org.apache.tika.parser.mp4.DirectFileReadDataSource Maven / Gradle / Ivy
/*
* 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.tika.parser.mp4;
import static com.googlecode.mp4parser.util.CastUtils.l2i;
import java.io.File;
import java.io.IOException;
import java.io.RandomAccessFile;
import java.math.BigInteger;
import java.nio.ByteBuffer;
import java.nio.channels.WritableByteChannel;
import com.googlecode.mp4parser.DataSource;
/**
* A {@link DataSource} implementation that relies on direct reads from a {@link RandomAccessFile}.
* It should be slower than {@link com.googlecode.mp4parser.FileDataSourceImpl} but does not incur the implicit file locks of
* memory mapped I/O on some JVMs. This implementation allows for a more controlled deletion of files
* and might be preferred when working with temporary files.
* @see JDK-4724038 : (fs) Add unmap method to MappedByteBuffer
* @see JDK-6359560 : (fs) File.deleteOnExit() doesn't work when MappedByteBuffer exists (win)
*/
public class DirectFileReadDataSource implements DataSource {
private static final int TRANSFER_SIZE = 8192;
private RandomAccessFile raf;
public DirectFileReadDataSource(File f) throws IOException {
this.raf = new RandomAccessFile(f, "r");
}
public int read(ByteBuffer byteBuffer) throws IOException {
int len = byteBuffer.remaining();
int totalRead = 0;
int bytesRead = 0;
byte[] buf = new byte[TRANSFER_SIZE];
while (totalRead < len) {
int bytesToRead = Math.min((len - totalRead), TRANSFER_SIZE);
bytesRead = raf.read(buf, 0, bytesToRead);
if (bytesRead < 0) {
break;
} else {
totalRead += bytesRead;
}
byteBuffer.put(buf, 0, bytesRead);
}
if (bytesRead < 0 && position() == size() && byteBuffer.hasRemaining()) {
throw new IOException("End of stream reached earlier than expected");
}
return ((bytesRead < 0) && (totalRead == 0)) ? -1 : totalRead;
}
public int readAllInOnce(ByteBuffer byteBuffer) throws IOException {
if (byteBuffer.remaining() > raf.length()) {
throw new IOException("trying to readAllInOnce past end of stream");
}
byte[] buf = new byte[byteBuffer.remaining()];
int read = raf.read(buf);
byteBuffer.put(buf, 0, read);
return read;
}
public long size() throws IOException {
return raf.length();
}
public long position() throws IOException {
return raf.getFilePointer();
}
public void position(long nuPos) throws IOException {
if (nuPos > raf.length()) {
throw new IOException("requesting seek past end of stream");
}
raf.seek(nuPos);
}
public long transferTo(long position, long count, WritableByteChannel target) throws IOException {
return target.write(map(position, count));
}
public ByteBuffer map(long startPosition, long size) throws IOException {
if (startPosition < 0 || size < 0) {
throw new IOException("startPosition and size must both be >= 0");
}
//make sure that start+size aren't greater than avail size
//in raf.
BigInteger end = BigInteger.valueOf(startPosition);
end = end.add(BigInteger.valueOf(size));
if (end.compareTo(BigInteger.valueOf(raf.length())) > 0) {
throw new IOException("requesting read past end of stream");
}
raf.seek(startPosition);
int payLoadSize = l2i(size);
//hack to check for potential overflow
if (Long.MAX_VALUE-payLoadSize < startPosition ||
Long.MAX_VALUE-payLoadSize > raf.length()) {
throw new IOException("requesting read past end of stream");
}
byte[] payload = new byte[payLoadSize];
raf.readFully(payload);
return ByteBuffer.wrap(payload);
}
@Override
public void close() throws IOException {
raf.close();
}
}