| /* |
| * Licensed to the Apache Software Foundation (ASF) under one |
| * or more contributor license agreements. See the NOTICE file |
| * distributed with this work for additional information |
| * regarding copyright ownership. The ASF licenses this file |
| * to you under the Apache License, Version 2.0 (the |
| * "License"); you may not use this file except in compliance |
| * with the License. You may obtain a copy of the License at |
| * |
| * http://www.apache.org/licenses/LICENSE-2.0 |
| * |
| * Unless required by applicable law or agreed to in writing, |
| * software distributed under the License is distributed on an |
| * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY |
| * KIND, either express or implied. See the License for the |
| * specific language governing permissions and limitations |
| * under the License. |
| */ |
| package org.apache.commons.compress.archivers.dump; |
| |
| import java.io.FilterInputStream; |
| import java.io.IOException; |
| import java.io.InputStream; |
| |
| import java.util.Arrays; |
| import java.util.zip.DataFormatException; |
| import java.util.zip.Inflater; |
| |
| |
| /** |
| * Filter stream that mimics a physical tape drive capable of compressing |
| * the data stream. |
| * |
| * @NotThreadSafe |
| */ |
| class TapeInputStream extends FilterInputStream { |
| private byte[] blockBuffer = new byte[DumpArchiveConstants.TP_SIZE]; |
| private int currBlkIdx = -1; |
| private int blockSize = DumpArchiveConstants.TP_SIZE; |
| private final int recordSize = DumpArchiveConstants.TP_SIZE; |
| private int readOffset = DumpArchiveConstants.TP_SIZE; |
| private boolean isCompressed = false; |
| private long bytesRead = 0; |
| |
| /** |
| * Constructor |
| */ |
| public TapeInputStream(InputStream in) { |
| super(in); |
| } |
| |
| /** |
| * Set the DumpArchive Buffer's block size. We need to sync the block size with the |
| * dump archive's actual block size since compression is handled at the |
| * block level. |
| * |
| * @param recsPerBlock |
| * records per block |
| * @param isCompressed |
| * true if the archive is compressed |
| * @throws IOException |
| * more than one block has been read |
| * @throws IOException |
| * there was an error reading additional blocks. |
| */ |
| public void resetBlockSize(int recsPerBlock, boolean isCompressed) |
| throws IOException { |
| this.isCompressed = isCompressed; |
| |
| blockSize = recordSize * recsPerBlock; |
| |
| // save first block in case we need it again |
| byte[] oldBuffer = blockBuffer; |
| |
| // read rest of new block |
| blockBuffer = new byte[blockSize]; |
| System.arraycopy(oldBuffer, 0, blockBuffer, 0, recordSize); |
| readFully(blockBuffer, recordSize, blockSize - recordSize); |
| |
| this.currBlkIdx = 0; |
| this.readOffset = recordSize; |
| } |
| |
| /** |
| * @see java.io.InputStream#available |
| */ |
| @Override |
| public int available() throws IOException { |
| if (readOffset < blockSize) { |
| return blockSize - readOffset; |
| } |
| |
| return in.available(); |
| } |
| |
| /** |
| * @see java.io.InputStream#read() |
| */ |
| @Override |
| public int read() throws IOException { |
| throw new IllegalArgumentException( |
| "all reads must be multiple of record size (" + recordSize + |
| " bytes."); |
| } |
| |
| /** |
| * {@inheritDoc} |
| * |
| * <p>reads the full given length unless EOF is reached.</p> |
| * |
| * @param len length to read, must be a multiple of the stream's |
| * record size |
| */ |
| @Override |
| public int read(byte[] b, int off, int len) throws IOException { |
| if ((len % recordSize) != 0) { |
| throw new IllegalArgumentException( |
| "all reads must be multiple of record size (" + recordSize + |
| " bytes."); |
| } |
| |
| int bytes = 0; |
| |
| while (bytes < len) { |
| // we need to read from the underlying stream. |
| // this will reset readOffset value. |
| // return -1 if there's a problem. |
| if ((readOffset == blockSize) && !readBlock(true)) { |
| return -1; |
| } |
| |
| int n = 0; |
| |
| if ((readOffset + (len - bytes)) <= blockSize) { |
| // we can read entirely from the buffer. |
| n = len - bytes; |
| } else { |
| // copy what we can from the buffer. |
| n = blockSize - readOffset; |
| } |
| |
| // copy data, increment counters. |
| System.arraycopy(blockBuffer, readOffset, b, off, n); |
| readOffset += n; |
| bytes += n; |
| off += n; |
| } |
| |
| return bytes; |
| } |
| |
| /** |
| * Skip bytes. Same as read but without the arraycopy. |
| * |
| * <p>skips the full given length unless EOF is reached.</p> |
| * |
| * @param len length to read, must be a multiple of the stream's |
| * record size |
| */ |
| @Override |
| public long skip(long len) throws IOException { |
| if ((len % recordSize) != 0) { |
| throw new IllegalArgumentException( |
| "all reads must be multiple of record size (" + recordSize + |
| " bytes."); |
| } |
| |
| long bytes = 0; |
| |
| while (bytes < len) { |
| // we need to read from the underlying stream. |
| // this will reset readOffset value. We do not perform |
| // any decompression if we won't eventually read the data. |
| // return -1 if there's a problem. |
| if ((readOffset == blockSize) && |
| !readBlock((len - bytes) < blockSize)) { |
| return -1; |
| } |
| |
| long n = 0; |
| |
| if ((readOffset + (len - bytes)) <= blockSize) { |
| // we can read entirely from the buffer. |
| n = len - bytes; |
| } else { |
| // copy what we can from the buffer. |
| n = blockSize - readOffset; |
| } |
| |
| // do not copy data but still increment counters. |
| readOffset += n; |
| bytes += n; |
| } |
| |
| return bytes; |
| } |
| |
| /** |
| * Close the input stream. |
| * |
| * @throws IOException on error |
| */ |
| @Override |
| public void close() throws IOException { |
| if (in != null && in != System.in) { |
| in.close(); |
| } |
| } |
| |
| /** |
| * Peek at the next record from the input stream and return the data. |
| * |
| * @return The record data. |
| * @throws IOException on error |
| */ |
| public byte[] peek() throws IOException { |
| // we need to read from the underlying stream. This |
| // isn't a problem since it would be the first step in |
| // any subsequent read() anyway. |
| if ((readOffset == blockSize) && !readBlock(true)) { |
| return null; |
| } |
| |
| // copy data, increment counters. |
| byte[] b = new byte[recordSize]; |
| System.arraycopy(blockBuffer, readOffset, b, 0, b.length); |
| |
| return b; |
| } |
| |
| /** |
| * Read a record from the input stream and return the data. |
| * |
| * @return The record data. |
| * @throws IOException on error |
| */ |
| public byte[] readRecord() throws IOException { |
| byte[] result = new byte[recordSize]; |
| |
| if (-1 == read(result, 0, result.length)) { |
| throw new ShortFileException(); |
| } |
| |
| return result; |
| } |
| |
| /** |
| * Read next block. All decompression is handled here. |
| * |
| * @param decompress if false the buffer will not be decompressed. |
| * This is an optimization for longer seeks. |
| * @return false if End-Of-File, else true |
| */ |
| private boolean readBlock(boolean decompress) throws IOException { |
| boolean success = true; |
| |
| if (in == null) { |
| throw new IOException("input buffer is closed"); |
| } |
| |
| if (!isCompressed || (currBlkIdx == -1)) { |
| // file is not compressed |
| success = readFully(blockBuffer, 0, blockSize); |
| bytesRead += blockSize; |
| } else { |
| if (!readFully(blockBuffer, 0, 4)) { |
| return false; |
| } |
| bytesRead += 4; |
| |
| int h = DumpArchiveUtil.convert32(blockBuffer, 0); |
| boolean compressed = (h & 0x01) == 0x01; |
| |
| if (!compressed) { |
| // file is compressed but this block is not. |
| success = readFully(blockBuffer, 0, blockSize); |
| bytesRead += blockSize; |
| } else { |
| // this block is compressed. |
| int flags = (h >> 1) & 0x07; |
| int length = (h >> 4) & 0x0FFFFFFF; |
| byte[] compBuffer = new byte[length]; |
| success = readFully(compBuffer, 0, length); |
| bytesRead += length; |
| |
| if (!decompress) { |
| // just in case someone reads the data. |
| Arrays.fill(blockBuffer, (byte) 0); |
| } else { |
| switch (DumpArchiveConstants.COMPRESSION_TYPE.find(flags & |
| 0x03)) { |
| case ZLIB: |
| |
| try { |
| Inflater inflator = new Inflater(); |
| inflator.setInput(compBuffer, 0, compBuffer.length); |
| length = inflator.inflate(blockBuffer); |
| |
| if (length != blockSize) { |
| throw new ShortFileException(); |
| } |
| |
| inflator.end(); |
| } catch (DataFormatException e) { |
| throw new DumpArchiveException("bad data", e); |
| } |
| |
| break; |
| |
| case BZLIB: |
| throw new UnsupportedCompressionAlgorithmException( |
| "BZLIB2"); |
| |
| case LZO: |
| throw new UnsupportedCompressionAlgorithmException( |
| "LZO"); |
| |
| default: |
| throw new UnsupportedCompressionAlgorithmException(); |
| } |
| } |
| } |
| } |
| |
| currBlkIdx++; |
| readOffset = 0; |
| |
| return success; |
| } |
| |
| /** |
| * Read buffer |
| */ |
| private boolean readFully(byte[] b, int off, int len) |
| throws IOException { |
| int count = 0; |
| |
| while (count < len) { |
| int n = in.read(b, off + count, len - count); |
| |
| if (n == -1) { |
| throw new ShortFileException(); |
| } |
| |
| count += n; |
| } |
| |
| return true; |
| } |
| |
| /** |
| * Get number of bytes read. |
| */ |
| public long getBytesRead() { |
| return bytesRead; |
| } |
| } |