not a valid |
|
* representation of a BigDecimal. |
|
* @since 1.5 |
|
*/ |
|
public BigDecimal(String val, MathContext mc) { |
|
this(val.toCharArray(), 0, val.length(), mc); |
|
} |
|
/** |
|
* Translates a {@code double} into a {@code BigDecimal} which |
|
* is the exact decimal representation of the {@code double}'s |
|
* binary floating-point value. The scale of the returned |
|
* {@code BigDecimal} is the smallest value such that |
|
* <tt>(10<sup>scale</sup> × val)</tt> is an integer. |
|
* <p> |
|
* <b>Notes:</b> |
|
* <ol> |
|
* <li> |
|
* The results of this constructor can be somewhat unpredictable. |
|
* One might assume that writing {@code new BigDecimal(0.1)} in |
|
* Java creates a {@code BigDecimal} which is exactly equal to |
|
* 0.1 (an unscaled value of 1, with a scale of 1), but it is |
|
* actually equal to |
|
* 0.1000000000000000055511151231257827021181583404541015625. |
|
* This is because 0.1 cannot be represented exactly as a |
|
* {@code double} (or, for that matter, as a binary fraction of |
|
* any finite length). Thus, the value that is being passed |
|
* <i>in</i> to the constructor is not exactly equal to 0.1, |
|
* appearances notwithstanding. |
|
* |
|
* <li> |
|
* The {@code String} constructor, on the other hand, is |
|
* perfectly predictable: writing {@code new BigDecimal("0.1")} |
|
* creates a {@code BigDecimal} which is <i>exactly</i> equal to |
|
* 0.1, as one would expect. Therefore, it is generally |
|
* recommended that the {@linkplain #BigDecimal(String) |
|
* <tt>String</tt> constructor} be used in preference to this one. |
|
* |
|
* <li> |
|
* When a {@code double} must be used as a source for a |
|
* {@code BigDecimal}, note that this constructor provides an |
|
* exact conversion; it does not give the same result as |
|
* converting the {@code double} to a {@code String} using the |
|
* {@link Double#toString(double)} method and then using the |
|
* {@link #BigDecimal(String)} constructor. To get that result, |
|
* use the {@code static} {@link #valueOf(double)} method. |
|
* </ol> |
|
* |
|
* @param val {@code double} value to be converted to |
|
* {@code BigDecimal}. |
|
* @throws NumberFormatException if {@code val} is infinite or NaN. |
|
*/ |
|
public BigDecimal(double val) { |
|
this(val,MathContext.UNLIMITED); |
|
} |
|
/** |
|
* Translates a {@code double} into a {@code BigDecimal}, with |
|
* rounding according to the context settings. The scale of the |
|
* {@code BigDecimal} is the smallest value such that |
|
* <tt>(10<sup>scale</sup> × val)</tt> is an integer. |
|
* |
|
* <p>The results of this constructor can be somewhat unpredictable |
|
* and its use is generally not recommended; see the notes under |
|
* the {@link #BigDecimal(double)} constructor. |
|
* |
|
* @param val {@code double} value to be converted to |
|
* {@code BigDecimal}. |
|
* @param mc the context to use. |
|
* @throws ArithmeticException if the result is inexact but the |
|
* RoundingMode is UNNECESSARY. |
|
* @throws NumberFormatException if {@code val} is infinite or NaN. |
|
* @since 1.5 |
|
*/ |
|
public BigDecimal(double val, MathContext mc) { |
|
if (Double.isInfinite(val) || Double.isNaN(val)) |
|
throw new NumberFormatException("Infinite or NaN"); |
|
// Translate the double into sign, exponent and significand, according |
|
// to the formulae in JLS, Section 20.10.22. |
|
long valBits = Double.doubleToLongBits(val); |
|
int sign = ((valBits >> 63) == 0 ? 1 : -1); |
|
int exponent = (int) ((valBits >> 52) & 0x7ffL); |
|
long significand = (exponent == 0 |
|
? (valBits & ((1L << 52) - 1)) << 1 |
|
: (valBits & ((1L << 52) - 1)) | (1L << 52)); |
|
exponent -= 1075; |
|
// At this point, val == sign * significand * 2**exponent. |
|
/* |
|
* Special case zero to supress nonterminating normalization and bogus |
|
* scale calculation. |
|
*/ |
|
if (significand == 0) { |
|
this.intVal = BigInteger.ZERO; |
|
this.scale = 0; |
|
this.intCompact = 0; |
|
this.precision = 1; |
|
return; |
|
} |
|
// Normalize |
|
while ((significand & 1) == 0) { // i.e., significand is even |
|
significand >>= 1; |
|
exponent++; |
|
} |
|
int scale = 0; |
|
// Calculate intVal and scale |
|
BigInteger intVal; |
|
long compactVal = sign * significand; |
|
if (exponent == 0) { |
|
intVal = (compactVal == INFLATED) ? INFLATED_BIGINT : null; |
|
} else { |
|
if (exponent < 0) { |
|
intVal = BigInteger.valueOf(5).pow(-exponent).multiply(compactVal); |
|
scale = -exponent; |
|
} else { // (exponent > 0) |
|
intVal = BigInteger.valueOf(2).pow(exponent).multiply(compactVal); |
|
} |
|
compactVal = compactValFor(intVal); |
|
} |
|
int prec = 0; |
|
int mcp = mc.precision; |
|
if (mcp > 0) { // do rounding |
|
int mode = mc.roundingMode.oldMode; |
|
int drop; |
|
if (compactVal == INFLATED) { |
|
prec = bigDigitLength(intVal); |
|
drop = prec - mcp; |
|
while (drop > 0) { |
|
scale = checkScaleNonZero((long) scale - drop); |
|
intVal = divideAndRoundByTenPow(intVal, drop, mode); |
|
compactVal = compactValFor(intVal); |
|
if (compactVal != INFLATED) { |
|
break; |
|
} |
|
prec = bigDigitLength(intVal); |
|
drop = prec - mcp; |
|
} |
|
} |
|
if (compactVal != INFLATED) { |
|
prec = longDigitLength(compactVal); |
|
drop = prec - mcp; |
|
while (drop > 0) { |
|
scale = checkScaleNonZero((long) scale - drop); |
|
compactVal = divideAndRound(compactVal, LONG_TEN_POWERS_TABLE[drop], mc.roundingMode.oldMode); |
|
prec = longDigitLength(compactVal); |
|
drop = prec - mcp; |
|
} |
|
intVal = null; |
|
} |
|
} |
|
this.intVal = intVal; |
|
this.intCompact = compactVal; |
|
this.scale = scale; |
|
this.precision = prec; |
|
} |
|
/** |
|
* Translates a {@code BigInteger} into a {@code BigDecimal}. |
|
* The scale of the {@code BigDecimal} is zero. |
|
* |
|
* @param val {@code BigInteger} value to be converted to |
|
* {@code BigDecimal}. |
|
*/ |
|
public BigDecimal(BigInteger val) { |
|
scale = 0; |
|
intVal = val; |
|
intCompact = compactValFor(val); |
|
} |
|
/** |
|
* Translates a {@code BigInteger} into a {@code BigDecimal} |
|
* rounding according to the context settings. The scale of the |
|
* {@code BigDecimal} is zero. |
|
* |
|
* @param val {@code BigInteger} value to be converted to |
|
* {@code BigDecimal}. |
|
* @param mc the context to use. |
|
* @throws ArithmeticException if the result is inexact but the |
|
* rounding mode is {@code UNNECESSARY}. |
|
* @since 1.5 |
|
*/ |
|
public BigDecimal(BigInteger val, MathContext mc) { |
|
this(val,0,mc); |
|
} |
|
/** |
|
* Translates a {@code BigInteger} unscaled value and an |
|
* {@code int} scale into a {@code BigDecimal}. The value of |
|
* the {@code BigDecimal} is |
|
* <tt>(unscaledVal × 10<sup>-scale</sup>)</tt>. |
|
* |
|
* @param unscaledVal unscaled value of the {@code BigDecimal}. |
|
* @param scale scale of the {@code BigDecimal}. |
|
*/ |
|
public BigDecimal(BigInteger unscaledVal, int scale) { |
|
// Negative scales are now allowed |
|
this.intVal = unscaledVal; |
|
this.intCompact = compactValFor(unscaledVal); |
|
this.scale = scale; |
|
} |
|
/** |
|
* Translates a {@code BigInteger} unscaled value and an |
|
* {@code int} scale into a {@code BigDecimal}, with rounding |
|
* according to the context settings. The value of the |
|
* {@code BigDecimal} is <tt>(unscaledVal × |
|
* 10<sup>-scale</sup>)</tt>, rounded according to the |
|
* {@code precision} and rounding mode settings. |
|
* |
|
* @param unscaledVal unscaled value of the {@code BigDecimal}. |
|
* @param scale scale of the {@code BigDecimal}. |
|
* @param mc the context to use. |
|
* @throws ArithmeticException if the result is inexact but the |
|
* rounding mode is {@code UNNECESSARY}. |
|
* @since 1.5 |
|
*/ |
|
public BigDecimal(BigInteger unscaledVal, int scale, MathContext mc) { |
|
long compactVal = compactValFor(unscaledVal); |
|
int mcp = mc.precision; |
|
int prec = 0; |
|
if (mcp > 0) { // do rounding |
|
int mode = mc.roundingMode.oldMode; |
|
if (compactVal == INFLATED) { |
|
prec = bigDigitLength(unscaledVal); |
|
int drop = prec - mcp; |
|
while (drop > 0) { |
|
scale = checkScaleNonZero((long) scale - drop); |
|
unscaledVal = divideAndRoundByTenPow(unscaledVal, drop, mode); |
|
compactVal = compactValFor(unscaledVal); |
|
if (compactVal != INFLATED) { |
|
break; |
|
} |
|
prec = bigDigitLength(unscaledVal); |
|
drop = prec - mcp; |
|
} |
|
} |
|
if (compactVal != INFLATED) { |
|
prec = longDigitLength(compactVal); |
|
int drop = prec - mcp; // drop can't be more than 18 |
|
while (drop > 0) { |
|
scale = checkScaleNonZero((long) scale - drop); |
|
compactVal = divideAndRound(compactVal, LONG_TEN_POWERS_TABLE[drop], mode); |
|
prec = longDigitLength(compactVal); |
|
drop = prec - mcp; |
|
} |
|
unscaledVal = null; |
|
} |
|
} |
|
this.intVal = unscaledVal; |
|
this.intCompact = compactVal; |
|
this.scale = scale; |
|
this.precision = prec; |
|
} |
|
/** |
|
* Translates an {@code int} into a {@code BigDecimal}. The |
|
* scale of the {@code BigDecimal} is zero. |
|
* |
|
* @param val {@code int} value to be converted to |
|
* {@code BigDecimal}. |
|
* @since 1.5 |
|
*/ |
|
public BigDecimal(int val) { |
|
this.intCompact = val; |
|
this.scale = 0; |
|
this.intVal = null; |
|
} |
|
/** |
|
* Translates an {@code int} into a {@code BigDecimal}, with |
|
* rounding according to the context settings. The scale of the |
|
* {@code BigDecimal}, before any rounding, is zero. |
|
* |
|
* @param val {@code int} value to be converted to {@code BigDecimal}. |
|
* @param mc the context to use. |
|
* @throws ArithmeticException if the result is inexact but the |
|
* rounding mode is {@code UNNECESSARY}. |
|
* @since 1.5 |
|
*/ |
|
public BigDecimal(int val, MathContext mc) { |
|
int mcp = mc.precision; |
|
long compactVal = val; |
|
int scale = 0; |
|
int prec = 0; |
|
if (mcp > 0) { // do rounding |
|
prec = longDigitLength(compactVal); |
|
int drop = prec - mcp; // drop can't be more than 18 |
|
while (drop > 0) { |
|
scale = checkScaleNonZero((long) scale - drop); |
|
compactVal = divideAndRound(compactVal, LONG_TEN_POWERS_TABLE[drop], mc.roundingMode.oldMode); |
|
prec = longDigitLength(compactVal); |
|
drop = prec - mcp; |
|
} |
|
} |
|
this.intVal = null; |
|
this.intCompact = compactVal; |
|
this.scale = scale; |
|
this.precision = prec; |
|
} |
|
/** |
|
* Translates a {@code long} into a {@code BigDecimal}. The |
|
* scale of the {@code BigDecimal} is zero. |
|
* |
|
* @param val {@code long} value to be converted to {@code BigDecimal}. |
|
* @since 1.5 |
|
*/ |
|
public BigDecimal(long val) { |
|
this.intCompact = val; |
|
this.intVal = (val == INFLATED) ? INFLATED_BIGINT : null; |
|
this.scale = 0; |
|
} |
|
/** |
|
* Translates a {@code long} into a {@code BigDecimal}, with |
|
* rounding according to the context settings. The scale of the |
|
* {@code BigDecimal}, before any rounding, is zero. |
|
* |
|
* @param val {@code long} value to be converted to {@code BigDecimal}. |
|
* @param mc the context to use. |
|
* @throws ArithmeticException if the result is inexact but the |
|
* rounding mode is {@code UNNECESSARY}. |
|
* @since 1.5 |
|
*/ |
|
public BigDecimal(long val, MathContext mc) { |
|
int mcp = mc.precision; |
|
int mode = mc.roundingMode.oldMode; |
|
int prec = 0; |
|
int scale = 0; |
|
BigInteger intVal = (val == INFLATED) ? INFLATED_BIGINT : null; |
|
if (mcp > 0) { // do rounding |
|
if (val == INFLATED) { |
|
prec = 19; |
|
int drop = prec - mcp; |
|
while (drop > 0) { |
|
scale = checkScaleNonZero((long) scale - drop); |
|
intVal = divideAndRoundByTenPow(intVal, drop, mode); |
|
val = compactValFor(intVal); |
|
if (val != INFLATED) { |
|
break; |
|
} |
|
prec = bigDigitLength(intVal); |
|
drop = prec - mcp; |
|
} |
|
} |
|
if (val != INFLATED) { |
|
prec = longDigitLength(val); |
|
int drop = prec - mcp; |
|
while (drop > 0) { |
|
scale = checkScaleNonZero((long) scale - drop); |
|
val = divideAndRound(val, LONG_TEN_POWERS_TABLE[drop], mc.roundingMode.oldMode); |
|
prec = longDigitLength(val); |
|
drop = prec - mcp; |
|
} |
|
intVal = null; |
|
} |
|
} |
|
this.intVal = intVal; |
|
this.intCompact = val; |
|
this.scale = scale; |
|
this.precision = prec; |
|
} |
|
// Static Factory Methods |
|
/** |
|
* Translates a {@code long} unscaled value and an |
|
* {@code int} scale into a {@code BigDecimal}. This |
|
* {@literal "static factory method"} is provided in preference to |
|
* a ({@code long}, {@code int}) constructor because it |
|
* allows for reuse of frequently used {@code BigDecimal} values.. |
|
* |
|
* @param unscaledVal unscaled value of the {@code BigDecimal}. |
|
* @param scale scale of the {@code BigDecimal}. |
|
* @return a {@code BigDecimal} whose value is |
|
* <tt>(unscaledVal × 10<sup>-scale</sup>)</tt>. |
|
*/ |
|
public static BigDecimal valueOf(long unscaledVal, int scale) { |
|
if (scale == 0) |
|
return valueOf(unscaledVal); |
|
else if (unscaledVal == 0) { |
|
return zeroValueOf(scale); |
|
} |
|
return new BigDecimal(unscaledVal == INFLATED ? |
|
INFLATED_BIGINT : null, |
|
unscaledVal, scale, 0); |
|
} |
|
/** |
|
* Translates a {@code long} value into a {@code BigDecimal} |
|
* with a scale of zero. This {@literal "static factory method"} |
|
* is provided in preference to a ({@code long}) constructor |
|
* because it allows for reuse of frequently used |
|
* {@code BigDecimal} values. |
|
* |
|
* @param val value of the {@code BigDecimal}. |
|
* @return a {@code BigDecimal} whose value is {@code val}. |
|
*/ |
|
public static BigDecimal valueOf(long val) { |
|
if (val >= 0 && val < zeroThroughTen.length) |
|
return zeroThroughTen[(int)val]; |
|
else if (val != INFLATED) |
|
return new BigDecimal(null, val, 0, 0); |
|
return new BigDecimal(INFLATED_BIGINT, val, 0, 0); |
|
} |
|
static BigDecimal valueOf(long unscaledVal, int scale, int prec) { |
|
if (scale == 0 && unscaledVal >= 0 && unscaledVal < zeroThroughTen.length) { |
|
return zeroThroughTen[(int) unscaledVal]; |
|
} else if (unscaledVal == 0) { |
|
return zeroValueOf(scale); |
|
} |
|
return new BigDecimal(unscaledVal == INFLATED ? INFLATED_BIGINT : null, |
|
unscaledVal, scale, prec); |
|
} |
|
static BigDecimal valueOf(BigInteger intVal, int scale, int prec) { |
|
long val = compactValFor(intVal); |
|
if (val == 0) { |
|
return zeroValueOf(scale); |
|
} else if (scale == 0 && val >= 0 && val < zeroThroughTen.length) { |
|
return zeroThroughTen[(int) val]; |
|
} |
|
return new BigDecimal(intVal, val, scale, prec); |
|
} |
|
static BigDecimal zeroValueOf(int scale) { |
|
if (scale >= 0 && scale < ZERO_SCALED_BY.length) |
|
return ZERO_SCALED_BY[scale]; |
|
else |
|
return new BigDecimal(BigInteger.ZERO, 0, scale, 1); |
|
} |
|
/** |
|
* Translates a {@code double} into a {@code BigDecimal}, using |
|
* the {@code double}'s canonical string representation provided |
|
* by the {@link Double#toString(double)} method. |
|
* |
|
* <p><b>Note:</b> This is generally the preferred way to convert |
|
* a {@code double} (or {@code float}) into a |
|
* {@code BigDecimal}, as the value returned is equal to that |
|
* resulting from constructing a {@code BigDecimal} from the |
|
* result of using {@link Double#toString(double)}. |
|
* |
|
* @param val {@code double} to convert to a {@code BigDecimal}. |
|
* @return a {@code BigDecimal} whose value is equal to or approximately |
|
* equal to the value of {@code val}. |
|
* @throws NumberFormatException if {@code val} is infinite or NaN. |
|
* @since 1.5 |
|
*/ |
|
public static BigDecimal valueOf(double val) { |
|
// Reminder: a zero double returns '0.0', so we cannot fastpath |
|
// to use the constant ZERO. This might be important enough to |
|
// justify a factory approach, a cache, or a few private |
|
// constants, later. |
|
return new BigDecimal(Double.toString(val)); |
|
} |
|
// Arithmetic Operations |
|
/** |
|
* Returns a {@code BigDecimal} whose value is {@code (this + |
|
* augend)}, and whose scale is {@code max(this.scale(), |
|
* augend.scale())}. |
|
* |
|
* @param augend value to be added to this {@code BigDecimal}. |
|
* @return {@code this + augend} |
|
*/ |
|
public BigDecimal add(BigDecimal augend) { |
|
if (this.intCompact != INFLATED) { |
|
if ((augend.intCompact != INFLATED)) { |
|
return add(this.intCompact, this.scale, augend.intCompact, augend.scale); |
|
} else { |
|
return add(this.intCompact, this.scale, augend.intVal, augend.scale); |
|
} |
|
} else { |
|
if ((augend.intCompact != INFLATED)) { |
|
return add(augend.intCompact, augend.scale, this.intVal, this.scale); |
|
} else { |
|
return add(this.intVal, this.scale, augend.intVal, augend.scale); |
|
} |
|
} |
|
} |
|
/** |
|
* Returns a {@code BigDecimal} whose value is {@code (this + augend)}, |
|
* with rounding according to the context settings. |
|
* |
|
* If either number is zero and the precision setting is nonzero then |
|
* the other number, rounded if necessary, is used as the result. |
|
* |
|
* @param augend value to be added to this {@code BigDecimal}. |
|
* @param mc the context to use. |
|
* @return {@code this + augend}, rounded as necessary. |
|
* @throws ArithmeticException if the result is inexact but the |
|
* rounding mode is {@code UNNECESSARY}. |
|
* @since 1.5 |
|
*/ |
|
public BigDecimal add(BigDecimal augend, MathContext mc) { |
|
if (mc.precision == 0) |
|
return add(augend); |
|
BigDecimal lhs = this; |
|
// If either number is zero then the other number, rounded and |
|
// scaled if necessary, is used as the result. |
|
{ |
|
boolean lhsIsZero = lhs.signum() == 0; |
|
boolean augendIsZero = augend.signum() == 0; |
|
if (lhsIsZero || augendIsZero) { |
|
int preferredScale = Math.max(lhs.scale(), augend.scale()); |
|
BigDecimal result; |
|
if (lhsIsZero && augendIsZero) |
|
return zeroValueOf(preferredScale); |
|
result = lhsIsZero ? doRound(augend, mc) : doRound(lhs, mc); |
|
if (result.scale() == preferredScale) |
|
return result; |
|
else if (result.scale() > preferredScale) { |
|
return stripZerosToMatchScale(result.intVal, result.intCompact, result.scale, preferredScale); |
|
} else { // result.scale < preferredScale |
|
int precisionDiff = mc.precision - result.precision(); |
|
int scaleDiff = preferredScale - result.scale(); |
|
if (precisionDiff >= scaleDiff) |
|
return result.setScale(preferredScale); // can achieve target scale |
|
else |
|
return result.setScale(result.scale() + precisionDiff); |
|
} |
|
} |
|
} |
|
long padding = (long) lhs.scale - augend.scale; |
|
if (padding != 0) { // scales differ; alignment needed |
|
BigDecimal arg[] = preAlign(lhs, augend, padding, mc); |
|
matchScale(arg); |
|
lhs = arg[0]; |
|
augend = arg[1]; |
|
} |
|
return doRound(lhs.inflated().add(augend.inflated()), lhs.scale, mc); |
|
} |
|
/** |
|
* Returns an array of length two, the sum of whose entries is |
|
* equal to the rounded sum of the {@code BigDecimal} arguments. |
|
* |
|
* <p>If the digit positions of the arguments have a sufficient |
|
* gap between them, the value smaller in magnitude can be |
|
* condensed into a {@literal "sticky bit"} and the end result will |
|
* round the same way <em>if</em> the precision of the final |
|
* result does not include the high order digit of the small |
|
* magnitude operand. |
|
* |
|
* <p>Note that while strictly speaking this is an optimization, |
|
* it makes a much wider range of additions practical. |
|
* |
|
* <p>This corresponds to a pre-shift operation in a fixed |
|
* precision floating-point adder; this method is complicated by |
|
* variable precision of the result as determined by the |
|
* MathContext. A more nuanced operation could implement a |
|
* {@literal "right shift"} on the smaller magnitude operand so |
|
* that the number of digits of the smaller operand could be |
|
* reduced even though the significands partially overlapped. |
|
*/ |
|
private BigDecimal[] preAlign(BigDecimal lhs, BigDecimal augend, long padding, MathContext mc) { |
|
assert padding != 0; |
|
BigDecimal big; |
|
BigDecimal small; |
|
if (padding < 0) { // lhs is big; augend is small |
|
big = lhs; |
|
small = augend; |
|
} else { // lhs is small; augend is big |
|
big = augend; |
|
small = lhs; |
|
} |
|
/* |
|
* This is the estimated scale of an ulp of the result; it assumes that |
|
* the result doesn't have a carry-out on a true add (e.g. 999 + 1 => |
|
* 1000) or any subtractive cancellation on borrowing (e.g. 100 - 1.2 => |
|
* 98.8) |
|
*/ |
|
long estResultUlpScale = (long) big.scale - big.precision() + mc.precision; |
|
/* |
|
* The low-order digit position of big is big.scale(). This |
|
* is true regardless of whether big has a positive or |
|
* negative scale. The high-order digit position of small is |
|
* small.scale - (small.precision() - 1). To do the full |
|
* condensation, the digit positions of big and small must be |
|
* disjoint *and* the digit positions of small should not be |
|
* directly visible in the result. |
|
*/ |
|
long smallHighDigitPos = (long) small.scale - small.precision() + 1; |
|
if (smallHighDigitPos > big.scale + 2 && // big and small disjoint |
|
smallHighDigitPos > estResultUlpScale + 2) { // small digits not visible |
|
small = BigDecimal.valueOf(small.signum(), this.checkScale(Math.max(big.scale, estResultUlpScale) + 3)); |
|
} |
|
// Since addition is symmetric, preserving input order in |
|
// returned operands doesn't matter |
|
BigDecimal[] result = {big, small}; |
|
return result; |
|
} |
|
/** |
|
* Returns a {@code BigDecimal} whose value is {@code (this - |
|
* subtrahend)}, and whose scale is {@code max(this.scale(), |
|
* subtrahend.scale())}. |
|
* |
|
* @param subtrahend value to be subtracted from this {@code BigDecimal}. |
|
* @return {@code this - subtrahend} |
|
*/ |
|
public BigDecimal subtract(BigDecimal subtrahend) { |
|
if (this.intCompact != INFLATED) { |
|
if ((subtrahend.intCompact != INFLATED)) { |
|
return add(this.intCompact, this.scale, -subtrahend.intCompact, subtrahend.scale); |
|
} else { |
|
return add(this.intCompact, this.scale, subtrahend.intVal.negate(), subtrahend.scale); |
|
} |
|
} else { |
|
if ((subtrahend.intCompact != INFLATED)) { |
|
// Pair of subtrahend values given before pair of |
|
// values from this BigDecimal to avoid need for |
|
// method overloading on the specialized add method |
|
return add(-subtrahend.intCompact, subtrahend.scale, this.intVal, this.scale); |
|
} else { |
|
return add(this.intVal, this.scale, subtrahend.intVal.negate(), subtrahend.scale); |
|
} |
|
} |
|
} |
|
/** |
|
* Returns a {@code BigDecimal} whose value is {@code (this - subtrahend)}, |
|
* with rounding according to the context settings. |
|
* |
|
* If {@code subtrahend} is zero then this, rounded if necessary, is used as the |
|
* result. If this is zero then the result is {@code subtrahend.negate(mc)}. |
|
* |
|
* @param subtrahend value to be subtracted from this {@code BigDecimal}. |
|
* @param mc the context to use. |
|
* @return {@code this - subtrahend}, rounded as necessary. |
|
* @throws ArithmeticException if the result is inexact but the |
|
* rounding mode is {@code UNNECESSARY}. |
|
* @since 1.5 |
|
*/ |
|
public BigDecimal subtract(BigDecimal subtrahend, MathContext mc) { |
|
if (mc.precision == 0) |
|
return subtract(subtrahend); |
|
// share the special rounding code in add() |
|
return add(subtrahend.negate(), mc); |
|
} |
|
/** |
|
* Returns a {@code BigDecimal} whose value is <tt>(this × |
|
* multiplicand)</tt>, and whose scale is {@code (this.scale() + |
|
* multiplicand.scale())}. |
|
* |
|
* @param multiplicand value to be multiplied by this {@code BigDecimal}. |
|
* @return {@code this * multiplicand} |
|
*/ |
|
public BigDecimal multiply(BigDecimal multiplicand) { |
|
int productScale = checkScale((long) scale + multiplicand.scale); |
|
if (this.intCompact != INFLATED) { |
|
if ((multiplicand.intCompact != INFLATED)) { |
|
return multiply(this.intCompact, multiplicand.intCompact, productScale); |
|
} else { |
|
return multiply(this.intCompact, multiplicand.intVal, productScale); |
|
} |
|
} else { |
|
if ((multiplicand.intCompact != INFLATED)) { |
|
return multiply(multiplicand.intCompact, this.intVal, productScale); |
|
} else { |
|
return multiply(this.intVal, multiplicand.intVal, productScale); |
|
} |
|
} |
|
} |
|
/** |
|
* Returns a {@code BigDecimal} whose value is <tt>(this × |
|
* multiplicand)</tt>, with rounding according to the context settings. |
|
* |
|
* @param multiplicand value to be multiplied by this {@code BigDecimal}. |
|
* @param mc the context to use. |
|
* @return {@code this * multiplicand}, rounded as necessary. |
|
* @throws ArithmeticException if the result is inexact but the |
|
* rounding mode is {@code UNNECESSARY}. |
|
* @since 1.5 |
|
*/ |
|
public BigDecimal multiply(BigDecimal multiplicand, MathContext mc) { |
|
if (mc.precision == 0) |
|
return multiply(multiplicand); |
|
int productScale = checkScale((long) scale + multiplicand.scale); |
|
if (this.intCompact != INFLATED) { |
|
if ((multiplicand.intCompact != INFLATED)) { |
|
return multiplyAndRound(this.intCompact, multiplicand.intCompact, productScale, mc); |
|
} else { |
|
return multiplyAndRound(this.intCompact, multiplicand.intVal, productScale, mc); |
|
} |
|
} else { |
|
if ((multiplicand.intCompact != INFLATED)) { |
|
return multiplyAndRound(multiplicand.intCompact, this.intVal, productScale, mc); |
|
} else { |
|
return multiplyAndRound(this.intVal, multiplicand.intVal, productScale, mc); |
|
} |
|
} |
|
} |
|
/** |
|
* Returns a {@code BigDecimal} whose value is {@code (this / |
|
* divisor)}, and whose scale is as specified. If rounding must |
|
* be performed to generate a result with the specified scale, the |
|
* specified rounding mode is applied. |
|
* |
|
* <p>The new {@link #divide(BigDecimal, int, RoundingMode)} method |
|
* should be used in preference to this legacy method. |
|
* |
|
* @param divisor value by which this {@code BigDecimal} is to be divided. |
|
* @param scale scale of the {@code BigDecimal} quotient to be returned. |
|
* @param roundingMode rounding mode to apply. |
|
* @return {@code this / divisor} |
|
* @throws ArithmeticException if {@code divisor} is zero, |
|
* {@code roundingMode==ROUND_UNNECESSARY} and |
|
* the specified scale is insufficient to represent the result |
|
* of the division exactly. |
|
* @throws IllegalArgumentException if {@code roundingMode} does not |
|
* represent a valid rounding mode. |
|
* @see #ROUND_UP |
|
* @see #ROUND_DOWN |
|
* @see #ROUND_CEILING |
|
* @see #ROUND_FLOOR |
|
* @see #ROUND_HALF_UP |
|
* @see #ROUND_HALF_DOWN |
|
* @see #ROUND_HALF_EVEN |
|
* @see #ROUND_UNNECESSARY |
|
*/ |
|
public BigDecimal divide(BigDecimal divisor, int scale, int roundingMode) { |
|
if (roundingMode < ROUND_UP || roundingMode > ROUND_UNNECESSARY) |
|
throw new IllegalArgumentException("Invalid rounding mode"); |
|
if (this.intCompact != INFLATED) { |
|
if ((divisor.intCompact != INFLATED)) { |
|
return divide(this.intCompact, this.scale, divisor.intCompact, divisor.scale, scale, roundingMode); |
|
} else { |
|
return divide(this.intCompact, this.scale, divisor.intVal, divisor.scale, scale, roundingMode); |
|
} |
|
} else { |
|
if ((divisor.intCompact != INFLATED)) { |
|
return divide(this.intVal, this.scale, divisor.intCompact, divisor.scale, scale, roundingMode); |
|
} else { |
|
return divide(this.intVal, this.scale, divisor.intVal, divisor.scale, scale, roundingMode); |
|
} |
|
} |
|
} |
|
/** |
|
* Returns a {@code BigDecimal} whose value is {@code (this / |
|
* divisor)}, and whose scale is as specified. If rounding must |
|
* be performed to generate a result with the specified scale, the |
|
* specified rounding mode is applied. |
|
* |
|
* @param divisor value by which this {@code BigDecimal} is to be divided. |
|
* @param scale scale of the {@code BigDecimal} quotient to be returned. |
|
* @param roundingMode rounding mode to apply. |
|
* @return {@code this / divisor} |
|
* @throws ArithmeticException if {@code divisor} is zero, |
|
* {@code roundingMode==RoundingMode.UNNECESSARY} and |
|
* the specified scale is insufficient to represent the result |
|
* of the division exactly. |
|
* @since 1.5 |
|
*/ |
|
public BigDecimal divide(BigDecimal divisor, int scale, RoundingMode roundingMode) { |
|
return divide(divisor, scale, roundingMode.oldMode); |
|
} |
|
/** |
|
* Returns a {@code BigDecimal} whose value is {@code (this / |
|
* divisor)}, and whose scale is {@code this.scale()}. If |
|
* rounding must be performed to generate a result with the given |
|
* scale, the specified rounding mode is applied. |
|
* |
|
* <p>The new {@link #divide(BigDecimal, RoundingMode)} method |
|
* should be used in preference to this legacy method. |
|
* |
|
* @param divisor value by which this {@code BigDecimal} is to be divided. |
|
* @param roundingMode rounding mode to apply. |
|
* @return {@code this / divisor} |
|
* @throws ArithmeticException if {@code divisor==0}, or |
|
* {@code roundingMode==ROUND_UNNECESSARY} and |
|
* {@code this.scale()} is insufficient to represent the result |
|
* of the division exactly. |
|
* @throws IllegalArgumentException if {@code roundingMode} does not |
|
* represent a valid rounding mode. |
|
* @see #ROUND_UP |
|
* @see #ROUND_DOWN |
|
* @see #ROUND_CEILING |
|
* @see #ROUND_FLOOR |
|
* @see #ROUND_HALF_UP |
|
* @see #ROUND_HALF_DOWN |
|
* @see #ROUND_HALF_EVEN |
|
* @see #ROUND_UNNECESSARY |
|
*/ |
|
public BigDecimal divide(BigDecimal divisor, int roundingMode) { |
|
return this.divide(divisor, scale, roundingMode); |
|
} |
|
/** |
|
* Returns a {@code BigDecimal} whose value is {@code (this / |
|
* divisor)}, and whose scale is {@code this.scale()}. If |
|
* rounding must be performed to generate a result with the given |
|
* scale, the specified rounding mode is applied. |
|
* |
|
* @param divisor value by which this {@code BigDecimal} is to be divided. |
|
* @param roundingMode rounding mode to apply. |
|
* @return {@code this / divisor} |
|
* @throws ArithmeticException if {@code divisor==0}, or |
|
* {@code roundingMode==RoundingMode.UNNECESSARY} and |
|
* {@code this.scale()} is insufficient to represent the result |
|
* of the division exactly. |
|
* @since 1.5 |
|
*/ |
|
public BigDecimal divide(BigDecimal divisor, RoundingMode roundingMode) { |
|
return this.divide(divisor, scale, roundingMode.oldMode); |
|
} |
|
/** |
|
* Returns a {@code BigDecimal} whose value is {@code (this / |
|
* divisor)}, and whose preferred scale is {@code (this.scale() - |
|
* divisor.scale())}; if the exact quotient cannot be |
|
* represented (because it has a non-terminating decimal |
|
* expansion) an {@code ArithmeticException} is thrown. |
|
* |
|
* @param divisor value by which this {@code BigDecimal} is to be divided. |
|
* @throws ArithmeticException if the exact quotient does not have a |
|
* terminating decimal expansion |
|
* @return {@code this / divisor} |
|
* @since 1.5 |
|
* @author Joseph D. Darcy |
|
*/ |
|
public BigDecimal divide(BigDecimal divisor) { |
|
/* |
|
* Handle zero cases first. |
|
*/ |
|
if (divisor.signum() == 0) { // x/0 |
|
if (this.signum() == 0) // 0/0 |
|
throw new ArithmeticException("Division undefined"); // NaN |
|
throw new ArithmeticException("Division by zero"); |
|
} |
|
// Calculate preferred scale |
|
int preferredScale = saturateLong((long) this.scale - divisor.scale); |
|
if (this.signum() == 0) // 0/y |
|
return zeroValueOf(preferredScale); |
|
else { |
|
/* |
|
* If the quotient this/divisor has a terminating decimal |
|
* expansion, the expansion can have no more than |
|
* (a.precision() + ceil(10*b.precision)/3) digits. |
|
* Therefore, create a MathContext object with this |
|
* precision and do a divide with the UNNECESSARY rounding |
|
* mode. |
|
*/ |
|
MathContext mc = new MathContext( (int)Math.min(this.precision() + |
|
(long)Math.ceil(10.0*divisor.precision()/3.0), |
|
Integer.MAX_VALUE), |
|
RoundingMode.UNNECESSARY); |
|
BigDecimal quotient; |
|
try { |
|
quotient = this.divide(divisor, mc); |
|
} catch (ArithmeticException e) { |
|
throw new ArithmeticException("Non-terminating decimal expansion; " + |
|
"no exact representable decimal result."); |
|
} |
|
int quotientScale = quotient.scale(); |
|
// divide(BigDecimal, mc) tries to adjust the quotient to |
|
// the desired one by removing trailing zeros; since the |
|
// exact divide method does not have an explicit digit |
|
// limit, we can add zeros too. |
|
if (preferredScale > quotientScale) |
|
return quotient.setScale(preferredScale, ROUND_UNNECESSARY); |
|
return quotient; |
|
} |
|
} |
|
/** |
|
* Returns a {@code BigDecimal} whose value is {@code (this / |
|
* divisor)}, with rounding according to the context settings. |
|
* |
|
* @param divisor value by which this {@code BigDecimal} is to be divided. |
|
* @param mc the context to use. |
|
* @return {@code this / divisor}, rounded as necessary. |
|
* @throws ArithmeticException if the result is inexact but the |
|
* rounding mode is {@code UNNECESSARY} or |
|
* {@code mc.precision == 0} and the quotient has a |
|
* non-terminating decimal expansion. |
|
* @since 1.5 |
|
*/ |
|
public BigDecimal divide(BigDecimal divisor, MathContext mc) { |
|
int mcp = mc.precision; |
|
if (mcp == 0) |
|
return divide(divisor); |
|
BigDecimal dividend = this; |
|
long preferredScale = (long)dividend.scale - divisor.scale; |
|
// Now calculate the answer. We use the existing |
|
// divide-and-round method, but as this rounds to scale we have |
|
// to normalize the values here to achieve the desired result. |
|
// For x/y we first handle y=0 and x=0, and then normalize x and |
|
// y to give x' and y' with the following constraints: |
|
// (a) 0.1 <= x' < 1 |
|
// (b) x' <= y' < 10*x' |
|
// Dividing x'/y' with the required scale set to mc.precision then |
|
// will give a result in the range 0.1 to 1 rounded to exactly |
|
// the right number of digits (except in the case of a result of |
|
// 1.000... which can arise when x=y, or when rounding overflows |
|
// The 1.000... case will reduce properly to 1. |
|
if (divisor.signum() == 0) { // x/0 |
|
if (dividend.signum() == 0) // 0/0 |
|
throw new ArithmeticException("Division undefined"); // NaN |
|
throw new ArithmeticException("Division by zero"); |
|
} |
|
if (dividend.signum() == 0) // 0/y |
|
return zeroValueOf(saturateLong(preferredScale)); |
|
int xscale = dividend.precision(); |
|
int yscale = divisor.precision(); |
|
if(dividend.intCompact!=INFLATED) { |
|
if(divisor.intCompact!=INFLATED) { |
|
return divide(dividend.intCompact, xscale, divisor.intCompact, yscale, preferredScale, mc); |
|
} else { |
|
return divide(dividend.intCompact, xscale, divisor.intVal, yscale, preferredScale, mc); |
|
} |
|
} else { |
|
if(divisor.intCompact!=INFLATED) { |
|
return divide(dividend.intVal, xscale, divisor.intCompact, yscale, preferredScale, mc); |
|
} else { |
|
return divide(dividend.intVal, xscale, divisor.intVal, yscale, preferredScale, mc); |
|
} |
|
} |
|
} |
|
/** |
|
* Returns a {@code BigDecimal} whose value is the integer part |
|
* of the quotient {@code (this / divisor)} rounded down. The |
|
* preferred scale of the result is {@code (this.scale() - |
|
* divisor.scale())}. |
|
* |
|
* @param divisor value by which this {@code BigDecimal} is to be divided. |
|
* @return The integer part of {@code this / divisor}. |
|
* @throws ArithmeticException if {@code divisor==0} |
|
* @since 1.5 |
|
*/ |
|
public BigDecimal divideToIntegralValue(BigDecimal divisor) { |
|
// Calculate preferred scale |
|
int preferredScale = saturateLong((long) this.scale - divisor.scale); |
|
if (this.compareMagnitude(divisor) < 0) { |
|
// much faster when this << divisor |
|
return zeroValueOf(preferredScale); |
|
} |
|
if (this.signum() == 0 && divisor.signum() != 0) |
|
return this.setScale(preferredScale, ROUND_UNNECESSARY); |
|
// Perform a divide with enough digits to round to a correct |
|
// integer value; then remove any fractional digits |
|
int maxDigits = (int)Math.min(this.precision() + |
|
(long)Math.ceil(10.0*divisor.precision()/3.0) + |
|
Math.abs((long)this.scale() - divisor.scale()) + 2, |
|
Integer.MAX_VALUE); |
|
BigDecimal quotient = this.divide(divisor, new MathContext(maxDigits, |
|
RoundingMode.DOWN)); |
|
if (quotient.scale > 0) { |
|
quotient = quotient.setScale(0, RoundingMode.DOWN); |
|
quotient = stripZerosToMatchScale(quotient.intVal, quotient.intCompact, quotient.scale, preferredScale); |
|
} |
|
if (quotient.scale < preferredScale) { |
|
// pad with zeros if necessary |
|
quotient = quotient.setScale(preferredScale, ROUND_UNNECESSARY); |
|
} |
|
return quotient; |
|
} |
|
/** |
|
* Returns a {@code BigDecimal} whose value is the integer part |
|
* of {@code (this / divisor)}. Since the integer part of the |
|
* exact quotient does not depend on the rounding mode, the |
|
* rounding mode does not affect the values returned by this |
|
* method. The preferred scale of the result is |
|
* {@code (this.scale() - divisor.scale())}. An |
|
* {@code ArithmeticException} is thrown if the integer part of |
|
* the exact quotient needs more than {@code mc.precision} |
|
* digits. |
|
* |
|
* @param divisor value by which this {@code BigDecimal} is to be divided. |
|
* @param mc the context to use. |
|
* @return The integer part of {@code this / divisor}. |
|
* @throws ArithmeticException if {@code divisor==0} |
|
* @throws ArithmeticException if {@code mc.precision} {@literal >} 0 and the result |
|
* requires a precision of more than {@code mc.precision} digits. |
|
* @since 1.5 |
|
* @author Joseph D. Darcy |
|
*/ |
|
public BigDecimal divideToIntegralValue(BigDecimal divisor, MathContext mc) { |
|
if (mc.precision == 0 || // exact result |
|
(this.compareMagnitude(divisor) < 0)) // zero result |
|
return divideToIntegralValue(divisor); |
|
// Calculate preferred scale |
|
int preferredScale = saturateLong((long)this.scale - divisor.scale); |
|
/* |
|
* Perform a normal divide to mc.precision digits. If the |
|
* remainder has absolute value less than the divisor, the |
|
* integer portion of the quotient fits into mc.precision |
|
* digits. Next, remove any fractional digits from the |
|
* quotient and adjust the scale to the preferred value. |
|
*/ |
|
BigDecimal result = this.divide(divisor, new MathContext(mc.precision, RoundingMode.DOWN)); |
|
if (result.scale() < 0) { |
|
/* |
|
* Result is an integer. See if quotient represents the |
|
* full integer portion of the exact quotient; if it does, |
|
* the computed remainder will be less than the divisor. |
|
*/ |
|
BigDecimal product = result.multiply(divisor); |
|
// If the quotient is the full integer value, |
|
// |dividend-product| < |divisor|. |
|
if (this.subtract(product).compareMagnitude(divisor) >= 0) { |
|
throw new ArithmeticException("Division impossible"); |
|
} |
|
} else if (result.scale() > 0) { |
|
/* |
|
* Integer portion of quotient will fit into precision |
|
* digits; recompute quotient to scale 0 to avoid double |
|
* rounding and then try to adjust, if necessary. |
|
*/ |
|
result = result.setScale(0, RoundingMode.DOWN); |
|
} |
|
// else result.scale() == 0; |
|
int precisionDiff; |
|
if ((preferredScale > result.scale()) && |
|
(precisionDiff = mc.precision - result.precision()) > 0) { |
|
return result.setScale(result.scale() + |
|
Math.min(precisionDiff, preferredScale - result.scale) ); |
|
} else { |
|
return stripZerosToMatchScale(result.intVal,result.intCompact,result.scale,preferredScale); |
|
} |
|
} |
|
/** |
|
* Returns a {@code BigDecimal} whose value is {@code (this % divisor)}. |
|
* |
|
* <p>The remainder is given by |
|
* {@code this.subtract(this.divideToIntegralValue(divisor).multiply(divisor))}. |
|
* Note that this is not the modulo operation (the result can be |
|
* negative). |
|
* |
|
* @param divisor value by which this {@code BigDecimal} is to be divided. |
|
* @return {@code this % divisor}. |
|
* @throws ArithmeticException if {@code divisor==0} |
|
* @since 1.5 |
|
*/ |
|
public BigDecimal remainder(BigDecimal divisor) { |
|
BigDecimal divrem[] = this.divideAndRemainder(divisor); |
|
return divrem[1]; |
|
} |
|
/** |
|
* Returns a {@code BigDecimal} whose value is {@code (this % |
|
* divisor)}, with rounding according to the context settings. |
|
* The {@code MathContext} settings affect the implicit divide |
|
* used to compute the remainder. The remainder computation |
|
* itself is by definition exact. Therefore, the remainder may |
|
* contain more than {@code mc.getPrecision()} digits. |
|
* |
|
* <p>The remainder is given by |
|
* {@code this.subtract(this.divideToIntegralValue(divisor, |
|
* mc).multiply(divisor))}. Note that this is not the modulo |
|
* operation (the result can be negative). |
|
* |
|
* @param divisor value by which this {@code BigDecimal} is to be divided. |
|
* @param mc the context to use. |
|
* @return {@code this % divisor}, rounded as necessary. |
|
* @throws ArithmeticException if {@code divisor==0} |
|
* @throws ArithmeticException if the result is inexact but the |
|
* rounding mode is {@code UNNECESSARY}, or {@code mc.precision} |
|
* {@literal >} 0 and the result of {@code this.divideToIntgralValue(divisor)} would |
|
* require a precision of more than {@code mc.precision} digits. |
|
* @see #divideToIntegralValue(java.math.BigDecimal, java.math.MathContext) |
|
* @since 1.5 |
|
*/ |
|
public BigDecimal remainder(BigDecimal divisor, MathContext mc) { |
|
BigDecimal divrem[] = this.divideAndRemainder(divisor, mc); |
|
return divrem[1]; |
|
} |
|
/** |
|
* Returns a two-element {@code BigDecimal} array containing the |
|
* result of {@code divideToIntegralValue} followed by the result of |
|
* {@code remainder} on the two operands. |
|
* |
|
* <p>Note that if both the integer quotient and remainder are |
|
* needed, this method is faster than using the |
|
* {@code divideToIntegralValue} and {@code remainder} methods |
|
* separately because the division need only be carried out once. |
|
* |
|
* @param divisor value by which this {@code BigDecimal} is to be divided, |
|
* and the remainder computed. |
|
* @return a two element {@code BigDecimal} array: the quotient |
|
* (the result of {@code divideToIntegralValue}) is the initial element |
|
* and the remainder is the final element. |
|
* @throws ArithmeticException if {@code divisor==0} |
|
* @see #divideToIntegralValue(java.math.BigDecimal, java.math.MathContext) |
|
* @see #remainder(java.math.BigDecimal, java.math.MathContext) |
|
* @since 1.5 |
|
*/ |
|
public BigDecimal[] divideAndRemainder(BigDecimal divisor) { |
|
// we use the identity x = i * y + r to determine r |
|
BigDecimal[] result = new BigDecimal[2]; |
|
result[0] = this.divideToIntegralValue(divisor); |
|
result[1] = this.subtract(result[0].multiply(divisor)); |
|
return result; |
|
} |
|
/** |
|
* Returns a two-element {@code BigDecimal} array containing the |
|
* result of {@code divideToIntegralValue} followed by the result of |
|
* {@code remainder} on the two operands calculated with rounding |
|
* according to the context settings. |
|
* |
|
* <p>Note that if both the integer quotient and remainder are |
|
* needed, this method is faster than using the |
|
* {@code divideToIntegralValue} and {@code remainder} methods |
|
* separately because the division need only be carried out once. |
|
* |
|
* @param divisor value by which this {@code BigDecimal} is to be divided, |
|
* and the remainder computed. |
|
* @param mc the context to use. |
|
* @return a two element {@code BigDecimal} array: the quotient |
|
* (the result of {@code divideToIntegralValue}) is the |
|
* initial element and the remainder is the final element. |
|
* @throws ArithmeticException if {@code divisor==0} |
|
* @throws ArithmeticException if the result is inexact but the |
|
* rounding mode is {@code UNNECESSARY}, or {@code mc.precision} |
|
* {@literal >} 0 and the result of {@code this.divideToIntgralValue(divisor)} would |
|
* require a precision of more than {@code mc.precision} digits. |
|
* @see #divideToIntegralValue(java.math.BigDecimal, java.math.MathContext) |
|
* @see #remainder(java.math.BigDecimal, java.math.MathContext) |
|
* @since 1.5 |
|
*/ |
|
public BigDecimal[] divideAndRemainder(BigDecimal divisor, MathContext mc) { |
|
if (mc.precision == 0) |
|
return divideAndRemainder(divisor); |
|
BigDecimal[] result = new BigDecimal[2]; |
|
BigDecimal lhs = this; |
|
result[0] = lhs.divideToIntegralValue(divisor, mc); |
|
result[1] = lhs.subtract(result[0].multiply(divisor)); |
|
return result; |
|
} |
|
/** |
|
* Returns a {@code BigDecimal} whose value is |
|
* <tt>(this<sup>n</sup>)</tt>, The power is computed exactly, to |
|
* unlimited precision. |
|
* |
|
* <p>The parameter {@code n} must be in the range 0 through |
|
* 999999999, inclusive. {@code ZERO.pow(0)} returns {@link |
|
* #ONE}. |
|
* |
|
* Note that future releases may expand the allowable exponent |
|
* range of this method. |
|
* |
|
* @param n power to raise this {@code BigDecimal} to. |
|
* @return <tt>this<sup>n</sup></tt> |
|
* @throws ArithmeticException if {@code n} is out of range. |
|
* @since 1.5 |
|
*/ |
|
public BigDecimal pow(int n) { |
|
if (n < 0 || n > 999999999) |
|
throw new ArithmeticException("Invalid operation"); |
|
// No need to calculate pow(n) if result will over/underflow. |
|
// Don't attempt to support "supernormal" numbers. |
|
int newScale = checkScale((long)scale * n); |
|
return new BigDecimal(this.inflated().pow(n), newScale); |
|
} |
|
/** |
|
* Returns a {@code BigDecimal} whose value is |
|
* <tt>(this<sup>n</sup>)</tt>. The current implementation uses |
|
* the core algorithm defined in ANSI standard X3.274-1996 with |
|
* rounding according to the context settings. In general, the |
|
* returned numerical value is within two ulps of the exact |
|
* numerical value for the chosen precision. Note that future |
|
* releases may use a different algorithm with a decreased |
|
* allowable error bound and increased allowable exponent range. |
|
* |
|
* <p>The X3.274-1996 algorithm is: |
|
* |
|
* <ul> |
|
* <li> An {@code ArithmeticException} exception is thrown if |
|
* <ul> |
|
* <li>{@code abs(n) > 999999999} |
|
* <li>{@code mc.precision == 0} and {@code n < 0} |
|
* <li>{@code mc.precision > 0} and {@code n} has more than |
|
* {@code mc.precision} decimal digits |
|
* </ul> |
|
* |
|
* <li> if {@code n} is zero, {@link #ONE} is returned even if |
|
* {@code this} is zero, otherwise |
|
* <ul> |
|
* <li> if {@code n} is positive, the result is calculated via |
|
* the repeated squaring technique into a single accumulator. |
|
* The individual multiplications with the accumulator use the |
|
* same math context settings as in {@code mc} except for a |
|
* precision increased to {@code mc.precision + elength + 1} |
|
* where {@code elength} is the number of decimal digits in |
|
* {@code n}. |
|
* |
|
* <li> if {@code n} is negative, the result is calculated as if |
|
* {@code n} were positive; this value is then divided into one |
|
* using the working precision specified above. |
|
* |
|
* <li> The final value from either the positive or negative case |
|
* is then rounded to the destination precision. |
|
* </ul> |
|
* </ul> |
|
* |
|
* @param n power to raise this {@code BigDecimal} to. |
|
* @param mc the context to use. |
|
* @return <tt>this<sup>n</sup></tt> using the ANSI standard X3.274-1996 |
|
* algorithm |
|
* @throws ArithmeticException if the result is inexact but the |
|
* rounding mode is {@code UNNECESSARY}, or {@code n} is out |
|
* of range. |
|
* @since 1.5 |
|
*/ |
|
public BigDecimal pow(int n, MathContext mc) { |
|
if (mc.precision == 0) |
|
return pow(n); |
|
if (n < -999999999 || n > 999999999) |
|
throw new ArithmeticException("Invalid operation"); |
|
if (n == 0) |
|
return ONE; // x**0 == 1 in X3.274 |
|
BigDecimal lhs = this; |
|
MathContext workmc = mc; // working settings |
|
int mag = Math.abs(n); // magnitude of n |
|
if (mc.precision > 0) { |
|
int elength = longDigitLength(mag); // length of n in digits |
|
if (elength > mc.precision) // X3.274 rule |
|
throw new ArithmeticException("Invalid operation"); |
|
workmc = new MathContext(mc.precision + elength + 1, |
|
mc.roundingMode); |
|
} |
|
// ready to carry out power calculation... |
|
BigDecimal acc = ONE; // accumulator |
|
boolean seenbit = false; // set once we've seen a 1-bit |
|
for (int i=1;;i++) { // for each bit [top bit ignored] |
|
mag += mag; // shift left 1 bit |
|
if (mag < 0) { // top bit is set |
|
seenbit = true; // OK, we're off |
|
acc = acc.multiply(lhs, workmc); // acc=acc*x |
|
} |
|
if (i == 31) |
|
break; // that was the last bit |
|
if (seenbit) |
|
acc=acc.multiply(acc, workmc); // acc=acc*acc [square] |
|
// else (!seenbit) no point in squaring ONE |
|
} |
|
// if negative n, calculate the reciprocal using working precision |
|
if (n < 0) // [hence mc.precision>0] |
|
acc=ONE.divide(acc, workmc); |
|
// round to final precision and strip zeros |
|
return doRound(acc, mc); |
|
} |
|
/** |
|
* Returns a {@code BigDecimal} whose value is the absolute value |
|
* of this {@code BigDecimal}, and whose scale is |
|
* {@code this.scale()}. |
|
* |
|
* @return {@code abs(this)} |
|
*/ |
|
public BigDecimal abs() { |
|
return (signum() < 0 ? negate() : this); |
|
} |
|
/** |
|
* Returns a {@code BigDecimal} whose value is the absolute value |
|
* of this {@code BigDecimal}, with rounding according to the |
|
* context settings. |
|
* |
|
* @param mc the context to use. |
|
* @return {@code abs(this)}, rounded as necessary. |
|
* @throws ArithmeticException if the result is inexact but the |
|
* rounding mode is {@code UNNECESSARY}. |
|
* @since 1.5 |
|
*/ |
|
public BigDecimal abs(MathContext mc) { |
|
return (signum() < 0 ? negate(mc) : plus(mc)); |
|
} |
|
/** |
|
* Returns a {@code BigDecimal} whose value is {@code (-this)}, |
|
* and whose scale is {@code this.scale()}. |
|
* |
|
* @return {@code -this}. |
|
*/ |
|
public BigDecimal negate() { |
|
if (intCompact == INFLATED) { |
|
return new BigDecimal(intVal.negate(), INFLATED, scale, precision); |
|
} else { |
|
return valueOf(-intCompact, scale, precision); |
|
} |
|
} |
|
/** |
|
* Returns a {@code BigDecimal} whose value is {@code (-this)}, |
|
* with rounding according to the context settings. |
|
* |
|
* @param mc the context to use. |
|
* @return {@code -this}, rounded as necessary. |
|
* @throws ArithmeticException if the result is inexact but the |
|
* rounding mode is {@code UNNECESSARY}. |
|
* @since 1.5 |
|
*/ |
|
public BigDecimal negate(MathContext mc) { |
|
return negate().plus(mc); |
|
} |
|
/** |
|
* Returns a {@code BigDecimal} whose value is {@code (+this)}, and whose |
|
* scale is {@code this.scale()}. |
|
* |
|
* <p>This method, which simply returns this {@code BigDecimal} |
|
* is included for symmetry with the unary minus method {@link |
|
* #negate()}. |
|
* |
|
* @return {@code this}. |
|
* @see #negate() |
|
* @since 1.5 |
|
*/ |
|
public BigDecimal plus() { |
|
return this; |
|
} |
|
/** |
|
* Returns a {@code BigDecimal} whose value is {@code (+this)}, |
|
* with rounding according to the context settings. |
|
* |
|
* <p>The effect of this method is identical to that of the {@link |
|
* #round(MathContext)} method. |
|
* |
|
* @param mc the context to use. |
|
* @return {@code this}, rounded as necessary. A zero result will |
|
* have a scale of 0. |
|
* @throws ArithmeticException if the result is inexact but the |
|
* rounding mode is {@code UNNECESSARY}. |
|
* @see #round(MathContext) |
|
* @since 1.5 |
|
*/ |
|
public BigDecimal plus(MathContext mc) { |
|
if (mc.precision == 0) // no rounding please |
|
return this; |
|
return doRound(this, mc); |
|
} |
|
/** |
|
* Returns the signum function of this {@code BigDecimal}. |
|
* |
|
* @return -1, 0, or 1 as the value of this {@code BigDecimal} |
|
* is negative, zero, or positive. |
|
*/ |
|
public int signum() { |
|
return (intCompact != INFLATED)? |
|
Long.signum(intCompact): |
|
intVal.signum(); |
|
} |
|
/** |
|
* Returns the <i>scale</i> of this {@code BigDecimal}. If zero |
|
* or positive, the scale is the number of digits to the right of |
|
* the decimal point. If negative, the unscaled value of the |
|
* number is multiplied by ten to the power of the negation of the |
|
* scale. For example, a scale of {@code -3} means the unscaled |
|
* value is multiplied by 1000. |
|
* |
|
* @return the scale of this {@code BigDecimal}. |
|
*/ |
|
public int scale() { |
|
return scale; |
|
} |
|
/** |
|
* Returns the <i>precision</i> of this {@code BigDecimal}. (The |
|
* precision is the number of digits in the unscaled value.) |
|
* |
|
* <p>The precision of a zero value is 1. |
|
* |
|
* @return the precision of this {@code BigDecimal}. |
|
* @since 1.5 |
|
*/ |
|
public int precision() { |
|
int result = precision; |
|
if (result == 0) { |
|
long s = intCompact; |
|
if (s != INFLATED) |
|
result = longDigitLength(s); |
|
else |
|
result = bigDigitLength(intVal); |
|
precision = result; |
|
} |
|
return result; |
|
} |
|
/** |
|
* Returns a {@code BigInteger} whose value is the <i>unscaled |
|
* value</i> of this {@code BigDecimal}. (Computes <tt>(this * |
|
* 10<sup>this.scale()</sup>)</tt>.) |
|
* |
|
* @return the unscaled value of this {@code BigDecimal}. |
|
* @since 1.2 |
|
*/ |
|
public BigInteger unscaledValue() { |
|
return this.inflated(); |
|
} |
|
// Rounding Modes |
|
/** |
|
* Rounding mode to round away from zero. Always increments the |
|
* digit prior to a nonzero discarded fraction. Note that this rounding |
|
* mode never decreases the magnitude of the calculated value. |
|
*/ |
|
public final static int ROUND_UP = 0; |
|
/** |
|
* Rounding mode to round towards zero. Never increments the digit |
|
* prior to a discarded fraction (i.e., truncates). Note that this |
|
* rounding mode never increases the magnitude of the calculated value. |
|
*/ |
|
public final static int ROUND_DOWN = 1; |
|
/** |
|
* Rounding mode to round towards positive infinity. If the |
|
* {@code BigDecimal} is positive, behaves as for |
|
* {@code ROUND_UP}; if negative, behaves as for |
|
* {@code ROUND_DOWN}. Note that this rounding mode never |
|
* decreases the calculated value. |
|
*/ |
|
public final static int ROUND_CEILING = 2; |
|
/** |
|
* Rounding mode to round towards negative infinity. If the |
|
* {@code BigDecimal} is positive, behave as for |
|
* {@code ROUND_DOWN}; if negative, behave as for |
|
* {@code ROUND_UP}. Note that this rounding mode never |
|
* increases the calculated value. |
|
*/ |
|
public final static int ROUND_FLOOR = 3; |
|
/** |
|
* Rounding mode to round towards {@literal "nearest neighbor"} |
|
* unless both neighbors are equidistant, in which case round up. |
|
* Behaves as for {@code ROUND_UP} if the discarded fraction is |
|
* ≥ 0.5; otherwise, behaves as for {@code ROUND_DOWN}. Note |
|
* that this is the rounding mode that most of us were taught in |
|
* grade school. |
|
*/ |
|
public final static int ROUND_HALF_UP = 4; |
|
/** |
|
* Rounding mode to round towards {@literal "nearest neighbor"} |
|
* unless both neighbors are equidistant, in which case round |
|
* down. Behaves as for {@code ROUND_UP} if the discarded |
|
* fraction is {@literal >} 0.5; otherwise, behaves as for |
|
* {@code ROUND_DOWN}. |
|
*/ |
|
public final static int ROUND_HALF_DOWN = 5; |
|
/** |
|
* Rounding mode to round towards the {@literal "nearest neighbor"} |
|
* unless both neighbors are equidistant, in which case, round |
|
* towards the even neighbor. Behaves as for |
|
* {@code ROUND_HALF_UP} if the digit to the left of the |
|
* discarded fraction is odd; behaves as for |
|
* {@code ROUND_HALF_DOWN} if it's even. Note that this is the |
|
* rounding mode that minimizes cumulative error when applied |
|
* repeatedly over a sequence of calculations. |
|
*/ |
|
public final static int ROUND_HALF_EVEN = 6; |
|
/** |
|
* Rounding mode to assert that the requested operation has an exact |
|
* result, hence no rounding is necessary. If this rounding mode is |
|
* specified on an operation that yields an inexact result, an |
|
* {@code ArithmeticException} is thrown. |
|
*/ |
|
public final static int ROUND_UNNECESSARY = 7; |
|
// Scaling/Rounding Operations |
|
/** |
|
* Returns a {@code BigDecimal} rounded according to the |
|
* {@code MathContext} settings. If the precision setting is 0 then |
|
* no rounding takes place. |
|
* |
|
* <p>The effect of this method is identical to that of the |
|
* {@link #plus(MathContext)} method. |
|
* |
|
* @param mc the context to use. |
|
* @return a {@code BigDecimal} rounded according to the |
|
* {@code MathContext} settings. |
|
* @throws ArithmeticException if the rounding mode is |
|
* {@code UNNECESSARY} and the |
|
* {@code BigDecimal} operation would require rounding. |
|
* @see #plus(MathContext) |
|
* @since 1.5 |
|
*/ |
|
public BigDecimal round(MathContext mc) { |
|
return plus(mc); |
|
} |
|
/** |
|
* Returns a {@code BigDecimal} whose scale is the specified |
|
* value, and whose unscaled value is determined by multiplying or |
|
* dividing this {@code BigDecimal}'s unscaled value by the |
|
* appropriate power of ten to maintain its overall value. If the |
|
* scale is reduced by the operation, the unscaled value must be |
|
* divided (rather than multiplied), and the value may be changed; |
|
* in this case, the specified rounding mode is applied to the |
|
* division. |
|
* |
|
* <p>Note that since BigDecimal objects are immutable, calls of |
|
* this method do <i>not</i> result in the original object being |
|
* modified, contrary to the usual convention of having methods |
|
* named <tt>set<i>X</i></tt> mutate field <i>{@code X}</i>. |
|
* Instead, {@code setScale} returns an object with the proper |
|
* scale; the returned object may or may not be newly allocated. |
|
* |
|
* @param newScale scale of the {@code BigDecimal} value to be returned. |
|
* @param roundingMode The rounding mode to apply. |
|
* @return a {@code BigDecimal} whose scale is the specified value, |
|
* and whose unscaled value is determined by multiplying or |
|
* dividing this {@code BigDecimal}'s unscaled value by the |
|
* appropriate power of ten to maintain its overall value. |
|
* @throws ArithmeticException if {@code roundingMode==UNNECESSARY} |
|
* and the specified scaling operation would require |
|
* rounding. |
|
* @see RoundingMode |
|
* @since 1.5 |
|
*/ |
|
public BigDecimal setScale(int newScale, RoundingMode roundingMode) { |
|
return setScale(newScale, roundingMode.oldMode); |
|
} |
|
/** |
|
* Returns a {@code BigDecimal} whose scale is the specified |
|
* value, and whose unscaled value is determined by multiplying or |
|
* dividing this {@code BigDecimal}'s unscaled value by the |
|
* appropriate power of ten to maintain its overall value. If the |
|
* scale is reduced by the operation, the unscaled value must be |
|
* divided (rather than multiplied), and the value may be changed; |
|
* in this case, the specified rounding mode is applied to the |
|
* division. |
|
* |
|
* <p>Note that since BigDecimal objects are immutable, calls of |
|
* this method do <i>not</i> result in the original object being |
|
* modified, contrary to the usual convention of having methods |
|
* named <tt>set<i>X</i></tt> mutate field <i>{@code X}</i>. |
|
* Instead, {@code setScale} returns an object with the proper |
|
* scale; the returned object may or may not be newly allocated. |
|
* |
|
* <p>The new {@link #setScale(int, RoundingMode)} method should |
|
* be used in preference to this legacy method. |
|
* |
|
* @param newScale scale of the {@code BigDecimal} value to be returned. |
|
* @param roundingMode The rounding mode to apply. |
|
* @return a {@code BigDecimal} whose scale is the specified value, |
|
* and whose unscaled value is determined by multiplying or |
|
* dividing this {@code BigDecimal}'s unscaled value by the |
|
* appropriate power of ten to maintain its overall value. |
|
* @throws ArithmeticException if {@code roundingMode==ROUND_UNNECESSARY} |
|
* and the specified scaling operation would require |
|
* rounding. |
|
* @throws IllegalArgumentException if {@code roundingMode} does not |
|
* represent a valid rounding mode. |
|
* @see #ROUND_UP |
|
* @see #ROUND_DOWN |
|
* @see #ROUND_CEILING |
|
* @see #ROUND_FLOOR |
|
* @see #ROUND_HALF_UP |
|
* @see #ROUND_HALF_DOWN |
|
* @see #ROUND_HALF_EVEN |
|
* @see #ROUND_UNNECESSARY |
|
*/ |
|
public BigDecimal setScale(int newScale, int roundingMode) { |
|
if (roundingMode < ROUND_UP || roundingMode > ROUND_UNNECESSARY) |
|
throw new IllegalArgumentException("Invalid rounding mode"); |
|
int oldScale = this.scale; |
|
if (newScale == oldScale) // easy case |
|
return this; |
|
if (this.signum() == 0) // zero can have any scale |
|
return zeroValueOf(newScale); |
|
if(this.intCompact!=INFLATED) { |
|
long rs = this.intCompact; |
|
if (newScale > oldScale) { |
|
int raise = checkScale((long) newScale - oldScale); |
|
if ((rs = longMultiplyPowerTen(rs, raise)) != INFLATED) { |
|
return valueOf(rs,newScale); |
|
} |
|
BigInteger rb = bigMultiplyPowerTen(raise); |
|
return new BigDecimal(rb, INFLATED, newScale, (precision > 0) ? precision + raise : 0); |
|
} else { |
|
// newScale < oldScale -- drop some digits |
|
// Can't predict the precision due to the effect of rounding. |
|
int drop = checkScale((long) oldScale - newScale); |
|
if (drop < LONG_TEN_POWERS_TABLE.length) { |
|
return divideAndRound(rs, LONG_TEN_POWERS_TABLE[drop], newScale, roundingMode, newScale); |
|
} else { |
|
return divideAndRound(this.inflated(), bigTenToThe(drop), newScale, roundingMode, newScale); |
|
} |
|
} |
|
} else { |
|
if (newScale > oldScale) { |
|
int raise = checkScale((long) newScale - oldScale); |
|
BigInteger rb = bigMultiplyPowerTen(this.intVal,raise); |
|
return new BigDecimal(rb, INFLATED, newScale, (precision > 0) ? precision + raise : 0); |
|
} else { |
|
// newScale < oldScale -- drop some digits |
|
// Can't predict the precision due to the effect of rounding. |
|
int drop = checkScale((long) oldScale - newScale); |
|
if (drop < LONG_TEN_POWERS_TABLE.length) |
|
return divideAndRound(this.intVal, LONG_TEN_POWERS_TABLE[drop], newScale, roundingMode, |
|
newScale); |
|
else |
|
return divideAndRound(this.intVal, bigTenToThe(drop), newScale, roundingMode, newScale); |
|
} |
|
} |
|
} |
|
/** |
|
* Returns a {@code BigDecimal} whose scale is the specified |
|
* value, and whose value is numerically equal to this |
|
* {@code BigDecimal}'s. Throws an {@code ArithmeticException} |
|
* if this is not possible. |
|
* |
|
* <p>This call is typically used to increase the scale, in which |
|
* case it is guaranteed that there exists a {@code BigDecimal} |
|
* of the specified scale and the correct value. The call can |
|
* also be used to reduce the scale if the caller knows that the |
|
* {@code BigDecimal} has sufficiently many zeros at the end of |
|
* its fractional part (i.e., factors of ten in its integer value) |
|
* to allow for the rescaling without changing its value. |
|
* |
|
* <p>This method returns the same result as the two-argument |
|
* versions of {@code setScale}, but saves the caller the trouble |
|
* of specifying a rounding mode in cases where it is irrelevant. |
|
* |
|
* <p>Note that since {@code BigDecimal} objects are immutable, |
|
* calls of this method do <i>not</i> result in the original |
|
* object being modified, contrary to the usual convention of |
|
* having methods named <tt>set<i>X</i></tt> mutate field |
|
* <i>{@code X}</i>. Instead, {@code setScale} returns an |
|
* object with the proper scale; the returned object may or may |
|
* not be newly allocated. |
|
* |
|
* @param newScale scale of the {@code BigDecimal} value to be returned. |
|
* @return a {@code BigDecimal} whose scale is the specified value, and |
|
* whose unscaled value is determined by multiplying or dividing |
|
* this {@code BigDecimal}'s unscaled value by the appropriate |
|
* power of ten to maintain its overall value. |
|
* @throws ArithmeticException if the specified scaling operation would |
|
* require rounding. |
|
* @see #setScale(int, int) |
|
* @see #setScale(int, RoundingMode) |
|
*/ |
|
public BigDecimal setScale(int newScale) { |
|
return setScale(newScale, ROUND_UNNECESSARY); |
|
} |
|
// Decimal Point Motion Operations |
|
/** |
|
* Returns a {@code BigDecimal} which is equivalent to this one |
|
* with the decimal point moved {@code n} places to the left. If |
|
* {@code n} is non-negative, the call merely adds {@code n} to |
|
* the scale. If {@code n} is negative, the call is equivalent |
|
* to {@code movePointRight(-n)}. The {@code BigDecimal} |
|
* returned by this call has value <tt>(this × |
|
* 10<sup>-n</sup>)</tt> and scale {@code max(this.scale()+n, |
|
* 0)}. |
|
* |
|
* @param n number of places to move the decimal point to the left. |
|
* @return a {@code BigDecimal} which is equivalent to this one with the |
|
* decimal point moved {@code n} places to the left. |
|
* @throws ArithmeticException if scale overflows. |
|
*/ |
|
public BigDecimal movePointLeft(int n) { |
|
// Cannot use movePointRight(-n) in case of n==Integer.MIN_VALUE |
|
int newScale = checkScale((long)scale + n); |
|
BigDecimal num = new BigDecimal(intVal, intCompact, newScale, 0); |
|
return num.scale < 0 ? num.setScale(0, ROUND_UNNECESSARY) : num; |
|
} |
|
/** |
|
* Returns a {@code BigDecimal} which is equivalent to this one |
|
* with the decimal point moved {@code n} places to the right. |
|
* If {@code n} is non-negative, the call merely subtracts |
|
* {@code n} from the scale. If {@code n} is negative, the call |
|
* is equivalent to {@code movePointLeft(-n)}. The |
|
* {@code BigDecimal} returned by this call has value <tt>(this |
|
* × 10<sup>n</sup>)</tt> and scale {@code max(this.scale()-n, |
|
* 0)}. |
|
* |
|
* @param n number of places to move the decimal point to the right. |
|
* @return a {@code BigDecimal} which is equivalent to this one |
|
* with the decimal point moved {@code n} places to the right. |
|
* @throws ArithmeticException if scale overflows. |
|
*/ |
|
public BigDecimal movePointRight(int n) { |
|
// Cannot use movePointLeft(-n) in case of n==Integer.MIN_VALUE |
|
int newScale = checkScale((long)scale - n); |
|
BigDecimal num = new BigDecimal(intVal, intCompact, newScale, 0); |
|
return num.scale < 0 ? num.setScale(0, ROUND_UNNECESSARY) : num; |
|
} |
|
/** |
|
* Returns a BigDecimal whose numerical value is equal to |
|
* ({@code this} * 10<sup>n</sup>). The scale of |
|
* the result is {@code (this.scale() - n)}. |
|
* |
|
* @param n the exponent power of ten to scale by |
|
* @return a BigDecimal whose numerical value is equal to |
|
* ({@code this} * 10<sup>n</sup>) |
|
* @throws ArithmeticException if the scale would be |
|
* outside the range of a 32-bit integer. |
|
* |
|
* @since 1.5 |
|
*/ |
|
public BigDecimal scaleByPowerOfTen(int n) { |
|
return new BigDecimal(intVal, intCompact, |
|
checkScale((long)scale - n), precision); |
|
} |
|
/** |
|
* Returns a {@code BigDecimal} which is numerically equal to |
|
* this one but with any trailing zeros removed from the |
|
* representation. For example, stripping the trailing zeros from |
|
* the {@code BigDecimal} value {@code 600.0}, which has |
|
* [{@code BigInteger}, {@code scale}] components equals to |
|
* [6000, 1], yields {@code 6E2} with [{@code BigInteger}, |
|
* {@code scale}] components equals to [6, -2]. If |
|
* this BigDecimal is numerically equal to zero, then |
|
* {@code BigDecimal.ZERO} is returned. |
|
* |
|
* @return a numerically equal {@code BigDecimal} with any |
|
* trailing zeros removed. |
|
* @since 1.5 |
|
*/ |
|
public BigDecimal stripTrailingZeros() { |
|
if (intCompact == 0 || (intVal != null && intVal.signum() == 0)) { |
|
return BigDecimal.ZERO; |
|
} else if (intCompact != INFLATED) { |
|
return createAndStripZerosToMatchScale(intCompact, scale, Long.MIN_VALUE); |
|
} else { |
|
return createAndStripZerosToMatchScale(intVal, scale, Long.MIN_VALUE); |
|
} |
|
} |
|
// Comparison Operations |
|
/** |
|
* Compares this {@code BigDecimal} with the specified |
|
* {@code BigDecimal}. Two {@code BigDecimal} objects that are |
|
* equal in value but have a different scale (like 2.0 and 2.00) |
|
* are considered equal by this method. This method is provided |
|
* in preference to individual methods for each of the six boolean |
|
* comparison operators ({@literal <}, ==, |
|
* {@literal >}, {@literal >=}, !=, {@literal <=}). The |
|
* suggested idiom for performing these comparisons is: |
|
* {@code (x.compareTo(y)} <<i>op</i>> {@code 0)}, where |
|
* <<i>op</i>> is one of the six comparison operators. |
|
* |
|
* @param val {@code BigDecimal} to which this {@code BigDecimal} is |
|
* to be compared. |
|
* @return -1, 0, or 1 as this {@code BigDecimal} is numerically |
|
* less than, equal to, or greater than {@code val}. |
|
*/ |
|
public int compareTo(BigDecimal val) { |
|
// Quick path for equal scale and non-inflated case. |
|
if (scale == val.scale) { |
|
long xs = intCompact; |
|
long ys = val.intCompact; |
|
if (xs != INFLATED && ys != INFLATED) |
|
return xs != ys ? ((xs > ys) ? 1 : -1) : 0; |
|
} |
|
int xsign = this.signum(); |
|
int ysign = val.signum(); |
|
if (xsign != ysign) |
|
return (xsign > ysign) ? 1 : -1; |
|
if (xsign == 0) |
|
return 0; |
|
int cmp = compareMagnitude(val); |
|
return (xsign > 0) ? cmp : -cmp; |
|
} |
|
/** |
|
* Version of compareTo that ignores sign. |
|
*/ |
|
private int compareMagnitude(BigDecimal val) { |
|
// Match scales, avoid unnecessary inflation |
|
long ys = val.intCompact; |
|
long xs = this.intCompact; |
|
if (xs == 0) |
|
return (ys == 0) ? 0 : -1; |
|
if (ys == 0) |
|
return 1; |
|
long sdiff = (long)this.scale - val.scale; |
|
if (sdiff != 0) { |
|
// Avoid matching scales if the (adjusted) exponents differ |
|
long xae = (long)this.precision() - this.scale; // [-1] |
|
long yae = (long)val.precision() - val.scale; // [-1] |
|
if (xae < yae) |
|
return -1; |
|
if (xae > yae) |
|
return 1; |
|
BigInteger rb = null; |
|
if (sdiff < 0) { |
|
// The cases sdiff <= Integer.MIN_VALUE intentionally fall through. |
|
if ( sdiff > Integer.MIN_VALUE && |
|
(xs == INFLATED || |
|
(xs = longMultiplyPowerTen(xs, (int)-sdiff)) == INFLATED) && |
|
ys == INFLATED) { |
|
rb = bigMultiplyPowerTen((int)-sdiff); |
|
return rb.compareMagnitude(val.intVal); |
|
} |
|
} else { // sdiff > 0 |
|
// The cases sdiff > Integer.MAX_VALUE intentionally fall through. |
|
if ( sdiff <= Integer.MAX_VALUE && |
|
(ys == INFLATED || |
|
(ys = longMultiplyPowerTen(ys, (int)sdiff)) == INFLATED) && |
|
xs == INFLATED) { |
|
rb = val.bigMultiplyPowerTen((int)sdiff); |
|
return this.intVal.compareMagnitude(rb); |
|
} |
|
} |
|
} |
|
if (xs != INFLATED) |
|
return (ys != INFLATED) ? longCompareMagnitude(xs, ys) : -1; |
|
else if (ys != INFLATED) |
|
return 1; |
|
else |
|
return this.intVal.compareMagnitude(val.intVal); |
|
} |
|
/** |
|
* Compares this {@code BigDecimal} with the specified |
|
* {@code Object} for equality. Unlike {@link |
|
* #compareTo(BigDecimal) compareTo}, this method considers two |
|
* {@code BigDecimal} objects equal only if they are equal in |
|
* value and scale (thus 2.0 is not equal to 2.00 when compared by |
|
* this method). |
|
* |
|
* @param x {@code Object} to which this {@code BigDecimal} is |
|
* to be compared. |
|
* @return {@code true} if and only if the specified {@code Object} is a |
|
* {@code BigDecimal} whose value and scale are equal to this |
|
* {@code BigDecimal}'s. |
|
* @see #compareTo(java.math.BigDecimal) |
|
* @see #hashCode |
|
*/ |
|
@Override |
|
public boolean equals(Object x) { |
|
if (!(x instanceof BigDecimal)) |
|
return false; |
|
BigDecimal xDec = (BigDecimal) x; |
|
if (x == this) |
|
return true; |
|
if (scale != xDec.scale) |
|
return false; |
|
long s = this.intCompact; |
|
long xs = xDec.intCompact; |
|
if (s != INFLATED) { |
|
if (xs == INFLATED) |
|
xs = compactValFor(xDec.intVal); |
|
return xs == s; |
|
} else if (xs != INFLATED) |
|
return xs == compactValFor(this.intVal); |
|
return this.inflated().equals(xDec.inflated()); |
|
} |
|
/** |
|
* Returns the minimum of this {@code BigDecimal} and |
|
* {@code val}. |
|
* |
|
* @param val value with which the minimum is to be computed. |
|
* @return the {@code BigDecimal} whose value is the lesser of this |
|
* {@code BigDecimal} and {@code val}. If they are equal, |
|
* as defined by the {@link #compareTo(BigDecimal) compareTo} |
|
* method, {@code this} is returned. |
|
* @see #compareTo(java.math.BigDecimal) |
|
*/ |
|
public BigDecimal min(BigDecimal val) { |
|
return (compareTo(val) <= 0 ? this : val); |
|
} |
|
/** |
|
* Returns the maximum of this {@code BigDecimal} and {@code val}. |
|
* |
|
* @param val value with which the maximum is to be computed. |
|
* @return the {@code BigDecimal} whose value is the greater of this |
|
* {@code BigDecimal} and {@code val}. If they are equal, |
|
* as defined by the {@link #compareTo(BigDecimal) compareTo} |
|
* method, {@code this} is returned. |
|
* @see #compareTo(java.math.BigDecimal) |
|
*/ |
|
public BigDecimal max(BigDecimal val) { |
|
return (compareTo(val) >= 0 ? this : val); |
|
} |
|
// Hash Function |
|
/** |
|
* Returns the hash code for this {@code BigDecimal}. Note that |
|
* two {@code BigDecimal} objects that are numerically equal but |
|
* differ in scale (like 2.0 and 2.00) will generally <i>not</i> |
|
* have the same hash code. |
|
* |
|
* @return hash code for this {@code BigDecimal}. |
|
* @see #equals(Object) |
|
*/ |
|
@Override |
|
public int hashCode() { |
|
if (intCompact != INFLATED) { |
|
long val2 = (intCompact < 0)? -intCompact : intCompact; |
|
int temp = (int)( ((int)(val2 >>> 32)) * 31 + |
|
(val2 & LONG_MASK)); |
|
return 31*((intCompact < 0) ?-temp:temp) + scale; |
|
} else |
|
return 31*intVal.hashCode() + scale; |
|
} |
|
// Format Converters |
|
/** |
|
* Returns the string representation of this {@code BigDecimal}, |
|
* using scientific notation if an exponent is needed. |
|
* |
|
* <p>A standard canonical string form of the {@code BigDecimal} |
|
* is created as though by the following steps: first, the |
|
* absolute value of the unscaled value of the {@code BigDecimal} |
|
* is converted to a string in base ten using the characters |
|
* {@code '0'} through {@code '9'} with no leading zeros (except |
|
* if its value is zero, in which case a single {@code '0'} |
|
* character is used). |
|
* |
|
* <p>Next, an <i>adjusted exponent</i> is calculated; this is the |
|
* negated scale, plus the number of characters in the converted |
|
* unscaled value, less one. That is, |
|
* {@code -scale+(ulength-1)}, where {@code ulength} is the |
|
* length of the absolute value of the unscaled value in decimal |
|
* digits (its <i>precision</i>). |
|
* |
|
* <p>If the scale is greater than or equal to zero and the |
|
* adjusted exponent is greater than or equal to {@code -6}, the |
|
* number will be converted to a character form without using |
|
* exponential notation. In this case, if the scale is zero then |
|
* no decimal point is added and if the scale is positive a |
|
* decimal point will be inserted with the scale specifying the |
|
* number of characters to the right of the decimal point. |
|
* {@code '0'} characters are added to the left of the converted |
|
* unscaled value as necessary. If no character precedes the |
|
* decimal point after this insertion then a conventional |
|
* {@code '0'} character is prefixed. |
|
* |
|
* <p>Otherwise (that is, if the scale is negative, or the |
|
* adjusted exponent is less than {@code -6}), the number will be |
|
* converted to a character form using exponential notation. In |
|
* this case, if the converted {@code BigInteger} has more than |
|
* one digit a decimal point is inserted after the first digit. |
|
* An exponent in character form is then suffixed to the converted |
|
* unscaled value (perhaps with inserted decimal point); this |
|
* comprises the letter {@code 'E'} followed immediately by the |
|
* adjusted exponent converted to a character form. The latter is |
|
* in base ten, using the characters {@code '0'} through |
|
* {@code '9'} with no leading zeros, and is always prefixed by a |
|
* sign character {@code '-'} (<tt>'\u002D'</tt>) if the |
|
* adjusted exponent is negative, {@code '+'} |
|
* (<tt>'\u002B'</tt>) otherwise). |
|
* |
|
* <p>Finally, the entire string is prefixed by a minus sign |
|
* character {@code '-'} (<tt>'\u002D'</tt>) if the unscaled |
|
* value is less than zero. No sign character is prefixed if the |
|
* unscaled value is zero or positive. |
|
* |
|
* <p><b>Examples:</b> |
|
* <p>For each representation [<i>unscaled value</i>, <i>scale</i>] |
|
* on the left, the resulting string is shown on the right. |
|
* <pre> |
|
* [123,0] "123" |
|
* [-123,0] "-123" |
|
* [123,-1] "1.23E+3" |
|
* [123,-3] "1.23E+5" |
|
* [123,1] "12.3" |
|
* [123,5] "0.00123" |
|
* [123,10] "1.23E-8" |
|
* [-123,12] "-1.23E-10" |
|
* </pre> |
|
* |
|
* <b>Notes:</b> |
|
* <ol> |
|
* |
|
* <li>There is a one-to-one mapping between the distinguishable |
|
* {@code BigDecimal} values and the result of this conversion. |
|
* That is, every distinguishable {@code BigDecimal} value |
|
* (unscaled value and scale) has a unique string representation |
|
* as a result of using {@code toString}. If that string |
|
* representation is converted back to a {@code BigDecimal} using |
|
* the {@link #BigDecimal(String)} constructor, then the original |
|
* value will be recovered. |
|
* |
|
* <li>The string produced for a given number is always the same; |
|
* it is not affected by locale. This means that it can be used |
|
* as a canonical string representation for exchanging decimal |
|
* data, or as a key for a Hashtable, etc. Locale-sensitive |
|
* number formatting and parsing is handled by the {@link |
|
* java.text.NumberFormat} class and its subclasses. |
|
* |
|
* <li>The {@link #toEngineeringString} method may be used for |
|
* presenting numbers with exponents in engineering notation, and the |
|
* {@link #setScale(int,RoundingMode) setScale} method may be used for |
|
* rounding a {@code BigDecimal} so it has a known number of digits after |
|
* the decimal point. |
|
* |
|
* <li>The digit-to-character mapping provided by |
|
* {@code Character.forDigit} is used. |
|
* |
|
* </ol> |
|
* |
|
* @return string representation of this {@code BigDecimal}. |
|
* @see Character#forDigit |
|
* @see #BigDecimal(java.lang.String) |
|
*/ |
|
@Override |
|
public String toString() { |
|
String sc = stringCache; |
|
if (sc == null) |
|
stringCache = sc = layoutChars(true); |
|
return sc; |
|
} |
|
/** |
|
* Returns a string representation of this {@code BigDecimal}, |
|
* using engineering notation if an exponent is needed. |
|
* |
|
* <p>Returns a string that represents the {@code BigDecimal} as |
|
* described in the {@link #toString()} method, except that if |
|
* exponential notation is used, the power of ten is adjusted to |
|
* be a multiple of three (engineering notation) such that the |
|
* integer part of nonzero values will be in the range 1 through |
|
* 999. If exponential notation is used for zero values, a |
|
* decimal point and one or two fractional zero digits are used so |
|
* that the scale of the zero value is preserved. Note that |
|
* unlike the output of {@link #toString()}, the output of this |
|
* method is <em>not</em> guaranteed to recover the same [integer, |
|
* scale] pair of this {@code BigDecimal} if the output string is |
|
* converting back to a {@code BigDecimal} using the {@linkplain |
|
* #BigDecimal(String) string constructor}. The result of this method meets |
|
* the weaker constraint of always producing a numerically equal |
|
* result from applying the string constructor to the method's output. |
|
* |
|
* @return string representation of this {@code BigDecimal}, using |
|
* engineering notation if an exponent is needed. |
|
* @since 1.5 |
|
*/ |
|
public String toEngineeringString() { |
|
return layoutChars(false); |
|
} |
|
/** |
|
* Returns a string representation of this {@code BigDecimal} |
|
* without an exponent field. For values with a positive scale, |
|
* the number of digits to the right of the decimal point is used |
|
* to indicate scale. For values with a zero or negative scale, |
|
* the resulting string is generated as if the value were |
|
* converted to a numerically equal value with zero scale and as |
|
* if all the trailing zeros of the zero scale value were present |
|
* in the result. |
|
* |
|
* The entire string is prefixed by a minus sign character '-' |
|
* (<tt>'\u002D'</tt>) if the unscaled value is less than |
|
* zero. No sign character is prefixed if the unscaled value is |
|
* zero or positive. |
|
* |
|
* Note that if the result of this method is passed to the |
|
* {@linkplain #BigDecimal(String) string constructor}, only the |
|
* numerical value of this {@code BigDecimal} will necessarily be |
|
* recovered; the representation of the new {@code BigDecimal} |
|
* may have a different scale. In particular, if this |
|
* {@code BigDecimal} has a negative scale, the string resulting |
|
* from this method will have a scale of zero when processed by |
|
* the string constructor. |
|
* |
|
* (This method behaves analogously to the {@code toString} |
|
* method in 1.4 and earlier releases.) |
|
* |
|
* @return a string representation of this {@code BigDecimal} |
|
* without an exponent field. |
|
* @since 1.5 |
|
* @see #toString() |
|
* @see #toEngineeringString() |
|
*/ |
|
public String toPlainString() { |
|
if(scale==0) { |
|
if(intCompact!=INFLATED) { |
|
return Long.toString(intCompact); |
|
} else { |
|
return intVal.toString(); |
|
} |
|
} |
|
if(this.scale<0) { // No decimal point |
|
if(signum()==0) { |
|
return "0"; |
|
} |
|
int tailingZeros = checkScaleNonZero((-(long)scale)); |
|
StringBuilder buf; |
|
if(intCompact!=INFLATED) { |
|
buf = new StringBuilder(20+tailingZeros); |
|
buf.append(intCompact); |
|
} else { |
|
String str = intVal.toString(); |
|
buf = new StringBuilder(str.length()+tailingZeros); |
|
buf.append(str); |
|
} |
|
for (int i = 0; i < tailingZeros; i++) |
|
buf.append('0'); |
|
return buf.toString(); |
|
} |
|
String str ; |
|
if(intCompact!=INFLATED) { |
|
str = Long.toString(Math.abs(intCompact)); |
|
} else { |
|
str = intVal.abs().toString(); |
|
} |
|
return getValueString(signum(), str, scale); |
|
} |
|
/* Returns a digit.digit string */ |
|
private String getValueString(int signum, String intString, int scale) { |
|
/* Insert decimal point */ |
|
StringBuilder buf; |
|
int insertionPoint = intString.length() - scale; |
|
if (insertionPoint == 0) { /* Point goes right before intVal */ |
|
return (signum<0 ? "-0." : "0.") + intString; |
|
} else if (insertionPoint > 0) { /* Point goes inside intVal */ |
|
buf = new StringBuilder(intString); |
|
buf.insert(insertionPoint, '.'); |
|
if (signum < 0) |
|
buf.insert(0, '-'); |
|
} else { /* We must insert zeros between point and intVal */ |
|
buf = new StringBuilder(3-insertionPoint + intString.length()); |
|
buf.append(signum<0 ? "-0." : "0."); |
|
for (int i=0; i<-insertionPoint; i++) |
|
buf.append('0'); |
|
buf.append(intString); |
|
} |
|
return buf.toString(); |
|
} |
|
/** |
|
* Converts this {@code BigDecimal} to a {@code BigInteger}. |
|
* This conversion is analogous to the |
|
* <i>narrowing primitive conversion</i> from {@code double} to |
|
* {@code long} as defined in section 5.1.3 of |
|
* <cite>The Java™ Language Specification</cite>: |
|
* any fractional part of this |
|
* {@code BigDecimal} will be discarded. Note that this |
|
* conversion can lose information about the precision of the |
|
* {@code BigDecimal} value. |
|
* <p> |
|
* To have an exception thrown if the conversion is inexact (in |
|
* other words if a nonzero fractional part is discarded), use the |
|
* {@link #toBigIntegerExact()} method. |
|
* |
|
* @return this {@code BigDecimal} converted to a {@code BigInteger}. |
|
*/ |
|
public BigInteger toBigInteger() { |
|
// force to an integer, quietly |
|
return this.setScale(0, ROUND_DOWN).inflated(); |
|
} |
|
/** |
|
* Converts this {@code BigDecimal} to a {@code BigInteger}, |
|
* checking for lost information. An exception is thrown if this |
|
* {@code BigDecimal} has a nonzero fractional part. |
|
* |
|
* @return this {@code BigDecimal} converted to a {@code BigInteger}. |
|
* @throws ArithmeticException if {@code this} has a nonzero |
|
* fractional part. |
|
* @since 1.5 |
|
*/ |
|
public BigInteger toBigIntegerExact() { |
|
// round to an integer, with Exception if decimal part non-0 |
|
return this.setScale(0, ROUND_UNNECESSARY).inflated(); |
|
} |
|
/** |
|
* Converts this {@code BigDecimal} to a {@code long}. |
|
* This conversion is analogous to the |
|
* <i>narrowing primitive conversion</i> from {@code double} to |
|
* {@code short} as defined in section 5.1.3 of |
|
* <cite>The Java™ Language Specification</cite>: |
|
* any fractional part of this |
|
* {@code BigDecimal} will be discarded, and if the resulting |
|
* "{@code BigInteger}" is too big to fit in a |
|
* {@code long}, only the low-order 64 bits are returned. |
|
* Note that this conversion can lose information about the |
|
* overall magnitude and precision of this {@code BigDecimal} value as well |
|
* as return a result with the opposite sign. |
|
* |
|
* @return this {@code BigDecimal} converted to a {@code long}. |
|
*/ |
|
public long longValue(){ |
|
if (intCompact != INFLATED && scale == 0) { |
|
return intCompact; |
|
} else { |
|
// Fastpath zero and small values |
|
if (this.signum() == 0 || fractionOnly() || |
|
// Fastpath very large-scale values that will result |
|
// in a truncated value of zero. If the scale is -64 |
|
// or less, there are at least 64 powers of 10 in the |
|
// value of the numerical result. Since 10 = 2*5, in |
|
// that case there would also be 64 powers of 2 in the |
|
// result, meaning all 64 bits of a long will be zero. |
|
scale <= -64) { |
|
return 0; |
|
} else { |
|
return toBigInteger().longValue(); |
|
} |
|
} |
|
} |
|
/** |
|
* Return true if a nonzero BigDecimal has an absolute value less |
|
* than one; i.e. only has fraction digits. |
|
*/ |
|
private boolean fractionOnly() { |
|
assert this.signum() != 0; |
|
return (this.precision() - this.scale) <= 0; |
|
} |
|
/** |
|
* Converts this {@code BigDecimal} to a {@code long}, checking |
|
* for lost information. If this {@code BigDecimal} has a |
|
* nonzero fractional part or is out of the possible range for a |
|
* {@code long} result then an {@code ArithmeticException} is |
|
* thrown. |
|
* |
|
* @return this {@code BigDecimal} converted to a {@code long}. |
|
* @throws ArithmeticException if {@code this} has a nonzero |
|
* fractional part, or will not fit in a {@code long}. |
|
* @since 1.5 |
|
*/ |
|
public long longValueExact() { |
|
if (intCompact != INFLATED && scale == 0) |
|
return intCompact; |
|
// Fastpath zero |
|
if (this.signum() == 0) |
|
return 0; |
|
// Fastpath numbers less than 1.0 (the latter can be very slow |
|
// to round if very small) |
|
if (fractionOnly()) |
|
throw new ArithmeticException("Rounding necessary"); |
|
// If more than 19 digits in integer part it cannot possibly fit |
|
if ((precision() - scale) > 19) // [OK for negative scale too] |
|
throw new java.lang.ArithmeticException("Overflow"); |
|
// round to an integer, with Exception if decimal part non-0 |
|
BigDecimal num = this.setScale(0, ROUND_UNNECESSARY); |
|
if (num.precision() >= 19) // need to check carefully |
|
LongOverflow.check(num); |
|
return num.inflated().longValue(); |
|
} |
|
private static class LongOverflow { |
|
/** BigInteger equal to Long.MIN_VALUE. */ |
|
private static final BigInteger LONGMIN = BigInteger.valueOf(Long.MIN_VALUE); |
|
/** BigInteger equal to Long.MAX_VALUE. */ |
|
private static final BigInteger LONGMAX = BigInteger.valueOf(Long.MAX_VALUE); |
|
public static void check(BigDecimal num) { |
|
BigInteger intVal = num.inflated(); |
|
if (intVal.compareTo(LONGMIN) < 0 || |
|
intVal.compareTo(LONGMAX) > 0) |
|
throw new java.lang.ArithmeticException("Overflow"); |
|
} |
|
} |
|
/** |
|
* Converts this {@code BigDecimal} to an {@code int}. |
|
* This conversion is analogous to the |
|
* <i>narrowing primitive conversion</i> from {@code double} to |
|
* {@code short} as defined in section 5.1.3 of |
|
* <cite>The Java™ Language Specification</cite>: |
|
* any fractional part of this |
|
* {@code BigDecimal} will be discarded, and if the resulting |
|
* "{@code BigInteger}" is too big to fit in an |
|
* {@code int}, only the low-order 32 bits are returned. |
|
* Note that this conversion can lose information about the |
|
* overall magnitude and precision of this {@code BigDecimal} |
|
* value as well as return a result with the opposite sign. |
|
* |
|
* @return this {@code BigDecimal} converted to an {@code int}. |
|
*/ |
|
public int intValue() { |
|
return (intCompact != INFLATED && scale == 0) ? |
|
(int)intCompact : |
|
(int)longValue(); |
|
} |
|
/** |
|
* Converts this {@code BigDecimal} to an {@code int}, checking |
|
* for lost information. If this {@code BigDecimal} has a |
|
* nonzero fractional part or is out of the possible range for an |
|
* {@code int} result then an {@code ArithmeticException} is |
|
* thrown. |
|
* |
|
* @return this {@code BigDecimal} converted to an {@code int}. |
|
* @throws ArithmeticException if {@code this} has a nonzero |
|
* fractional part, or will not fit in an {@code int}. |
|
* @since 1.5 |
|
*/ |
|
public int intValueExact() { |
|
long num; |
|
num = this.longValueExact(); // will check decimal part |
|
if ((int)num != num) |
|
throw new java.lang.ArithmeticException("Overflow"); |
|
return (int)num; |
|
} |
|
/** |
|
* Converts this {@code BigDecimal} to a {@code short}, checking |
|
* for lost information. If this {@code BigDecimal} has a |
|
* nonzero fractional part or is out of the possible range for a |
|
* {@code short} result then an {@code ArithmeticException} is |
|
* thrown. |
|
* |
|
* @return this {@code BigDecimal} converted to a {@code short}. |
|
* @throws ArithmeticException if {@code this} has a nonzero |
|
* fractional part, or will not fit in a {@code short}. |
|
* @since 1.5 |
|
*/ |
|
public short shortValueExact() { |
|
long num; |
|
num = this.longValueExact(); // will check decimal part |
|
if ((short)num != num) |
|
throw new java.lang.ArithmeticException("Overflow"); |
|
return (short)num; |
|
} |
|
/** |
|
* Converts this {@code BigDecimal} to a {@code byte}, checking |
|
* for lost information. If this {@code BigDecimal} has a |
|
* nonzero fractional part or is out of the possible range for a |
|
* {@code byte} result then an {@code ArithmeticException} is |
|
* thrown. |
|
* |
|
* @return this {@code BigDecimal} converted to a {@code byte}. |
|
* @throws ArithmeticException if {@code this} has a nonzero |
|
* fractional part, or will not fit in a {@code byte}. |
|
* @since 1.5 |
|
*/ |
|
public byte byteValueExact() { |
|
long num; |
|
num = this.longValueExact(); // will check decimal part |
|
if ((byte)num != num) |
|
throw new java.lang.ArithmeticException("Overflow"); |
|
return (byte)num; |
|
} |
|
/** |
|
* Converts this {@code BigDecimal} to a {@code float}. |
|
* This conversion is similar to the |
|
* <i>narrowing primitive conversion</i> from {@code double} to |
|
* {@code float} as defined in section 5.1.3 of |
|
* <cite>The Java™ Language Specification</cite>: |
|
* if this {@code BigDecimal} has too great a |
|
* magnitude to represent as a {@code float}, it will be |
|
* converted to {@link Float#NEGATIVE_INFINITY} or {@link |
|
* Float#POSITIVE_INFINITY} as appropriate. Note that even when |
|
* the return value is finite, this conversion can lose |
|
* information about the precision of the {@code BigDecimal} |
|
* value. |
|
* |
|
* @return this {@code BigDecimal} converted to a {@code float}. |
|
*/ |
|
public float floatValue(){ |
|
if(intCompact != INFLATED) { |
|
if (scale == 0) { |
|
return (float)intCompact; |
|
} else { |
|
/* |
|
* If both intCompact and the scale can be exactly |
|
* represented as float values, perform a single float |
|
* multiply or divide to compute the (properly |
|
* rounded) result. |
|
*/ |
|
if (Math.abs(intCompact) < 1L<<22 ) { |
|
// Don't have too guard against |
|
// Math.abs(MIN_VALUE) because of outer check |
|
// against INFLATED. |
|
if (scale > 0 && scale < float10pow.length) { |
|
return (float)intCompact / float10pow[scale]; |
|
} else if (scale < 0 && scale > -float10pow.length) { |
|
return (float)intCompact * float10pow[-scale]; |
|
} |
|
} |
|
} |
|
} |
|
// Somewhat inefficient, but guaranteed to work. |
|
return Float.parseFloat(this.toString()); |
|
} |
|
/** |
|
* Converts this {@code BigDecimal} to a {@code double}. |
|
* This conversion is similar to the |
|
* <i>narrowing primitive conversion</i> from {@code double} to |
|
* {@code float} as defined in section 5.1.3 of |
|
* <cite>The Java™ Language Specification</cite>: |
|
* if this {@code BigDecimal} has too great a |
|
* magnitude represent as a {@code double}, it will be |
|
* converted to {@link Double#NEGATIVE_INFINITY} or {@link |
|
* Double#POSITIVE_INFINITY} as appropriate. Note that even when |
|
* the return value is finite, this conversion can lose |
|
* information about the precision of the {@code BigDecimal} |
|
* value. |
|
* |
|
* @return this {@code BigDecimal} converted to a {@code double}. |
|
*/ |
|
public double doubleValue(){ |
|
if(intCompact != INFLATED) { |
|
if (scale == 0) { |
|
return (double)intCompact; |
|
} else { |
|
/* |
|
* If both intCompact and the scale can be exactly |
|
* represented as double values, perform a single |
|
* double multiply or divide to compute the (properly |
|
* rounded) result. |
|
*/ |
|
if (Math.abs(intCompact) < 1L<<52 ) { |
|
// Don't have too guard against |
|
// Math.abs(MIN_VALUE) because of outer check |
|
// against INFLATED. |
|
if (scale > 0 && scale < double10pow.length) { |
|
return (double)intCompact / double10pow[scale]; |
|
} else if (scale < 0 && scale > -double10pow.length) { |
|
return (double)intCompact * double10pow[-scale]; |
|
} |
|
} |
|
} |
|
} |
|
// Somewhat inefficient, but guaranteed to work. |
|
return Double.parseDouble(this.toString()); |
|
} |
|
/** |
|
* Powers of 10 which can be represented exactly in {@code |
|
* double}. |
|
*/ |
|
private static final double double10pow[] = { |
|
1.0e0, 1.0e1, 1.0e2, 1.0e3, 1.0e4, 1.0e5, |
|
1.0e6, 1.0e7, 1.0e8, 1.0e9, 1.0e10, 1.0e11, |
|
1.0e12, 1.0e13, 1.0e14, 1.0e15, 1.0e16, 1.0e17, |
|
1.0e18, 1.0e19, 1.0e20, 1.0e21, 1.0e22 |
|
}; |
|
/** |
|
* Powers of 10 which can be represented exactly in {@code |
|
* float}. |
|
*/ |
|
private static final float float10pow[] = { |
|
1.0e0f, 1.0e1f, 1.0e2f, 1.0e3f, 1.0e4f, 1.0e5f, |
|
1.0e6f, 1.0e7f, 1.0e8f, 1.0e9f, 1.0e10f |
|
}; |
|
/** |
|
* Returns the size of an ulp, a unit in the last place, of this |
|
* {@code BigDecimal}. An ulp of a nonzero {@code BigDecimal} |
|
* value is the positive distance between this value and the |
|
* {@code BigDecimal} value next larger in magnitude with the |
|
* same number of digits. An ulp of a zero value is numerically |
|
* equal to 1 with the scale of {@code this}. The result is |
|
* stored with the same scale as {@code this} so the result |
|
* for zero and nonzero values is equal to {@code [1, |
|
* this.scale()]}. |
|
* |
|
* @return the size of an ulp of {@code this} |
|
* @since 1.5 |
|
*/ |
|
public BigDecimal ulp() { |
|
return BigDecimal.valueOf(1, this.scale(), 1); |
|
} |
|
// Private class to build a string representation for BigDecimal object. |
|
// "StringBuilderHelper" is constructed as a thread local variable so it is |
|
// thread safe. The StringBuilder field acts as a buffer to hold the temporary |
|
// representation of BigDecimal. The cmpCharArray holds all the characters for |
|
// the compact representation of BigDecimal (except for '-' sign' if it is |
|
// negative) if its intCompact field is not INFLATED. It is shared by all |
|
// calls to toString() and its variants in that particular thread. |
|
static class StringBuilderHelper { |
|
final StringBuilder sb; // Placeholder for BigDecimal string |
|
final char[] cmpCharArray; // character array to place the intCompact |
|
StringBuilderHelper() { |
|
sb = new StringBuilder(); |
|
// All non negative longs can be made to fit into 19 character array. |
|
cmpCharArray = new char[19]; |
|
} |
|
// Accessors. |
|
StringBuilder getStringBuilder() { |
|
sb.setLength(0); |
|
return sb; |
|
} |
|
char[] getCompactCharArray() { |
|
return cmpCharArray; |
|
} |
|
/** |
|
* Places characters representing the intCompact in {@code long} into |
|
* cmpCharArray and returns the offset to the array where the |
|
* representation starts. |
|
* |
|
* @param intCompact the number to put into the cmpCharArray. |
|
* @return offset to the array where the representation starts. |
|
* Note: intCompact must be greater or equal to zero. |
|
*/ |
|
int putIntCompact(long intCompact) { |
|
assert intCompact >= 0; |
|
long q; |
|
int r; |
|
// since we start from the least significant digit, charPos points to |
|
// the last character in cmpCharArray. |
|
int charPos = cmpCharArray.length; |
|
// Get 2 digits/iteration using longs until quotient fits into an int |
|
while (intCompact > Integer.MAX_VALUE) { |
|
q = intCompact / 100; |
|
r = (int)(intCompact - q * 100); |
|
intCompact = q; |
|
cmpCharArray[--charPos] = DIGIT_ONES[r]; |
|
cmpCharArray[--charPos] = DIGIT_TENS[r]; |
|
} |
|
// Get 2 digits/iteration using ints when i2 >= 100 |
|
int q2; |
|
int i2 = (int)intCompact; |
|
while (i2 >= 100) { |
|
q2 = i2 / 100; |
|
r = i2 - q2 * 100; |
|
i2 = q2; |
|
cmpCharArray[--charPos] = DIGIT_ONES[r]; |
|
cmpCharArray[--charPos] = DIGIT_TENS[r]; |
|
} |
|
cmpCharArray[--charPos] = DIGIT_ONES[i2]; |
|
if (i2 >= 10) |
|
cmpCharArray[--charPos] = DIGIT_TENS[i2]; |
|
return charPos; |
|
} |
|
final static char[] DIGIT_TENS = { |
|
'0', '0', '0', '0', '0', '0', '0', '0', '0', '0', |
|
'1', '1', '1', '1', '1', '1', '1', '1', '1', '1', |
|
'2', '2', '2', '2', '2', '2', '2', '2', '2', '2', |
|
'3', '3', '3', '3', '3', '3', '3', '3', '3', '3', |
|
'4', '4', '4', '4', '4', '4', '4', '4', '4', '4', |
|
'5', '5', '5', '5', '5', '5', '5', '5', '5', '5', |
|
'6', '6', '6', '6', '6', '6', '6', '6', '6', '6', |
|
'7', '7', '7', '7', '7', '7', '7', '7', '7', '7', |
|
'8', '8', '8', '8', '8', '8', '8', '8', '8', '8', |
|
'9', '9', '9', '9', '9', '9', '9', '9', '9', '9', |
|
}; |
|
final static char[] DIGIT_ONES = { |
|
'0', '1', '2', '3', '4', '5', '6', '7', '8', '9', |
|
'0', '1', '2', '3', '4', '5', '6', '7', '8', '9', |
|
'0', '1', '2', '3', '4', '5', '6', '7', '8', '9', |
|
'0', '1', '2', '3', '4', '5', '6', '7', '8', '9', |
|
'0', '1', '2', '3', '4', '5', '6', '7', '8', '9', |
|
'0', '1', '2', '3', '4', '5', '6', '7', '8', '9', |
|
'0', '1', '2', '3', '4', '5', '6', '7', '8', '9', |
|
'0', '1', '2', '3', '4', '5', '6', '7', '8', '9', |
|
'0', '1', '2', '3', '4', '5', '6', '7', '8', '9', |
|
'0', '1', '2', '3', '4', '5', '6', '7', '8', '9', |
|
}; |
|
} |
|
/** |
|
* Lay out this {@code BigDecimal} into a {@code char[]} array. |
|
* The Java 1.2 equivalent to this was called {@code getValueString}. |
|
* |
|
* @param sci {@code true} for Scientific exponential notation; |
|
* {@code false} for Engineering |
|
* @return string with canonical string representation of this |
|
* {@code BigDecimal} |
|
*/ |
|
private String layoutChars(boolean sci) { |
|
if (scale == 0) // zero scale is trivial |
|
return (intCompact != INFLATED) ? |
|
Long.toString(intCompact): |
|
intVal.toString(); |
|
if (scale == 2 && |
|
intCompact >= 0 && intCompact < Integer.MAX_VALUE) { |
|
// currency fast path |
|
int lowInt = (int)intCompact % 100; |
|
int highInt = (int)intCompact / 100; |
|
return (Integer.toString(highInt) + '.' + |
|
StringBuilderHelper.DIGIT_TENS[lowInt] + |
|
StringBuilderHelper.DIGIT_ONES[lowInt]) ; |
|
} |
|
StringBuilderHelper sbHelper = threadLocalStringBuilderHelper.get(); |
|
char[] coeff; |
|
int offset; // offset is the starting index for coeff array |
|
// Get the significand as an absolute value |
|
if (intCompact != INFLATED) { |
|
offset = sbHelper.putIntCompact(Math.abs(intCompact)); |
|
coeff = sbHelper.getCompactCharArray(); |
|
} else { |
|
offset = 0; |
|
coeff = intVal.abs().toString().toCharArray(); |
|
} |
|
// Construct a buffer, with sufficient capacity for all cases. |
|
// If E-notation is needed, length will be: +1 if negative, +1 |
|
// if '.' needed, +2 for "E+", + up to 10 for adjusted exponent. |
|
// Otherwise it could have +1 if negative, plus leading "0.00000" |
|
StringBuilder buf = sbHelper.getStringBuilder(); |
|
if (signum() < 0) // prefix '-' if negative |
|
buf.append('-'); |
|
int coeffLen = coeff.length - offset; |
|
long adjusted = -(long)scale + (coeffLen -1); |
|
if ((scale >= 0) && (adjusted >= -6)) { // plain number |
|
int pad = scale - coeffLen; // count of padding zeros |
|
if (pad >= 0) { // 0.xxx form |
|
buf.append('0'); |
|
buf.append('.'); |
|
for (; pad>0; pad--) { |
|
buf.append('0'); |
|
} |
|
buf.append(coeff, offset, coeffLen); |
|
} else { // xx.xx form |
|
buf.append(coeff, offset, -pad); |
|
buf.append('.'); |
|
buf.append(coeff, -pad + offset, scale); |
|
} |
|
} else { // E-notation is needed |
|
if (sci) { // Scientific notation |
|
buf.append(coeff[offset]); // first character |
|
if (coeffLen > 1) { // more to come |
|
buf.append('.'); |
|
buf.append(coeff, offset + 1, coeffLen - 1); |
|
} |
|
} else { // Engineering notation |
|
int sig = (int)(adjusted % 3); |
|
if (sig < 0) |
|
sig += 3; // [adjusted was negative] |
|
adjusted -= sig; // now a multiple of 3 |
|
sig++; |
|
if (signum() == 0) { |
|
switch (sig) { |
|
case 1: |
|
buf.append('0'); // exponent is a multiple of three |
|
break; |
|
case 2: |
|
buf.append("0.00"); |
|
adjusted += 3; |
|
break; |
|
case 3: |
|
buf.append("0.0"); |
|
adjusted += 3; |
|
break; |
|
default: |
|
throw new AssertionError("Unexpected sig value " + sig); |
|
} |
|
} else if (sig >= coeffLen) { // significand all in integer |
|
buf.append(coeff, offset, coeffLen); |
|
// may need some zeros, too |
|
for (int i = sig - coeffLen; i > 0; i--) |
|
buf.append('0'); |
|
} else { // xx.xxE form |
|
buf.append(coeff, offset, sig); |
|
buf.append('.'); |
|
buf.append(coeff, offset + sig, coeffLen - sig); |
|
} |
|
} |
|
if (adjusted != 0) { // [!sci could have made 0] |
|
buf.append('E'); |
|
if (adjusted > 0) // force sign for positive |
|
buf.append('+'); |
|
buf.append(adjusted); |
|
} |
|
} |
|
return buf.toString(); |
|
} |
|
/** |
|
* Return 10 to the power n, as a {@code BigInteger}. |
|
* |
|
* @param n the power of ten to be returned (>=0) |
|
* @return a {@code BigInteger} with the value (10<sup>n</sup>) |
|
*/ |
|
private static BigInteger bigTenToThe(int n) { |
|
if (n < 0) |
|
return BigInteger.ZERO; |
|
if (n < BIG_TEN_POWERS_TABLE_MAX) { |
|
BigInteger[] pows = BIG_TEN_POWERS_TABLE; |
|
if (n < pows.length) |
|
return pows[n]; |
|
else |
|
return expandBigIntegerTenPowers(n); |
|
} |
|
return BigInteger.TEN.pow(n); |
|
} |
|
/** |
|
* Expand the BIG_TEN_POWERS_TABLE array to contain at least 10**n. |
|
* |
|
* @param n the power of ten to be returned (>=0) |
|
* @return a {@code BigDecimal} with the value (10<sup>n</sup>) and |
|
* in the meantime, the BIG_TEN_POWERS_TABLE array gets |
|
* expanded to the size greater than n. |
|
*/ |
|
private static BigInteger expandBigIntegerTenPowers(int n) { |
|
synchronized(BigDecimal.class) { |
|
BigInteger[] pows = BIG_TEN_POWERS_TABLE; |
|
int curLen = pows.length; |
|
// The following comparison and the above synchronized statement is |
|
// to prevent multiple threads from expanding the same array. |
|
if (curLen <= n) { |
|
int newLen = curLen << 1; |
|
while (newLen <= n) |
|
newLen <<= 1; |
|
pows = Arrays.copyOf(pows, newLen); |
|
for (int i = curLen; i < newLen; i++) |
|
pows[i] = pows[i - 1].multiply(BigInteger.TEN); |
|
// Based on the following facts: |
|
// 1. pows is a private local varible; |
|
// 2. the following store is a volatile store. |
|
// the newly created array elements can be safely published. |
|
BIG_TEN_POWERS_TABLE = pows; |
|
} |
|
return pows[n]; |
|
} |
|
} |
|
private static final long[] LONG_TEN_POWERS_TABLE = { |
|
1, // 0 / 10^0 |
|
10, // 1 / 10^1 |
|
100, // 2 / 10^2 |
|
1000, // 3 / 10^3 |
|
10000, // 4 / 10^4 |
|
100000, // 5 / 10^5 |
|
1000000, // 6 / 10^6 |
|
10000000, // 7 / 10^7 |
|
100000000, // 8 / 10^8 |
|
1000000000, // 9 / 10^9 |
|
10000000000L, // 10 / 10^10 |
|
100000000000L, // 11 / 10^11 |
|
1000000000000L, // 12 / 10^12 |
|
10000000000000L, // 13 / 10^13 |
|
100000000000000L, // 14 / 10^14 |
|
1000000000000000L, // 15 / 10^15 |
|
10000000000000000L, // 16 / 10^16 |
|
100000000000000000L, // 17 / 10^17 |
|
1000000000000000000L // 18 / 10^18 |
|
}; |
|
private static volatile BigInteger BIG_TEN_POWERS_TABLE[] = { |
|
BigInteger.ONE, |
|
BigInteger.valueOf(10), |
|
BigInteger.valueOf(100), |
|
BigInteger.valueOf(1000), |
|
BigInteger.valueOf(10000), |
|
BigInteger.valueOf(100000), |
|
BigInteger.valueOf(1000000), |
|
BigInteger.valueOf(10000000), |
|
BigInteger.valueOf(100000000), |
|
BigInteger.valueOf(1000000000), |
|
BigInteger.valueOf(10000000000L), |
|
BigInteger.valueOf(100000000000L), |
|
BigInteger.valueOf(1000000000000L), |
|
BigInteger.valueOf(10000000000000L), |
|
BigInteger.valueOf(100000000000000L), |
|
BigInteger.valueOf(1000000000000000L), |
|
BigInteger.valueOf(10000000000000000L), |
|
BigInteger.valueOf(100000000000000000L), |
|
BigInteger.valueOf(1000000000000000000L) |
|
}; |
|
private static final int BIG_TEN_POWERS_TABLE_INITLEN = |
|
BIG_TEN_POWERS_TABLE.length; |
|
private static final int BIG_TEN_POWERS_TABLE_MAX = |
|
16 * BIG_TEN_POWERS_TABLE_INITLEN; |
|
private static final long THRESHOLDS_TABLE[] = { |
|
Long.MAX_VALUE, // 0 |
|
Long.MAX_VALUE/10L, // 1 |
|
Long.MAX_VALUE/100L, // 2 |
|
Long.MAX_VALUE/1000L, // 3 |
|
Long.MAX_VALUE/10000L, // 4 |
|
Long.MAX_VALUE/100000L, // 5 |
|
Long.MAX_VALUE/1000000L, // 6 |
|
Long.MAX_VALUE/10000000L, // 7 |
|
Long.MAX_VALUE/100000000L, // 8 |
|
Long.MAX_VALUE/1000000000L, // 9 |
|
Long.MAX_VALUE/10000000000L, // 10 |
|
Long.MAX_VALUE/100000000000L, // 11 |
|
Long.MAX_VALUE/1000000000000L, // 12 |
|
Long.MAX_VALUE/10000000000000L, // 13 |
|
Long.MAX_VALUE/100000000000000L, // 14 |
|
Long.MAX_VALUE/1000000000000000L, // 15 |
|
Long.MAX_VALUE/10000000000000000L, // 16 |
|
Long.MAX_VALUE/100000000000000000L, // 17 |
|
Long.MAX_VALUE/1000000000000000000L // 18 |
|
}; |
|
/** |
|
* Compute val * 10 ^ n; return this product if it is |
|
* representable as a long, INFLATED otherwise. |
|
*/ |
|
private static long longMultiplyPowerTen(long val, int n) { |
|
if (val == 0 || n <= 0) |
|
return val; |
|
long[] tab = LONG_TEN_POWERS_TABLE; |
|
long[] bounds = THRESHOLDS_TABLE; |
|
if (n < tab.length && n < bounds.length) { |
|
long tenpower = tab[n]; |
|
if (val == 1) |
|
return tenpower; |
|
if (Math.abs(val) <= bounds[n]) |
|
return val * tenpower; |
|
} |
|
return INFLATED; |
|
} |
|
/** |
|
* Compute this * 10 ^ n. |
|
* Needed mainly to allow special casing to trap zero value |
|
*/ |
|
private BigInteger bigMultiplyPowerTen(int n) { |
|
if (n <= 0) |
|
return this.inflated(); |
|
if (intCompact != INFLATED) |
|
return bigTenToThe(n).multiply(intCompact); |
|
else |
|
return intVal.multiply(bigTenToThe(n)); |
|
} |
|
/** |
|
* Returns appropriate BigInteger from intVal field if intVal is |
|
* null, i.e. the compact representation is in use. |
|
*/ |
|
private BigInteger inflated() { |
|
if (intVal == null) { |
|
return BigInteger.valueOf(intCompact); |
|
} |
|
return intVal; |
|
} |
|
/** |
|
* Match the scales of two {@code BigDecimal}s to align their |
|
* least significant digits. |
|
* |
|
* <p>If the scales of val[0] and val[1] differ, rescale |
|
* (non-destructively) the lower-scaled {@code BigDecimal} so |
|
* they match. That is, the lower-scaled reference will be |
|
* replaced by a reference to a new object with the same scale as |
|
* the other {@code BigDecimal}. |
|
* |
|
* @param val array of two elements referring to the two |
|
* {@code BigDecimal}s to be aligned. |
|
*/ |
|
private static void matchScale(BigDecimal[] val) { |
|
if (val[0].scale == val[1].scale) { |
|
return; |
|
} else if (val[0].scale < val[1].scale) { |
|
val[0] = val[0].setScale(val[1].scale, ROUND_UNNECESSARY); |
|
} else if (val[1].scale < val[0].scale) { |
|
val[1] = val[1].setScale(val[0].scale, ROUND_UNNECESSARY); |
|
} |
|
} |
|
private static class UnsafeHolder { |
|
private static final sun.misc.Unsafe unsafe; |
|
private static final long intCompactOffset; |
|
private static final long intValOffset; |
|
static { |
|
try { |
|
unsafe = sun.misc.Unsafe.getUnsafe(); |
|
intCompactOffset = unsafe.objectFieldOffset |
|
(BigDecimal.class.getDeclaredField("intCompact")); |
|
intValOffset = unsafe.objectFieldOffset |
|
(BigDecimal.class.getDeclaredField("intVal")); |
|
} catch (Exception ex) { |
|
throw new ExceptionInInitializerError(ex); |
|
} |
|
} |
|
static void setIntCompactVolatile(BigDecimal bd, long val) { |
|
unsafe.putLongVolatile(bd, intCompactOffset, val); |
|
} |
|
static void setIntValVolatile(BigDecimal bd, BigInteger val) { |
|
unsafe.putObjectVolatile(bd, intValOffset, val); |
|
} |
|
} |
|
/** |
|
* Reconstitute the {@code BigDecimal} instance from a stream (that is, |
|
* deserialize it). |
|
* |
|
* @param s the stream being read. |
|
*/ |
|
private void readObject(java.io.ObjectInputStream s) |
|
throws java.io.IOException, ClassNotFoundException { |
|
// Read in all fields |
|
s.defaultReadObject(); |
|
// validate possibly bad fields |
|
if (intVal == null) { |
|
String message = "BigDecimal: null intVal in stream"; |
|
throw new java.io.StreamCorruptedException(message); |
|
// [all values of scale are now allowed] |
|
} |
|
UnsafeHolder.setIntCompactVolatile(this, compactValFor(intVal)); |
|
} |
|
/** |
|
* Serialize this {@code BigDecimal} to the stream in question |
|
* |
|
* @param s the stream to serialize to. |
|
*/ |
|
private void writeObject(java.io.ObjectOutputStream s) |
|
throws java.io.IOException { |
|
// Must inflate to maintain compatible serial form. |
|
if (this.intVal == null) |
|
UnsafeHolder.setIntValVolatile(this, BigInteger.valueOf(this.intCompact)); |
|
// Could reset intVal back to null if it has to be set. |
|
s.defaultWriteObject(); |
|
} |
|
/** |
|
* Returns the length of the absolute value of a {@code long}, in decimal |
|
* digits. |
|
* |
|
* @param x the {@code long} |
|
* @return the length of the unscaled value, in deciaml digits. |
|
*/ |
|
static int longDigitLength(long x) { |
|
/* |
|
* As described in "Bit Twiddling Hacks" by Sean Anderson, |
|
* (http://graphics.stanford.edu/~seander/bithacks.html) |
|
* integer log 10 of x is within 1 of (1233/4096)* (1 + |
|
* integer log 2 of x). The fraction 1233/4096 approximates |
|
* log10(2). So we first do a version of log2 (a variant of |
|
* Long class with pre-checks and opposite directionality) and |
|
* then scale and check against powers table. This is a little |
|
* simpler in present context than the version in Hacker's |
|
* Delight sec 11-4. Adding one to bit length allows comparing |
|
* downward from the LONG_TEN_POWERS_TABLE that we need |
|
* anyway. |
|
*/ |
|
assert x != BigDecimal.INFLATED; |
|
if (x < 0) |
|
x = -x; |
|
if (x < 10) // must screen for 0, might as well 10 |
|
return 1; |
|
int r = ((64 - Long.numberOfLeadingZeros(x) + 1) * 1233) >>> 12; |
|
long[] tab = LONG_TEN_POWERS_TABLE; |
|
// if r >= length, must have max possible digits for long |
|
return (r >= tab.length || x < tab[r]) ? r : r + 1; |
|
} |
|
/** |
|
* Returns the length of the absolute value of a BigInteger, in |
|
* decimal digits. |
|
* |
|
* @param b the BigInteger |
|
* @return the length of the unscaled value, in decimal digits |
|
*/ |
|
private static int bigDigitLength(BigInteger b) { |
|
/* |
|
* Same idea as the long version, but we need a better |
|
* approximation of log10(2). Using 646456993/2^31 |
|
* is accurate up to max possible reported bitLength. |
|
*/ |
|
if (b.signum == 0) |
|
return 1; |
|
int r = (int)((((long)b.bitLength() + 1) * 646456993) >>> 31); |
|
return b.compareMagnitude(bigTenToThe(r)) < 0? r : r+1; |
|
} |
|
/** |
|
* Check a scale for Underflow or Overflow. If this BigDecimal is |
|
* nonzero, throw an exception if the scale is outof range. If this |
|
* is zero, saturate the scale to the extreme value of the right |
|
* sign if the scale is out of range. |
|
* |
|
* @param val The new scale. |
|
* @throws ArithmeticException (overflow or underflow) if the new |
|
* scale is out of range. |
|
* @return validated scale as an int. |
|
*/ |
|
private int checkScale(long val) { |
|
int asInt = (int)val; |
|
if (asInt != val) { |
|
asInt = val>Integer.MAX_VALUE ? Integer.MAX_VALUE : Integer.MIN_VALUE; |
|
BigInteger b; |
|
if (intCompact != 0 && |
|
((b = intVal) == null || b.signum() != 0)) |
|
throw new ArithmeticException(asInt>0 ? "Underflow":"Overflow"); |
|
} |
|
return asInt; |
|
} |
|
/** |
|
* Returns the compact value for given {@code BigInteger}, or |
|
* INFLATED if too big. Relies on internal representation of |
|
* {@code BigInteger}. |
|
*/ |
|
private static long compactValFor(BigInteger b) { |
|
int[] m = b.mag; |
|
int len = m.length; |
|
if (len == 0) |
|
return 0; |
|
int d = m[0]; |
|
if (len > 2 || (len == 2 && d < 0)) |
|
return INFLATED; |
|
long u = (len == 2)? |
|
(((long) m[1] & LONG_MASK) + (((long)d) << 32)) : |
|
(((long)d) & LONG_MASK); |
|
return (b.signum < 0)? -u : u; |
|
} |
|
private static int longCompareMagnitude(long x, long y) { |
|
if (x < 0) |
|
x = -x; |
|
if (y < 0) |
|
y = -y; |
|
return (x < y) ? -1 : ((x == y) ? 0 : 1); |
|
} |
|
private static int saturateLong(long s) { |
|
int i = (int)s; |
|
return (s == i) ? i : (s < 0 ? Integer.MIN_VALUE : Integer.MAX_VALUE); |
|
} |
|
/* |
|
* Internal printing routine |
|
*/ |
|
private static void print(String name, BigDecimal bd) { |
|
System.err.format("%s:\tintCompact %d\tintVal %d\tscale %d\tprecision %d%n", |
|
name, |
|
bd.intCompact, |
|
bd.intVal, |
|
bd.scale, |
|
bd.precision); |
|
} |
|
/** |
|
* Check internal invariants of this BigDecimal. These invariants |
|
* include: |
|
* |
|
* <ul> |
|
* |
|
* <li>The object must be initialized; either intCompact must not be |
|
* INFLATED or intVal is non-null. Both of these conditions may |
|
* be true. |
|
* |
|
* <li>If both intCompact and intVal and set, their values must be |
|
* consistent. |
|
* |
|
* <li>If precision is nonzero, it must have the right value. |
|
* </ul> |
|
* |
|
* Note: Since this is an audit method, we are not supposed to change the |
|
* state of this BigDecimal object. |
|
*/ |
|
private BigDecimal audit() { |
|
if (intCompact == INFLATED) { |
|
if (intVal == null) { |
|
print("audit", this); |
|
throw new AssertionError("null intVal"); |
|
} |
|
// Check precision |
|
if (precision > 0 && precision != bigDigitLength(intVal)) { |
|
print("audit", this); |
|
throw new AssertionError("precision mismatch"); |
|
} |
|
} else { |
|
if (intVal != null) { |
|
long val = intVal.longValue(); |
|
if (val != intCompact) { |
|
print("audit", this); |
|
throw new AssertionError("Inconsistent state, intCompact=" + |
|
intCompact + "\t intVal=" + val); |
|
} |
|
} |
|
// Check precision |
|
if (precision > 0 && precision != longDigitLength(intCompact)) { |
|
print("audit", this); |
|
throw new AssertionError("precision mismatch"); |
|
} |
|
} |
|
return this; |
|
} |
|
/* the same as checkScale where value!=0 */ |
|
private static int checkScaleNonZero(long val) { |
|
int asInt = (int)val; |
|
if (asInt != val) { |
|
throw new ArithmeticException(asInt>0 ? "Underflow":"Overflow"); |
|
} |
|
return asInt; |
|
} |
|
private static int checkScale(long intCompact, long val) { |
|
int asInt = (int)val; |
|
if (asInt != val) { |
|
asInt = val>Integer.MAX_VALUE ? Integer.MAX_VALUE : Integer.MIN_VALUE; |
|
if (intCompact != 0) |
|
throw new ArithmeticException(asInt>0 ? "Underflow":"Overflow"); |
|
} |
|
return asInt; |
|
} |
|
private static int checkScale(BigInteger intVal, long val) { |
|
int asInt = (int)val; |
|
if (asInt != val) { |
|
asInt = val>Integer.MAX_VALUE ? Integer.MAX_VALUE : Integer.MIN_VALUE; |
|
if (intVal.signum() != 0) |
|
throw new ArithmeticException(asInt>0 ? "Underflow":"Overflow"); |
|
} |
|
return asInt; |
|
} |
|
/** |
|
* Returns a {@code BigDecimal} rounded according to the MathContext |
|
* settings; |
|
* If rounding is needed a new {@code BigDecimal} is created and returned. |
|
* |
|
* @param val the value to be rounded |
|
* @param mc the context to use. |
|
* @return a {@code BigDecimal} rounded according to the MathContext |
|
* settings. May return {@code value}, if no rounding needed. |
|
* @throws ArithmeticException if the rounding mode is |
|
* {@code RoundingMode.UNNECESSARY} and the |
|
* result is inexact. |
|
*/ |
|
private static BigDecimal doRound(BigDecimal val, MathContext mc) { |
|
int mcp = mc.precision; |
|
boolean wasDivided = false; |
|
if (mcp > 0) { |
|
BigInteger intVal = val.intVal; |
|
long compactVal = val.intCompact; |
|
int scale = val.scale; |
|
int prec = val.precision(); |
|
int mode = mc.roundingMode.oldMode; |
|
int drop; |
|
if (compactVal == INFLATED) { |
|
drop = prec - mcp; |
|
while (drop > 0) { |
|
scale = checkScaleNonZero((long) scale - drop); |
|
intVal = divideAndRoundByTenPow(intVal, drop, mode); |
|
wasDivided = true; |
|
compactVal = compactValFor(intVal); |
|
if (compactVal != INFLATED) { |
|
prec = longDigitLength(compactVal); |
|
break; |
|
} |
|
prec = bigDigitLength(intVal); |
|
drop = prec - mcp; |
|
} |
|
} |
|
if (compactVal != INFLATED) { |
|
drop = prec - mcp; // drop can't be more than 18 |
|
while (drop > 0) { |
|
scale = checkScaleNonZero((long) scale - drop); |
|
compactVal = divideAndRound(compactVal, LONG_TEN_POWERS_TABLE[drop], mc.roundingMode.oldMode); |
|
wasDivided = true; |
|
prec = longDigitLength(compactVal); |
|
drop = prec - mcp; |
|
intVal = null; |
|
} |
|
} |
|
return wasDivided ? new BigDecimal(intVal,compactVal,scale,prec) : val; |
|
} |
|
return val; |
|
} |
|
/* |
|
* Returns a {@code BigDecimal} created from {@code long} value with |
|
* given scale rounded according to the MathContext settings |
|
*/ |
|
private static BigDecimal doRound(long compactVal, int scale, MathContext mc) { |
|
int mcp = mc.precision; |
|
if (mcp > 0 && mcp < 19) { |
|
int prec = longDigitLength(compactVal); |
|
int drop = prec - mcp; // drop can't be more than 18 |
|
while (drop > 0) { |
|
scale = checkScaleNonZero((long) scale - drop); |
|
compactVal = divideAndRound(compactVal, LONG_TEN_POWERS_TABLE[drop], mc.roundingMode.oldMode); |
|
prec = longDigitLength(compactVal); |
|
drop = prec - mcp; |
|
} |
|
return valueOf(compactVal, scale, prec); |
|
} |
|
return valueOf(compactVal, scale); |
|
} |
|
/* |
|
* Returns a {@code BigDecimal} created from {@code BigInteger} value with |
|
* given scale rounded according to the MathContext settings |
|
*/ |
|
private static BigDecimal doRound(BigInteger intVal, int scale, MathContext mc) { |
|
int mcp = mc.precision; |
|
int prec = 0; |
|
if (mcp > 0) { |
|
long compactVal = compactValFor(intVal); |
|
int mode = mc.roundingMode.oldMode; |
|
int drop; |
|
if (compactVal == INFLATED) { |
|
prec = bigDigitLength(intVal); |
|
drop = prec - mcp; |
|
while (drop > 0) { |
|
scale = checkScaleNonZero((long) scale - drop); |
|
intVal = divideAndRoundByTenPow(intVal, drop, mode); |
|
compactVal = compactValFor(intVal); |
|
if (compactVal != INFLATED) { |
|
break; |
|
} |
|
prec = bigDigitLength(intVal); |
|
drop = prec - mcp; |
|
} |
|
} |
|
if (compactVal != INFLATED) { |
|
prec = longDigitLength(compactVal); |
|
drop = prec - mcp; // drop can't be more than 18 |
|
while (drop > 0) { |
|
scale = checkScaleNonZero((long) scale - drop); |
|
compactVal = divideAndRound(compactVal, LONG_TEN_POWERS_TABLE[drop], mc.roundingMode.oldMode); |
|
prec = longDigitLength(compactVal); |
|
drop = prec - mcp; |
|
} |
|
return valueOf(compactVal,scale,prec); |
|
} |
|
} |
|
return new BigDecimal(intVal,INFLATED,scale,prec); |
|
} |
|
/* |
|
* Divides {@code BigInteger} value by ten power. |
|
*/ |
|
private static BigInteger divideAndRoundByTenPow(BigInteger intVal, int tenPow, int roundingMode) { |
|
if (tenPow < LONG_TEN_POWERS_TABLE.length) |
|
intVal = divideAndRound(intVal, LONG_TEN_POWERS_TABLE[tenPow], roundingMode); |
|
else |
|
intVal = divideAndRound(intVal, bigTenToThe(tenPow), roundingMode); |
|
return intVal; |
|
} |
|
/** |
|
* Internally used for division operation for division {@code long} by |
|
* {@code long}. |
|
* The returned {@code BigDecimal} object is the quotient whose scale is set |
|
* to the passed in scale. If the remainder is not zero, it will be rounded |
|
* based on the passed in roundingMode. Also, if the remainder is zero and |
|
* the last parameter, i.e. preferredScale is NOT equal to scale, the |
|
* trailing zeros of the result is stripped to match the preferredScale. |
|
*/ |
|
private static BigDecimal divideAndRound(long ldividend, long ldivisor, int scale, int roundingMode, |
|
int preferredScale) { |
|
int qsign; // quotient sign |
|
long q = ldividend / ldivisor; // store quotient in long |
|
if (roundingMode == ROUND_DOWN && scale == preferredScale) |
|
return valueOf(q, scale); |
|
long r = ldividend % ldivisor; // store remainder in long |
|
qsign = ((ldividend < 0) == (ldivisor < 0)) ? 1 : -1; |
|
if (r != 0) { |
|
boolean increment = needIncrement(ldivisor, roundingMode, qsign, q, r); |
|
return valueOf((increment ? q + qsign : q), scale); |
|
} else { |
|
if (preferredScale != scale) |
|
return createAndStripZerosToMatchScale(q, scale, preferredScale); |
|
else |
|
return valueOf(q, scale); |
|
} |
|
} |
|
/** |
|
* Divides {@code long} by {@code long} and do rounding based on the |
|
* passed in roundingMode. |
|
*/ |
|
private static long divideAndRound(long ldividend, long ldivisor, int roundingMode) { |
|
int qsign; // quotient sign |
|
long q = ldividend / ldivisor; // store quotient in long |
|
if (roundingMode == ROUND_DOWN) |
|
return q; |
|
long r = ldividend % ldivisor; // store remainder in long |
|
qsign = ((ldividend < 0) == (ldivisor < 0)) ? 1 : -1; |
|
if (r != 0) { |
|
boolean increment = needIncrement(ldivisor, roundingMode, qsign, q, r); |
|
return increment ? q + qsign : q; |
|
} else { |
|
return q; |
|
} |
|
} |
|
/** |
|
* Shared logic of need increment computation. |
|
*/ |
|
private static boolean commonNeedIncrement(int roundingMode, int qsign, |
|
int cmpFracHalf, boolean oddQuot) { |
|
switch(roundingMode) { |
|
case ROUND_UNNECESSARY: |
|
throw new ArithmeticException("Rounding necessary"); |
|
case ROUND_UP: // Away from zero |
|
return true; |
|
case ROUND_DOWN: // Towards zero |
|
return false; |
|
case ROUND_CEILING: // Towards +infinity |
|
return qsign > 0; |
|
case ROUND_FLOOR: // Towards -infinity |
|
return qsign < 0; |
|
default: // Some kind of half-way rounding |
|
assert roundingMode >= ROUND_HALF_UP && |
|
roundingMode <= ROUND_HALF_EVEN: "Unexpected rounding mode" + RoundingMode.valueOf(roundingMode); |
|
if (cmpFracHalf < 0 ) // We're closer to higher digit |
|
return false; |
|
else if (cmpFracHalf > 0 ) // We're closer to lower digit |
|
return true; |
|
else { // half-way |
|
assert cmpFracHalf == 0; |
|
switch(roundingMode) { |
|
case ROUND_HALF_DOWN: |
|
return false; |
|
case ROUND_HALF_UP: |
|
return true; |
|
case ROUND_HALF_EVEN: |
|
return oddQuot; |
|
default: |
|
throw new AssertionError("Unexpected rounding mode" + roundingMode); |
|
} |
|
} |
|
} |
|
} |
|
/** |
|
* Tests if quotient has to be incremented according the roundingMode |
|
*/ |
|
private static boolean needIncrement(long ldivisor, int roundingMode, |
|
int qsign, long q, long r) { |
|
assert r != 0L; |
|
int cmpFracHalf; |
|
if (r <= HALF_LONG_MIN_VALUE || r > HALF_LONG_MAX_VALUE) { |
|
cmpFracHalf = 1; // 2 * r can't fit into long |
|
} else { |
|
cmpFracHalf = longCompareMagnitude(2 * r, ldivisor); |
|
} |
|
return commonNeedIncrement(roundingMode, qsign, cmpFracHalf, (q & 1L) != 0L); |
|
} |
|
/** |
|
* Divides {@code BigInteger} value by {@code long} value and |
|
* do rounding based on the passed in roundingMode. |
|
*/ |
|
private static BigInteger divideAndRound(BigInteger bdividend, long ldivisor, int roundingMode) { |
|
boolean isRemainderZero; // record remainder is zero or not |
|
int qsign; // quotient sign |
|
long r = 0; // store quotient & remainder in long |
|
MutableBigInteger mq = null; // store quotient |
|
// Descend into mutables for faster remainder checks |
|
MutableBigInteger mdividend = new MutableBigInteger(bdividend.mag); |
|
mq = new MutableBigInteger(); |
|
r = mdividend.divide(ldivisor, mq); |
|
isRemainderZero = (r == 0); |
|
qsign = (ldivisor < 0) ? -bdividend.signum : bdividend.signum; |
|
if (!isRemainderZero) { |
|
if(needIncrement(ldivisor, roundingMode, qsign, mq, r)) { |
|
mq.add(MutableBigInteger.ONE); |
|
} |
|
} |
|
return mq.toBigInteger(qsign); |
|
} |
|
/** |
|
* Internally used for division operation for division {@code BigInteger} |
|
* by {@code long}. |
|
* The returned {@code BigDecimal} object is the quotient whose scale is set |
|
* to the passed in scale. If the remainder is not zero, it will be rounded |
|
* based on the passed in roundingMode. Also, if the remainder is zero and |
|
* the last parameter, i.e. preferredScale is NOT equal to scale, the |
|
* trailing zeros of the result is stripped to match the preferredScale. |
|
*/ |
|
private static BigDecimal divideAndRound(BigInteger bdividend, |
|
long ldivisor, int scale, int roundingMode, int preferredScale) { |
|
boolean isRemainderZero; // record remainder is zero or not |
|
int qsign; // quotient sign |
|
long r = 0; // store quotient & remainder in long |
|
MutableBigInteger mq = null; // store quotient |
|
// Descend into mutables for faster remainder checks |
|
MutableBigInteger mdividend = new MutableBigInteger(bdividend.mag); |
|
mq = new MutableBigInteger(); |
|
r = mdividend.divide(ldivisor, mq); |
|
isRemainderZero = (r == 0); |
|
qsign = (ldivisor < 0) ? -bdividend.signum : bdividend.signum; |
|
if (!isRemainderZero) { |
|
if(needIncrement(ldivisor, roundingMode, qsign, mq, r)) { |
|
mq.add(MutableBigInteger.ONE); |
|
} |
|
return mq.toBigDecimal(qsign, scale); |
|
} else { |
|
if (preferredScale != scale) { |
|
long compactVal = mq.toCompactValue(qsign); |
|
if(compactVal!=INFLATED) { |
|
return createAndStripZerosToMatchScale(compactVal, scale, preferredScale); |
|
} |
|
BigInteger intVal = mq.toBigInteger(qsign); |
|
return createAndStripZerosToMatchScale(intVal,scale, preferredScale); |
|
} else { |
|
return mq.toBigDecimal(qsign, scale); |
|
} |
|
} |
|
} |
|
/** |
|
* Tests if quotient has to be incremented according the roundingMode |
|
*/ |
|
private static boolean needIncrement(long ldivisor, int roundingMode, |
|
int qsign, MutableBigInteger mq, long r) { |
|
assert r != 0L; |
|
int cmpFracHalf; |
|
if (r <= HALF_LONG_MIN_VALUE || r > HALF_LONG_MAX_VALUE) { |
|
cmpFracHalf = 1; // 2 * r can't fit into long |
|
} else { |
|
cmpFracHalf = longCompareMagnitude(2 * r, ldivisor); |
|
} |
|
return commonNeedIncrement(roundingMode, qsign, cmpFracHalf, mq.isOdd()); |
|
} |
|
/** |
|
* Divides {@code BigInteger} value by {@code BigInteger} value and |
|
* do rounding based on the passed in roundingMode. |
|
*/ |
|
private static BigInteger divideAndRound(BigInteger bdividend, BigInteger bdivisor, int roundingMode) { |
|
boolean isRemainderZero; // record remainder is zero or not |
|
int qsign; // quotient sign |
|
// Descend into mutables for faster remainder checks |
|
MutableBigInteger mdividend = new MutableBigInteger(bdividend.mag); |
|
MutableBigInteger mq = new MutableBigInteger(); |
|
MutableBigInteger mdivisor = new MutableBigInteger(bdivisor.mag); |
|
MutableBigInteger mr = mdividend.divide(mdivisor, mq); |
|
isRemainderZero = mr.isZero(); |
|
qsign = (bdividend.signum != bdivisor.signum) ? -1 : 1; |
|
if (!isRemainderZero) { |
|
if (needIncrement(mdivisor, roundingMode, qsign, mq, mr)) { |
|
mq.add(MutableBigInteger.ONE); |
|
} |
|
} |
|
return mq.toBigInteger(qsign); |
|
} |
|
/** |
|
* Internally used for division operation for division {@code BigInteger} |
|
* by {@code BigInteger}. |
|
* The returned {@code BigDecimal} object is the quotient whose scale is set |
|
* to the passed in scale. If the remainder is not zero, it will be rounded |
|
* based on the passed in roundingMode. Also, if the remainder is zero and |
|
* the last parameter, i.e. preferredScale is NOT equal to scale, the |
|
* trailing zeros of the result is stripped to match the preferredScale. |
|
*/ |
|
private static BigDecimal divideAndRound(BigInteger bdividend, BigInteger bdivisor, int scale, int roundingMode, |
|
int preferredScale) { |
|
boolean isRemainderZero; // record remainder is zero or not |
|
int qsign; // quotient sign |
|
// Descend into mutables for faster remainder checks |
|
MutableBigInteger mdividend = new MutableBigInteger(bdividend.mag); |
|
MutableBigInteger mq = new MutableBigInteger(); |
|
MutableBigInteger mdivisor = new MutableBigInteger(bdivisor.mag); |
|
MutableBigInteger mr = mdividend.divide(mdivisor, mq); |
|
isRemainderZero = mr.isZero(); |
|
qsign = (bdividend.signum != bdivisor.signum) ? -1 : 1; |
|
if (!isRemainderZero) { |
|
if (needIncrement(mdivisor, roundingMode, qsign, mq, mr)) { |
|
mq.add(MutableBigInteger.ONE); |
|
} |
|
return mq.toBigDecimal(qsign, scale); |
|
} else { |
|
if (preferredScale != scale) { |
|
long compactVal = mq.toCompactValue(qsign); |
|
if (compactVal != INFLATED) { |
|
return createAndStripZerosToMatchScale(compactVal, scale, preferredScale); |
|
} |
|
BigInteger intVal = mq.toBigInteger(qsign); |
|
return createAndStripZerosToMatchScale(intVal, scale, preferredScale); |
|
} else { |
|
return mq.toBigDecimal(qsign, scale); |
|
} |
|
} |
|
} |
|
/** |
|
* Tests if quotient has to be incremented according the roundingMode |
|
*/ |
|
private static boolean needIncrement(MutableBigInteger mdivisor, int roundingMode, |
|
int qsign, MutableBigInteger mq, MutableBigInteger mr) { |
|
assert !mr.isZero(); |
|
int cmpFracHalf = mr.compareHalf(mdivisor); |
|
return commonNeedIncrement(roundingMode, qsign, cmpFracHalf, mq.isOdd()); |
|
} |
|
/** |
|
* Remove insignificant trailing zeros from this |
|
* {@code BigInteger} value until the preferred scale is reached or no |
|
* more zeros can be removed. If the preferred scale is less than |
|
* Integer.MIN_VALUE, all the trailing zeros will be removed. |
|
* |
|
* @return new {@code BigDecimal} with a scale possibly reduced |
|
* to be closed to the preferred scale. |
|
*/ |
|
private static BigDecimal createAndStripZerosToMatchScale(BigInteger intVal, int scale, long preferredScale) { |
|
BigInteger qr[]; // quotient-remainder pair |
|
while (intVal.compareMagnitude(BigInteger.TEN) >= 0 |
|
&& scale > preferredScale) { |
|
if (intVal.testBit(0)) |
|
break; // odd number cannot end in 0 |
|
qr = intVal.divideAndRemainder(BigInteger.TEN); |
|
if (qr[1].signum() != 0) |
|
break; // non-0 remainder |
|
intVal = qr[0]; |
|
scale = checkScale(intVal,(long) scale - 1); // could Overflow |
|
} |
|
return valueOf(intVal, scale, 0); |
|
} |
|
/** |
|
* Remove insignificant trailing zeros from this |
|
* {@code long} value until the preferred scale is reached or no |
|
* more zeros can be removed. If the preferred scale is less than |
|
* Integer.MIN_VALUE, all the trailing zeros will be removed. |
|
* |
|
* @return new {@code BigDecimal} with a scale possibly reduced |
|
* to be closed to the preferred scale. |
|
*/ |
|
private static BigDecimal createAndStripZerosToMatchScale(long compactVal, int scale, long preferredScale) { |
|
while (Math.abs(compactVal) >= 10L && scale > preferredScale) { |
|
if ((compactVal & 1L) != 0L) |
|
break; // odd number cannot end in 0 |
|
long r = compactVal % 10L; |
|
if (r != 0L) |
|
break; // non-0 remainder |
|
compactVal /= 10; |
|
scale = checkScale(compactVal, (long) scale - 1); // could Overflow |
|
} |
|
return valueOf(compactVal, scale); |
|
} |
|
private static BigDecimal stripZerosToMatchScale(BigInteger intVal, long intCompact, int scale, int preferredScale) { |
|
if(intCompact!=INFLATED) { |
|
return createAndStripZerosToMatchScale(intCompact, scale, preferredScale); |
|
} else { |
|
return createAndStripZerosToMatchScale(intVal==null ? INFLATED_BIGINT : intVal, |
|
scale, preferredScale); |
|
} |
|
} |
|
/* |
|
* returns INFLATED if oveflow |
|
*/ |
|
private static long add(long xs, long ys){ |
|
long sum = xs + ys; |
|
// See "Hacker's Delight" section 2-12 for explanation of |
|
// the overflow test. |
|
if ( (((sum ^ xs) & (sum ^ ys))) >= 0L) { // not overflowed |
|
return sum; |
|
} |
|
return INFLATED; |
|
} |
|
private static BigDecimal add(long xs, long ys, int scale){ |
|
long sum = add(xs, ys); |
|
if (sum!=INFLATED) |
|
return BigDecimal.valueOf(sum, scale); |
|
return new BigDecimal(BigInteger.valueOf(xs).add(ys), scale); |
|
} |
|
private static BigDecimal add(final long xs, int scale1, final long ys, int scale2) { |
|
long sdiff = (long) scale1 - scale2; |
|
if (sdiff == 0) { |
|
return add(xs, ys, scale1); |
|
} else if (sdiff < 0) { |
|
int raise = checkScale(xs,-sdiff); |
|
long scaledX = longMultiplyPowerTen(xs, raise); |
|
if (scaledX != INFLATED) { |
|
return add(scaledX, ys, scale2); |
|
} else { |
|
BigInteger bigsum = bigMultiplyPowerTen(xs,raise).add(ys); |
|
return ((xs^ys)>=0) ? // same sign test |
|
new BigDecimal(bigsum, INFLATED, scale2, 0) |
|
: valueOf(bigsum, scale2, 0); |
|
} |
|
} else { |
|
int raise = checkScale(ys,sdiff); |
|
long scaledY = longMultiplyPowerTen(ys, raise); |
|
if (scaledY != INFLATED) { |
|
return add(xs, scaledY, scale1); |
|
} else { |
|
BigInteger bigsum = bigMultiplyPowerTen(ys,raise).add(xs); |
|
return ((xs^ys)>=0) ? |
|
new BigDecimal(bigsum, INFLATED, scale1, 0) |
|
: valueOf(bigsum, scale1, 0); |
|
} |
|
} |
|
} |
|
private static BigDecimal add(final long xs, int scale1, BigInteger snd, int scale2) { |
|
int rscale = scale1; |
|
long sdiff = (long)rscale - scale2; |
|
boolean sameSigns = (Long.signum(xs) == snd.signum); |
|
BigInteger sum; |
|
if (sdiff < 0) { |
|
int raise = checkScale(xs,-sdiff); |
|
rscale = scale2; |
|
long scaledX = longMultiplyPowerTen(xs, raise); |
|
if (scaledX == INFLATED) { |
|
sum = snd.add(bigMultiplyPowerTen(xs,raise)); |
|
} else { |
|
sum = snd.add(scaledX); |
|
} |
|
} else { //if (sdiff > 0) { |
|
int raise = checkScale(snd,sdiff); |
|
snd = bigMultiplyPowerTen(snd,raise); |
|
sum = snd.add(xs); |
|
} |
|
return (sameSigns) ? |
|
new BigDecimal(sum, INFLATED, rscale, 0) : |
|
valueOf(sum, rscale, 0); |
|
} |
|
private static BigDecimal add(BigInteger fst, int scale1, BigInteger snd, int scale2) { |
|
int rscale = scale1; |
|
long sdiff = (long)rscale - scale2; |
|
if (sdiff != 0) { |
|
if (sdiff < 0) { |
|
int raise = checkScale(fst,-sdiff); |
|
rscale = scale2; |
|
fst = bigMultiplyPowerTen(fst,raise); |
|
} else { |
|
int raise = checkScale(snd,sdiff); |
|
snd = bigMultiplyPowerTen(snd,raise); |
|
} |
|
} |
|
BigInteger sum = fst.add(snd); |
|
return (fst.signum == snd.signum) ? |
|
new BigDecimal(sum, INFLATED, rscale, 0) : |
|
valueOf(sum, rscale, 0); |
|
} |
|
private static BigInteger bigMultiplyPowerTen(long value, int n) { |
|
if (n <= 0) |
|
return BigInteger.valueOf(value); |
|
return bigTenToThe(n).multiply(value); |
|
} |
|
private static BigInteger bigMultiplyPowerTen(BigInteger value, int n) { |
|
if (n <= 0) |
|
return value; |
|
if(n<LONG_TEN_POWERS_TABLE.length) { |
|
return value.multiply(LONG_TEN_POWERS_TABLE[n]); |
|
} |
|
return value.multiply(bigTenToThe(n)); |
|
} |
|
/** |
|
* Returns a {@code BigDecimal} whose value is {@code (xs / |
|
* ys)}, with rounding according to the context settings. |
|
* |
|
* Fast path - used only when (xscale <= yscale && yscale < 18 |
|
* && mc.presision<18) { |
|
*/ |
|
private static BigDecimal divideSmallFastPath(final long xs, int xscale, |
|
final long ys, int yscale, |
|
long preferredScale, MathContext mc) { |
|
int mcp = mc.precision; |
|
int roundingMode = mc.roundingMode.oldMode; |
|
assert (xscale <= yscale) && (yscale < 18) && (mcp < 18); |
|
int xraise = yscale - xscale; // xraise >=0 |
|
long scaledX = (xraise==0) ? xs : |
|
longMultiplyPowerTen(xs, xraise); // can't overflow here! |
|
BigDecimal quotient; |
|
int cmp = longCompareMagnitude(scaledX, ys); |
|
if(cmp > 0) { // satisfy constraint (b) |
|
yscale -= 1; // [that is, divisor *= 10] |
|
int scl = checkScaleNonZero(preferredScale + yscale - xscale + mcp); |
|
if (checkScaleNonZero((long) mcp + yscale - xscale) > 0) { |
|
// assert newScale >= xscale |
|
int raise = checkScaleNonZero((long) mcp + yscale - xscale); |
|
long scaledXs; |
|
if ((scaledXs = longMultiplyPowerTen(xs, raise)) == INFLATED) { |
|
quotient = null; |
|
if((mcp-1) >=0 && (mcp-1)<LONG_TEN_POWERS_TABLE.length) { |
|
quotient = multiplyDivideAndRound(LONG_TEN_POWERS_TABLE[mcp-1], scaledX, ys, scl, roundingMode, checkScaleNonZero(preferredScale)); |
|
} |
|
if(quotient==null) { |
|
BigInteger rb = bigMultiplyPowerTen(scaledX,mcp-1); |
|
quotient = divideAndRound(rb, ys, |
|
scl, roundingMode, checkScaleNonZero(preferredScale)); |
|
} |
|
} else { |
|
quotient = divideAndRound(scaledXs, ys, scl, roundingMode, checkScaleNonZero(preferredScale)); |
|
} |
|
} else { |
|
int newScale = checkScaleNonZero((long) xscale - mcp); |
|
// assert newScale >= yscale |
|
if (newScale == yscale) { // easy case |
|
quotient = divideAndRound(xs, ys, scl, roundingMode,checkScaleNonZero(preferredScale)); |
|
} else { |
|
int raise = checkScaleNonZero((long) newScale - yscale); |
|
long scaledYs; |
|
if ((scaledYs = longMultiplyPowerTen(ys, raise)) == INFLATED) { |
|
BigInteger rb = bigMultiplyPowerTen(ys,raise); |
|
quotient = divideAndRound(BigInteger.valueOf(xs), |
|
rb, scl, roundingMode,checkScaleNonZero(preferredScale)); |
|
} else { |
|
quotient = divideAndRound(xs, scaledYs, scl, roundingMode,checkScaleNonZero(preferredScale)); |
|
} |
|
} |
|
} |
|
} else { |
|
// abs(scaledX) <= abs(ys) |
|
// result is "scaledX * 10^msp / ys" |
|
int scl = checkScaleNonZero(preferredScale + yscale - xscale + mcp); |
|
if(cmp==0) { |
|
// abs(scaleX)== abs(ys) => result will be scaled 10^mcp + correct sign |
|
quotient = roundedTenPower(((scaledX < 0) == (ys < 0)) ? 1 : -1, mcp, scl, checkScaleNonZero(preferredScale)); |
|
} else { |
|
// abs(scaledX) < abs(ys) |
|
long scaledXs; |
|
if ((scaledXs = longMultiplyPowerTen(scaledX, mcp)) == INFLATED) { |
|
quotient = null; |
|
if(mcp<LONG_TEN_POWERS_TABLE.length) { |
|
quotient = multiplyDivideAndRound(LONG_TEN_POWERS_TABLE[mcp], scaledX, ys, scl, roundingMode, checkScaleNonZero(preferredScale)); |
|
} |
|
if(quotient==null) { |
|
BigInteger rb = bigMultiplyPowerTen(scaledX,mcp); |
|
quotient = divideAndRound(rb, ys, |
|
scl, roundingMode, checkScaleNonZero(preferredScale)); |
|
} |
|
} else { |
|
quotient = divideAndRound(scaledXs, ys, scl, roundingMode, checkScaleNonZero(preferredScale)); |
|
} |
|
} |
|
} |
|
// doRound, here, only affects 1000000000 case. |
|
return doRound(quotient,mc); |
|
} |
|
/** |
|
* Returns a {@code BigDecimal} whose value is {@code (xs / |
|
* ys)}, with rounding according to the context settings. |
|
*/ |
|
private static BigDecimal divide(final long xs, int xscale, final long ys, int yscale, long preferredScale, MathContext mc) { |
|
int mcp = mc.precision; |
|
if(xscale <= yscale && yscale < 18 && mcp<18) { |
|
return divideSmallFastPath(xs, xscale, ys, yscale, preferredScale, mc); |
|
} |
|
if (compareMagnitudeNormalized(xs, xscale, ys, yscale) > 0) {// satisfy constraint (b) |
|
yscale -= 1; // [that is, divisor *= 10] |
|
} |
|
int roundingMode = mc.roundingMode.oldMode; |
|
// In order to find out whether the divide generates the exact result, |
|
// we avoid calling the above divide method. 'quotient' holds the |
|
// return BigDecimal object whose scale will be set to 'scl'. |
|
int scl = checkScaleNonZero(preferredScale + yscale - xscale + mcp); |
|
BigDecimal quotient; |
|
if (checkScaleNonZero((long) mcp + yscale - xscale) > 0) { |
|
int raise = checkScaleNonZero((long) mcp + yscale - xscale); |
|
long scaledXs; |
|
if ((scaledXs = longMultiplyPowerTen(xs, raise)) == INFLATED) { |
|
BigInteger rb = bigMultiplyPowerTen(xs,raise); |
|
quotient = divideAndRound(rb, ys, scl, roundingMode, checkScaleNonZero(preferredScale)); |
|
} else { |
|
quotient = divideAndRound(scaledXs, ys, scl, roundingMode, checkScaleNonZero(preferredScale)); |
|
} |
|
} else { |
|
int newScale = checkScaleNonZero((long) xscale - mcp); |
|
// assert newScale >= yscale |
|
if (newScale == yscale) { // easy case |
|
quotient = divideAndRound(xs, ys, scl, roundingMode,checkScaleNonZero(preferredScale)); |
|
} else { |
|
int raise = checkScaleNonZero((long) newScale - yscale); |
|
long scaledYs; |
|
if ((scaledYs = longMultiplyPowerTen(ys, raise)) == INFLATED) { |
|
BigInteger rb = bigMultiplyPowerTen(ys,raise); |
|
quotient = divideAndRound(BigInteger.valueOf(xs), |
|
rb, scl, roundingMode,checkScaleNonZero(preferredScale)); |
|
} else { |
|
quotient = divideAndRound(xs, scaledYs, scl, roundingMode,checkScaleNonZero(preferredScale)); |
|
} |
|
} |
|
} |
|
// doRound, here, only affects 1000000000 case. |
|
return doRound(quotient,mc); |
|
} |
|
/** |
|
* Returns a {@code BigDecimal} whose value is {@code (xs / |
|
* ys)}, with rounding according to the context settings. |
|
*/ |
|
private static BigDecimal divide(BigInteger xs, int xscale, long ys, int yscale, long preferredScale, MathContext mc) { |
|
// Normalize dividend & divisor so that both fall into [0.1, 0.999...] |
|
if ((-compareMagnitudeNormalized(ys, yscale, xs, xscale)) > 0) {// satisfy constraint (b) |
|
yscale -= 1; // [that is, divisor *= 10] |
|
} |
|
int mcp = mc.precision; |
|
int roundingMode = mc.roundingMode.oldMode; |
|
// In order to find out whether the divide generates the exact result, |
|
// we avoid calling the above divide method. 'quotient' holds the |
|
// return BigDecimal object whose scale will be set to 'scl'. |
|
BigDecimal quotient; |
|
int scl = checkScaleNonZero(preferredScale + yscale - xscale + mcp); |
|
if (checkScaleNonZero((long) mcp + yscale - xscale) > 0) { |
|
int raise = checkScaleNonZero((long) mcp + yscale - xscale); |
|
BigInteger rb = bigMultiplyPowerTen(xs,raise); |
|
quotient = divideAndRound(rb, ys, scl, roundingMode, checkScaleNonZero(preferredScale)); |
|
} else { |
|
int newScale = checkScaleNonZero((long) xscale - mcp); |
|
// assert newScale >= yscale |
|
if (newScale == yscale) { // easy case |
|
quotient = divideAndRound(xs, ys, scl, roundingMode,checkScaleNonZero(preferredScale)); |
|
} else { |
|
int raise = checkScaleNonZero((long) newScale - yscale); |
|
long scaledYs; |
|
if ((scaledYs = longMultiplyPowerTen(ys, raise)) == INFLATED) { |
|
BigInteger rb = bigMultiplyPowerTen(ys,raise); |
|
quotient = divideAndRound(xs, rb, scl, roundingMode,checkScaleNonZero(preferredScale)); |
|
} else { |
|
quotient = divideAndRound(xs, scaledYs, scl, roundingMode,checkScaleNonZero(preferredScale)); |
|
} |
|
} |
|
} |
|
// doRound, here, only affects 1000000000 case. |
|
return doRound(quotient, mc); |
|
} |
|
/** |
|
* Returns a {@code BigDecimal} whose value is {@code (xs / |
|
* ys)}, with rounding according to the context settings. |
|
*/ |
|
private static BigDecimal divide(long xs, int xscale, BigInteger ys, int yscale, long preferredScale, MathContext mc) { |
|
// Normalize dividend & divisor so that both fall into [0.1, 0.999...] |
|
if (compareMagnitudeNormalized(xs, xscale, ys, yscale) > 0) {// satisfy constraint (b) |
|
yscale -= 1; // [that is, divisor *= 10] |
|
} |
|
int mcp = mc.precision; |
|
int roundingMode = mc.roundingMode.oldMode; |
|
// In order to find out whether the divide generates the exact result, |
|
// we avoid calling the above divide method. 'quotient' holds the |
|
// return BigDecimal object whose scale will be set to 'scl'. |
|
BigDecimal quotient; |
|
int scl = checkScaleNonZero(preferredScale + yscale - xscale + mcp); |
|
if (checkScaleNonZero((long) mcp + yscale - xscale) > 0) { |
|
int raise = checkScaleNonZero((long) mcp + yscale - xscale); |
|
BigInteger rb = bigMultiplyPowerTen(xs,raise); |
|
quotient = divideAndRound(rb, ys, scl, roundingMode, checkScaleNonZero(preferredScale)); |
|
} else { |
|
int newScale = checkScaleNonZero((long) xscale - mcp); |
|
int raise = checkScaleNonZero((long) newScale - yscale); |
|
BigInteger rb = bigMultiplyPowerTen(ys,raise); |
|
quotient = divideAndRound(BigInteger.valueOf(xs), rb, scl, roundingMode,checkScaleNonZero(preferredScale)); |
|
} |
|
// doRound, here, only affects 1000000000 case. |
|
return doRound(quotient, mc); |
|
} |
|
/** |
|
* Returns a {@code BigDecimal} whose value is {@code (xs / |
|
* ys)}, with rounding according to the context settings. |
|
*/ |
|
private static BigDecimal divide(BigInteger xs, int xscale, BigInteger ys, int yscale, long preferredScale, MathContext mc) { |
|
// Normalize dividend & divisor so that both fall into [0.1, 0.999...] |
|
if (compareMagnitudeNormalized(xs, xscale, ys, yscale) > 0) {// satisfy constraint (b) |
|
yscale -= 1; // [that is, divisor *= 10] |
|
} |
|
int mcp = mc.precision; |
|
int roundingMode = mc.roundingMode.oldMode; |
|
// In order to find out whether the divide generates the exact result, |
|
// we avoid calling the above divide method. 'quotient' holds the |
|
// return BigDecimal object whose scale will be set to 'scl'. |
|
BigDecimal quotient; |
|
int scl = checkScaleNonZero(preferredScale + yscale - xscale + mcp); |
|
if (checkScaleNonZero((long) mcp + yscale - xscale) > 0) { |
|
int raise = checkScaleNonZero((long) mcp + yscale - xscale); |
|
BigInteger rb = bigMultiplyPowerTen(xs,raise); |
|
quotient = divideAndRound(rb, ys, scl, roundingMode, checkScaleNonZero(preferredScale)); |
|
} else { |
|
int newScale = checkScaleNonZero((long) xscale - mcp); |
|
int raise = checkScaleNonZero((long) newScale - yscale); |
|
BigInteger rb = bigMultiplyPowerTen(ys,raise); |
|
quotient = divideAndRound(xs, rb, scl, roundingMode,checkScaleNonZero(preferredScale)); |
|
} |
|
// doRound, here, only affects 1000000000 case. |
|
return doRound(quotient, mc); |
|
} |
|
/* |
|
* performs divideAndRound for (dividend0*dividend1, divisor) |
|
* returns null if quotient can't fit into long value; |
|
*/ |
|
private static BigDecimal multiplyDivideAndRound(long dividend0, long dividend1, long divisor, int scale, int roundingMode, |
|
int preferredScale) { |
|
int qsign = Long.signum(dividend0)*Long.signum(dividend1)*Long.signum(divisor); |
|
dividend0 = Math.abs(dividend0); |
|
dividend1 = Math.abs(dividend1); |
|
divisor = Math.abs(divisor); |
|
// multiply dividend0 * dividend1 |
|
long d0_hi = dividend0 >>> 32; |
|
long d0_lo = dividend0 & LONG_MASK; |
|
long d1_hi = dividend1 >>> 32; |
|
long d1_lo = dividend1 & LONG_MASK; |
|
long product = d0_lo * d1_lo; |
|
long d0 = product & LONG_MASK; |
|
long d1 = product >>> 32; |
|
product = d0_hi * d1_lo + d1; |
|
d1 = product & LONG_MASK; |
|
long d2 = product >>> 32; |
|
product = d0_lo * d1_hi + d1; |
|
d1 = product & LONG_MASK; |
|
d2 += product >>> 32; |
|
long d3 = d2>>>32; |
|
d2 &= LONG_MASK; |
|
product = d0_hi*d1_hi + d2; |
|
d2 = product & LONG_MASK; |
|
d3 = ((product>>>32) + d3) & LONG_MASK; |
|
final long dividendHi = make64(d3,d2); |
|
final long dividendLo = make64(d1,d0); |
|
// divide |
|
return divideAndRound128(dividendHi, dividendLo, divisor, qsign, scale, roundingMode, preferredScale); |
|
} |
|
private static final long DIV_NUM_BASE = (1L<<32); // Number base (32 bits). |
|
/* |
|
* divideAndRound 128-bit value by long divisor. |
|
* returns null if quotient can't fit into long value; |
|
* Specialized version of Knuth's division |
|
*/ |
|
private static BigDecimal divideAndRound128(final long dividendHi, final long dividendLo, long divisor, int sign, |
|
int scale, int roundingMode, int preferredScale) { |
|
if (dividendHi >= divisor) { |
|
return null; |
|
} |
|
final int shift = Long.numberOfLeadingZeros(divisor); |
|
divisor <<= shift; |
|
final long v1 = divisor >>> 32; |
|
final long v0 = divisor & LONG_MASK; |
|
long tmp = dividendLo << shift; |
|
long u1 = tmp >>> 32; |
|
long u0 = tmp & LONG_MASK; |
|
tmp = (dividendHi << shift) | (dividendLo >>> 64 - shift); |
|
long u2 = tmp & LONG_MASK; |
|
long q1, r_tmp; |
|
if (v1 == 1) { |
|
q1 = tmp; |
|
r_tmp = 0; |
|
} else if (tmp >= 0) { |
|
q1 = tmp / v1; |
|
r_tmp = tmp - q1 * v1; |
|
} else { |
|
long[] rq = divRemNegativeLong(tmp, v1); |
|
q1 = rq[1]; |
|
r_tmp = rq[0]; |
|
} |
|
while(q1 >= DIV_NUM_BASE || unsignedLongCompare(q1*v0, make64(r_tmp, u1))) { |
|
q1--; |
|
r_tmp += v1; |
|
if (r_tmp >= DIV_NUM_BASE) |
|
break; |
|
} |
|
tmp = mulsub(u2,u1,v1,v0,q1); |
|
u1 = tmp & LONG_MASK; |
|
long q0; |
|
if (v1 == 1) { |
|
q0 = tmp; |
|
r_tmp = 0; |
|
} else if (tmp >= 0) { |
|
q0 = tmp / v1; |
|
r_tmp = tmp - q0 * v1; |
|
} else { |
|
long[] rq = divRemNegativeLong(tmp, v1); |
|
q0 = rq[1]; |
|
r_tmp = rq[0]; |
|
} |
|
while(q0 >= DIV_NUM_BASE || unsignedLongCompare(q0*v0,make64(r_tmp,u0))) { |
|
q0--; |
|
r_tmp += v1; |
|
if (r_tmp >= DIV_NUM_BASE) |
|
break; |
|
} |
|
if((int)q1 < 0) { |
|
// result (which is positive and unsigned here) |
|
// can't fit into long due to sign bit is used for value |
|
MutableBigInteger mq = new MutableBigInteger(new int[]{(int)q1, (int)q0}); |
|
if (roundingMode == ROUND_DOWN && scale == preferredScale) { |
|
return mq.toBigDecimal(sign, scale); |
|
} |
|
long r = mulsub(u1, u0, v1, v0, q0) >>> shift; |
|
if (r != 0) { |
|
if(needIncrement(divisor >>> shift, roundingMode, sign, mq, r)){ |
|
mq.add(MutableBigInteger.ONE); |
|
} |
|
return mq.toBigDecimal(sign, scale); |
|
} else { |
|
if (preferredScale != scale) { |
|
BigInteger intVal = mq.toBigInteger(sign); |
|
return createAndStripZerosToMatchScale(intVal,scale, preferredScale); |
|
} else { |
|
return mq.toBigDecimal(sign, scale); |
|
} |
|
} |
|
} |
|
long q = make64(q1,q0); |
|
q*=sign; |
|
if (roundingMode == ROUND_DOWN && scale == preferredScale) |
|
return valueOf(q, scale); |
|
long r = mulsub(u1, u0, v1, v0, q0) >>> shift; |
|
if (r != 0) { |
|
boolean increment = needIncrement(divisor >>> shift, roundingMode, sign, q, r); |
|
return valueOf((increment ? q + sign : q), scale); |
|
} else { |
|
if (preferredScale != scale) { |
|
return createAndStripZerosToMatchScale(q, scale, preferredScale); |
|
} else { |
|
return valueOf(q, scale); |
|
} |
|
} |
|
} |
|
/* |
|
* calculate divideAndRound for ldividend*10^raise / divisor |
|
* when abs(dividend)==abs(divisor); |
|
*/ |
|
private static BigDecimal roundedTenPower(int qsign, int raise, int scale, int preferredScale) { |
|
if (scale > preferredScale) { |
|
int diff = scale - preferredScale; |
|
if(diff < raise) { |
|
return scaledTenPow(raise - diff, qsign, preferredScale); |
|
} else { |
|
return valueOf(qsign,scale-raise); |
|
} |
|
} else { |
|
return scaledTenPow(raise, qsign, scale); |
|
} |
|
} |
|
static BigDecimal scaledTenPow(int n, int sign, int scale) { |
|
if (n < LONG_TEN_POWERS_TABLE.length) |
|
return valueOf(sign*LONG_TEN_POWERS_TABLE[n],scale); |
|
else { |
|
BigInteger unscaledVal = bigTenToThe(n); |
|
if(sign==-1) { |
|
unscaledVal = unscaledVal.negate(); |
|
} |
|
return new BigDecimal(unscaledVal, INFLATED, scale, n+1); |
|
} |
|
} |
|
/** |
|
* Calculate the quotient and remainder of dividing a negative long by |
|
* another long. |
|
* |
|
* @param n the numerator; must be negative |
|
* @param d the denominator; must not be unity |
|
* @return a two-element {@long} array with the remainder and quotient in |
|
* the initial and final elements, respectively |
|
*/ |
|
private static long[] divRemNegativeLong(long n, long d) { |
|
assert n < 0 : "Non-negative numerator " + n; |
|
assert d != 1 : "Unity denominator"; |
|
// Approximate the quotient and remainder |
|
long q = (n >>> 1) / (d >>> 1); |
|
long r = n - q * d; |
|
// Correct the approximation |
|
while (r < 0) { |
|
r += d; |
|
q--; |
|
} |
|
while (r >= d) { |
|
r -= d; |
|
q++; |
|
} |
|
// n - q*d == r && 0 <= r < d, hence we're done. |
|
return new long[] {r, q}; |
|
} |
|
private static long make64(long hi, long lo) { |
|
return hi<<32 | lo; |
|
} |
|
private static long mulsub(long u1, long u0, final long v1, final long v0, long q0) { |
|
long tmp = u0 - q0*v0; |
|
return make64(u1 + (tmp>>>32) - q0*v1,tmp & LONG_MASK); |
|
} |
|
private static boolean unsignedLongCompare(long one, long two) { |
|
return (one+Long.MIN_VALUE) > (two+Long.MIN_VALUE); |
|
} |
|
private static boolean unsignedLongCompareEq(long one, long two) { |
|
return (one+Long.MIN_VALUE) >= (two+Long.MIN_VALUE); |
|
} |
|
// Compare Normalize dividend & divisor so that both fall into [0.1, 0.999...] |
|
private static int compareMagnitudeNormalized(long xs, int xscale, long ys, int yscale) { |
|
// assert xs!=0 && ys!=0 |
|
int sdiff = xscale - yscale; |
|
if (sdiff != 0) { |
|
if (sdiff < 0) { |
|
xs = longMultiplyPowerTen(xs, -sdiff); |
|
} else { // sdiff > 0 |
|
ys = longMultiplyPowerTen(ys, sdiff); |
|
} |
|
} |
|
if (xs != INFLATED) |
|
return (ys != INFLATED) ? longCompareMagnitude(xs, ys) : -1; |
|
else |
|
return 1; |
|
} |
|
// Compare Normalize dividend & divisor so that both fall into [0.1, 0.999...] |
|
private static int compareMagnitudeNormalized(long xs, int xscale, BigInteger ys, int yscale) { |
|
// assert "ys can't be represented as long" |
|
if (xs == 0) |
|
return -1; |
|
int sdiff = xscale - yscale; |
|
if (sdiff < 0) { |
|
if (longMultiplyPowerTen(xs, -sdiff) == INFLATED ) { |
|
return bigMultiplyPowerTen(xs, -sdiff).compareMagnitude(ys); |
|
} |
|
} |
|
return -1; |
|
} |
|
// Compare Normalize dividend & divisor so that both fall into [0.1, 0.999...] |
|
private static int compareMagnitudeNormalized(BigInteger xs, int xscale, BigInteger ys, int yscale) { |
|
int sdiff = xscale - yscale; |
|
if (sdiff < 0) { |
|
return bigMultiplyPowerTen(xs, -sdiff).compareMagnitude(ys); |
|
} else { // sdiff >= 0 |
|
return xs.compareMagnitude(bigMultiplyPowerTen(ys, sdiff)); |
|
} |
|
} |
|
private static long multiply(long x, long y){ |
|
long product = x * y; |
|
long ax = Math.abs(x); |
|
long ay = Math.abs(y); |
|
if (((ax | ay) >>> 31 == 0) || (y == 0) || (product / y == x)){ |
|
return product; |
|
} |
|
return INFLATED; |
|
} |
|
private static BigDecimal multiply(long x, long y, int scale) { |
|
long product = multiply(x, y); |
|
if(product!=INFLATED) { |
|
return valueOf(product,scale); |
|
} |
|
return new BigDecimal(BigInteger.valueOf(x).multiply(y),INFLATED,scale,0); |
|
} |
|
private static BigDecimal multiply(long x, BigInteger y, int scale) { |
|
if(x==0) { |
|
return zeroValueOf(scale); |
|
} |
|
return new BigDecimal(y.multiply(x),INFLATED,scale,0); |
|
} |
|
private static BigDecimal multiply(BigInteger x, BigInteger y, int scale) { |
|
return new BigDecimal(x.multiply(y),INFLATED,scale,0); |
|
} |
|
/** |
|
* Multiplies two long values and rounds according {@code MathContext} |
|
*/ |
|
private static BigDecimal multiplyAndRound(long x, long y, int scale, MathContext mc) { |
|
long product = multiply(x, y); |
|
if(product!=INFLATED) { |
|
return doRound(product, scale, mc); |
|
} |
|
// attempt to do it in 128 bits |
|
int rsign = 1; |
|
if(x < 0) { |
|
x = -x; |
|
rsign = -1; |
|
} |
|
if(y < 0) { |
|
y = -y; |
|
rsign *= -1; |
|
} |
|
// multiply dividend0 * dividend1 |
|
long m0_hi = x >>> 32; |
|
long m0_lo = x & LONG_MASK; |
|
long m1_hi = y >>> 32; |
|
long m1_lo = y & LONG_MASK; |
|
product = m0_lo * m1_lo; |
|
long m0 = product & LONG_MASK; |
|
long m1 = product >>> 32; |
|
product = m0_hi * m1_lo + m1; |
|
m1 = product & LONG_MASK; |
|
long m2 = product >>> 32; |
|
product = m0_lo * m1_hi + m1; |
|
m1 = product & LONG_MASK; |
|
m2 += product >>> 32; |
|
long m3 = m2>>>32; |
|
m2 &= LONG_MASK; |
|
product = m0_hi*m1_hi + m2; |
|
m2 = product & LONG_MASK; |
|
m3 = ((product>>>32) + m3) & LONG_MASK; |
|
final long mHi = make64(m3,m2); |
|
final long mLo = make64(m1,m0); |
|
BigDecimal res = doRound128(mHi, mLo, rsign, scale, mc); |
|
if(res!=null) { |
|
return res; |
|
} |
|
res = new BigDecimal(BigInteger.valueOf(x).multiply(y*rsign), INFLATED, scale, 0); |
|
return doRound(res,mc); |
|
} |
|
private static BigDecimal multiplyAndRound(long x, BigInteger y, int scale, MathContext mc) { |
|
if(x==0) { |
|
return zeroValueOf(scale); |
|
} |
|
return doRound(y.multiply(x), scale, mc); |
|
} |
|
private static BigDecimal multiplyAndRound(BigInteger x, BigInteger y, int scale, MathContext mc) { |
|
return doRound(x.multiply(y), scale, mc); |
|
} |
|
/** |
|
* rounds 128-bit value according {@code MathContext} |
|
* returns null if result can't be repsented as compact BigDecimal. |
|
*/ |
|
private static BigDecimal doRound128(long hi, long lo, int sign, int scale, MathContext mc) { |
|
int mcp = mc.precision; |
|
int drop; |
|
BigDecimal res = null; |
|
if(((drop = precision(hi, lo) - mcp) > 0)&&(drop<LONG_TEN_POWERS_TABLE.length)) { |
|
scale = checkScaleNonZero((long)scale - drop); |
|
res = divideAndRound128(hi, lo, LONG_TEN_POWERS_TABLE[drop], sign, scale, mc.roundingMode.oldMode, scale); |
|
} |
|
if(res!=null) { |
|
return doRound(res,mc); |
|
} |
|
return null; |
|
} |
|
private static final long[][] LONGLONG_TEN_POWERS_TABLE = { |
|
{ 0L, 0x8AC7230489E80000L }, //10^19 |
|
{ 0x5L, 0x6bc75e2d63100000L }, //10^20 |
|
{ 0x36L, 0x35c9adc5dea00000L }, //10^21 |
|
{ 0x21eL, 0x19e0c9bab2400000L }, //10^22 |
|
{ 0x152dL, 0x02c7e14af6800000L }, //10^23 |
|
{ 0xd3c2L, 0x1bcecceda1000000L }, //10^24 |
|
{ 0x84595L, 0x161401484a000000L }, //10^25 |
|
{ 0x52b7d2L, 0xdcc80cd2e4000000L }, //10^26 |
|
{ 0x33b2e3cL, 0x9fd0803ce8000000L }, //10^27 |
|
{ 0x204fce5eL, 0x3e25026110000000L }, //10^28 |
|
{ 0x1431e0faeL, 0x6d7217caa0000000L }, //10^29 |
|
{ 0xc9f2c9cd0L, 0x4674edea40000000L }, //10^30 |
|
{ 0x7e37be2022L, 0xc0914b2680000000L }, //10^31 |
|
{ 0x4ee2d6d415bL, 0x85acef8100000000L }, //10^32 |
|
{ 0x314dc6448d93L, 0x38c15b0a00000000L }, //10^33 |
|
{ 0x1ed09bead87c0L, 0x378d8e6400000000L }, //10^34 |
|
{ 0x13426172c74d82L, 0x2b878fe800000000L }, //10^35 |
|
{ 0xc097ce7bc90715L, 0xb34b9f1000000000L }, //10^36 |
|
{ 0x785ee10d5da46d9L, 0x00f436a000000000L }, //10^37 |
|
{ 0x4b3b4ca85a86c47aL, 0x098a224000000000L }, //10^38 |
|
}; |
|
/* |
|
* returns precision of 128-bit value |
|
*/ |
|
private static int precision(long hi, long lo){ |
|
if(hi==0) { |
|
if(lo>=0) { |
|
return longDigitLength(lo); |
|
} |
|
return (unsignedLongCompareEq(lo, LONGLONG_TEN_POWERS_TABLE[0][1])) ? 20 : 19; |
|
// 0x8AC7230489E80000L = unsigned 2^19 |
|
} |
|
int r = ((128 - Long.numberOfLeadingZeros(hi) + 1) * 1233) >>> 12; |
|
int idx = r-19; |
|
return (idx >= LONGLONG_TEN_POWERS_TABLE.length || longLongCompareMagnitude(hi, lo, |
|
LONGLONG_TEN_POWERS_TABLE[idx][0], LONGLONG_TEN_POWERS_TABLE[idx][1])) ? r : r + 1; |
|
} |
|
/* |
|
* returns true if 128 bit number <hi0,lo0> is less then <hi1,lo1> |
|
* hi0 & hi1 should be non-negative |
|
*/ |
|
private static boolean longLongCompareMagnitude(long hi0, long lo0, long hi1, long lo1) { |
|
if(hi0!=hi1) { |
|
return hi0<hi1; |
|
} |
|
return (lo0+Long.MIN_VALUE) <(lo1+Long.MIN_VALUE); |
|
} |
|
private static BigDecimal divide(long dividend, int dividendScale, long divisor, int divisorScale, int scale, int roundingMode) { |
|
if (checkScale(dividend,(long)scale + divisorScale) > dividendScale) { |
|
int newScale = scale + divisorScale; |
|
int raise = newScale - dividendScale; |
|
if(raise<LONG_TEN_POWERS_TABLE.length) { |
|
long xs = dividend; |
|
if ((xs = longMultiplyPowerTen(xs, raise)) != INFLATED) { |
|
return divideAndRound(xs, divisor, scale, roundingMode, scale); |
|
} |
|
BigDecimal q = multiplyDivideAndRound(LONG_TEN_POWERS_TABLE[raise], dividend, divisor, scale, roundingMode, scale); |
|
if(q!=null) { |
|
return q; |
|
} |
|
} |
|
BigInteger scaledDividend = bigMultiplyPowerTen(dividend, raise); |
|
return divideAndRound(scaledDividend, divisor, scale, roundingMode, scale); |
|
} else { |
|
int newScale = checkScale(divisor,(long)dividendScale - scale); |
|
int raise = newScale - divisorScale; |
|
if(raise<LONG_TEN_POWERS_TABLE.length) { |
|
long ys = divisor; |
|
if ((ys = longMultiplyPowerTen(ys, raise)) != INFLATED) { |
|
return divideAndRound(dividend, ys, scale, roundingMode, scale); |
|
} |
|
} |
|
BigInteger scaledDivisor = bigMultiplyPowerTen(divisor, raise); |
|
return divideAndRound(BigInteger.valueOf(dividend), scaledDivisor, scale, roundingMode, scale); |
|
} |
|
} |
|
private static BigDecimal divide(BigInteger dividend, int dividendScale, long divisor, int divisorScale, int scale, int roundingMode) { |
|
if (checkScale(dividend,(long)scale + divisorScale) > dividendScale) { |
|
int newScale = scale + divisorScale; |
|
int raise = newScale - dividendScale; |
|
BigInteger scaledDividend = bigMultiplyPowerTen(dividend, raise); |
|
return divideAndRound(scaledDividend, divisor, scale, roundingMode, scale); |
|
} else { |
|
int newScale = checkScale(divisor,(long)dividendScale - scale); |
|
int raise = newScale - divisorScale; |
|
if(raise<LONG_TEN_POWERS_TABLE.length) { |
|
long ys = divisor; |
|
if ((ys = longMultiplyPowerTen(ys, raise)) != INFLATED) { |
|
return divideAndRound(dividend, ys, scale, roundingMode, scale); |
|
} |
|
} |
|
BigInteger scaledDivisor = bigMultiplyPowerTen(divisor, raise); |
|
return divideAndRound(dividend, scaledDivisor, scale, roundingMode, scale); |
|
} |
|
} |
|
private static BigDecimal divide(long dividend, int dividendScale, BigInteger divisor, int divisorScale, int scale, int roundingMode) { |
|
if (checkScale(dividend,(long)scale + divisorScale) > dividendScale) { |
|
int newScale = scale + divisorScale; |
|
int raise = newScale - dividendScale; |
|
BigInteger scaledDividend = bigMultiplyPowerTen(dividend, raise); |
|
return divideAndRound(scaledDividend, divisor, scale, roundingMode, scale); |
|
} else { |
|
int newScale = checkScale(divisor,(long)dividendScale - scale); |
|
int raise = newScale - divisorScale; |
|
BigInteger scaledDivisor = bigMultiplyPowerTen(divisor, raise); |
|
return divideAndRound(BigInteger.valueOf(dividend), scaledDivisor, scale, roundingMode, scale); |
|
} |
|
} |
|
private static BigDecimal divide(BigInteger dividend, int dividendScale, BigInteger divisor, int divisorScale, int scale, int roundingMode) { |
|
if (checkScale(dividend,(long)scale + divisorScale) > dividendScale) { |
|
int newScale = scale + divisorScale; |
|
int raise = newScale - dividendScale; |
|
BigInteger scaledDividend = bigMultiplyPowerTen(dividend, raise); |
|
return divideAndRound(scaledDividend, divisor, scale, roundingMode, scale); |
|
} else { |
|
int newScale = checkScale(divisor,(long)dividendScale - scale); |
|
int raise = newScale - divisorScale; |
|
BigInteger scaledDivisor = bigMultiplyPowerTen(divisor, raise); |
|
return divideAndRound(dividend, scaledDivisor, scale, roundingMode, scale); |
|
} |
|
} |
|
} |