6642323: Speeding up Single Byte Decoders
6642328: Speeding up Single Byte Encoders
Summary: re-implementation of mapping based sbcs charts
Reviewed-by: alanb
/*
* Copyright 2008 Sun Microsystems, Inc. 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. Sun designates this
* particular file as subject to the "Classpath" exception as provided
* by Sun 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 Sun Microsystems, Inc., 4150 Network Circle, Santa Clara,
* CA 95054 USA or visit www.sun.com if you need additional information or
* have any questions.
*/
package sun.nio.cs;
import java.nio.Buffer;
import java.nio.ByteBuffer;
import java.nio.CharBuffer;
import java.nio.charset.Charset;
import java.nio.charset.CharsetDecoder;
import java.nio.charset.CharsetEncoder;
import java.nio.charset.CoderResult;
import static sun.nio.cs.CharsetMapping.*;
public class SingleByte
{
private static final CoderResult withResult(CoderResult cr,
Buffer src, int sp,
Buffer dst, int dp)
{
src.position(sp - src.arrayOffset());
dst.position(dp - dst.arrayOffset());
return cr;
}
public static class Decoder extends CharsetDecoder {
private final char[] b2c;
public Decoder(Charset cs, char[] b2c) {
super(cs, 1.0f, 1.0f);
this.b2c = b2c;
}
private CoderResult decodeArrayLoop(ByteBuffer src, CharBuffer dst) {
byte[] sa = src.array();
int sp = src.arrayOffset() + src.position();
int sl = src.arrayOffset() + src.limit();
char[] da = dst.array();
int dp = dst.arrayOffset() + dst.position();
int dl = dst.arrayOffset() + dst.limit();
CoderResult cr = CoderResult.UNDERFLOW;
if ((dl - dp) < (sl - sp)) {
sl = sp + (dl - dp);
cr = CoderResult.OVERFLOW;
}
while (sp < sl) {
char c = decode(sa[sp]);
if (c == UNMAPPABLE_DECODING) {
return withResult(CoderResult.unmappableForLength(1),
src, sp, dst, dp);
}
da[dp++] = c;
sp++;
}
return withResult(cr, src, sp, dst, dp);
}
private CoderResult decodeBufferLoop(ByteBuffer src, CharBuffer dst) {
int mark = src.position();
try {
while (src.hasRemaining()) {
char c = decode(src.get());
if (c == UNMAPPABLE_DECODING)
return CoderResult.unmappableForLength(1);
if (!dst.hasRemaining())
return CoderResult.OVERFLOW;
dst.put(c);
mark++;
}
return CoderResult.UNDERFLOW;
} finally {
src.position(mark);
}
}
protected CoderResult decodeLoop(ByteBuffer src, CharBuffer dst) {
if (src.hasArray() && dst.hasArray())
return decodeArrayLoop(src, dst);
else
return decodeBufferLoop(src, dst);
}
private final char decode(int b) {
return b2c[b + 128];
}
}
public static class Encoder extends CharsetEncoder {
private Surrogate.Parser sgp;
private final char[] c2b;
private final char[] c2bIndex;
public Encoder(Charset cs, char[] c2b, char[] c2bIndex) {
super(cs, 1.0f, 1.0f);
this.c2b = c2b;
this.c2bIndex = c2bIndex;
}
public boolean canEncode(char c) {
return encode(c) != UNMAPPABLE_ENCODING;
}
private CoderResult encodeArrayLoop(CharBuffer src, ByteBuffer dst) {
char[] sa = src.array();
int sp = src.arrayOffset() + src.position();
int sl = src.arrayOffset() + src.limit();
byte[] da = dst.array();
int dp = dst.arrayOffset() + dst.position();
int dl = dst.arrayOffset() + dst.limit();
CoderResult cr = CoderResult.UNDERFLOW;
if ((dl - dp) < (sl - sp)) {
sl = sp + (dl - dp);
cr = CoderResult.OVERFLOW;
}
while (sp < sl) {
char c = sa[sp];
int b = encode(c);
if (b == UNMAPPABLE_ENCODING) {
if (Surrogate.is(c)) {
if (sgp == null)
sgp = new Surrogate.Parser();
if (sgp.parse(c, sa, sp, sl) < 0)
return withResult(sgp.error(), src, sp, dst, dp);
return withResult(sgp.unmappableResult(), src, sp, dst, dp);
}
return withResult(CoderResult.unmappableForLength(1),
src, sp, dst, dp);
}
da[dp++] = (byte)b;
sp++;
}
return withResult(cr, src, sp, dst, dp);
}
private CoderResult encodeBufferLoop(CharBuffer src, ByteBuffer dst) {
int mark = src.position();
try {
while (src.hasRemaining()) {
char c = src.get();
int b = encode(c);
if (b == UNMAPPABLE_ENCODING) {
if (Surrogate.is(c)) {
if (sgp == null)
sgp = new Surrogate.Parser();
if (sgp.parse(c, src) < 0)
return sgp.error();
return sgp.unmappableResult();
}
return CoderResult.unmappableForLength(1);
}
if (!dst.hasRemaining())
return CoderResult.OVERFLOW;
dst.put((byte)b);
mark++;
}
return CoderResult.UNDERFLOW;
} finally {
src.position(mark);
}
}
protected CoderResult encodeLoop(CharBuffer src, ByteBuffer dst) {
if (src.hasArray() && dst.hasArray())
return encodeArrayLoop(src, dst);
else
return encodeBufferLoop(src, dst);
}
private final int encode(char ch) {
char index = c2bIndex[ch >> 8];
if (index == UNMAPPABLE_ENCODING)
return UNMAPPABLE_ENCODING;
return c2b[index + (ch & 0xff)];
}
}
// init the c2b and c2bIndex tables from b2c.
public static void initC2B(char[] b2c, char[] c2bNR,
char[] c2b, char[] c2bIndex) {
for (int i = 0; i < c2bIndex.length; i++)
c2bIndex[i] = UNMAPPABLE_ENCODING;
for (int i = 0; i < c2b.length; i++)
c2b[i] = UNMAPPABLE_ENCODING;
int off = 0;
for (int i = 0; i < b2c.length; i++) {
char c = b2c[i];
if (c == UNMAPPABLE_DECODING)
continue;
int index = (c >> 8);
if (c2bIndex[index] == UNMAPPABLE_ENCODING) {
c2bIndex[index] = (char)off;
off += 0x100;
}
index = c2bIndex[index] + (c & 0xff);
c2b[index] = (char)((i>=0x80)?(i-0x80):(i+0x80));
}
if (c2bNR != null) {
// c-->b nr entries
int i = 0;
while (i < c2bNR.length) {
char b = c2bNR[i++];
char c = c2bNR[i++];
int index = (c >> 8);
if (c2bIndex[index] == UNMAPPABLE_ENCODING) {
c2bIndex[index] = (char)off;
off += 0x100;
}
index = c2bIndex[index] + (c & 0xff);
c2b[index] = b;
}
}
}
}