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Diffstat (limited to 'framework/src/ant/apache-ant-1.9.6/src/main/org/apache/tools/tar/TarBuffer.java')
| -rw-r--r-- | framework/src/ant/apache-ant-1.9.6/src/main/org/apache/tools/tar/TarBuffer.java | 463 |
1 files changed, 463 insertions, 0 deletions
diff --git a/framework/src/ant/apache-ant-1.9.6/src/main/org/apache/tools/tar/TarBuffer.java b/framework/src/ant/apache-ant-1.9.6/src/main/org/apache/tools/tar/TarBuffer.java new file mode 100644 index 00000000..b089d9bf --- /dev/null +++ b/framework/src/ant/apache-ant-1.9.6/src/main/org/apache/tools/tar/TarBuffer.java @@ -0,0 +1,463 @@ +/* + * 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. + * + */ + +/* + * This package is based on the work done by Timothy Gerard Endres + * (time@ice.com) to whom the Ant project is very grateful for his great code. + */ + +package org.apache.tools.tar; + +import java.io.IOException; +import java.io.InputStream; +import java.io.OutputStream; +import java.util.Arrays; + +/** + * The TarBuffer class implements the tar archive concept + * of a buffered input stream. This concept goes back to the + * days of blocked tape drives and special io devices. In the + * Java universe, the only real function that this class + * performs is to ensure that files have the correct "block" + * size, or other tars will complain. + * <p> + * You should never have a need to access this class directly. + * TarBuffers are created by Tar IO Streams. + * + */ + +public class TarBuffer { + + /** Default record size */ + public static final int DEFAULT_RCDSIZE = (512); + + /** Default block size */ + public static final int DEFAULT_BLKSIZE = (DEFAULT_RCDSIZE * 20); + + private InputStream inStream; + private OutputStream outStream; + private final int blockSize; + private final int recordSize; + private final int recsPerBlock; + private final byte[] blockBuffer; + + private int currBlkIdx; + private int currRecIdx; + private boolean debug; + + /** + * Constructor for a TarBuffer on an input stream. + * @param inStream the input stream to use + */ + public TarBuffer(InputStream inStream) { + this(inStream, TarBuffer.DEFAULT_BLKSIZE); + } + + /** + * Constructor for a TarBuffer on an input stream. + * @param inStream the input stream to use + * @param blockSize the block size to use + */ + public TarBuffer(InputStream inStream, int blockSize) { + this(inStream, blockSize, TarBuffer.DEFAULT_RCDSIZE); + } + + /** + * Constructor for a TarBuffer on an input stream. + * @param inStream the input stream to use + * @param blockSize the block size to use + * @param recordSize the record size to use + */ + public TarBuffer(InputStream inStream, int blockSize, int recordSize) { + this(inStream, null, blockSize, recordSize); + } + + /** + * Constructor for a TarBuffer on an output stream. + * @param outStream the output stream to use + */ + public TarBuffer(OutputStream outStream) { + this(outStream, TarBuffer.DEFAULT_BLKSIZE); + } + + /** + * Constructor for a TarBuffer on an output stream. + * @param outStream the output stream to use + * @param blockSize the block size to use + */ + public TarBuffer(OutputStream outStream, int blockSize) { + this(outStream, blockSize, TarBuffer.DEFAULT_RCDSIZE); + } + + /** + * Constructor for a TarBuffer on an output stream. + * @param outStream the output stream to use + * @param blockSize the block size to use + * @param recordSize the record size to use + */ + public TarBuffer(OutputStream outStream, int blockSize, int recordSize) { + this(null, outStream, blockSize, recordSize); + } + + /** + * Private constructor to perform common setup. + */ + private TarBuffer(InputStream inStream, OutputStream outStream, int blockSize, int recordSize) { + this.inStream = inStream; + this.outStream = outStream; + this.debug = false; + this.blockSize = blockSize; + this.recordSize = recordSize; + this.recsPerBlock = (this.blockSize / this.recordSize); + this.blockBuffer = new byte[this.blockSize]; + + if (this.inStream != null) { + this.currBlkIdx = -1; + this.currRecIdx = this.recsPerBlock; + } else { + this.currBlkIdx = 0; + this.currRecIdx = 0; + } + } + + /** + * Get the TAR Buffer's block size. Blocks consist of multiple records. + * @return the block size + */ + public int getBlockSize() { + return this.blockSize; + } + + /** + * Get the TAR Buffer's record size. + * @return the record size + */ + public int getRecordSize() { + return this.recordSize; + } + + /** + * Set the debugging flag for the buffer. + * + * @param debug If true, print debugging output. + */ + public void setDebug(boolean debug) { + this.debug = debug; + } + + /** + * Determine if an archive record indicate End of Archive. End of + * archive is indicated by a record that consists entirely of null bytes. + * + * @param record The record data to check. + * @return true if the record data is an End of Archive + */ + public boolean isEOFRecord(byte[] record) { + for (int i = 0, sz = getRecordSize(); i < sz; ++i) { + if (record[i] != 0) { + return false; + } + } + + return true; + } + + /** + * Skip over a record on the input stream. + * @throws IOException on error + */ + public void skipRecord() throws IOException { + if (debug) { + System.err.println("SkipRecord: recIdx = " + currRecIdx + + " blkIdx = " + currBlkIdx); + } + + if (inStream == null) { + throw new IOException("reading (via skip) from an output buffer"); + } + + if (currRecIdx >= recsPerBlock && !readBlock()) { + return; // UNDONE + } + + currRecIdx++; + } + + /** + * Read a record from the input stream and return the data. + * + * @return The record data. + * @throws IOException on error + */ + public byte[] readRecord() throws IOException { + if (debug) { + System.err.println("ReadRecord: recIdx = " + currRecIdx + + " blkIdx = " + currBlkIdx); + } + + if (inStream == null) { + if (outStream == null) { + throw new IOException("input buffer is closed"); + } + throw new IOException("reading from an output buffer"); + } + + if (currRecIdx >= recsPerBlock && !readBlock()) { + return null; + } + + byte[] result = new byte[recordSize]; + + System.arraycopy(blockBuffer, + (currRecIdx * recordSize), result, 0, + recordSize); + + currRecIdx++; + + return result; + } + + /** + * @return false if End-Of-File, else true + */ + private boolean readBlock() throws IOException { + if (debug) { + System.err.println("ReadBlock: blkIdx = " + currBlkIdx); + } + + if (inStream == null) { + throw new IOException("reading from an output buffer"); + } + + currRecIdx = 0; + + int offset = 0; + int bytesNeeded = blockSize; + + while (bytesNeeded > 0) { + long numBytes = inStream.read(blockBuffer, offset, + bytesNeeded); + + // + // NOTE + // We have fit EOF, and the block is not full! + // + // This is a broken archive. It does not follow the standard + // blocking algorithm. However, because we are generous, and + // it requires little effort, we will simply ignore the error + // and continue as if the entire block were read. This does + // not appear to break anything upstream. We used to return + // false in this case. + // + // Thanks to 'Yohann.Roussel@alcatel.fr' for this fix. + // + if (numBytes == -1) { + if (offset == 0) { + // Ensure that we do not read gigabytes of zeros + // for a corrupt tar file. + // See http://issues.apache.org/bugzilla/show_bug.cgi?id=39924 + return false; + } + // However, just leaving the unread portion of the buffer dirty does + // cause problems in some cases. This problem is described in + // http://issues.apache.org/bugzilla/show_bug.cgi?id=29877 + // + // The solution is to fill the unused portion of the buffer with zeros. + + Arrays.fill(blockBuffer, offset, offset + bytesNeeded, (byte) 0); + + break; + } + + offset += numBytes; + bytesNeeded -= numBytes; + + if (numBytes != blockSize) { + if (debug) { + System.err.println("ReadBlock: INCOMPLETE READ " + + numBytes + " of " + blockSize + + " bytes read."); + } + } + } + + currBlkIdx++; + + return true; + } + + /** + * Get the current block number, zero based. + * + * @return The current zero based block number. + */ + public int getCurrentBlockNum() { + return currBlkIdx; + } + + /** + * Get the current record number, within the current block, zero based. + * Thus, current offset = (currentBlockNum * recsPerBlk) + currentRecNum. + * + * @return The current zero based record number. + */ + public int getCurrentRecordNum() { + return currRecIdx - 1; + } + + /** + * Write an archive record to the archive. + * + * @param record The record data to write to the archive. + * @throws IOException on error + */ + public void writeRecord(byte[] record) throws IOException { + if (debug) { + System.err.println("WriteRecord: recIdx = " + currRecIdx + + " blkIdx = " + currBlkIdx); + } + + if (outStream == null) { + if (inStream == null){ + throw new IOException("Output buffer is closed"); + } + throw new IOException("writing to an input buffer"); + } + + if (record.length != recordSize) { + throw new IOException("record to write has length '" + + record.length + + "' which is not the record size of '" + + recordSize + "'"); + } + + if (currRecIdx >= recsPerBlock) { + writeBlock(); + } + + System.arraycopy(record, 0, blockBuffer, + (currRecIdx * recordSize), + recordSize); + + currRecIdx++; + } + + /** + * Write an archive record to the archive, where the record may be + * inside of a larger array buffer. The buffer must be "offset plus + * record size" long. + * + * @param buf The buffer containing the record data to write. + * @param offset The offset of the record data within buf. + * @throws IOException on error + */ + public void writeRecord(byte[] buf, int offset) throws IOException { + if (debug) { + System.err.println("WriteRecord: recIdx = " + currRecIdx + + " blkIdx = " + currBlkIdx); + } + + if (outStream == null) { + if (inStream == null){ + throw new IOException("Output buffer is closed"); + } + throw new IOException("writing to an input buffer"); + } + + if ((offset + recordSize) > buf.length) { + throw new IOException("record has length '" + buf.length + + "' with offset '" + offset + + "' which is less than the record size of '" + + recordSize + "'"); + } + + if (currRecIdx >= recsPerBlock) { + writeBlock(); + } + + System.arraycopy(buf, offset, blockBuffer, + (currRecIdx * recordSize), + recordSize); + + currRecIdx++; + } + + /** + * Write a TarBuffer block to the archive. + */ + private void writeBlock() throws IOException { + if (debug) { + System.err.println("WriteBlock: blkIdx = " + currBlkIdx); + } + + if (outStream == null) { + throw new IOException("writing to an input buffer"); + } + + outStream.write(blockBuffer, 0, blockSize); + outStream.flush(); + + currRecIdx = 0; + currBlkIdx++; + Arrays.fill(blockBuffer, (byte) 0); + } + + /** + * Flush the current data block if it has any data in it. + */ + void flushBlock() throws IOException { + if (debug) { + System.err.println("TarBuffer.flushBlock() called."); + } + + if (outStream == null) { + throw new IOException("writing to an input buffer"); + } + + if (currRecIdx > 0) { + writeBlock(); + } + } + + /** + * Close the TarBuffer. If this is an output buffer, also flush the + * current block before closing. + * @throws IOException on error + */ + public void close() throws IOException { + if (debug) { + System.err.println("TarBuffer.closeBuffer()."); + } + + if (outStream != null) { + flushBlock(); + + if (outStream != System.out + && outStream != System.err) { + outStream.close(); + + outStream = null; + } + } else if (inStream != null) { + if (inStream != System.in) { + inStream.close(); + } + inStream = null; + } + } +} |