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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 | +} | |