001/* 002 * Licensed to the Apache Software Foundation (ASF) under one 003 * or more contributor license agreements. See the NOTICE file 004 * distributed with this work for additional information 005 * regarding copyright ownership. The ASF licenses this file 006 * to you under the Apache License, Version 2.0 (the 007 * "License"); you may not use this file except in compliance 008 * with the License. You may obtain a copy of the License at 009 * 010 * http://www.apache.org/licenses/LICENSE-2.0 011 * 012 * Unless required by applicable law or agreed to in writing, 013 * software distributed under the License is distributed on an 014 * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY 015 * KIND, either express or implied. See the License for the 016 * specific language governing permissions and limitations 017 * under the License. 018 */ 019package org.apache.commons.compress.compressors.xz; 020 021import java.io.IOException; 022import java.io.InputStream; 023 024import org.apache.commons.compress.MemoryLimitException; 025import org.apache.commons.compress.compressors.CompressorInputStream; 026import org.apache.commons.compress.utils.CountingInputStream; 027import org.apache.commons.compress.utils.IOUtils; 028import org.apache.commons.compress.utils.InputStreamStatistics; 029import org.tukaani.xz.SingleXZInputStream; 030import org.tukaani.xz.XZ; 031import org.tukaani.xz.XZInputStream; 032 033/** 034 * XZ decompressor. 035 * @since 1.4 036 */ 037public class XZCompressorInputStream extends CompressorInputStream 038 implements InputStreamStatistics { 039 040 /** 041 * Checks if the signature matches what is expected for a .xz file. 042 * 043 * @param signature the bytes to check 044 * @param length the number of bytes to check 045 * @return true if signature matches the .xz magic bytes, false otherwise 046 */ 047 public static boolean matches(final byte[] signature, final int length) { 048 if (length < XZ.HEADER_MAGIC.length) { 049 return false; 050 } 051 052 for (int i = 0; i < XZ.HEADER_MAGIC.length; ++i) { 053 if (signature[i] != XZ.HEADER_MAGIC[i]) { 054 return false; 055 } 056 } 057 058 return true; 059 } 060 private final CountingInputStream countingStream; 061 062 private final InputStream in; 063 064 /** 065 * Creates a new input stream that decompresses XZ-compressed data 066 * from the specified input stream. This doesn't support 067 * concatenated .xz files. 068 * 069 * @param inputStream where to read the compressed data 070 * 071 * @throws IOException if the input is not in the .xz format, 072 * the input is corrupt or truncated, the .xz 073 * headers specify options that are not supported 074 * by this implementation, or the underlying 075 * {@code inputStream} throws an exception 076 */ 077 public XZCompressorInputStream(final InputStream inputStream) 078 throws IOException { 079 this(inputStream, false); 080 } 081 082 /** 083 * Creates a new input stream that decompresses XZ-compressed data 084 * from the specified input stream. 085 * 086 * @param inputStream where to read the compressed data 087 * @param decompressConcatenated 088 * if true, decompress until the end of the 089 * input; if false, stop after the first .xz 090 * stream and leave the input position to point 091 * to the next byte after the .xz stream 092 * 093 * @throws IOException if the input is not in the .xz format, 094 * the input is corrupt or truncated, the .xz 095 * headers specify options that are not supported 096 * by this implementation, or the underlying 097 * {@code inputStream} throws an exception 098 */ 099 public XZCompressorInputStream(final InputStream inputStream, 100 final boolean decompressConcatenated) 101 throws IOException { 102 this(inputStream, decompressConcatenated, -1); 103 } 104 105 /** 106 * Creates a new input stream that decompresses XZ-compressed data 107 * from the specified input stream. 108 * 109 * @param inputStream where to read the compressed data 110 * @param decompressConcatenated 111 * if true, decompress until the end of the 112 * input; if false, stop after the first .xz 113 * stream and leave the input position to point 114 * to the next byte after the .xz stream 115 * @param memoryLimitInKb memory limit used when reading blocks. If 116 * the estimated memory limit is exceeded on {@link #read()}, 117 * a {@link MemoryLimitException} is thrown. 118 * 119 * @throws IOException if the input is not in the .xz format, 120 * the input is corrupt or truncated, the .xz 121 * headers specify options that are not supported 122 * by this implementation, 123 * or the underlying {@code inputStream} throws an exception 124 * 125 * @since 1.14 126 */ 127 public XZCompressorInputStream(final InputStream inputStream, 128 final boolean decompressConcatenated, final int memoryLimitInKb) 129 throws IOException { 130 countingStream = new CountingInputStream(inputStream); 131 if (decompressConcatenated) { 132 in = new XZInputStream(countingStream, memoryLimitInKb); 133 } else { 134 in = new SingleXZInputStream(countingStream, memoryLimitInKb); 135 } 136 } 137 138 @Override 139 public int available() throws IOException { 140 return in.available(); 141 } 142 143 @Override 144 public void close() throws IOException { 145 in.close(); 146 } 147 148 /** 149 * @since 1.17 150 */ 151 @Override 152 public long getCompressedCount() { 153 return countingStream.getBytesRead(); 154 } 155 156 @Override 157 public int read() throws IOException { 158 try { 159 final int ret = in.read(); 160 count(ret == -1 ? -1 : 1); 161 return ret; 162 } catch (final org.tukaani.xz.MemoryLimitException e) { 163 throw new MemoryLimitException(e.getMemoryNeeded(), e.getMemoryLimit(), e); 164 } 165 } 166 167 @Override 168 public int read(final byte[] buf, final int off, final int len) throws IOException { 169 if (len == 0) { 170 return 0; 171 } 172 try { 173 final int ret = in.read(buf, off, len); 174 count(ret); 175 return ret; 176 } catch (final org.tukaani.xz.MemoryLimitException e) { 177 //convert to commons-compress MemoryLimtException 178 throw new MemoryLimitException(e.getMemoryNeeded(), e.getMemoryLimit(), e); 179 } 180 } 181 182 @Override 183 public long skip(final long n) throws IOException { 184 try { 185 return IOUtils.skip(in, n); 186 } catch (final org.tukaani.xz.MemoryLimitException e) { 187 //convert to commons-compress MemoryLimtException 188 throw new MemoryLimitException(e.getMemoryNeeded(), e.getMemoryLimit(), e); 189 } 190 } 191}