com.ibm.icu.impl.CharTrie Maven / Gradle / Ivy
Go to download
Show more of this group Show more artifacts with this name
Show all versions of icu4j Show documentation
Show all versions of icu4j Show documentation
International Component for Unicode for Java (ICU4J) is a mature, widely used Java library
providing Unicode and Globalization support
// © 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_[];
}