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	/*
	* Copyright (c) 2017, 2021, Oracle and/or its affiliates. All rights reserved.
	*/
	/*
	* Licensed to the Apache Software Foundation (ASF) under one or more
	* contributor license agreements. See the NOTICE file distributed with
	* this work for additional information regarding copyright ownership.
	* The ASF licenses this file to You under the Apache License, Version 2.0
	* (the "License"); you may not use this file except in compliance with
	* the License. You may obtain a copy of the License at
	*
	* http://www.apache.org/licenses/LICENSE-2.0
	*
	* Unless required by applicable law or agreed to in writing, software
	* distributed under the License is distributed on an "AS IS" BASIS,
	* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
	* See the License for the specific language governing permissions and
	* limitations under the License.
	*/
	package com.sun.org.apache.bcel.internal.classfile;

	import com.sun.org.apache.bcel.internal.Const;
	import java.io.DataInput;
	import java.io.DataOutputStream;
	import java.io.IOException;
	import jdk.xml.internal.SecuritySupport;

	/**
	* This class represents a table of line numbers for debugging
	* purposes. This attribute is used by the <em>Code</em> attribute. It
	* contains pairs of PCs and line numbers.
	*
	* @see Code
	* @see LineNumber
	* @LastModified: May 2021
	*/
	public final class LineNumberTable extends Attribute {

	private static final int MAX_LINE_LENGTH = 72;
	private LineNumber[] lineNumberTable; // Table of line/numbers pairs


	/*
	* Initialize from another object. Note that both objects use the same
	* references (shallow copy). Use copy() for a physical copy.
	*/
	public LineNumberTable(final LineNumberTable c) {
	this(c.getNameIndex(), c.getLength(), c.getLineNumberTable(), c.getConstantPool());
	}


	/*
	* @param name_index Index of name
	* @param length Content length in bytes
	* @param lineNumberTable Table of line/numbers pairs
	* @param constant_pool Array of constants
	*/
	public LineNumberTable(final int name_index, final int length, final LineNumber[] line_number_table,
	final ConstantPool constant_pool) {
	super(Const.ATTR_LINE_NUMBER_TABLE, name_index, length, constant_pool);
	this.lineNumberTable = line_number_table;
	}

	/**
	* Construct object from input stream.
	* @param name_index Index of name
	* @param length Content length in bytes
	* @param input Input stream
	* @param constant_pool Array of constants
	* @throws IOException if an I/O Exception occurs in readUnsignedShort
	*/
	LineNumberTable(final int name_index, final int length, final DataInput input, final ConstantPool constant_pool)
	throws IOException {
	this(name_index, length, (LineNumber[]) null, constant_pool);
	final int line_number_table_length = input.readUnsignedShort();
	lineNumberTable = new LineNumber[line_number_table_length];
	for (int i = 0; i < line_number_table_length; i++) {
	lineNumberTable[i] = new LineNumber(input);
	}
	}

	/**
	* Called by objects that are traversing the nodes of the tree implicitely
	* defined by the contents of a Java class. I.e., the hierarchy of methods,
	* fields, attributes, etc. spawns a tree of objects.
	*
	* @param v Visitor object
	*/
	@Override
	public void accept( final Visitor v ) {
	v.visitLineNumberTable(this);
	}

	/**
	* Dump line number table attribute to file stream in binary format.
	*
	* @param file Output file stream
	* @throws IOException if an I/O Exception occurs in writeShort
	*/
	@Override
	public void dump( final DataOutputStream file ) throws IOException {
	super.dump(file);
	file.writeShort(lineNumberTable.length);
	for (final LineNumber lineNumber : lineNumberTable) {
	lineNumber.dump(file);
	}
	}

	/**
	* @return Array of (pc offset, line number) pairs.
	*/
	public LineNumber[] getLineNumberTable() {
	return lineNumberTable;
	}

	/**
	* @param lineNumberTable the line number entries for this table
	*/
	public void setLineNumberTable( final LineNumber[] lineNumberTable ) {
	this.lineNumberTable = lineNumberTable;
	}

	/**
	* @return String representation.
	*/
	@Override
	public String toString() {
	final StringBuilder buf = new StringBuilder();
	final StringBuilder line = new StringBuilder();

	for (int i = 0; i < lineNumberTable.length; i++) {
	line.append(lineNumberTable[i].toString());
	if (i < lineNumberTable.length - 1) {
	line.append(", ");
	}
	if ((line.length() > MAX_LINE_LENGTH) && (i < lineNumberTable.length - 1)) {
	line.append(SecuritySupport.NEWLINE);
	buf.append(line);
	line.setLength(0);
	}
	}
	buf.append(line);
	return buf.toString();
	}

	/**
	* Map byte code positions to source code lines.
	*
	* @param pos byte code offset
	* @return corresponding line in source code
	*/
	public int getSourceLine( final int pos ) {
	int l = 0;
	int r = lineNumberTable.length - 1;
	if (r < 0) {
	return -1;
	}
	int min_index = -1;
	int min = -1;
	/* Do a binary search since the array is ordered.
	*/
	do {
	final int i = (l + r) >>> 1;
	final int j = lineNumberTable[i].getStartPC();
	if (j == pos) {
	return lineNumberTable[i].getLineNumber();
	} else if (pos < j) {
	r = i - 1;
	} else {
	l = i + 1;
	}
	/* If exact match can't be found (which is the most common case)
	* return the line number that corresponds to the greatest index less
	* than pos.
	*/
	if (j < pos && j > min) {
	min = j;
	min_index = i;
	}
	} while (l <= r);
	/* It's possible that we did not find any valid entry for the bytecode
	* offset we were looking for.
	*/
	if (min_index < 0) {
	return -1;
	}
	return lineNumberTable[min_index].getLineNumber();
	}

	/**
	* @return deep copy of this attribute
	*/
	@Override
	public Attribute copy( final ConstantPool _constant_pool ) {
	// TODO could use the lower level constructor and thereby allow
	// lineNumberTable to be made final
	final LineNumberTable c = (LineNumberTable) clone();
	c.lineNumberTable = new LineNumber[lineNumberTable.length];
	for (int i = 0; i < lineNumberTable.length; i++) {
	c.lineNumberTable[i] = lineNumberTable[i].copy();
	}
	c.setConstantPool(_constant_pool);
	return c;
	}


	public int getTableLength() {
	return lineNumberTable == null ? 0 : lineNumberTable.length;
	}
	}

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