package org.apache.lucene.util;
/**
* 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.
*/
/*
* Some of this code came from the excellent Unicode
* conversion examples from:
*
* http://www.unicode.org/Public/PROGRAMS/CVTUTF
*
* Full Copyright for that code follows:
*/
/*
* Copyright 2001-2004 Unicode, Inc.
*
* Disclaimer
*
* This source code is provided as is by Unicode, Inc. No claims are
* made as to fitness for any particular purpose. No warranties of any
* kind are expressed or implied. The recipient agrees to determine
* applicability of information provided. If this file has been
* purchased on magnetic or optical media from Unicode, Inc., the
* sole remedy for any claim will be exchange of defective media
* within 90 days of receipt.
*
* Limitations on Rights to Redistribute This Code
*
* Unicode, Inc. hereby grants the right to freely use the information
* supplied in this file in the creation of products supporting the
* Unicode Standard, and to make copies of this file in any form
* for internal or external distribution as long as this notice
* remains attached.
*/
/*
* Additional code came from the IBM ICU library.
*
* http://www.icu-project.org
*
* Full Copyright for that code follows.
*/
/*
* Copyright (C) 1999-2010, International Business Machines
* Corporation and others. All Rights Reserved.
*
* Permission is hereby granted, free of charge, to any person obtaining a copy
* of this software and associated documentation files (the "Software"), to deal
* in the Software without restriction, including without limitation the rights
* to use, copy, modify, merge, publish, distribute, and/or sell copies of the
* Software, and to permit persons to whom the Software is furnished to do so,
* provided that the above copyright notice(s) and this permission notice appear
* in all copies of the Software and that both the above copyright notice(s) and
* this permission notice appear in supporting documentation.
*
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT OF THIRD PARTY RIGHTS.
* IN NO EVENT SHALL THE COPYRIGHT HOLDER OR HOLDERS INCLUDED IN THIS NOTICE BE
* LIABLE FOR ANY CLAIM, OR ANY SPECIAL INDIRECT OR CONSEQUENTIAL DAMAGES, OR
* ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER
* IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT
* OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
*
* Except as contained in this notice, the name of a copyright holder shall not
* be used in advertising or otherwise to promote the sale, use or other
* dealings in this Software without prior written authorization of the
* copyright holder.
*/
/**
* Class to encode java's UTF16 char[] into UTF8 byte[]
* without always allocating a new byte[] as
* String.getBytes("UTF-8") does.
*
* @lucene.internal
*/
public final class UnicodeUtil {
private UnicodeUtil() {} // no instance
public static final int UNI_SUR_HIGH_START = 0xD800;
public static final int UNI_SUR_HIGH_END = 0xDBFF;
public static final int UNI_SUR_LOW_START = 0xDC00;
public static final int UNI_SUR_LOW_END = 0xDFFF;
public static final int UNI_REPLACEMENT_CHAR = 0xFFFD;
private static final long UNI_MAX_BMP = 0x0000FFFF;
private static final int HALF_BASE = 0x0010000;
private static final long HALF_SHIFT = 10;
private static final long HALF_MASK = 0x3FFL;
private static final int SURROGATE_OFFSET =
Character.MIN_SUPPLEMENTARY_CODE_POINT -
(UNI_SUR_HIGH_START << HALF_SHIFT) - UNI_SUR_LOW_START;
/**
* @lucene.internal
*/
public static final class UTF8Result {
public byte[] result = new byte[10];
public int length;
public void setLength(int newLength) {
if (result.length < newLength) {
result = ArrayUtil.grow(result, newLength);
}
length = newLength;
}
}
/**
* @lucene.internal
*/
public static final class UTF16Result {
public char[] result = new char[10];
public int[] offsets = new int[10];
public int length;
public void setLength(int newLength) {
if (result.length < newLength) {
result = ArrayUtil.grow(result, newLength);
}
length = newLength;
}
public void copyText(UTF16Result other) {
setLength(other.length);
System.arraycopy(other.result, 0, result, 0, length);
}
}
/** Encode characters from a char[] source, starting at
* offset for length chars. Returns a hash of the resulting bytes. After encoding, result.offset will always be 0. */
public static int UTF16toUTF8WithHash(final char[] source, final int offset, final int length, BytesRef result) {
int hash = 0;
int upto = 0;
int i = offset;
final int end = offset + length;
byte[] out = result.bytes;
// Pre-allocate for worst case 4-for-1
final int maxLen = length * 4;
if (out.length < maxLen)
out = result.bytes = new byte[ArrayUtil.oversize(maxLen, 1)];
result.offset = 0;
while(i < end) {
final int code = (int) source[i++];
if (code < 0x80) {
hash = 31*hash + (out[upto++] = (byte) code);
} else if (code < 0x800) {
hash = 31*hash + (out[upto++] = (byte) (0xC0 | (code >> 6)));
hash = 31*hash + (out[upto++] = (byte)(0x80 | (code & 0x3F)));
} else if (code < 0xD800 || code > 0xDFFF) {
hash = 31*hash + (out[upto++] = (byte)(0xE0 | (code >> 12)));
hash = 31*hash + (out[upto++] = (byte)(0x80 | ((code >> 6) & 0x3F)));
hash = 31*hash + (out[upto++] = (byte)(0x80 | (code & 0x3F)));
} else {
// surrogate pair
// confirm valid high surrogate
if (code < 0xDC00 && i < end) {
int utf32 = (int) source[i];
// confirm valid low surrogate and write pair
if (utf32 >= 0xDC00 && utf32 <= 0xDFFF) {
utf32 = (code << 10) + utf32 + SURROGATE_OFFSET;
i++;
hash = 31*hash + (out[upto++] = (byte)(0xF0 | (utf32 >> 18)));
hash = 31*hash + (out[upto++] = (byte)(0x80 | ((utf32 >> 12) & 0x3F)));
hash = 31*hash + (out[upto++] = (byte)(0x80 | ((utf32 >> 6) & 0x3F)));
hash = 31*hash + (out[upto++] = (byte)(0x80 | (utf32 & 0x3F)));
continue;
}
}
// replace unpaired surrogate or out-of-order low surrogate
// with substitution character
hash = 31*hash + (out[upto++] = (byte) 0xEF);
hash = 31*hash + (out[upto++] = (byte) 0xBF);
hash = 31*hash + (out[upto++] = (byte) 0xBD);
}
}
//assert matches(source, offset, length, out, upto);
result.length = upto;
return hash;
}
/** Encode characters from a char[] source, starting at
* offset and stopping when the character 0xffff is seen.
* Returns the number of bytes written to bytesOut. */
public static void UTF16toUTF8(final char[] source, final int offset, UTF8Result result) {
int upto = 0;
int i = offset;
byte[] out = result.result;
while(true) {
final int code = (int) source[i++];
if (upto+4 > out.length) {
out = result.result = ArrayUtil.grow(out, upto+4);
}
if (code < 0x80)
out[upto++] = (byte) code;
else if (code < 0x800) {
out[upto++] = (byte) (0xC0 | (code >> 6));
out[upto++] = (byte)(0x80 | (code & 0x3F));
} else if (code < 0xD800 || code > 0xDFFF) {
if (code == 0xffff)
// END
break;
out[upto++] = (byte)(0xE0 | (code >> 12));
out[upto++] = (byte)(0x80 | ((code >> 6) & 0x3F));
out[upto++] = (byte)(0x80 | (code & 0x3F));
} else {
// surrogate pair
// confirm valid high surrogate
if (code < 0xDC00 && source[i] != 0xffff) {
int utf32 = (int) source[i];
// confirm valid low surrogate and write pair
if (utf32 >= 0xDC00 && utf32 <= 0xDFFF) {
utf32 = ((code - 0xD7C0) << 10) + (utf32 & 0x3FF);
i++;
out[upto++] = (byte)(0xF0 | (utf32 >> 18));
out[upto++] = (byte)(0x80 | ((utf32 >> 12) & 0x3F));
out[upto++] = (byte)(0x80 | ((utf32 >> 6) & 0x3F));
out[upto++] = (byte)(0x80 | (utf32 & 0x3F));
continue;
}
}
// replace unpaired surrogate or out-of-order low surrogate
// with substitution character
out[upto++] = (byte) 0xEF;
out[upto++] = (byte) 0xBF;
out[upto++] = (byte) 0xBD;
}
}
//assert matches(source, offset, i-offset-1, out, upto);
result.length = upto;
}
/** Encode characters from a char[] source, starting at
* offset for length chars. Returns the number of bytes
* written to bytesOut. */
public static void UTF16toUTF8(final char[] source, final int offset, final int length, UTF8Result result) {
int upto = 0;
int i = offset;
final int end = offset + length;
byte[] out = result.result;
while(i < end) {
final int code = (int) source[i++];
if (upto+4 > out.length) {
out = result.result = ArrayUtil.grow(out, upto+4);
}
if (code < 0x80)
out[upto++] = (byte) code;
else if (code < 0x800) {
out[upto++] = (byte) (0xC0 | (code >> 6));
out[upto++] = (byte)(0x80 | (code & 0x3F));
} else if (code < 0xD800 || code > 0xDFFF) {
out[upto++] = (byte)(0xE0 | (code >> 12));
out[upto++] = (byte)(0x80 | ((code >> 6) & 0x3F));
out[upto++] = (byte)(0x80 | (code & 0x3F));
} else {
// surrogate pair
// confirm valid high surrogate
if (code < 0xDC00 && i < end && source[i] != 0xffff) {
int utf32 = (int) source[i];
// confirm valid low surrogate and write pair
if (utf32 >= 0xDC00 && utf32 <= 0xDFFF) {
utf32 = ((code - 0xD7C0) << 10) + (utf32 & 0x3FF);
i++;
out[upto++] = (byte)(0xF0 | (utf32 >> 18));
out[upto++] = (byte)(0x80 | ((utf32 >> 12) & 0x3F));
out[upto++] = (byte)(0x80 | ((utf32 >> 6) & 0x3F));
out[upto++] = (byte)(0x80 | (utf32 & 0x3F));
continue;
}
}
// replace unpaired surrogate or out-of-order low surrogate
// with substitution character
out[upto++] = (byte) 0xEF;
out[upto++] = (byte) 0xBF;
out[upto++] = (byte) 0xBD;
}
}
//assert matches(source, offset, length, out, upto);
result.length = upto;
}
/** Encode characters from this String, starting at offset
* for length characters. Returns the number of bytes
* written to bytesOut. */
public static void UTF16toUTF8(final String s, final int offset, final int length, UTF8Result result) {
final int end = offset + length;
byte[] out = result.result;
int upto = 0;
for(int i=offset;i<end;i++) {
final int code = (int) s.charAt(i);
if (upto+4 > out.length) {
out = result.result = ArrayUtil.grow(out, upto+4);
}
if (code < 0x80)
out[upto++] = (byte) code;
else if (code < 0x800) {
out[upto++] = (byte) (0xC0 | (code >> 6));
out[upto++] = (byte)(0x80 | (code & 0x3F));
} else if (code < 0xD800 || code > 0xDFFF) {
out[upto++] = (byte)(0xE0 | (code >> 12));
out[upto++] = (byte)(0x80 | ((code >> 6) & 0x3F));
out[upto++] = (byte)(0x80 | (code & 0x3F));
} else {
// surrogate pair
// confirm valid high surrogate
if (code < 0xDC00 && (i < end-1)) {
int utf32 = (int) s.charAt(i+1);
// confirm valid low surrogate and write pair
if (utf32 >= 0xDC00 && utf32 <= 0xDFFF) {
utf32 = ((code - 0xD7C0) << 10) + (utf32 & 0x3FF);
i++;
out[upto++] = (byte)(0xF0 | (utf32 >> 18));
out[upto++] = (byte)(0x80 | ((utf32 >> 12) & 0x3F));
out[upto++] = (byte)(0x80 | ((utf32 >> 6) & 0x3F));
out[upto++] = (byte)(0x80 | (utf32 & 0x3F));
continue;
}
}
// replace unpaired surrogate or out-of-order low surrogate
// with substitution character
out[upto++] = (byte) 0xEF;
out[upto++] = (byte) 0xBF;
out[upto++] = (byte) 0xBD;
}
}
//assert matches(s, offset, length, out, upto);
result.length = upto;
}
/** Encode characters from this String, starting at offset
* for length characters. After encoding, result.offset will always be 0.
*/
public static void UTF16toUTF8(final CharSequence s, final int offset, final int length, BytesRef result) {
final int end = offset + length;
byte[] out = result.bytes;
result.offset = 0;
// Pre-allocate for worst case 4-for-1
final int maxLen = length * 4;
if (out.length < maxLen)
out = result.bytes = new byte[maxLen];
int upto = 0;
for(int i=offset;i<end;i++) {
final int code = (int) s.charAt(i);
if (code < 0x80)
out[upto++] = (byte) code;
else if (code < 0x800) {
out[upto++] = (byte) (0xC0 | (code >> 6));
out[upto++] = (byte)(0x80 | (code & 0x3F));
} else if (code < 0xD800 || code > 0xDFFF) {
out[upto++] = (byte)(0xE0 | (code >> 12));
out[upto++] = (byte)(0x80 | ((code >> 6) & 0x3F));
out[upto++] = (byte)(0x80 | (code & 0x3F));
} else {
// surrogate pair
// confirm valid high surrogate
if (code < 0xDC00 && (i < end-1)) {
int utf32 = (int) s.charAt(i+1);
// confirm valid low surrogate and write pair
if (utf32 >= 0xDC00 && utf32 <= 0xDFFF) {
utf32 = (code << 10) + utf32 + SURROGATE_OFFSET;
i++;
out[upto++] = (byte)(0xF0 | (utf32 >> 18));
out[upto++] = (byte)(0x80 | ((utf32 >> 12) & 0x3F));
out[upto++] = (byte)(0x80 | ((utf32 >> 6) & 0x3F));
out[upto++] = (byte)(0x80 | (utf32 & 0x3F));
continue;
}
}
// replace unpaired surrogate or out-of-order low surrogate
// with substitution character
out[upto++] = (byte) 0xEF;
out[upto++] = (byte) 0xBF;
out[upto++] = (byte) 0xBD;
}
}
//assert matches(s, offset, length, out, upto);
result.length = upto;
}
/** Encode characters from a char[] source, starting at
* offset for length chars. After encoding, result.offset will always be 0.
*/
public static void UTF16toUTF8(final char[] source, final int offset, final int length, BytesRef result) {
int upto = 0;
int i = offset;
final int end = offset + length;
byte[] out = result.bytes;
// Pre-allocate for worst case 4-for-1
final int maxLen = length * 4;
if (out.length < maxLen)
out = result.bytes = new byte[maxLen];
result.offset = 0;
while(i < end) {
final int code = (int) source[i++];
if (code < 0x80)
out[upto++] = (byte) code;
else if (code < 0x800) {
out[upto++] = (byte) (0xC0 | (code >> 6));
out[upto++] = (byte)(0x80 | (code & 0x3F));
} else if (code < 0xD800 || code > 0xDFFF) {
out[upto++] = (byte)(0xE0 | (code >> 12));
out[upto++] = (byte)(0x80 | ((code >> 6) & 0x3F));
out[upto++] = (byte)(0x80 | (code & 0x3F));
} else {
// surrogate pair
// confirm valid high surrogate
if (code < 0xDC00 && i < end) {
int utf32 = (int) source[i];
// confirm valid low surrogate and write pair
if (utf32 >= 0xDC00 && utf32 <= 0xDFFF) {
utf32 = (code << 10) + utf32 + SURROGATE_OFFSET;
i++;
out[upto++] = (byte)(0xF0 | (utf32 >> 18));
out[upto++] = (byte)(0x80 | ((utf32 >> 12) & 0x3F));
out[upto++] = (byte)(0x80 | ((utf32 >> 6) & 0x3F));
out[upto++] = (byte)(0x80 | (utf32 & 0x3F));
continue;
}
}
// replace unpaired surrogate or out-of-order low surrogate
// with substitution character
out[upto++] = (byte) 0xEF;
out[upto++] = (byte) 0xBF;
out[upto++] = (byte) 0xBD;
}
}
//assert matches(source, offset, length, out, upto);
result.length = upto;
}
/** Convert UTF8 bytes into UTF16 characters. If offset
* is non-zero, conversion starts at that starting point
* in utf8, re-using the results from the previous call
* up until offset. */
public static void UTF8toUTF16(final byte[] utf8, final int offset, final int length, final UTF16Result result) {
final int end = offset + length;
char[] out = result.result;
if (result.offsets.length <= end) {
result.offsets = ArrayUtil.grow(result.offsets, end+1);
}
final int[] offsets = result.offsets;
// If incremental decoding fell in the middle of a
// single unicode character, rollback to its start:
int upto = offset;
while(offsets[upto] == -1)
upto--;
int outUpto = offsets[upto];
// Pre-allocate for worst case 1-for-1
if (outUpto+length >= out.length) {
out = result.result = ArrayUtil.grow(out, outUpto+length+1);
}
while (upto < end) {
final int b = utf8[upto]&0xff;
final int ch;
offsets[upto++] = outUpto;
if (b < 0xc0) {
assert b < 0x80;
ch = b;
} else if (b < 0xe0) {
ch = ((b&0x1f)<<6) + (utf8[upto]&0x3f);
offsets[upto++] = -1;
} else if (b < 0xf0) {
ch = ((b&0xf)<<12) + ((utf8[upto]&0x3f)<<6) + (utf8[upto+1]&0x3f);
offsets[upto++] = -1;
offsets[upto++] = -1;
} else {
assert b < 0xf8;
ch = ((b&0x7)<<18) + ((utf8[upto]&0x3f)<<12) + ((utf8[upto+1]&0x3f)<<6) + (utf8[upto+2]&0x3f);
offsets[upto++] = -1;
offsets[upto++] = -1;
offsets[upto++] = -1;
}
if (ch <= UNI_MAX_BMP) {
// target is a character <= 0xFFFF
out[outUpto++] = (char) ch;
} else {
// target is a character in range 0xFFFF - 0x10FFFF
final int chHalf = ch - HALF_BASE;
out[outUpto++] = (char) ((chHalf >> HALF_SHIFT) + UNI_SUR_HIGH_START);
out[outUpto++] = (char) ((chHalf & HALF_MASK) + UNI_SUR_LOW_START);
}
}
offsets[upto] = outUpto;
result.length = outUpto;
}
// Only called from assert
/*
private static boolean matches(char[] source, int offset, int length, byte[] result, int upto) {
try {
String s1 = new String(source, offset, length);
String s2 = new String(result, 0, upto, "UTF-8");
if (!s1.equals(s2)) {
//System.out.println("DIFF: s1 len=" + s1.length());
//for(int i=0;i<s1.length();i++)
// System.out.println(" " + i + ": " + (int) s1.charAt(i));
//System.out.println("s2 len=" + s2.length());
//for(int i=0;i<s2.length();i++)
// System.out.println(" " + i + ": " + (int) s2.charAt(i));
// If the input string was invalid, then the
// difference is OK
if (!validUTF16String(s1))
return true;
return false;
}
return s1.equals(s2);
} catch (UnsupportedEncodingException uee) {
return false;
}
}
// Only called from assert
private static boolean matches(String source, int offset, int length, byte[] result, int upto) {
try {
String s1 = source.substring(offset, offset+length);
String s2 = new String(result, 0, upto, "UTF-8");
if (!s1.equals(s2)) {
// Allow a difference if s1 is not valid UTF-16
//System.out.println("DIFF: s1 len=" + s1.length());
//for(int i=0;i<s1.length();i++)
// System.out.println(" " + i + ": " + (int) s1.charAt(i));
//System.out.println(" s2 len=" + s2.length());
//for(int i=0;i<s2.length();i++)
// System.out.println(" " + i + ": " + (int) s2.charAt(i));
// If the input string was invalid, then the
// difference is OK
if (!validUTF16String(s1))
return true;
return false;
}
return s1.equals(s2);
} catch (UnsupportedEncodingException uee) {
return false;
}
}
public static final boolean validUTF16String(String s) {
final int size = s.length();
for(int i=0;i<size;i++) {
char ch = s.charAt(i);
if (ch >= UNI_SUR_HIGH_START && ch <= UNI_SUR_HIGH_END) {
if (i < size-1) {
i++;
char nextCH = s.charAt(i);
if (nextCH >= UNI_SUR_LOW_START && nextCH <= UNI_SUR_LOW_END) {
// Valid surrogate pair
} else
// Unmatched high surrogate
return false;
} else
// Unmatched high surrogate
return false;
} else if (ch >= UNI_SUR_LOW_START && ch <= UNI_SUR_LOW_END)
// Unmatched low surrogate
return false;
}
return true;
}
public static final boolean validUTF16String(char[] s, int size) {
for(int i=0;i<size;i++) {
char ch = s[i];
if (ch >= UNI_SUR_HIGH_START && ch <= UNI_SUR_HIGH_END) {
if (i < size-1) {
i++;
char nextCH = s[i];
if (nextCH >= UNI_SUR_LOW_START && nextCH <= UNI_SUR_LOW_END) {
// Valid surrogate pair
} else
return false;
} else
return false;
} else if (ch >= UNI_SUR_LOW_START && ch <= UNI_SUR_LOW_END)
// Unmatched low surrogate
return false;
}
return true;
}
*/
/** Shift value for lead surrogate to form a supplementary character. */
private static final int LEAD_SURROGATE_SHIFT_ = 10;
/** Mask to retrieve the significant value from a trail surrogate.*/
private static final int TRAIL_SURROGATE_MASK_ = 0x3FF;
/** Trail surrogate minimum value */
private static final int TRAIL_SURROGATE_MIN_VALUE = 0xDC00;
/** Lead surrogate minimum value */
private static final int LEAD_SURROGATE_MIN_VALUE = 0xD800;
/** The minimum value for Supplementary code points */
private static final int SUPPLEMENTARY_MIN_VALUE = 0x10000;
/** Value that all lead surrogate starts with */
private static final int LEAD_SURROGATE_OFFSET_ = LEAD_SURROGATE_MIN_VALUE
- (SUPPLEMENTARY_MIN_VALUE >> LEAD_SURROGATE_SHIFT_);
/**
* Cover JDK 1.5 API. Create a String from an array of codePoints.
*
* @param codePoints The code array
* @param offset The start of the text in the code point array
* @param count The number of code points
* @return a String representing the code points between offset and count
* @throws IllegalArgumentException If an invalid code point is encountered
* @throws IndexOutOfBoundsException If the offset or count are out of bounds.
*/
public static String newString(int[] codePoints, int offset, int count) {
if (count < 0) {
throw new IllegalArgumentException();
}
char[] chars = new char[count];
int w = 0;
for (int r = offset, e = offset + count; r < e; ++r) {
int cp = codePoints[r];
if (cp < 0 || cp > 0x10ffff) {
throw new IllegalArgumentException();
}
while (true) {
try {
if (cp < 0x010000) {
chars[w] = (char) cp;
w++;
} else {
chars[w] = (char) (LEAD_SURROGATE_OFFSET_ + (cp >> LEAD_SURROGATE_SHIFT_));
chars[w + 1] = (char) (TRAIL_SURROGATE_MIN_VALUE + (cp & TRAIL_SURROGATE_MASK_));
w += 2;
}
break;
} catch (IndexOutOfBoundsException ex) {
int newlen = (int) (Math.ceil((double) codePoints.length * (w + 2)
/ (r - offset + 1)));
char[] temp = new char[newlen];
System.arraycopy(chars, 0, temp, 0, w);
chars = temp;
}
}
}
return new String(chars, 0, w);
}
/**
* Interprets the given byte array as UTF-8 and converts to UTF-16. The {@link CharsRef} will be extended if
* it doesn't provide enough space to hold the worst case of each byte becoming a UTF-16 codepoint.
* <p>
* NOTE: Full characters are read, even if this reads past the length passed (and
* can result in an ArrayOutOfBoundsException if invalid UTF-8 is passed).
* Explicit checks for valid UTF-8 are not performed.
*/
public static void UTF8toUTF16(byte[] utf8, int offset, int length, CharsRef chars) {
int out_offset = chars.offset = 0;
final char[] out = chars.chars = ArrayUtil.grow(chars.chars, length);
final int limit = offset + length;
while (offset < limit) {
int b = utf8[offset++]&0xff;
if (b < 0xc0) {
assert b < 0x80;
out[out_offset++] = (char)b;
} else if (b < 0xe0) {
out[out_offset++] = (char)(((b&0x1f)<<6) + (utf8[offset++]&0x3f));
} else if (b < 0xf0) {
out[out_offset++] = (char)(((b&0xf)<<12) + ((utf8[offset]&0x3f)<<6) + (utf8[offset+1]&0x3f));
offset += 2;
} else {
assert b < 0xf8;
int ch = ((b&0x7)<<18) + ((utf8[offset]&0x3f)<<12) + ((utf8[offset+1]&0x3f)<<6) + (utf8[offset+2]&0x3f);
offset += 3;
if (ch < UNI_MAX_BMP) {
out[out_offset++] = (char)ch;
} else {
int chHalf = ch - 0x0010000;
out[out_offset++] = (char) ((chHalf >> 10) + 0xD800);
out[out_offset++] = (char) ((chHalf & HALF_MASK) + 0xDC00);
}
}
}
chars.length = out_offset - chars.offset;
}
/**
* Utility method for {@link #UTF8toUTF16(byte[], int, int, CharsRef)}
* @see #UTF8toUTF16(byte[], int, int, CharsRef)
*/
public static void UTF8toUTF16(BytesRef bytesRef, CharsRef chars) {
UTF8toUTF16(bytesRef.bytes, bytesRef.offset, bytesRef.length, chars);
}
}