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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) 2009-2015, International Business Machines Corporation and
* others. All Rights Reserved.
*******************************************************************************
*/
package com.ibm.icu.impl;
import java.io.DataOutputStream;
import java.io.IOException;
import java.io.InputStream;
import java.nio.ByteBuffer;
import java.nio.ByteOrder;
import java.util.Iterator;
import java.util.NoSuchElementException;
/**
* This is the interface and common implementation of a Unicode Trie2.
* It is a kind of compressed table that maps from Unicode code points (0..0x10ffff)
* to 16- or 32-bit integer values. It works best when there are ranges of
* characters with the same value, which is generally the case with Unicode
* character properties.
*
* This is the second common version of a Unicode trie (hence the name Trie2).
*
*/
public abstract class Trie2 implements Iterable {
/**
* Create a Trie2 from its serialized form. Inverse of utrie2_serialize().
*
* Reads from the current position and leaves the buffer after the end of the trie.
*
* The serialized format is identical between ICU4C and ICU4J, so this function
* will work with serialized Trie2s from either.
*
* The actual type of the returned Trie2 will be either Trie2_16 or Trie2_32, depending
* on the width of the data.
*
* To obtain the width of the Trie2, check the actual class type of the returned Trie2.
* Or use the createFromSerialized() function of Trie2_16 or Trie2_32, which will
* return only Tries of their specific type/size.
*
* The serialized Trie2 on the stream may be in either little or big endian byte order.
* This allows using serialized Tries from ICU4C without needing to consider the
* byte order of the system that created them.
*
* @param bytes a byte buffer to the serialized form of a UTrie2.
* @return An unserialized Trie2, ready for use.
* @throws IllegalArgumentException if the stream does not contain a serialized Trie2.
* @throws IOException if a read error occurs in the buffer.
*
*/
public static Trie2 createFromSerialized(ByteBuffer bytes) throws IOException {
// From ICU4C utrie2_impl.h
// * Trie2 data structure in serialized form:
// *
// * UTrie2Header header;
// * uint16_t index[header.index2Length];
// * uint16_t data[header.shiftedDataLength<<2]; -- or uint32_t data[...]
// * @internal
// */
// typedef struct UTrie2Header {
// /** "Tri2" in big-endian US-ASCII (0x54726932) */
// uint32_t signature;
// /**
// * options bit field:
// * 15.. 4 reserved (0)
// * 3.. 0 UTrie2ValueBits valueBits
// */
// uint16_t options;
//
// /** UTRIE2_INDEX_1_OFFSET..UTRIE2_MAX_INDEX_LENGTH */
// uint16_t indexLength;
//
// /** (UTRIE2_DATA_START_OFFSET..UTRIE2_MAX_DATA_LENGTH)>>UTRIE2_INDEX_SHIFT */
// uint16_t shiftedDataLength;
//
// /** Null index and data blocks, not shifted. */
// uint16_t index2NullOffset, dataNullOffset;
//
// /**
// * First code point of the single-value range ending with U+10ffff,
// * rounded up and then shifted right by UTRIE2_SHIFT_1.
// */
// uint16_t shiftedHighStart;
// } UTrie2Header;
ByteOrder outerByteOrder = bytes.order();
try {
UTrie2Header header = new UTrie2Header();
/* check the signature */
header.signature = bytes.getInt();
switch (header.signature) {
case 0x54726932:
// The buffer is already set to the trie data byte order.
break;
case 0x32697254:
// Temporarily reverse the byte order.
boolean isBigEndian = outerByteOrder == ByteOrder.BIG_ENDIAN;
bytes.order(isBigEndian ? ByteOrder.LITTLE_ENDIAN : ByteOrder.BIG_ENDIAN);
header.signature = 0x54726932;
break;
default:
throw new IllegalArgumentException("Buffer does not contain a serialized UTrie2");
}
header.options = bytes.getChar();
header.indexLength = bytes.getChar();
header.shiftedDataLength = bytes.getChar();
header.index2NullOffset = bytes.getChar();
header.dataNullOffset = bytes.getChar();
header.shiftedHighStart = bytes.getChar();
// Trie2 data width - 0: 16 bits
// 1: 32 bits
if ((header.options & UTRIE2_OPTIONS_VALUE_BITS_MASK) > 1) {
throw new IllegalArgumentException("UTrie2 serialized format error.");
}
ValueWidth width;
Trie2 This;
if ((header.options & UTRIE2_OPTIONS_VALUE_BITS_MASK) == 0) {
width = ValueWidth.BITS_16;
This = new Trie2_16();
} else {
width = ValueWidth.BITS_32;
This = new Trie2_32();
}
This.header = header;
/* get the length values and offsets */
This.indexLength = header.indexLength;
This.dataLength = header.shiftedDataLength << UTRIE2_INDEX_SHIFT;
This.index2NullOffset = header.index2NullOffset;
This.dataNullOffset = header.dataNullOffset;
This.highStart = header.shiftedHighStart << UTRIE2_SHIFT_1;
This.highValueIndex = This.dataLength - UTRIE2_DATA_GRANULARITY;
if (width == ValueWidth.BITS_16) {
This.highValueIndex += This.indexLength;
}
// Allocate the Trie2 index array. If the data width is 16 bits, the array also
// includes the space for the data.
int indexArraySize = This.indexLength;
if (width == ValueWidth.BITS_16) {
indexArraySize += This.dataLength;
}
/* Read in the index */
This.index = ICUBinary.getChars(bytes, indexArraySize, 0);
/* Read in the data. 16 bit data goes in the same array as the index.
* 32 bit data goes in its own separate data array.
*/
if (width == ValueWidth.BITS_16) {
This.data16 = This.indexLength;
} else {
This.data32 = ICUBinary.getInts(bytes, This.dataLength, 0);
}
switch(width) {
case BITS_16:
This.data32 = null;
This.initialValue = This.index[This.dataNullOffset];
This.errorValue = This.index[This.data16+UTRIE2_BAD_UTF8_DATA_OFFSET];
break;
case BITS_32:
This.data16=0;
This.initialValue = This.data32[This.dataNullOffset];
This.errorValue = This.data32[UTRIE2_BAD_UTF8_DATA_OFFSET];
break;
default:
throw new IllegalArgumentException("UTrie2 serialized format error.");
}
return This;
} finally {
bytes.order(outerByteOrder);
}
}
/**
* Get the UTrie version from an InputStream containing the serialized form
* of either a Trie (version 1) or a Trie2 (version 2).
*
* @param is an InputStream containing the serialized form
* of a UTrie, version 1 or 2. The stream must support mark() and reset().
* The position of the input stream will be left unchanged.
* @param littleEndianOk If FALSE, only big-endian (Java native) serialized forms are recognized.
* If TRUE, little-endian serialized forms are recognized as well.
* @return the Trie version of the serialized form, or 0 if it is not
* recognized as a serialized UTrie
* @throws IOException on errors in reading from the input stream.
*/
public static int getVersion(InputStream is, boolean littleEndianOk) throws IOException {
if (! is.markSupported()) {
throw new IllegalArgumentException("Input stream must support mark().");
}
is.mark(4);
byte sig[] = new byte[4];
int read = is.read(sig);
is.reset();
if (read != sig.length) {
return 0;
}
if (sig[0]=='T' && sig[1]=='r' && sig[2]=='i' && sig[3]=='e') {
return 1;
}
if (sig[0]=='T' && sig[1]=='r' && sig[2]=='i' && sig[3]=='2') {
return 2;
}
if (littleEndianOk) {
if (sig[0]=='e' && sig[1]=='i' && sig[2]=='r' && sig[3]=='T') {
return 1;
}
if (sig[0]=='2' && sig[1]=='i' && sig[2]=='r' && sig[3]=='T') {
return 2;
}
}
return 0;
}
/**
* Get the value for a code point as stored in the Trie2.
*
* @param codePoint the code point
* @return the value
*/
abstract public int get(int codePoint);
/**
* Get the trie value for a UTF-16 code unit.
*
* A Trie2 stores two distinct values for input in the lead surrogate
* range, one for lead surrogates, which is the value that will be
* returned by this function, and a second value that is returned
* by Trie2.get().
*
* For code units outside of the lead surrogate range, this function
* returns the same result as Trie2.get().
*
* This function, together with the alternate value for lead surrogates,
* makes possible very efficient processing of UTF-16 strings without
* first converting surrogate pairs to their corresponding 32 bit code point
* values.
*
* At build-time, enumerate the contents of the Trie2 to see if there
* is non-trivial (non-initialValue) data for any of the supplementary
* code points associated with a lead surrogate.
* If so, then set a special (application-specific) value for the
* lead surrogate code _unit_, with Trie2Writable.setForLeadSurrogateCodeUnit().
*
* At runtime, use Trie2.getFromU16SingleLead(). If there is non-trivial
* data and the code unit is a lead surrogate, then check if a trail surrogate
* follows. If so, assemble the supplementary code point and look up its value
* with Trie2.get(); otherwise reset the lead
* surrogate's value or do a code point lookup for it.
*
* If there is only trivial data for lead and trail surrogates, then processing
* can often skip them. For example, in normalization or case mapping
* all characters that do not have any mappings are simply copied as is.
*
* @param c the code point or lead surrogate value.
* @return the value
*/
abstract public int getFromU16SingleLead(char c);
/**
* Equals function. Two Tries are equal if their contents are equal.
* The type need not be the same, so a Trie2Writable will be equal to
* (read-only) Trie2_16 or Trie2_32 so long as they are storing the same values.
*
*/
@Override
public final boolean equals(Object other) {
if(!(other instanceof Trie2)) {
return false;
}
Trie2 OtherTrie = (Trie2)other;
Range rangeFromOther;
Iterator otherIter = OtherTrie.iterator();
for (Trie2.Range rangeFromThis: this) {
if (otherIter.hasNext() == false) {
return false;
}
rangeFromOther = otherIter.next();
if (!rangeFromThis.equals(rangeFromOther)) {
return false;
}
}
if (otherIter.hasNext()) {
return false;
}
if (errorValue != OtherTrie.errorValue ||
initialValue != OtherTrie.initialValue) {
return false;
}
return true;
}
@Override
public int hashCode() {
if (fHash == 0) {
int hash = initHash();
for (Range r: this) {
hash = hashInt(hash, r.hashCode());
}
if (hash == 0) {
hash = 1;
}
fHash = hash;
}
return fHash;
}
/**
* When iterating over the contents of a Trie2, Elements of this type are produced.
* The iterator will return one item for each contiguous range of codepoints having the same value.
*
* When iterating, the same Trie2EnumRange object will be reused and returned for each range.
* If you need to retain complete iteration results, clone each returned Trie2EnumRange,
* or save the range in some other way, before advancing to the next iteration step.
*/
public static class Range {
public int startCodePoint;
public int endCodePoint; // Inclusive.
public int value;
public boolean leadSurrogate;
@Override
public boolean equals(Object other) {
if (other == null || !(other.getClass().equals(getClass()))) {
return false;
}
Range tother = (Range)other;
return this.startCodePoint == tother.startCodePoint &&
this.endCodePoint == tother.endCodePoint &&
this.value == tother.value &&
this.leadSurrogate == tother.leadSurrogate;
}
@Override
public int hashCode() {
int h = initHash();
h = hashUChar32(h, startCodePoint);
h = hashUChar32(h, endCodePoint);
h = hashInt(h, value);
h = hashByte(h, leadSurrogate? 1: 0);
return h;
}
}
/**
* Create an iterator over the value ranges in this Trie2.
* Values from the Trie2 are not remapped or filtered, but are returned as they
* are stored in the Trie2.
*
* @return an Iterator
*/
@Override
public Iterator iterator() {
return iterator(defaultValueMapper);
}
private static ValueMapper defaultValueMapper = new ValueMapper() {
@Override
public int map(int in) {
return in;
}
};
/**
* Create an iterator over the value ranges from this Trie2.
* Values from the Trie2 are passed through a caller-supplied remapping function,
* and it is the remapped values that determine the ranges that
* will be produced by the iterator.
*
*
* @param mapper provides a function to remap values obtained from the Trie2.
* @return an Iterator
*/
public Iterator iterator(ValueMapper mapper) {
return new Trie2Iterator(mapper);
}
/**
* Create an iterator over the Trie2 values for the 1024=0x400 code points
* corresponding to a given lead surrogate.
* For example, for the lead surrogate U+D87E it will enumerate the values
* for [U+2F800..U+2FC00[.
* Used by data builder code that sets special lead surrogate code unit values
* for optimized UTF-16 string processing.
*
* Do not modify the Trie2 during the iteration.
*
* Except for the limited code point range, this functions just like Trie2.iterator().
*
*/
public Iterator iteratorForLeadSurrogate(char lead, ValueMapper mapper) {
return new Trie2Iterator(lead, mapper);
}
/**
* Create an iterator over the Trie2 values for the 1024=0x400 code points
* corresponding to a given lead surrogate.
* For example, for the lead surrogate U+D87E it will enumerate the values
* for [U+2F800..U+2FC00[.
* Used by data builder code that sets special lead surrogate code unit values
* for optimized UTF-16 string processing.
*
* Do not modify the Trie2 during the iteration.
*
* Except for the limited code point range, this functions just like Trie2.iterator().
*
*/
public Iterator iteratorForLeadSurrogate(char lead) {
return new Trie2Iterator(lead, defaultValueMapper);
}
/**
* When iterating over the contents of a Trie2, an instance of TrieValueMapper may
* be used to remap the values from the Trie2. The remapped values will be used
* both in determining the ranges of codepoints and as the value to be returned
* for each range.
*
* Example of use, with an anonymous subclass of TrieValueMapper:
*
*
* ValueMapper m = new ValueMapper() {
* int map(int in) {return in & 0x1f;};
* }
* for (Iterator iter = trie.iterator(m); i.hasNext(); ) {
* Trie2EnumRange r = i.next();
* ... // Do something with the range r.
* }
*
*/
public interface ValueMapper {
public int map(int originalVal);
}
/**
* Serialize a trie2 Header and Index onto an OutputStream. This is
* common code used for both the Trie2_16 and Trie2_32 serialize functions.
* @param dos the stream to which the serialized Trie2 data will be written.
* @return the number of bytes written.
*/
protected int serializeHeader(DataOutputStream dos) throws IOException {
// Write the header. It is already set and ready to use, having been
// created when the Trie2 was unserialized or when it was frozen.
int bytesWritten = 0;
dos.writeInt(header.signature);
dos.writeShort(header.options);
dos.writeShort(header.indexLength);
dos.writeShort(header.shiftedDataLength);
dos.writeShort(header.index2NullOffset);
dos.writeShort(header.dataNullOffset);
dos.writeShort(header.shiftedHighStart);
bytesWritten += 16;
// Write the index
int i;
for (i=0; i< header.indexLength; i++) {
dos.writeChar(index[i]);
}
bytesWritten += header.indexLength;
return bytesWritten;
}
/**
* Struct-like class for holding the results returned by a UTrie2 CharSequence iterator.
* The iteration walks over a CharSequence, and for each Unicode code point therein
* returns the character and its associated Trie2 value.
*/
public static class CharSequenceValues {
/** string index of the current code point. */
public int index;
/** The code point at index. */
public int codePoint;
/** The Trie2 value for the current code point */
public int value;
}
/**
* Create an iterator that will produce the values from the Trie2 for
* the sequence of code points in an input text.
*
* @param text A text string to be iterated over.
* @param index The starting iteration position within the input text.
* @return the CharSequenceIterator
*/
public CharSequenceIterator charSequenceIterator(CharSequence text, int index) {
return new CharSequenceIterator(text, index);
}
// TODO: Survey usage of the equivalent of CharSequenceIterator in ICU4C
// and if there is none, remove it from here.
// Don't waste time testing and maintaining unused code.
/**
* An iterator that operates over an input CharSequence, and for each Unicode code point
* in the input returns the associated value from the Trie2.
*
* The iterator can move forwards or backwards, and can be reset to an arbitrary index.
*
* Note that Trie2_16 and Trie2_32 subclass Trie2.CharSequenceIterator. This is done
* only for performance reasons. It does require that any changes made here be propagated
* into the corresponding code in the subclasses.
*/
public class CharSequenceIterator implements Iterator {
/**
* Internal constructor.
*/
CharSequenceIterator(CharSequence t, int index) {
text = t;
textLength = text.length();
set(index);
}
private CharSequence text;
private int textLength;
private int index;
private Trie2.CharSequenceValues fResults = new Trie2.CharSequenceValues();
public void set(int i) {
if (i < 0 || i > textLength) {
throw new IndexOutOfBoundsException();
}
index = i;
}
@Override
public final boolean hasNext() {
return index0;
}
@Override
public Trie2.CharSequenceValues next() {
int c = Character.codePointAt(text, index);
int val = get(c);
fResults.index = index;
fResults.codePoint = c;
fResults.value = val;
index++;
if (c >= 0x10000) {
index++;
}
return fResults;
}
public Trie2.CharSequenceValues previous() {
int c = Character.codePointBefore(text, index);
int val = get(c);
index--;
if (c >= 0x10000) {
index--;
}
fResults.index = index;
fResults.codePoint = c;
fResults.value = val;
return fResults;
}
/**
* Iterator.remove() is not supported by Trie2.CharSequenceIterator.
* @throws UnsupportedOperationException Always thrown because this operation is not supported
* @see java.util.Iterator#remove()
*/
@Override
public void remove() {
throw new UnsupportedOperationException("Trie2.CharSequenceIterator does not support remove().");
}
}
//--------------------------------------------------------------------------------
//
// Below this point are internal implementation items. No further public API.
//
//--------------------------------------------------------------------------------
/**
* Selectors for the width of a UTrie2 data value.
*/
enum ValueWidth {
BITS_16,
BITS_32
}
/**
* Trie2 data structure in serialized form:
*
* UTrie2Header header;
* uint16_t index[header.index2Length];
* uint16_t data[header.shiftedDataLength<<2]; -- or uint32_t data[...]
*
* For Java, this is read from the stream into an instance of UTrie2Header.
* (The C version just places a struct over the raw serialized data.)
*
* @internal
*/
static class UTrie2Header {
/** "Tri2" in big-endian US-ASCII (0x54726932) */
int signature;
/**
* options bit field (uint16_t):
* 15.. 4 reserved (0)
* 3.. 0 UTrie2ValueBits valueBits
*/
int options;
/** UTRIE2_INDEX_1_OFFSET..UTRIE2_MAX_INDEX_LENGTH (uint16_t) */
int indexLength;
/** (UTRIE2_DATA_START_OFFSET..UTRIE2_MAX_DATA_LENGTH)>>UTRIE2_INDEX_SHIFT (uint16_t) */
int shiftedDataLength;
/** Null index and data blocks, not shifted. (uint16_t) */
int index2NullOffset, dataNullOffset;
/**
* First code point of the single-value range ending with U+10ffff,
* rounded up and then shifted right by UTRIE2_SHIFT_1. (uint16_t)
*/
int shiftedHighStart;
}
//
// Data members of UTrie2.
//
UTrie2Header header;
char index[]; // Index array. Includes data for 16 bit Tries.
int data16; // Offset to data portion of the index array, if 16 bit data.
// zero if 32 bit data.
int data32[]; // NULL if 16b data is used via index
int indexLength;
int dataLength;
int index2NullOffset; // 0xffff if there is no dedicated index-2 null block
int initialValue;
/** Value returned for out-of-range code points and illegal UTF-8. */
int errorValue;
/* Start of the last range which ends at U+10ffff, and its value. */
int highStart;
int highValueIndex;
int dataNullOffset;
int fHash; // Zero if not yet computed.
// Shared by Trie2Writable, Trie2_16, Trie2_32.
// Thread safety: if two racing threads compute
// the same hash on a frozen Trie2, no damage is done.
/**
* Trie2 constants, defining shift widths, index array lengths, etc.
*
* These are needed for the runtime macros but users can treat these as
* implementation details and skip to the actual public API further below.
*/
static final int UTRIE2_OPTIONS_VALUE_BITS_MASK=0x000f;
/** Shift size for getting the index-1 table offset. */
static final int UTRIE2_SHIFT_1=6+5;
/** Shift size for getting the index-2 table offset. */
static final int UTRIE2_SHIFT_2=5;
/**
* Difference between the two shift sizes,
* for getting an index-1 offset from an index-2 offset. 6=11-5
*/
static final int UTRIE2_SHIFT_1_2=UTRIE2_SHIFT_1-UTRIE2_SHIFT_2;
/**
* Number of index-1 entries for the BMP. 32=0x20
* This part of the index-1 table is omitted from the serialized form.
*/
static final int UTRIE2_OMITTED_BMP_INDEX_1_LENGTH=0x10000>>UTRIE2_SHIFT_1;
/** Number of code points per index-1 table entry. 2048=0x800 */
static final int UTRIE2_CP_PER_INDEX_1_ENTRY=1<>UTRIE2_SHIFT_2.
*/
static final int UTRIE2_INDEX_2_OFFSET=0;
/**
* The part of the index-2 table for U+D800..U+DBFF stores values for
* lead surrogate code _units_ not code _points_.
* Values for lead surrogate code _points_ are indexed with this portion of the table.
* Length=32=0x20=0x400>>UTRIE2_SHIFT_2. (There are 1024=0x400 lead surrogates.)
*/
static final int UTRIE2_LSCP_INDEX_2_OFFSET=0x10000>>UTRIE2_SHIFT_2;
static final int UTRIE2_LSCP_INDEX_2_LENGTH=0x400>>UTRIE2_SHIFT_2;
/** Count the lengths of both BMP pieces. 2080=0x820 */
static final int UTRIE2_INDEX_2_BMP_LENGTH=UTRIE2_LSCP_INDEX_2_OFFSET+UTRIE2_LSCP_INDEX_2_LENGTH;
/**
* The 2-byte UTF-8 version of the index-2 table follows at offset 2080=0x820.
* Length 32=0x20 for lead bytes C0..DF, regardless of UTRIE2_SHIFT_2.
*/
static final int UTRIE2_UTF8_2B_INDEX_2_OFFSET=UTRIE2_INDEX_2_BMP_LENGTH;
static final int UTRIE2_UTF8_2B_INDEX_2_LENGTH=0x800>>6; /* U+0800 is the first code point after 2-byte UTF-8 */
/**
* The index-1 table, only used for supplementary code points, at offset 2112=0x840.
* Variable length, for code points up to highStart, where the last single-value range starts.
* Maximum length 512=0x200=0x100000>>UTRIE2_SHIFT_1.
* (For 0x100000 supplementary code points U+10000..U+10ffff.)
*
* The part of the index-2 table for supplementary code points starts
* after this index-1 table.
*
* Both the index-1 table and the following part of the index-2 table
* are omitted completely if there is only BMP data.
*/
static final int UTRIE2_INDEX_1_OFFSET=UTRIE2_UTF8_2B_INDEX_2_OFFSET+UTRIE2_UTF8_2B_INDEX_2_LENGTH;
static final int UTRIE2_MAX_INDEX_1_LENGTH=0x100000>>UTRIE2_SHIFT_1;
/*
* Fixed layout of the first part of the data array. -----------------------
* Starts with 4 blocks (128=0x80 entries) for ASCII.
*/
/**
* The illegal-UTF-8 data block follows the ASCII block, at offset 128=0x80.
* Used with linear access for single bytes 0..0xbf for simple error handling.
* Length 64=0x40, not UTRIE2_DATA_BLOCK_LENGTH.
*/
static final int UTRIE2_BAD_UTF8_DATA_OFFSET=0x80;
/** The start of non-linear-ASCII data blocks, at offset 192=0xc0. */
static final int UTRIE2_DATA_START_OFFSET=0xc0;
/* Building a Trie2 ---------------------------------------------------------- */
/*
* These definitions are mostly needed by utrie2_builder.c, but also by
* utrie2_get32() and utrie2_enum().
*/
/*
* At build time, leave a gap in the index-2 table,
* at least as long as the maximum lengths of the 2-byte UTF-8 index-2 table
* and the supplementary index-1 table.
* Round up to UTRIE2_INDEX_2_BLOCK_LENGTH for proper compacting.
*/
static final int UNEWTRIE2_INDEX_GAP_OFFSET = UTRIE2_INDEX_2_BMP_LENGTH;
static final int UNEWTRIE2_INDEX_GAP_LENGTH =
((UTRIE2_UTF8_2B_INDEX_2_LENGTH + UTRIE2_MAX_INDEX_1_LENGTH) + UTRIE2_INDEX_2_MASK) &
~UTRIE2_INDEX_2_MASK;
/**
* Maximum length of the build-time index-2 array.
* Maximum number of Unicode code points (0x110000) shifted right by UTRIE2_SHIFT_2,
* plus the part of the index-2 table for lead surrogate code points,
* plus the build-time index gap,
* plus the null index-2 block.
*/
static final int UNEWTRIE2_MAX_INDEX_2_LENGTH=
(0x110000>>UTRIE2_SHIFT_2)+
UTRIE2_LSCP_INDEX_2_LENGTH+
UNEWTRIE2_INDEX_GAP_LENGTH+
UTRIE2_INDEX_2_BLOCK_LENGTH;
static final int UNEWTRIE2_INDEX_1_LENGTH = 0x110000>>UTRIE2_SHIFT_1;
/**
* Maximum length of the build-time data array.
* One entry per 0x110000 code points, plus the illegal-UTF-8 block and the null block,
* plus values for the 0x400 surrogate code units.
*/
static final int UNEWTRIE2_MAX_DATA_LENGTH = (0x110000+0x40+0x40+0x400);
/**
* Implementation class for an iterator over a Trie2.
*
* Iteration over a Trie2 first returns all of the ranges that are indexed by code points,
* then returns the special alternate values for the lead surrogates
*
* @internal
*/
class Trie2Iterator implements Iterator {
// The normal constructor that configures the iterator to cover the complete
// contents of the Trie2
Trie2Iterator(ValueMapper vm) {
mapper = vm;
nextStart = 0;
limitCP = 0x110000;
doLeadSurrogates = true;
}
// An alternate constructor that configures the iterator to cover only the
// code points corresponding to a particular Lead Surrogate value.
Trie2Iterator(char leadSurrogate, ValueMapper vm) {
if (leadSurrogate < 0xd800 || leadSurrogate > 0xdbff) {
throw new IllegalArgumentException("Bad lead surrogate value.");
}
mapper = vm;
nextStart = (leadSurrogate - 0xd7c0) << 10;
limitCP = nextStart + 0x400;
doLeadSurrogates = false; // Do not iterate over lead the special lead surrogate
// values after completing iteration over code points.
}
/**
* The main next() function for Trie2 iterators
*
*/
@Override
public Range next() {
if (!hasNext()) {
throw new NoSuchElementException();
}
if (nextStart >= limitCP) {
// Switch over from iterating normal code point values to
// doing the alternate lead-surrogate values.
doingCodePoints = false;
nextStart = 0xd800;
}
int endOfRange = 0;
int val = 0;
int mappedVal = 0;
if (doingCodePoints) {
// Iteration over code point values.
val = get(nextStart);
mappedVal = mapper.map(val);
endOfRange = rangeEnd(nextStart, limitCP, val);
// Loop once for each range in the Trie2 with the same raw (unmapped) value.
// Loop continues so long as the mapped values are the same.
for (;;) {
if (endOfRange >= limitCP-1) {
break;
}
val = get(endOfRange+1);
if (mapper.map(val) != mappedVal) {
break;
}
endOfRange = rangeEnd(endOfRange+1, limitCP, val);
}
} else {
// Iteration over the alternate lead surrogate values.
val = getFromU16SingleLead((char)nextStart);
mappedVal = mapper.map(val);
endOfRange = rangeEndLS((char)nextStart);
// Loop once for each range in the Trie2 with the same raw (unmapped) value.
// Loop continues so long as the mapped values are the same.
for (;;) {
if (endOfRange >= 0xdbff) {
break;
}
val = getFromU16SingleLead((char)(endOfRange+1));
if (mapper.map(val) != mappedVal) {
break;
}
endOfRange = rangeEndLS((char)(endOfRange+1));
}
}
returnValue.startCodePoint = nextStart;
returnValue.endCodePoint = endOfRange;
returnValue.value = mappedVal;
returnValue.leadSurrogate = !doingCodePoints;
nextStart = endOfRange+1;
return returnValue;
}
/**
*
*/
@Override
public boolean hasNext() {
return doingCodePoints && (doLeadSurrogates || nextStart < limitCP) || nextStart < 0xdc00;
}
@Override
public void remove() {
throw new UnsupportedOperationException();
}
/**
* Find the last lead surrogate in a contiguous range with the
* same Trie2 value as the input character.
*
* Use the alternate Lead Surrogate values from the Trie2,
* not the code-point values.
*
* Note: Trie2_16 and Trie2_32 override this implementation with optimized versions,
* meaning that the implementation here is only being used with
* Trie2Writable. The code here is logically correct with any type
* of Trie2, however.
*
* @param c The character to begin with.
* @return The last contiguous character with the same value.
*/
private int rangeEndLS(char startingLS) {
if (startingLS >= 0xdbff) {
return 0xdbff;
}
int c;
int val = getFromU16SingleLead(startingLS);
for (c = startingLS+1; c <= 0x0dbff; c++) {
if (getFromU16SingleLead((char)c) != val) {
break;
}
}
return c-1;
}
//
// Iteration State Variables
//
private ValueMapper mapper;
private Range returnValue = new Range();
// The starting code point for the next range to be returned.
private int nextStart;
// The upper limit for the last normal range to be returned. Normally 0x110000, but
// may be lower when iterating over the code points for a single lead surrogate.
private int limitCP;
// True while iterating over the the Trie2 values for code points.
// False while iterating over the alternate values for lead surrogates.
private boolean doingCodePoints = true;
// True if the iterator should iterate the special values for lead surrogates in
// addition to the normal values for code points.
private boolean doLeadSurrogates = true;
}
/**
* Find the last character in a contiguous range of characters with the
* same Trie2 value as the input character.
*
* @param c The character to begin with.
* @return The last contiguous character with the same value.
*/
int rangeEnd(int start, int limitp, int val) {
int c;
int limit = Math.min(highStart, limitp);
for (c = start+1; c < limit; c++) {
if (get(c) != val) {
break;
}
}
if (c >= highStart) {
c = limitp;
}
return c - 1;
}
//
// Hashing implementation functions. FNV hash. Respected public domain algorithm.
//
private static int initHash() {
return 0x811c9DC5; // unsigned 2166136261
}
private static int hashByte(int h, int b) {
h = h * 16777619;
h = h ^ b;
return h;
}
private static int hashUChar32(int h, int c) {
h = Trie2.hashByte(h, c & 255);
h = Trie2.hashByte(h, (c>>8) & 255);
h = Trie2.hashByte(h, c>>16);
return h;
}
private static int hashInt(int h, int i) {
h = Trie2.hashByte(h, i & 255);
h = Trie2.hashByte(h, (i>>8) & 255);
h = Trie2.hashByte(h, (i>>16) & 255);
h = Trie2.hashByte(h, (i>>24) & 255);
return h;
}
}