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	/*
	* Copyright (c) 2005, 2015, Oracle and/or its affiliates. All rights reserved.
	* DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
	*
	* This code is free software; you can redistribute it and/or modify it
	* under the terms of the GNU General Public License version 2 only, as
	* published by the Free Software Foundation. Oracle designates this
	* particular file as subject to the "Classpath" exception as provided
	* by Oracle in the LICENSE file that accompanied this code.
	*
	* This code is distributed in the hope that it will be useful, but WITHOUT
	* ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
	* FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
	* version 2 for more details (a copy is included in the LICENSE file that
	* accompanied this code).
	*
	* You should have received a copy of the GNU General Public License version
	* 2 along with this work; if not, write to the Free Software Foundation,
	* Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
	*
	* Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
	* or visit www.oracle.com if you need additional information or have any
	* questions.
	*/

	/*
	******************************************************************************
	* Copyright (C) 1996-2014, International Business Machines Corporation and
	* others. All Rights Reserved.
	******************************************************************************
	*/

	package sun.text.normalizer;

	import java.io.DataInputStream;
	import java.io.InputStream;
	import java.io.IOException;

	/**
	* Trie implementation which stores data in char, 16 bits.
	* @author synwee
	* @see com.ibm.icu.impl.Trie
	* @since release 2.1, Jan 01 2002
	*/

	// note that i need to handle the block calculations later, since chartrie
	// in icu4c uses the same index array.
	public class CharTrie extends Trie
	{
	// public constructors ---------------------------------------------

	/**
	* <p>Creates a new Trie with the settings for the trie data.</p>
	* <p>Unserialize the 32-bit-aligned input stream and use the data for the
	* trie.</p>
	* @param inputStream file input stream to a ICU data file, containing
	* the trie
	* @param dataManipulate object which provides methods to parse the char
	* data
	* @throws IOException thrown when data reading fails
	* @draft 2.1
	*/
	public CharTrie(InputStream inputStream,
	DataManipulate dataManipulate) throws IOException
	{
	super(inputStream, dataManipulate);

	if (!isCharTrie()) {
	throw new IllegalArgumentException(
	"Data given does not belong to a char trie.");
	}
	}

	// public methods --------------------------------------------------

	/**
	* Gets the value associated with the codepoint.
	* If no value is associated with the codepoint, a default value will be
	* returned.
	* @param ch codepoint
	* @return offset to data
	*/
	public final char getCodePointValue(int ch)
	{
	int offset;

	// fastpath for U+0000..U+D7FF
	if(0 <= ch && ch < UTF16.LEAD_SURROGATE_MIN_VALUE) {
	// copy of getRawOffset()
	offset = (m_index_[ch >> INDEX_STAGE_1_SHIFT_] << INDEX_STAGE_2_SHIFT_)
	+ (ch & INDEX_STAGE_3_MASK_);
	return m_data_[offset];
	}

	// handle U+D800..U+10FFFF
	offset = getCodePointOffset(ch);

	// return -1 if there is an error, in this case we return the default
	// value: m_initialValue_
	return (offset >= 0) ? m_data_[offset] : m_initialValue_;
	}

	/**
	* Gets the value to the data which this lead surrogate character points
	* to.
	* Returned data may contain folding offset information for the next
	* trailing surrogate character.
	* This method does not guarantee correct results for trail surrogates.
	* @param ch lead surrogate character
	* @return data value
	*/
	public final char getLeadValue(char ch)
	{
	return m_data_[getLeadOffset(ch)];
	}

	// protected methods -----------------------------------------------

	/**
	* <p>Parses the input stream and stores its trie content into a index and
	* data array</p>
	* @param inputStream data input stream containing trie data
	* @exception IOException thrown when data reading fails
	*/
	protected final void unserialize(InputStream inputStream)
	throws IOException
	{
	DataInputStream input = new DataInputStream(inputStream);
	int indexDataLength = m_dataOffset_ + m_dataLength_;
	m_index_ = new char[indexDataLength];
	for (int i = 0; i < indexDataLength; i ++) {
	m_index_[i] = input.readChar();
	}
	m_data_ = m_index_;
	m_initialValue_ = m_data_[m_dataOffset_];
	}

	/**
	* Gets the offset to the data which the surrogate pair points to.
	* @param lead lead surrogate
	* @param trail trailing surrogate
	* @return offset to data
	* @draft 2.1
	*/
	protected final int getSurrogateOffset(char lead, char trail)
	{
	if (m_dataManipulate_ == null) {
	throw new NullPointerException(
	"The field DataManipulate in this Trie is null");
	}

	// get fold position for the next trail surrogate
	int offset = m_dataManipulate_.getFoldingOffset(getLeadValue(lead));

	// get the real data from the folded lead/trail units
	if (offset > 0) {
	return getRawOffset(offset, (char)(trail & SURROGATE_MASK_));
	}

	// return -1 if there is an error, in this case we return the default
	// value: m_initialValue_
	return -1;
	}

	// private data members --------------------------------------------

	/**
	* Default value
	*/
	private char m_initialValue_;
	/**
	* Array of char data
	*/
	private char m_data_[];
	}

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