/* * Copyright (c) 2002, 2005, 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 * or visit www.oracle.com if you need additional information or have any * questions. */ /* */ package sun.nio.cs.ext; import java.nio.ByteBuffer;import java.nio.CharBuffer;import java.nio.charset.Charset;import java.nio.charset.CharsetDecoder;import java.nio.charset.CoderResult; abstract class DoubleByteDecoder    extends CharsetDecoder{     private short index1[];     /*     * 2nd level index, provided by subclass     * every string has 0x10*(end-start+1) characters.     */    private String  index2[];     protected int start;    protected int end;     protected static final char REPLACE_CHAR = '\uFFFD';    protected char highSurrogate;    protected char lowSurrogate;     protected DoubleByteDecoder(Charset cs, short[] index1, String[] index2,                                int start, int end ) {        super(cs, 0.5f, 1.0f);        this.index1 = index1;        this.index2 = index2;        this.start = start;        this.end = end;    }     private CoderResult decodeArrayLoop(ByteBuffer src, CharBuffer dst) {        byte[] sa = src.array();        int sp = src.arrayOffset() + src.position();        int sl = src.arrayOffset() + src.limit();        assert (sp <= sl);        sp = (sp <= sl ? sp : sl);        char[] da = dst.array();        int dp = dst.arrayOffset() + dst.position();        int dl = dst.arrayOffset() + dst.limit();        assert (dp <= dl);        dp = (dp <= dl ? dp : dl);         try {            while (sp < sl) {                int b1, b2;                b1 = sa[sp];                int inputSize = 1;                int outputSize = 1;                highSurrogate = lowSurrogate = 0;                char c = decodeSingle(b1);                if (c == REPLACE_CHAR) {                    b1 &= 0xff;                    if (sl - sp < 2)                        return CoderResult.UNDERFLOW;                    b2 = sa[sp + 1] & 0xff;                    c = decodeDouble(b1, b2);                    inputSize = 2;                    if (c == REPLACE_CHAR)                        return CoderResult.unmappableForLength(inputSize);                    outputSize = (highSurrogate > 0) ? 2: 1;                }                 if (dl - dp < outputSize)                    return CoderResult.OVERFLOW;                if (outputSize == 2) {                    da[dp++] = highSurrogate;                    da[dp++] = lowSurrogate;                } else {                    da[dp++] = c;                }                sp += inputSize;            }            return CoderResult.UNDERFLOW;        } finally {            src.position(sp - src.arrayOffset());            dst.position(dp - dst.arrayOffset());        }    }     private CoderResult decodeBufferLoop(ByteBuffer src, CharBuffer dst) {        int mark = src.position();        int inputSize = 0;        int outputSize = 0;        try {            while (src.hasRemaining()) {                int b1 = src.get();                inputSize = 1;                outputSize = 1;                highSurrogate = lowSurrogate = 0;                 char c = decodeSingle(b1);                 if (c == REPLACE_CHAR) {                    if (src.remaining() < 1)                        return CoderResult.UNDERFLOW;                    b1 &= 0xff;                    int b2 = src.get() & 0xff;                    inputSize = 2;                     c = decodeDouble(b1, b2);                     if (c == REPLACE_CHAR)                        return CoderResult.unmappableForLength(2);                     outputSize =  (highSurrogate > 0) ? 2: 1;                }                if (dst.remaining() < outputSize)                    return CoderResult.OVERFLOW;                mark += inputSize;                 if (outputSize == 2) {                    dst.put(highSurrogate);                    dst.put(lowSurrogate);                } else {                    dst.put(c);                }            }            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);    }     /*     * Can be changed by subclass     */    protected char decodeSingle(int b) {        if (b >= 0)            return (char) b;        return REPLACE_CHAR;    }     protected char decodeDouble(int byte1, int byte2) {        if (((byte1 < 0) || (byte1 > index1.length))            || ((byte2 < start) || (byte2 > end)))            return REPLACE_CHAR;         int n = (index1[byte1] & 0xf) * (end - start + 1) + (byte2 - start);        return index2[index1[byte1] >> 4].charAt(n);    }}