/*
* Copyright 2011 The Netty Project
*
* The Netty Project 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 io.netty.handler.stream;
import static io.netty.buffer.ChannelBuffers.*;
import java.nio.ByteBuffer;
import java.nio.channels.ReadableByteChannel;
import io.netty.buffer.ChannelBuffer;
/**
* A {@link ChunkedInput} that fetches data from a {@link ReadableByteChannel}
* chunk by chunk. Please note that the {@link ReadableByteChannel} must
* operate in blocking mode. Non-blocking mode channels are not supported.
*/
public class ChunkedNioStream implements ChunkedInput {
private final ReadableByteChannel in;
private final int chunkSize;
private volatile long offset;
/**
* Associated ByteBuffer
*/
private final ByteBuffer byteBuffer;
/**
* Creates a new instance that fetches data from the specified channel.
*/
public ChunkedNioStream(ReadableByteChannel in) {
this(in, ChunkedStream.DEFAULT_CHUNK_SIZE);
}
/**
* Creates a new instance that fetches data from the specified channel.
*
* @param chunkSize the number of bytes to fetch on each
* {@link #nextChunk()} call
*/
public ChunkedNioStream(ReadableByteChannel in, int chunkSize) {
if (in == null) {
throw new NullPointerException("in");
}
if (chunkSize <= 0) {
throw new IllegalArgumentException("chunkSize: " + chunkSize +
" (expected: a positive integer)");
}
this.in = in;
offset = 0;
this.chunkSize = chunkSize;
byteBuffer = ByteBuffer.allocate(chunkSize);
}
/**
* Returns the number of transferred bytes.
*/
public long getTransferredBytes() {
return offset;
}
@Override
public boolean isEndOfInput() throws Exception {
if (byteBuffer.position() > 0) {
// A previous read was not over, so there is a next chunk in the buffer at least
return false;
}
if (in.isOpen()) {
// Try to read a new part, and keep this part (no rewind)
int b = in.read(byteBuffer);
if (b < 0) {
return true;
} else {
offset += b;
return false;
}
}
return true;
}
@Override
public void close() throws Exception {
in.close();
}
@Override
public Object nextChunk() throws Exception {
if (isEndOfInput()) {
return null;
}
// buffer cannot be not be empty from there
int readBytes = byteBuffer.position();
for (;;) {
int localReadBytes = in.read(byteBuffer);
if (localReadBytes < 0) {
break;
}
readBytes += localReadBytes;
offset += localReadBytes;
if (readBytes == chunkSize) {
break;
}
}
byteBuffer.flip();
// copy since buffer is keeped for next usage
ChannelBuffer buffer = copiedBuffer(byteBuffer);
byteBuffer.clear();
return buffer;
}
}