1 /*
2 * Copyright (c) 1996, 2013, 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 jdk.internal.ref.CleanerFactory;
29
30 import java.io.EOFException;
31 import java.io.FilterInputStream;
32 import java.io.IOException;
33 import java.io.InputStream;
34 import java.lang.ref.Cleaner;
35 import java.util.function.Consumer;
36 import java.util.function.Supplier;
37
38 /**
39 * This class implements a stream filter for uncompressing data in the
40 * "deflate" compression format. It is also used as the basis for other
41 * decompression filters, such as GZIPInputStream.
42 *
43 * @see Inflater
44 * @author David Connelly
45 * @since 1.1
46 */
47 public
48 class InflaterInputStream extends FilterInputStream {
49 /**
50 * Decompressor for this stream.
51 */
52 protected Inflater inf;
53
54 /**
55 * Input buffer for decompression.
56 */
57 protected byte[] buf;
58
59 /**
60 * Length of input buffer.
61 */
62 protected int len;
63
64 private boolean closed = false;
65 // this flag is set to true after EOF has reached
66 private boolean reachEOF = false;
67
68 // in case this stream manages own Inflater, else null
69 private final Cleaner.CleanableResource<Inflater> infRes;
70
71 /**
72 * Check to make sure that this stream has not been closed
73 */
74 private void ensureOpen() throws IOException {
75 if (closed) {
76 throw new IOException("Stream closed");
77 }
78 }
79
80
81 /**
82 * Creates a new input stream with the specified decompressor and
83 * buffer size.
84 * @param in the input stream
85 * @param inf the decompressor ("inflater")
86 * @param size the input buffer size
87 * @exception IllegalArgumentException if {@code size <= 0}
88 */
89 public InflaterInputStream(InputStream in, Inflater inf, int size) {
90 super(in);
91 if (in == null || inf == null) {
92 throw new NullPointerException();
93 } else if (size <= 0) {
94 throw new IllegalArgumentException("buffer size <= 0");
95 }
96 this.buf = new byte[size];
97 this.infRes = null; // uses specified/default decompressor
98 this.inf = inf;
99 }
100
101 /**
102 * Creates a new input stream with the specified decompressor and a
103 * default buffer size.
104 * @param in the input stream
105 * @param inf the decompressor ("inflater")
106 */
107 public InflaterInputStream(InputStream in, Inflater inf) {
108 this(in, inf, 512);
109 }
110
111 boolean usesDefaultInflater = false;
112
113 /**
114 * Creates a new input stream with a default decompressor and buffer size.
115 * @param in the input stream
116 */
117 public InflaterInputStream(InputStream in) {
118 this(in, new Inflater());
119 usesDefaultInflater = true;
120 }
121
122 /**
123 * Creates a new input stream with a decompressor allocated by inflaterAllocator
124 * and deallocated by inflaterDeallocator and buffer size.
125 * @param in the input stream
126 * @param inflaterAllocator the inflater allocator function
127 * @param inflaterDeallocator the inflater de-allocator function
128 * @param size the input buffer size
129 */
130 InflaterInputStream(InputStream in,
131 Supplier<Inflater> inflaterAllocator,
132 Consumer<Inflater> inflaterDeallocator,
133 int size) {
134 super(in);
135 if (in == null) {
136 throw new NullPointerException();
137 } else if (size <= 0) {
138 throw new IllegalArgumentException("buffer size <= 0");
139 }
140 this.buf = new byte[size];
141 this.infRes = CleanerFactory
142 .cleaner()
143 .createResource(this, inflaterAllocator, inflaterDeallocator);
144 this.inf = infRes.value();
145 }
146
147 private byte[] singleByteBuf = new byte[1];
148
149 /**
150 * Reads a byte of uncompressed data. This method will block until
151 * enough input is available for decompression.
152 * @return the byte read, or -1 if end of compressed input is reached
153 * @exception IOException if an I/O error has occurred
154 */
155 public int read() throws IOException {
156 ensureOpen();
157 return read(singleByteBuf, 0, 1) == -1 ? -1 : Byte.toUnsignedInt(singleByteBuf[0]);
158 }
159
160 /**
161 * Reads uncompressed data into an array of bytes. If <code>len</code> is not
162 * zero, the method will block until some input can be decompressed; otherwise,
163 * no bytes are read and <code>0</code> is returned.
164 * @param b the buffer into which the data is read
165 * @param off the start offset in the destination array <code>b</code>
166 * @param len the maximum number of bytes read
167 * @return the actual number of bytes read, or -1 if the end of the
168 * compressed input is reached or a preset dictionary is needed
169 * @exception NullPointerException If <code>b</code> is <code>null</code>.
170 * @exception IndexOutOfBoundsException If <code>off</code> is negative,
171 * <code>len</code> is negative, or <code>len</code> is greater than
172 * <code>b.length - off</code>
173 * @exception ZipException if a ZIP format error has occurred
174 * @exception IOException if an I/O error has occurred
175 */
176 public int read(byte[] b, int off, int len) throws IOException {
177 ensureOpen();
178 if (b == null) {
179 throw new NullPointerException();
180 } else if (off < 0 || len < 0 || len > b.length - off) {
181 throw new IndexOutOfBoundsException();
182 } else if (len == 0) {
183 return 0;
184 }
185 try {
186 int n;
187 while ((n = inf.inflate(b, off, len)) == 0) {
188 if (inf.finished() || inf.needsDictionary()) {
189 reachEOF = true;
190 return -1;
191 }
192 if (inf.needsInput()) {
193 fill();
194 }
195 }
196 return n;
197 } catch (DataFormatException e) {
198 String s = e.getMessage();
199 throw new ZipException(s != null ? s : "Invalid ZLIB data format");
200 }
201 }
202
203 /**
204 * Returns 0 after EOF has been reached, otherwise always return 1.
205 * <p>
206 * Programs should not count on this method to return the actual number
207 * of bytes that could be read without blocking.
208 *
209 * @return 1 before EOF and 0 after EOF.
210 * @exception IOException if an I/O error occurs.
211 *
212 */
213 public int available() throws IOException {
214 ensureOpen();
215 if (reachEOF) {
216 return 0;
217 } else if (inf.finished()) {
218 // the end of the compressed data stream has been reached
219 reachEOF = true;
220 return 0;
221 } else {
222 return 1;
223 }
224 }
225
226 private byte[] b = new byte[512];
227
228 /**
229 * Skips specified number of bytes of uncompressed data.
230 * @param n the number of bytes to skip
231 * @return the actual number of bytes skipped.
232 * @exception IOException if an I/O error has occurred
233 * @exception IllegalArgumentException if {@code n < 0}
234 */
235 public long skip(long n) throws IOException {
236 if (n < 0) {
237 throw new IllegalArgumentException("negative skip length");
238 }
239 ensureOpen();
240 int max = (int)Math.min(n, Integer.MAX_VALUE);
241 int total = 0;
242 while (total < max) {
243 int len = max - total;
244 if (len > b.length) {
245 len = b.length;
246 }
247 len = read(b, 0, len);
248 if (len == -1) {
249 reachEOF = true;
250 break;
251 }
252 total += len;
253 }
254 return total;
255 }
256
257 /**
258 * Closes this input stream and releases any system resources associated
259 * with the stream.
260 * @exception IOException if an I/O error has occurred
261 */
262 public void close() throws IOException {
263 if (!closed) {
264 if (infRes != null)
265 infRes.clean();
266 else if (usesDefaultInflater)
267 inf.end();
268 in.close();
269 closed = true;
270 }
271 }
272
273 /**
274 * Fills input buffer with more data to decompress.
275 * @exception IOException if an I/O error has occurred
276 */
277 protected void fill() throws IOException {
278 ensureOpen();
279 len = in.read(buf, 0, buf.length);
280 if (len == -1) {
281 throw new EOFException("Unexpected end of ZLIB input stream");
282 }
283 inf.setInput(buf, 0, len);
284 }
285
286 /**
287 * Tests if this input stream supports the <code>mark</code> and
288 * <code>reset</code> methods. The <code>markSupported</code>
289 * method of <code>InflaterInputStream</code> returns
290 * <code>false</code>.
291 *
292 * @return a <code>boolean</code> indicating if this stream type supports
293 * the <code>mark</code> and <code>reset</code> methods.
294 * @see java.io.InputStream#mark(int)
295 * @see java.io.InputStream#reset()
296 */
297 public boolean markSupported() {
298 return false;
299 }
300
301 /**
302 * Marks the current position in this input stream.
303 *
304 * <p> The <code>mark</code> method of <code>InflaterInputStream</code>
305 * does nothing.
306 *
307 * @param readlimit the maximum limit of bytes that can be read before
308 * the mark position becomes invalid.
309 * @see java.io.InputStream#reset()
310 */
311 public synchronized void mark(int readlimit) {
312 }
313
314 /**
315 * Repositions this stream to the position at the time the
316 * <code>mark</code> method was last called on this input stream.
317 *
318 * <p> The method <code>reset</code> for class
319 * <code>InflaterInputStream</code> does nothing except throw an
320 * <code>IOException</code>.
321 *
322 * @exception IOException if this method is invoked.
323 * @see java.io.InputStream#mark(int)
324 * @see java.io.IOException
325 */
326 public synchronized void reset() throws IOException {
327 throw new IOException("mark/reset not supported");
328 }
329 }