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| 1 | /* | ||
| 2 | * Copyright (c) 1996, 2010, 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 | package java.util.zip; | ||
| 27 | |||
| 28 | import java.io.SequenceInputStream; | ||
| 29 | import java.io.ByteArrayInputStream; | ||
| 30 | import java.io.InputStream; | ||
| 31 | import java.io.IOException; | ||
| 32 | import java.io.EOFException; | ||
| 33 | |||
| 34 | /** | ||
| 35 | * This class implements a stream filter for reading compressed data in | ||
| 36 | * the GZIP file format. | ||
| 37 | * | ||
| 38 | * @see InflaterInputStream | ||
| 39 | * @author David Connelly | ||
| 40 | * | ||
| 41 | */ | ||
| 42 | public | ||
| 43 | class GZIPInputStream extends InflaterInputStream { | ||
| 44 | /** | ||
| 45 | * CRC-32 for uncompressed data. | ||
| 46 | */ | ||
| 47 | protected CRC32 crc = new CRC32(); | ||
| 48 | |||
| 49 | /** | ||
| 50 | * Indicates end of input stream. | ||
| 51 | */ | ||
| 52 | protected boolean eos; | ||
| 53 | |||
| 54 | private boolean closed = false; | ||
| 55 | |||
| 56 | /** | ||
| 57 | * Check to make sure that this stream has not been closed | ||
| 58 | */ | ||
| 59 | private void ensureOpen() throws IOException { | ||
| 60 | if (closed) { | ||
| 61 | throw new IOException("Stream closed"); | ||
| 62 | } | ||
| 63 | } | ||
| 64 | |||
| 65 | /** | ||
| 66 | * Creates a new input stream with the specified buffer size. | ||
| 67 | * @param in the input stream | ||
| 68 | * @param size the input buffer size | ||
| 69 | * | ||
| 70 | * @exception ZipException if a GZIP format error has occurred or the | ||
| 71 | * compression method used is unsupported | ||
| 72 | * @exception IOException if an I/O error has occurred | ||
| 73 | * @exception IllegalArgumentException if size is <= 0 | ||
| 74 | */ | ||
| 75 | public GZIPInputStream(InputStream in, int size) throws IOException { | ||
| 76 | super(in, new Inflater(true), size); | ||
| 77 | usesDefaultInflater = true; | ||
| 78 | readHeader(in); | ||
| 79 | } | ||
| 80 | |||
| 81 | /** | ||
| 82 | * Creates a new input stream with a default buffer size. | ||
| 83 | * @param in the input stream | ||
| 84 | * | ||
| 85 | * @exception ZipException if a GZIP format error has occurred or the | ||
| 86 | * compression method used is unsupported | ||
| 87 | * @exception IOException if an I/O error has occurred | ||
| 88 | */ | ||
| 89 | public GZIPInputStream(InputStream in) throws IOException { | ||
| 90 | this(in, 512); | ||
| 91 | } | ||
| 92 | |||
| 93 | /** | ||
| 94 | * Reads uncompressed data into an array of bytes. If <code>len</code> is not | ||
| 95 | * zero, the method will block until some input can be decompressed; otherwise, | ||
| 96 | * no bytes are read and <code>0</code> is returned. | ||
| 97 | * @param buf the buffer into which the data is read | ||
| 98 | * @param off the start offset in the destination array <code>b</code> | ||
| 99 | * @param len the maximum number of bytes read | ||
| 100 | * @return the actual number of bytes read, or -1 if the end of the | ||
| 101 | * compressed input stream is reached | ||
| 102 | * | ||
| 103 | * @exception NullPointerException If <code>buf</code> is <code>null</code>. | ||
| 104 | * @exception IndexOutOfBoundsException If <code>off</code> is negative, | ||
| 105 | * <code>len</code> is negative, or <code>len</code> is greater than | ||
| 106 | * <code>buf.length - off</code> | ||
| 107 | * @exception ZipException if the compressed input data is corrupt. | ||
| 108 | * @exception IOException if an I/O error has occurred. | ||
| 109 | * | ||
| 110 | */ | ||
| 111 | public int read(byte[] buf, int off, int len) throws IOException { | ||
| 112 | ensureOpen(); | ||
| 113 | if (eos) { | ||
| 114 | return -1; | ||
| 115 | } | ||
| 116 | int n = super.read(buf, off, len); | ||
| 117 | if (n == -1) { | ||
| 118 | if (readTrailer()) | ||
| 119 | eos = true; | ||
| 120 | else | ||
| 121 | return this.read(buf, off, len); | ||
| 122 | } else { | ||
| 123 | crc.update(buf, off, n); | ||
| 124 | } | ||
| 125 | return n; | ||
| 126 | } | ||
| 127 | |||
| 128 | /** | ||
| 129 | * Closes this input stream and releases any system resources associated | ||
| 130 | * with the stream. | ||
| 131 | * @exception IOException if an I/O error has occurred | ||
| 132 | */ | ||
| 133 | public void close() throws IOException { | ||
| 134 | if (!closed) { | ||
| 135 | super.close(); | ||
| 136 | eos = true; | ||
| 137 | closed = true; | ||
| 138 | } | ||
| 139 | } | ||
| 140 | |||
| 141 | /** | ||
| 142 | * GZIP header magic number. | ||
| 143 | */ | ||
| 144 | public final static int GZIP_MAGIC = 0x8b1f; | ||
| 145 | |||
| 146 | /* | ||
| 147 | * File header flags. | ||
| 148 | */ | ||
| 149 | private final static int FTEXT = 1; // Extra text | ||
| 150 | private final static int FHCRC = 2; // Header CRC | ||
| 151 | private final static int FEXTRA = 4; // Extra field | ||
| 152 | private final static int FNAME = 8; // File name | ||
| 153 | private final static int FCOMMENT = 16; // File comment | ||
| 154 | |||
| 155 | /* | ||
| 156 | * Reads GZIP member header and returns the total byte number | ||
| 157 | * of this member header. | ||
| 158 | */ | ||
| 159 | private int readHeader(InputStream this_in) throws IOException { | ||
| 160 | CheckedInputStream in = new CheckedInputStream(this_in, crc); | ||
| 161 | crc.reset(); | ||
| 162 | // Check header magic | ||
| 163 | if (readUShort(in) != GZIP_MAGIC) { | ||
| 164 | throw new ZipException("Not in GZIP format"); | ||
| 165 | } | ||
| 166 | // Check compression method | ||
| 167 | if (readUByte(in) != 8) { | ||
| 168 | throw new ZipException("Unsupported compression method"); | ||
| 169 | } | ||
| 170 | // Read flags | ||
| 171 | int flg = readUByte(in); | ||
| 172 | // Skip MTIME, XFL, and OS fields | ||
| 173 | skipBytes(in, 6); | ||
| 174 | int n = 2 + 2 + 6; | ||
| 175 | // Skip optional extra field | ||
| 176 | if ((flg & FEXTRA) == FEXTRA) { | ||
| 177 | int m = readUShort(in); | ||
| 178 | skipBytes(in, m); | ||
| 179 | n += m + 2; | ||
| 180 | } | ||
| 181 | // Skip optional file name | ||
| 182 | if ((flg & FNAME) == FNAME) { | ||
| 183 | do { | ||
| 184 | n++; | ||
| 185 | } while (readUByte(in) != 0); | ||
| 186 | } | ||
| 187 | // Skip optional file comment | ||
| 188 | if ((flg & FCOMMENT) == FCOMMENT) { | ||
| 189 | do { | ||
| 190 | n++; | ||
| 191 | } while (readUByte(in) != 0); | ||
| 192 | } | ||
| 193 | // Check optional header CRC | ||
| 194 | if ((flg & FHCRC) == FHCRC) { | ||
| 195 | int v = (int)crc.getValue() & 0xffff; | ||
| 196 | if (readUShort(in) != v) { | ||
| 197 | throw new ZipException("Corrupt GZIP header"); | ||
| 198 | } | ||
| 199 | n += 2; | ||
| 200 | } | ||
| 201 | crc.reset(); | ||
| 202 | return n; | ||
| 203 | } | ||
| 204 | |||
| 205 | /* | ||
| 206 | * Reads GZIP member trailer and returns true if the eos | ||
| 207 | * reached, false if there are more (concatenated gzip | ||
| 208 | * data set) | ||
| 209 | */ | ||
| 210 | private boolean readTrailer() throws IOException { | ||
| 211 | InputStream in = this.in; | ||
| 212 | int n = inf.getRemaining(); | ||
| 213 | if (n > 0) { | ||
| 214 | in = new SequenceInputStream( | ||
| 215 | new ByteArrayInputStream(buf, len - n, n), in); | ||
| 216 | } | ||
| 217 | // Uses left-to-right evaluation order | ||
| 218 | if ((readUInt(in) != crc.getValue()) || | ||
| 219 | // rfc1952; ISIZE is the input size modulo 2^32 | ||
| 220 | (readUInt(in) != (inf.getBytesWritten() & 0xffffffffL))) | ||
| 221 | throw new ZipException("Corrupt GZIP trailer"); | ||
| 222 | |||
| 223 | // If there are more bytes available in "in" or | ||
| 224 | // the leftover in the "inf" is > 26 bytes: | ||
| 225 | // this.trailer(8) + next.header.min(10) + next.trailer(8) | ||
| 226 | // try concatenated case | ||
| 227 | if (this.in.available() > 0 || n > 26) { | ||
| 228 | int m = 8; // this.trailer | ||
| 229 | try { | ||
| 230 | m += readHeader(in); // next.header | ||
| 231 | } catch (IOException ze) { | ||
| 232 | return true; // ignore any malformed, do nothing | ||
| 233 | } | ||
| 234 | inf.reset(); | ||
| 235 | if (n > m) | ||
| 236 | inf.setInput(buf, len - n + m, n - m); | ||
| 237 | return false; | ||
| 238 | } | ||
| 239 | return true; | ||
| 240 | } | ||
| 241 | |||
| 242 | /* | ||
| 243 | * Reads unsigned integer in Intel byte order. | ||
| 244 | */ | ||
| 245 | private long readUInt(InputStream in) throws IOException { | ||
| 246 | long s = readUShort(in); | ||
| 247 | return ((long)readUShort(in) << 16) | s; | ||
| 248 | } | ||
| 249 | |||
| 250 | /* | ||
| 251 | * Reads unsigned short in Intel byte order. | ||
| 252 | */ | ||
| 253 | private int readUShort(InputStream in) throws IOException { | ||
| 254 | int b = readUByte(in); | ||
| 255 | return ((int)readUByte(in) << 8) | b; | ||
| 256 | } | ||
| 257 | |||
| 258 | /* | ||
| 259 | * Reads unsigned byte. | ||
| 260 | */ | ||
| 261 | private int readUByte(InputStream in) throws IOException { | ||
| 262 | int b = in.read(); | ||
| 263 | if (b == -1) { | ||
| 264 | throw new EOFException(); | ||
| 265 | } | ||
| 266 | if (b < -1 || b > 255) { | ||
| 267 | // Report on this.in, not argument in; see read{Header, Trailer}. | ||
| 268 | throw new IOException(this.in.getClass().getName() | ||
| 269 | + ".read() returned value out of range -1..255: " + b); | ||
| 270 | } | ||
| 271 | return b; | ||
| 272 | } | ||
| 273 | |||
| 274 | private byte[] tmpbuf = new byte[128]; | ||
| 275 | |||
| 276 | /* | ||
| 277 | * Skips bytes of input data blocking until all bytes are skipped. | ||
| 278 | * Does not assume that the input stream is capable of seeking. | ||
| 279 | */ | ||
| 280 | private void skipBytes(InputStream in, int n) throws IOException { | ||
| 281 | while (n > 0) { | ||
| 282 | int len = in.read(tmpbuf, 0, n < tmpbuf.length ? n : tmpbuf.length); | ||
| 283 | if (len == -1) { | ||
| 284 | throw new EOFException(); | ||
| 285 | } | ||
| 286 | n -= len; | ||
| 287 | } | ||
| 288 | } | ||
| 289 | } | ||