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| 1 | /* | ||
| 2 | * Copyright (c) 2001, 2005, Oracle and/or its affiliates. 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. Oracle designates this | ||
| 8 | * particular file as subject to the "Classpath" exception as provided | ||
| 9 | * by Oracle 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 Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA | ||
| 22 | * or visit www.oracle.com if you need additional information or have any | ||
| 23 | * questions. | ||
| 24 | */ | ||
| 25 | |||
| 26 | /* | ||
| 27 | */ | ||
| 28 | |||
| 29 | package sun.nio.cs; | ||
| 30 | |||
| 31 | import java.io.*; | ||
| 32 | import java.nio.*; | ||
| 33 | import java.nio.channels.*; | ||
| 34 | import java.nio.charset.*; | ||
| 35 | |||
| 36 | public class StreamDecoder extends Reader | ||
| 37 | { | ||
| 38 | |||
| 39 | private static final int MIN_BYTE_BUFFER_SIZE = 32; | ||
| 40 | private static final int DEFAULT_BYTE_BUFFER_SIZE = 8192; | ||
| 41 | |||
| 42 | private volatile boolean isOpen = true; | ||
| 43 | |||
| 44 | private void ensureOpen() throws IOException { | ||
| 45 | if (!isOpen) | ||
| 46 | throw new IOException("Stream closed"); | ||
| 47 | } | ||
| 48 | |||
| 49 | // In order to handle surrogates properly we must never try to produce | ||
| 50 | // fewer than two characters at a time. If we're only asked to return one | ||
| 51 | // character then the other is saved here to be returned later. | ||
| 52 | // | ||
| 53 | private boolean haveLeftoverChar = false; | ||
| 54 | private char leftoverChar; | ||
| 55 | |||
| 56 | |||
| 57 | // Factories for java.io.InputStreamReader | ||
| 58 | |||
| 59 | public static StreamDecoder forInputStreamReader(InputStream in, | ||
| 60 | Object lock, | ||
| 61 | String charsetName) | ||
| 62 | throws UnsupportedEncodingException | ||
| 63 | { | ||
| 64 | String csn = charsetName; | ||
| 65 | if (csn == null) | ||
| 66 | csn = Charset.defaultCharset().name(); | ||
| 67 | try { | ||
| 68 | if (Charset.isSupported(csn)) | ||
| 69 | return new StreamDecoder(in, lock, Charset.forName(csn)); | ||
| 70 | } catch (IllegalCharsetNameException x) { } | ||
| 71 | throw new UnsupportedEncodingException (csn); | ||
| 72 | } | ||
| 73 | |||
| 74 | public static StreamDecoder forInputStreamReader(InputStream in, | ||
| 75 | Object lock, | ||
| 76 | Charset cs) | ||
| 77 | { | ||
| 78 | return new StreamDecoder(in, lock, cs); | ||
| 79 | } | ||
| 80 | |||
| 81 | public static StreamDecoder forInputStreamReader(InputStream in, | ||
| 82 | Object lock, | ||
| 83 | CharsetDecoder dec) | ||
| 84 | { | ||
| 85 | return new StreamDecoder(in, lock, dec); | ||
| 86 | } | ||
| 87 | |||
| 88 | |||
| 89 | // Factory for java.nio.channels.Channels.newReader | ||
| 90 | |||
| 91 | public static StreamDecoder forDecoder(ReadableByteChannel ch, | ||
| 92 | CharsetDecoder dec, | ||
| 93 | int minBufferCap) | ||
| 94 | { | ||
| 95 | return new StreamDecoder(ch, dec, minBufferCap); | ||
| 96 | } | ||
| 97 | |||
| 98 | |||
| 99 | // -- Public methods corresponding to those in InputStreamReader -- | ||
| 100 | |||
| 101 | // All synchronization and state/argument checking is done in these public | ||
| 102 | // methods; the concrete stream-decoder subclasses defined below need not | ||
| 103 | // do any such checking. | ||
| 104 | |||
| 105 | public String getEncoding() { | ||
| 106 | if (isOpen()) | ||
| 107 | return encodingName(); | ||
| 108 | return null; | ||
| 109 | } | ||
| 110 | |||
| 111 | public int read() throws IOException { | ||
| 112 | return read0(); | ||
| 113 | } | ||
| 114 | |||
| 115 | private int read0() throws IOException { | ||
| 116 | synchronized (lock) { | ||
| 117 | |||
| 118 | // Return the leftover char, if there is one | ||
| 119 | if (haveLeftoverChar) { | ||
| 120 | haveLeftoverChar = false; | ||
| 121 | return leftoverChar; | ||
| 122 | } | ||
| 123 | |||
| 124 | // Convert more bytes | ||
| 125 | char cb[] = new char[2]; | ||
| 126 | int n = read(cb, 0, 2); | ||
| 127 | switch (n) { | ||
| 128 | case -1: | ||
| 129 | return -1; | ||
| 130 | case 2: | ||
| 131 | leftoverChar = cb[1]; | ||
| 132 | haveLeftoverChar = true; | ||
| 133 | // FALL THROUGH | ||
| 134 | case 1: | ||
| 135 | return cb[0]; | ||
| 136 | default: | ||
| 137 | assert false : n; | ||
| 138 | return -1; | ||
| 139 | } | ||
| 140 | } | ||
| 141 | } | ||
| 142 | |||
| 143 | public int read(char cbuf[], int offset, int length) throws IOException { | ||
| 144 | int off = offset; | ||
| 145 | int len = length; | ||
| 146 | synchronized (lock) { | ||
| 147 | ensureOpen(); | ||
| 148 | if ((off < 0) || (off > cbuf.length) || (len < 0) || | ||
| 149 | ((off + len) > cbuf.length) || ((off + len) < 0)) { | ||
| 150 | throw new IndexOutOfBoundsException(); | ||
| 151 | } | ||
| 152 | if (len == 0) | ||
| 153 | return 0; | ||
| 154 | |||
| 155 | int n = 0; | ||
| 156 | |||
| 157 | if (haveLeftoverChar) { | ||
| 158 | // Copy the leftover char into the buffer | ||
| 159 | cbuf[off] = leftoverChar; | ||
| 160 | off++; len--; | ||
| 161 | haveLeftoverChar = false; | ||
| 162 | n = 1; | ||
| 163 | if ((len == 0) || !implReady()) | ||
| 164 | // Return now if this is all we can produce w/o blocking | ||
| 165 | return n; | ||
| 166 | } | ||
| 167 | |||
| 168 | if (len == 1) { | ||
| 169 | // Treat single-character array reads just like read() | ||
| 170 | int c = read0(); | ||
| 171 | if (c == -1) | ||
| 172 | return (n == 0) ? -1 : n; | ||
| 173 | cbuf[off] = (char)c; | ||
| 174 | return n + 1; | ||
| 175 | } | ||
| 176 | |||
| 177 | return n + implRead(cbuf, off, off + len); | ||
| 178 | } | ||
| 179 | } | ||
| 180 | |||
| 181 | public boolean ready() throws IOException { | ||
| 182 | synchronized (lock) { | ||
| 183 | ensureOpen(); | ||
| 184 | return haveLeftoverChar || implReady(); | ||
| 185 | } | ||
| 186 | } | ||
| 187 | |||
| 188 | public void close() throws IOException { | ||
| 189 | synchronized (lock) { | ||
| 190 | if (!isOpen) | ||
| 191 | return; | ||
| 192 | implClose(); | ||
| 193 | isOpen = false; | ||
| 194 | } | ||
| 195 | } | ||
| 196 | |||
| 197 | private boolean isOpen() { | ||
| 198 | return isOpen; | ||
| 199 | } | ||
| 200 | |||
| 201 | |||
| 202 | // -- Charset-based stream decoder impl -- | ||
| 203 | |||
| 204 | // In the early stages of the build we haven't yet built the NIO native | ||
| 205 | // code, so guard against that by catching the first UnsatisfiedLinkError | ||
| 206 | // and setting this flag so that later attempts fail quickly. | ||
| 207 | // | ||
| 208 | private static volatile boolean channelsAvailable = true; | ||
| 209 | |||
| 210 | private static FileChannel getChannel(FileInputStream in) { | ||
| 211 | if (!channelsAvailable) | ||
| 212 | return null; | ||
| 213 | try { | ||
| 214 | return in.getChannel(); | ||
| 215 | } catch (UnsatisfiedLinkError x) { | ||
| 216 | channelsAvailable = false; | ||
| 217 | return null; | ||
| 218 | } | ||
| 219 | } | ||
| 220 | |||
| 221 | private Charset cs; | ||
| 222 | private CharsetDecoder decoder; | ||
| 223 | private ByteBuffer bb; | ||
| 224 | |||
| 225 | // Exactly one of these is non-null | ||
| 226 | private InputStream in; | ||
| 227 | private ReadableByteChannel ch; | ||
| 228 | |||
| 229 | StreamDecoder(InputStream in, Object lock, Charset cs) { | ||
| 230 | this(in, lock, | ||
| 231 | cs.newDecoder() | ||
| 232 | .onMalformedInput(CodingErrorAction.REPLACE) | ||
| 233 | .onUnmappableCharacter(CodingErrorAction.REPLACE)); | ||
| 234 | } | ||
| 235 | |||
| 236 | StreamDecoder(InputStream in, Object lock, CharsetDecoder dec) { | ||
| 237 | super(lock); | ||
| 238 | this.cs = dec.charset(); | ||
| 239 | this.decoder = dec; | ||
| 240 | |||
| 241 | // This path disabled until direct buffers are faster | ||
| 242 | if (false && in instanceof FileInputStream) { | ||
| 243 | ch = getChannel((FileInputStream)in); | ||
| 244 | if (ch != null) | ||
| 245 | bb = ByteBuffer.allocateDirect(DEFAULT_BYTE_BUFFER_SIZE); | ||
| 246 | } | ||
| 247 | if (ch == null) { | ||
| 248 | this.in = in; | ||
| 249 | this.ch = null; | ||
| 250 | bb = ByteBuffer.allocate(DEFAULT_BYTE_BUFFER_SIZE); | ||
| 251 | } | ||
| 252 | bb.flip(); // So that bb is initially empty | ||
| 253 | } | ||
| 254 | |||
| 255 | StreamDecoder(ReadableByteChannel ch, CharsetDecoder dec, int mbc) { | ||
| 256 | this.in = null; | ||
| 257 | this.ch = ch; | ||
| 258 | this.decoder = dec; | ||
| 259 | this.cs = dec.charset(); | ||
| 260 | this.bb = ByteBuffer.allocate(mbc < 0 | ||
| 261 | ? DEFAULT_BYTE_BUFFER_SIZE | ||
| 262 | : (mbc < MIN_BYTE_BUFFER_SIZE | ||
| 263 | ? MIN_BYTE_BUFFER_SIZE | ||
| 264 | : mbc)); | ||
| 265 | bb.flip(); | ||
| 266 | } | ||
| 267 | |||
| 268 | private int readBytes() throws IOException { | ||
| 269 | bb.compact(); | ||
| 270 | try { | ||
| 271 | if (ch != null) { | ||
| 272 | // Read from the channel | ||
| 273 | int n = ch.read(bb); | ||
| 274 | if (n < 0) | ||
| 275 | return n; | ||
| 276 | } else { | ||
| 277 | // Read from the input stream, and then update the buffer | ||
| 278 | int lim = bb.limit(); | ||
| 279 | int pos = bb.position(); | ||
| 280 | assert (pos <= lim); | ||
| 281 | int rem = (pos <= lim ? lim - pos : 0); | ||
| 282 | assert rem > 0; | ||
| 283 | int n = in.read(bb.array(), bb.arrayOffset() + pos, rem); | ||
| 284 | if (n < 0) | ||
| 285 | return n; | ||
| 286 | if (n == 0) | ||
| 287 | throw new IOException("Underlying input stream returned zero bytes"); | ||
| 288 | assert (n <= rem) : "n = " + n + ", rem = " + rem; | ||
| 289 | bb.position(pos + n); | ||
| 290 | } | ||
| 291 | } finally { | ||
| 292 | // Flip even when an IOException is thrown, | ||
| 293 | // otherwise the stream will stutter | ||
| 294 | bb.flip(); | ||
| 295 | } | ||
| 296 | |||
| 297 | int rem = bb.remaining(); | ||
| 298 | assert (rem != 0) : rem; | ||
| 299 | return rem; | ||
| 300 | } | ||
| 301 | |||
| 302 | int implRead(char[] cbuf, int off, int end) throws IOException { | ||
| 303 | |||
| 304 | // In order to handle surrogate pairs, this method requires that | ||
| 305 | // the invoker attempt to read at least two characters. Saving the | ||
| 306 | // extra character, if any, at a higher level is easier than trying | ||
| 307 | // to deal with it here. | ||
| 308 | assert (end - off > 1); | ||
| 309 | |||
| 310 | CharBuffer cb = CharBuffer.wrap(cbuf, off, end - off); | ||
| 311 | if (cb.position() != 0) | ||
| 312 | // Ensure that cb[0] == cbuf[off] | ||
| 313 | cb = cb.slice(); | ||
| 314 | |||
| 315 | boolean eof = false; | ||
| 316 | for (;;) { | ||
| 317 | CoderResult cr = decoder.decode(bb, cb, eof); | ||
| 318 | if (cr.isUnderflow()) { | ||
| 319 | if (eof) | ||
| 320 | break; | ||
| 321 | if (!cb.hasRemaining()) | ||
| 322 | break; | ||
| 323 | if ((cb.position() > 0) && !inReady()) | ||
| 324 | break; // Block at most once | ||
| 325 | int n = readBytes(); | ||
| 326 | if (n < 0) { | ||
| 327 | eof = true; | ||
| 328 | if ((cb.position() == 0) && (!bb.hasRemaining())) | ||
| 329 | break; | ||
| 330 | decoder.reset(); | ||
| 331 | } | ||
| 332 | continue; | ||
| 333 | } | ||
| 334 | if (cr.isOverflow()) { | ||
| 335 | assert cb.position() > 0; | ||
| 336 | break; | ||
| 337 | } | ||
| 338 | cr.throwException(); | ||
| 339 | } | ||
| 340 | |||
| 341 | if (eof) { | ||
| 342 | // ## Need to flush decoder | ||
| 343 | decoder.reset(); | ||
| 344 | } | ||
| 345 | |||
| 346 | if (cb.position() == 0) { | ||
| 347 | if (eof) | ||
| 348 | return -1; | ||
| 349 | assert false; | ||
| 350 | } | ||
| 351 | return cb.position(); | ||
| 352 | } | ||
| 353 | |||
| 354 | String encodingName() { | ||
| 355 | return ((cs instanceof HistoricallyNamedCharset) | ||
| 356 | ? ((HistoricallyNamedCharset)cs).historicalName() | ||
| 357 | : cs.name()); | ||
| 358 | } | ||
| 359 | |||
| 360 | private boolean inReady() { | ||
| 361 | try { | ||
| 362 | return (((in != null) && (in.available() > 0)) | ||
| 363 | || (ch instanceof FileChannel)); // ## RBC.available()? | ||
| 364 | } catch (IOException x) { | ||
| 365 | return false; | ||
| 366 | } | ||
| 367 | } | ||
| 368 | |||
| 369 | boolean implReady() { | ||
| 370 | return bb.hasRemaining() || inReady(); | ||
| 371 | } | ||
| 372 | |||
| 373 | void implClose() throws IOException { | ||
| 374 | if (ch != null) | ||
| 375 | ch.close(); | ||
| 376 | else | ||
| 377 | in.close(); | ||
| 378 | } | ||
| 379 | |||
| 380 | } | ||