J. Duke | 319a3b9 | 2007-12-01 00:00:00 +0000 | [diff] [blame^] | 1 | /* |
| 2 | * Copyright 2002-2005 Sun Microsystems, Inc. All Rights Reserved. |
| 3 | * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. |
| 4 | * |
| 5 | * This code is free software; you can redistribute it and/or modify it |
| 6 | * under the terms of the GNU General Public License version 2 only, as |
| 7 | * published by the Free Software Foundation. Sun designates this |
| 8 | * particular file as subject to the "Classpath" exception as provided |
| 9 | * by Sun in the LICENSE file that accompanied this code. |
| 10 | * |
| 11 | * This code is distributed in the hope that it will be useful, but WITHOUT |
| 12 | * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or |
| 13 | * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License |
| 14 | * version 2 for more details (a copy is included in the LICENSE file that |
| 15 | * accompanied this code). |
| 16 | * |
| 17 | * You should have received a copy of the GNU General Public License version |
| 18 | * 2 along with this work; if not, write to the Free Software Foundation, |
| 19 | * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. |
| 20 | * |
| 21 | * Please contact Sun Microsystems, Inc., 4150 Network Circle, Santa Clara, |
| 22 | * CA 95054 USA or visit www.sun.com if you need additional information or |
| 23 | * have any questions. |
| 24 | */ |
| 25 | |
| 26 | /* |
| 27 | */ |
| 28 | |
| 29 | package sun.nio.cs.ext; |
| 30 | |
| 31 | import java.nio.ByteBuffer; |
| 32 | import java.nio.CharBuffer; |
| 33 | import java.nio.charset.Charset; |
| 34 | import java.nio.charset.CharsetDecoder; |
| 35 | import java.nio.charset.CoderResult; |
| 36 | |
| 37 | abstract class DoubleByteDecoder |
| 38 | extends CharsetDecoder |
| 39 | { |
| 40 | |
| 41 | private short index1[]; |
| 42 | |
| 43 | /* |
| 44 | * 2nd level index, provided by subclass |
| 45 | * every string has 0x10*(end-start+1) characters. |
| 46 | */ |
| 47 | private String index2[]; |
| 48 | |
| 49 | protected int start; |
| 50 | protected int end; |
| 51 | |
| 52 | protected static final char REPLACE_CHAR = '\uFFFD'; |
| 53 | protected char highSurrogate; |
| 54 | protected char lowSurrogate; |
| 55 | |
| 56 | protected DoubleByteDecoder(Charset cs, short[] index1, String[] index2, |
| 57 | int start, int end ) { |
| 58 | super(cs, 0.5f, 1.0f); |
| 59 | this.index1 = index1; |
| 60 | this.index2 = index2; |
| 61 | this.start = start; |
| 62 | this.end = end; |
| 63 | } |
| 64 | |
| 65 | private CoderResult decodeArrayLoop(ByteBuffer src, CharBuffer dst) { |
| 66 | byte[] sa = src.array(); |
| 67 | int sp = src.arrayOffset() + src.position(); |
| 68 | int sl = src.arrayOffset() + src.limit(); |
| 69 | assert (sp <= sl); |
| 70 | sp = (sp <= sl ? sp : sl); |
| 71 | char[] da = dst.array(); |
| 72 | int dp = dst.arrayOffset() + dst.position(); |
| 73 | int dl = dst.arrayOffset() + dst.limit(); |
| 74 | assert (dp <= dl); |
| 75 | dp = (dp <= dl ? dp : dl); |
| 76 | |
| 77 | try { |
| 78 | while (sp < sl) { |
| 79 | int b1, b2; |
| 80 | b1 = sa[sp]; |
| 81 | int inputSize = 1; |
| 82 | int outputSize = 1; |
| 83 | highSurrogate = lowSurrogate = 0; |
| 84 | char c = decodeSingle(b1); |
| 85 | if (c == REPLACE_CHAR) { |
| 86 | b1 &= 0xff; |
| 87 | if (sl - sp < 2) |
| 88 | return CoderResult.UNDERFLOW; |
| 89 | b2 = sa[sp + 1] & 0xff; |
| 90 | c = decodeDouble(b1, b2); |
| 91 | inputSize = 2; |
| 92 | if (c == REPLACE_CHAR) |
| 93 | return CoderResult.unmappableForLength(inputSize); |
| 94 | outputSize = (highSurrogate > 0) ? 2: 1; |
| 95 | } |
| 96 | |
| 97 | if (dl - dp < outputSize) |
| 98 | return CoderResult.OVERFLOW; |
| 99 | if (outputSize == 2) { |
| 100 | da[dp++] = highSurrogate; |
| 101 | da[dp++] = lowSurrogate; |
| 102 | } else { |
| 103 | da[dp++] = c; |
| 104 | } |
| 105 | sp += inputSize; |
| 106 | } |
| 107 | return CoderResult.UNDERFLOW; |
| 108 | } finally { |
| 109 | src.position(sp - src.arrayOffset()); |
| 110 | dst.position(dp - dst.arrayOffset()); |
| 111 | } |
| 112 | } |
| 113 | |
| 114 | private CoderResult decodeBufferLoop(ByteBuffer src, CharBuffer dst) { |
| 115 | int mark = src.position(); |
| 116 | int inputSize = 0; |
| 117 | int outputSize = 0; |
| 118 | try { |
| 119 | while (src.hasRemaining()) { |
| 120 | int b1 = src.get(); |
| 121 | inputSize = 1; |
| 122 | outputSize = 1; |
| 123 | highSurrogate = lowSurrogate = 0; |
| 124 | |
| 125 | char c = decodeSingle(b1); |
| 126 | |
| 127 | if (c == REPLACE_CHAR) { |
| 128 | if (src.remaining() < 1) |
| 129 | return CoderResult.UNDERFLOW; |
| 130 | b1 &= 0xff; |
| 131 | int b2 = src.get() & 0xff; |
| 132 | inputSize = 2; |
| 133 | |
| 134 | c = decodeDouble(b1, b2); |
| 135 | |
| 136 | if (c == REPLACE_CHAR) |
| 137 | return CoderResult.unmappableForLength(2); |
| 138 | |
| 139 | outputSize = (highSurrogate > 0) ? 2: 1; |
| 140 | } |
| 141 | if (dst.remaining() < outputSize) |
| 142 | return CoderResult.OVERFLOW; |
| 143 | mark += inputSize; |
| 144 | |
| 145 | if (outputSize == 2) { |
| 146 | dst.put(highSurrogate); |
| 147 | dst.put(lowSurrogate); |
| 148 | } else { |
| 149 | dst.put(c); |
| 150 | } |
| 151 | } |
| 152 | return CoderResult.UNDERFLOW; |
| 153 | } finally { |
| 154 | src.position(mark); |
| 155 | } |
| 156 | } |
| 157 | |
| 158 | protected CoderResult decodeLoop(ByteBuffer src, CharBuffer dst) { |
| 159 | if (src.hasArray() && dst.hasArray()) |
| 160 | return decodeArrayLoop(src, dst); |
| 161 | else |
| 162 | return decodeBufferLoop(src, dst); |
| 163 | } |
| 164 | |
| 165 | /* |
| 166 | * Can be changed by subclass |
| 167 | */ |
| 168 | protected char decodeSingle(int b) { |
| 169 | if (b >= 0) |
| 170 | return (char) b; |
| 171 | return REPLACE_CHAR; |
| 172 | } |
| 173 | |
| 174 | protected char decodeDouble(int byte1, int byte2) { |
| 175 | if (((byte1 < 0) || (byte1 > index1.length)) |
| 176 | || ((byte2 < start) || (byte2 > end))) |
| 177 | return REPLACE_CHAR; |
| 178 | |
| 179 | int n = (index1[byte1] & 0xf) * (end - start + 1) + (byte2 - start); |
| 180 | return index2[index1[byte1] >> 4].charAt(n); |
| 181 | } |
| 182 | } |