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With inspiration from other libraries
// © 2016 and later: Unicode, Inc. and others.
// License & terms of use: http://www.unicode.org/copyright.html#License
/*
******************************************************************************
* Copyright (C) 1996-2015, International Business Machines Corporation and
* others. All Rights Reserved.
******************************************************************************
*/
package com.ibm.icu.impl;
import java.nio.ByteBuffer;
import com.ibm.icu.text.UTF16;
/**
* 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 ---------------------------------------------
/**
* Creates a new Trie with the settings for the trie data.
* Unserialize the 32-bit-aligned input buffer and use the data for the
* trie.
* @param bytes data of an ICU data file, containing the trie
* @param dataManipulate object which provides methods to parse the char
* data
*/
public CharTrie(ByteBuffer bytes, DataManipulate dataManipulate) {
super(bytes, dataManipulate);
if (!isCharTrie()) {
throw new IllegalArgumentException(
"Data given does not belong to a char trie.");
}
}
/**
* Make a dummy CharTrie.
* A dummy trie is an empty runtime trie, used when a real data trie cannot
* be loaded.
*
* The trie always returns the initialValue,
* or the leadUnitValue for lead surrogate code points.
* The Latin-1 part is always set up to be linear.
*
* @param initialValue the initial value that is set for all code points
* @param leadUnitValue the value for lead surrogate code _units_ that do not
* have associated supplementary data
* @param dataManipulate object which provides methods to parse the char data
*/
@SuppressWarnings("all") // No way to ignore dead code warning specifically - see eclipse bug#282770
public CharTrie(int initialValue, int leadUnitValue, DataManipulate dataManipulate) {
super(new char[BMP_INDEX_LENGTH+SURROGATE_BLOCK_COUNT], HEADER_OPTIONS_LATIN1_IS_LINEAR_MASK_, dataManipulate);
int dataLength, latin1Length, i, limit;
char block;
/* calculate the actual size of the dummy trie data */
/* max(Latin-1, block 0) */
dataLength=latin1Length= INDEX_STAGE_1_SHIFT_<=8 ? 256 : DATA_BLOCK_LENGTH;
if(leadUnitValue!=initialValue) {
dataLength+=DATA_BLOCK_LENGTH;
}
m_data_=new char[dataLength];
m_dataLength_=dataLength;
m_initialValue_=(char)initialValue;
/* fill the index and data arrays */
/* indexes are preset to 0 (block 0) */
/* Latin-1 data */
for(i=0; i>INDEX_STAGE_2_SHIFT_);
i=0xd800>>INDEX_STAGE_1_SHIFT_;
limit=0xdc00>>INDEX_STAGE_1_SHIFT_;
for(; i> 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)];
}
/**
* Get the value associated with the BMP code point.
* Lead surrogate code points are treated as normal code points, with
* unfolded values that may differ from getLeadValue() results.
* @param ch the input BMP code point
* @return trie data value associated with the BMP codepoint
*/
public final char getBMPValue(char ch)
{
return m_data_[getBMPOffset(ch)];
}
/**
* Get the value associated with a pair of surrogates.
* @param lead a lead surrogate
* @param trail a trail surrogate
*/
public final char getSurrogateValue(char lead, char trail)
{
int offset = getSurrogateOffset(lead, trail);
if (offset > 0) {
return m_data_[offset];
}
return m_initialValue_;
}
/**
* Get a value from a folding offset (from the value of a lead surrogate)
* and a trail surrogate.
* If the
* @param leadvalue value associated with the lead surrogate which contains
* the folding offset
* @param trail surrogate
* @return trie data value associated with the trail character
*/
public final char getTrailValue(int leadvalue, char trail)
{
if (m_dataManipulate_ == null) {
throw new NullPointerException(
"The field DataManipulate in this Trie is null");
}
int offset = m_dataManipulate_.getFoldingOffset(leadvalue);
if (offset > 0) {
return m_data_[getRawOffset(offset,
(char)(trail & SURROGATE_MASK_))];
}
return m_initialValue_;
}
/**
*
Gets the latin 1 fast path value.
* Note this only works if latin 1 characters have their own linear
* array.
* @param ch latin 1 characters
* @return value associated with latin character
*/
public final char getLatin1LinearValue(char ch)
{
return m_data_[INDEX_STAGE_3_MASK_ + 1 + m_dataOffset_ + ch];
}
/**
* Checks if the argument Trie has the same data as this Trie
* @param other Trie to check
* @return true if the argument Trie has the same data as this Trie, false
* otherwise
*/
///CLOVER:OFF
@Override
public boolean equals(Object other)
{
boolean result = super.equals(other);
if (result && other instanceof CharTrie) {
CharTrie othertrie = (CharTrie)other;
return m_initialValue_ == othertrie.m_initialValue_;
}
return false;
}
@Override
public int hashCode() {
assert false : "hashCode not designed";
return 42;
}
///CLOVER:ON
// protected methods -----------------------------------------------
/**
* Parses the byte buffer and stores its trie content into a index and
* data array
* @param bytes buffer containing trie data
*/
@Override
protected final void unserialize(ByteBuffer bytes)
{
int indexDataLength = m_dataOffset_ + m_dataLength_;
m_index_ = ICUBinary.getChars(bytes, indexDataLength, 0);
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
*/
@Override
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;
}
/**
* Gets the value at the argument index.
* For use internally in TrieIterator.
* @param index value at index will be retrieved
* @return 32 bit value
* @see com.ibm.icu.impl.TrieIterator
*/
@Override
protected final int getValue(int index)
{
return m_data_[index];
}
/**
* Gets the default initial value
* @return 32 bit value
*/
@Override
protected final int getInitialValue()
{
return m_initialValue_;
}
// private data members --------------------------------------------
/**
* Default value
*/
private char m_initialValue_;
/**
* Array of char data
*/
private char m_data_[];
}