[120] | 1 | /* |
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| 2 | * Licensed to the Apache Software Foundation (ASF) under one |
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| 3 | * or more contributor license agreements. See the NOTICE file |
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| 4 | * distributed with this work for additional information |
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| 5 | * regarding copyright ownership. The ASF licenses this file |
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| 6 | * to you under the Apache License, Version 2.0 (the |
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| 7 | * "License"); you may not use this file except in compliance |
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| 8 | * with the License. You may obtain a copy of the License at |
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| 9 | * |
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| 10 | * http://www.apache.org/licenses/LICENSE-2.0 |
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| 11 | * |
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| 12 | * Unless required by applicable law or agreed to in writing, software |
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| 13 | * distributed under the License is distributed on an "AS IS" BASIS, |
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| 14 | * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. |
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| 15 | * See the License for the specific language governing permissions and |
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| 16 | * limitations under the License. |
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| 17 | */ |
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| 18 | |
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| 19 | package org.apache.hadoop.io.compress; |
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| 20 | |
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| 21 | import java.io.EOFException; |
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| 22 | import java.io.IOException; |
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| 23 | import java.io.InputStream; |
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| 24 | |
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| 25 | import org.apache.hadoop.io.compress.Decompressor; |
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| 26 | |
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| 27 | public class DecompressorStream extends CompressionInputStream { |
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| 28 | protected Decompressor decompressor = null; |
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| 29 | protected byte[] buffer; |
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| 30 | protected boolean eof = false; |
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| 31 | protected boolean closed = false; |
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| 32 | |
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| 33 | public DecompressorStream(InputStream in, Decompressor decompressor, int bufferSize) { |
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| 34 | super(in); |
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| 35 | |
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| 36 | if (in == null || decompressor == null) { |
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| 37 | throw new NullPointerException(); |
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| 38 | } else if (bufferSize <= 0) { |
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| 39 | throw new IllegalArgumentException("Illegal bufferSize"); |
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| 40 | } |
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| 41 | |
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| 42 | this.decompressor = decompressor; |
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| 43 | buffer = new byte[bufferSize]; |
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| 44 | } |
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| 45 | |
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| 46 | public DecompressorStream(InputStream in, Decompressor decompressor) { |
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| 47 | this(in, decompressor, 512); |
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| 48 | } |
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| 49 | |
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| 50 | /** |
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| 51 | * Allow derived classes to directly set the underlying stream. |
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| 52 | * |
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| 53 | * @param in Underlying input stream. |
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| 54 | */ |
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| 55 | protected DecompressorStream(InputStream in) { |
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| 56 | super(in); |
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| 57 | } |
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| 58 | |
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| 59 | private byte[] oneByte = new byte[1]; |
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| 60 | public int read() throws IOException { |
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| 61 | checkStream(); |
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| 62 | return (read(oneByte, 0, oneByte.length) == -1) ? -1 : (oneByte[0] & 0xff); |
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| 63 | } |
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| 64 | |
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| 65 | public int read(byte[] b, int off, int len) throws IOException { |
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| 66 | checkStream(); |
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| 67 | |
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| 68 | if ((off | len | (off + len) | (b.length - (off + len))) < 0) { |
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| 69 | throw new IndexOutOfBoundsException(); |
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| 70 | } else if (len == 0) { |
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| 71 | return 0; |
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| 72 | } |
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| 73 | |
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| 74 | return decompress(b, off, len); |
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| 75 | } |
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| 76 | |
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| 77 | protected int decompress(byte[] b, int off, int len) throws IOException { |
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| 78 | int n = 0; |
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| 79 | |
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| 80 | while ((n = decompressor.decompress(b, off, len)) == 0) { |
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| 81 | if (decompressor.finished() || decompressor.needsDictionary()) { |
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| 82 | eof = true; |
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| 83 | return -1; |
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| 84 | } |
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| 85 | if (decompressor.needsInput()) { |
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| 86 | getCompressedData(); |
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| 87 | } |
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| 88 | } |
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| 89 | |
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| 90 | return n; |
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| 91 | } |
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| 92 | |
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| 93 | protected void getCompressedData() throws IOException { |
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| 94 | checkStream(); |
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| 95 | |
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| 96 | int n = in.read(buffer, 0, buffer.length); |
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| 97 | if (n == -1) { |
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| 98 | throw new EOFException("Unexpected end of input stream"); |
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| 99 | } |
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| 100 | |
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| 101 | decompressor.setInput(buffer, 0, n); |
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| 102 | } |
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| 103 | |
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| 104 | protected void checkStream() throws IOException { |
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| 105 | if (closed) { |
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| 106 | throw new IOException("Stream closed"); |
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| 107 | } |
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| 108 | } |
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| 109 | |
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| 110 | public void resetState() throws IOException { |
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| 111 | decompressor.reset(); |
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| 112 | } |
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| 113 | |
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| 114 | private byte[] skipBytes = new byte[512]; |
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| 115 | public long skip(long n) throws IOException { |
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| 116 | // Sanity checks |
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| 117 | if (n < 0) { |
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| 118 | throw new IllegalArgumentException("negative skip length"); |
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| 119 | } |
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| 120 | checkStream(); |
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| 121 | |
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| 122 | // Read 'n' bytes |
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| 123 | int skipped = 0; |
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| 124 | while (skipped < n) { |
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| 125 | int len = Math.min(((int)n - skipped), skipBytes.length); |
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| 126 | len = read(skipBytes, 0, len); |
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| 127 | if (len == -1) { |
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| 128 | eof = true; |
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| 129 | break; |
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| 130 | } |
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| 131 | skipped += len; |
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| 132 | } |
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| 133 | return skipped; |
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| 134 | } |
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| 135 | |
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| 136 | public int available() throws IOException { |
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| 137 | checkStream(); |
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| 138 | return (eof) ? 0 : 1; |
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| 139 | } |
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| 140 | |
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| 141 | public void close() throws IOException { |
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| 142 | if (!closed) { |
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| 143 | in.close(); |
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| 144 | closed = true; |
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| 145 | } |
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| 146 | } |
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| 147 | |
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| 148 | public boolean markSupported() { |
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| 149 | return false; |
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| 150 | } |
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| 151 | |
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| 152 | public synchronized void mark(int readlimit) { |
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| 153 | } |
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| 154 | |
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| 155 | public synchronized void reset() throws IOException { |
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| 156 | throw new IOException("mark/reset not supported"); |
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| 157 | } |
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| 158 | |
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| 159 | } |
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