/*
* ====================================================================
* 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 software consists of voluntary contributions made by many
* individuals on behalf of the Apache Software Foundation. For more
* information on the Apache Software Foundation, please see
* <http://www.apache.org/>.
*
*/
package org.apach3.http.impl.nio.codecs;
import java.io.IOException;
import java.nio.ByteBuffer;
import java.nio.channels.FileChannel;
import java.nio.channels.ReadableByteChannel;
import org.apach3.http.ConnectionClosedException;
import org.apach3.http.annotation.NotThreadSafe;
import org.apach3.http.impl.io.HttpTransportMetricsImpl;
import org.apach3.http.nio.FileContentDecoder;
import org.apach3.http.nio.reactor.SessionInputBuffer;
/**
* Content decoder that cuts off after a defined number of bytes. This class
* is used to receive content of HTTP messages where the end of the content
* entity is determined by the value of the <code>Content-Length header</code>.
* Entities transferred using this stream can be maximum {@link Long#MAX_VALUE}
* long.
* <p>
* This decoder is optimized to transfer data directly from the underlying
* I/O session's channel to a {@link FileChannel}, whenever
* possible avoiding intermediate buffering in the session buffer.
*
* @since 4.0
*/
@NotThreadSafe
public class LengthDelimitedDecoder extends AbstractContentDecoder
implements FileContentDecoder {
private final long contentLength;
private long len;
public LengthDelimitedDecoder(
final ReadableByteChannel channel,
final SessionInputBuffer buffer,
final HttpTransportMetricsImpl metrics,
long contentLength) {
super(channel, buffer, metrics);
if (contentLength < 0) {
throw new IllegalArgumentException("Content length may not be negative");
}
this.contentLength = contentLength;
}
public int read(final ByteBuffer dst) throws IOException {
if (dst == null) {
throw new IllegalArgumentException("Byte buffer may not be null");
}
if (this.completed) {
return -1;
}
int chunk = (int) Math.min((this.contentLength - this.len), Integer.MAX_VALUE);
int bytesRead;
if (this.buffer.hasData()) {
int maxLen = Math.min(chunk, this.buffer.length());
bytesRead = this.buffer.read(dst, maxLen);
} else {
if (dst.remaining() > chunk) {
int oldLimit = dst.limit();
int newLimit = oldLimit - (dst.remaining() - chunk);
dst.limit(newLimit);
bytesRead = this.channel.read(dst);
dst.limit(oldLimit);
} else {
bytesRead = this.channel.read(dst);
}
if (bytesRead > 0) {
this.metrics.incrementBytesTransferred(bytesRead);
}
}
if (bytesRead == -1) {
this.completed = true;
if (this.len < this.contentLength) {
throw new ConnectionClosedException(
"Premature end of Content-Length delimited message body (expected: "
+ this.contentLength + "; received: " + this.len);
}
}
this.len += bytesRead;
if (this.len >= this.contentLength) {
this.completed = true;
}
if (this.completed && bytesRead == 0) {
return -1;
} else {
return bytesRead;
}
}
public long transfer(
final FileChannel dst,
long position,
long count) throws IOException {
if (dst == null) {
return 0;
}
if (this.completed) {
return -1;
}
int chunk = (int) Math.min((this.contentLength - this.len), Integer.MAX_VALUE);
long bytesRead;
if (this.buffer.hasData()) {
int maxLen = Math.min(chunk, this.buffer.length());
dst.position(position);
bytesRead = this.buffer.read(dst, maxLen);
} else {
if (count > chunk) {
count = chunk;
}
if (this.channel.isOpen()) {
if (position > dst.size()) {
throw new IOException("Position past end of file [" + position +
" > " + dst.size() + "]");
}
bytesRead = dst.transferFrom(this.channel, position, count);
} else {
bytesRead = -1;
}
if (bytesRead > 0) {
this.metrics.incrementBytesTransferred(bytesRead);
}
}
if (bytesRead == -1) {
this.completed = true;
if (this.len < this.contentLength) {
throw new ConnectionClosedException(
"Premature end of Content-Length delimited message body (expected: "
+ this.contentLength + "; received: " + this.len);
}
}
this.len += bytesRead;
if (this.len >= this.contentLength) {
this.completed = true;
}
return bytesRead;
}
@Override
public String toString() {
StringBuilder buffer = new StringBuilder();
buffer.append("[content length: ");
buffer.append(this.contentLength);
buffer.append("; pos: ");
buffer.append(this.len);
buffer.append("; completed: ");
buffer.append(this.completed);
buffer.append("]");
return buffer.toString();
}
}