1 /*
2 * Licensed to the Apache Software Foundation (ASF) under one
3 * or more contributor license agreements. See the NOTICE file
4 * distributed with this work for additional information
5 * regarding copyright ownership. The ASF licenses this file
6 * to you under the Apache License, Version 2.0 (the
7 * "License"); you may not use this file except in compliance
8 * with the License. You may obtain a copy of the License at
9 *
10 * http://www.apache.org/licenses/LICENSE-2.0
11 *
12 * Unless required by applicable law or agreed to in writing,
13 * software distributed under the License is distributed on an
14 * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
15 * KIND, either express or implied. See the License for the
16 * specific language governing permissions and limitations
17 * under the License.
18 */
19 package org.apache.commons.compress.compressors.lzma;
20
21 import java.io.IOException;
22 import java.io.InputStream;
23
24 import org.apache.commons.compress.MemoryLimitException;
25 import org.apache.commons.compress.compressors.CompressorInputStream;
26 import org.apache.commons.compress.utils.InputStreamStatistics;
27 import org.apache.commons.io.input.BoundedInputStream;
28 import org.tukaani.xz.LZMAInputStream;
29
30 /**
31 * LZMA decompressor.
32 *
33 * @since 1.6
34 */
35 public class LZMACompressorInputStream extends CompressorInputStream implements InputStreamStatistics {
36
37 /**
38 * Checks if the signature matches what is expected for an LZMA file.
39 *
40 * @param signature the bytes to check
41 * @param length the number of bytes to check
42 * @return true, if this stream is an LZMA compressed stream, false otherwise
43 *
44 * @since 1.10
45 */
46 public static boolean matches(final byte[] signature, final int length) {
47 return signature != null && length >= 3 && signature[0] == 0x5d && signature[1] == 0 && signature[2] == 0;
48 }
49
50 private final BoundedInputStream countingStream;
51
52 private final InputStream in;
53
54 /**
55 * Creates a new input stream that decompresses LZMA-compressed data from the specified input stream.
56 *
57 * @param inputStream where to read the compressed data
58 *
59 * @throws IOException if the input is not in the .lzma format, the input is corrupt or truncated, the .lzma headers specify sizes that are not supported by
60 * this implementation, or the underlying {@code inputStream} throws an exception
61 */
62 public LZMACompressorInputStream(final InputStream inputStream) throws IOException {
63 in = new LZMAInputStream(countingStream = BoundedInputStream.builder().setInputStream(inputStream).get(), -1);
64 }
65
66 /**
67 * Creates a new input stream that decompresses LZMA-compressed data from the specified input stream.
68 *
69 * @param inputStream where to read the compressed data
70 *
71 * @param memoryLimitInKb calculated memory use threshold. Throws MemoryLimitException if calculate memory use is above this threshold
72 *
73 * @throws IOException if the input is not in the .lzma format, the input is corrupt or truncated, the .lzma headers specify sizes that are not supported by
74 * this implementation, or the underlying {@code inputStream} throws an exception
75 *
76 * @since 1.14
77 */
78 public LZMACompressorInputStream(final InputStream inputStream, final int memoryLimitInKb) throws IOException {
79 try {
80 in = new LZMAInputStream(countingStream = BoundedInputStream.builder().setInputStream(inputStream).get(), memoryLimitInKb);
81 } catch (final org.tukaani.xz.MemoryLimitException e) {
82 // convert to commons-compress exception
83 throw new MemoryLimitException(e.getMemoryNeeded(), e.getMemoryLimit(), e);
84 }
85 }
86
87 /** {@inheritDoc} */
88 @Override
89 public int available() throws IOException {
90 return in.available();
91 }
92
93 /** {@inheritDoc} */
94 @Override
95 public void close() throws IOException {
96 in.close();
97 }
98
99 /**
100 * @since 1.17
101 */
102 @Override
103 public long getCompressedCount() {
104 return countingStream.getCount();
105 }
106
107 /** {@inheritDoc} */
108 @Override
109 public int read() throws IOException {
110 final int ret = in.read();
111 count(ret == -1 ? 0 : 1);
112 return ret;
113 }
114
115 /** {@inheritDoc} */
116 @Override
117 public int read(final byte[] buf, final int off, final int len) throws IOException {
118 final int ret = in.read(buf, off, len);
119 count(ret);
120 return ret;
121 }
122
123 /** {@inheritDoc} */
124 @Override
125 public long skip(final long n) throws IOException {
126 return org.apache.commons.io.IOUtils.skip(in, n);
127 }
128 }