/*
* Copyright (c) 2005, 2010, Oracle and/or its affiliates. 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. Oracle designates this
* particular file as subject to the "Classpath" exception as provided
* by Oracle 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 Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
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package sun.nio.cs;
import java.nio.ByteBuffer;
import java.nio.CharBuffer;
import java.nio.charset.Charset;
import java.nio.charset.CoderResult;
import java.nio.charset.CharsetDecoder;
import java.nio.charset.CharsetEncoder;
class UTF_32Coder {
protected static final int BOM_BIG = 0xFEFF;
protected static final int BOM_LITTLE = 0xFFFE0000;
protected static final int NONE = 0;
protected static final int BIG = 1;
protected static final int LITTLE = 2;
protected static class Decoder extends CharsetDecoder {
private int currentBO;
private int expectedBO;
protected Decoder(Charset cs, int bo) {
super(cs, 0.25f, 1.0f);
this.expectedBO = bo;
this.currentBO = NONE;
}
private int getCP(ByteBuffer src) {
return (currentBO==BIG)
?(((src.get() & 0xff) << 24) |
((src.get() & 0xff) << 16) |
((src.get() & 0xff) << 8) |
(src.get() & 0xff))
:((src.get() & 0xff) |
((src.get() & 0xff) << 8) |
((src.get() & 0xff) << 16) |
((src.get() & 0xff) << 24));
}
protected CoderResult decodeLoop(ByteBuffer src, CharBuffer dst) {
if (src.remaining() < 4)
return CoderResult.UNDERFLOW;
int mark = src.position();
int cp;
try {
if (currentBO == NONE) {
cp = ((src.get() & 0xff) << 24) |
((src.get() & 0xff) << 16) |
((src.get() & 0xff) << 8) |
(src.get() & 0xff);
if (cp == BOM_BIG && expectedBO != LITTLE) {
currentBO = BIG;
mark += 4;
} else if (cp == BOM_LITTLE && expectedBO != BIG) {
currentBO = LITTLE;
mark += 4;
} else {
if (expectedBO == NONE)
currentBO = BIG;
else
currentBO = expectedBO;
src.position(mark);
}
}
while (src.remaining() >= 4) {
cp = getCP(src);
if (Character.isBmpCodePoint(cp)) {
if (!dst.hasRemaining())
return CoderResult.OVERFLOW;
mark += 4;
dst.put((char) cp);
} else if (Character.isValidCodePoint(cp)) {
if (dst.remaining() < 2)
return CoderResult.OVERFLOW;
mark += 4;
dst.put(Character.highSurrogate(cp));
dst.put(Character.lowSurrogate(cp));
} else {
return CoderResult.malformedForLength(4);
}
}
return CoderResult.UNDERFLOW;
} finally {
src.position(mark);
}
}
protected void implReset() {
currentBO = NONE;
}
}
protected static class Encoder extends CharsetEncoder {
private boolean doBOM = false;
private boolean doneBOM = true;
private int byteOrder;
protected void put(int cp, ByteBuffer dst) {
if (byteOrder==BIG) {
dst.put((byte)(cp >> 24));
dst.put((byte)(cp >> 16));
dst.put((byte)(cp >> 8));
dst.put((byte)cp);
} else {
dst.put((byte)cp);
dst.put((byte)(cp >> 8));
dst.put((byte)(cp >> 16));
dst.put((byte)(cp >> 24));
}
}
protected Encoder(Charset cs, int byteOrder, boolean doBOM) {
super(cs, 4.0f,
doBOM?8.0f:4.0f,
(byteOrder==BIG)?new byte[]{(byte)0, (byte)0, (byte)0xff, (byte)0xfd}
:new byte[]{(byte)0xfd, (byte)0xff, (byte)0, (byte)0});
this.byteOrder = byteOrder;
this.doBOM = doBOM;
this.doneBOM = !doBOM;
}
protected CoderResult encodeLoop(CharBuffer src, ByteBuffer dst) {
int mark = src.position();
if (!doneBOM && src.hasRemaining()) {
if (dst.remaining() < 4)
return CoderResult.OVERFLOW;
put(BOM_BIG, dst);
doneBOM = true;
}
try {
while (src.hasRemaining()) {
char c = src.get();
if (!Character.isSurrogate(c)) {
if (dst.remaining() < 4)
return CoderResult.OVERFLOW;
mark++;
put(c, dst);
} else if (Character.isHighSurrogate(c)) {
if (!src.hasRemaining())
return CoderResult.UNDERFLOW;
char low = src.get();
if (Character.isLowSurrogate(low)) {
if (dst.remaining() < 4)
return CoderResult.OVERFLOW;
mark += 2;
put(Character.toCodePoint(c, low), dst);
} else {
return CoderResult.malformedForLength(1);
}
} else {
// assert Character.isLowSurrogate(c);
return CoderResult.malformedForLength(1);
}
}
return CoderResult.UNDERFLOW;
} finally {
src.position(mark);
}
}
protected void implReset() {
doneBOM = !doBOM;
}
}
}