org.apache.http.impl.nio.codecs.IdentityDecoder Maven / Gradle / Ivy
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/*
* ====================================================================
* 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
* .
*
*/
package org.apache.http.impl.nio.codecs;
import java.io.IOException;
import java.nio.ByteBuffer;
import java.nio.channels.FileChannel;
import java.nio.channels.ReadableByteChannel;
import org.apache.http.impl.io.HttpTransportMetricsImpl;
import org.apache.http.nio.FileContentDecoder;
import org.apache.http.nio.reactor.SessionInputBuffer;
import org.apache.http.util.Args;
/**
* Content decoder that reads data without any transformation. The end of the
* content entity is delineated by closing the underlying connection
* (EOF condition). Entities transferred using this input stream can be of
* unlimited length.
*
* 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
*/
public class IdentityDecoder extends AbstractContentDecoder
implements FileContentDecoder {
public IdentityDecoder(
final ReadableByteChannel channel,
final SessionInputBuffer buffer,
final HttpTransportMetricsImpl metrics) {
super(channel, buffer, metrics);
}
/**
* Sets the completed status of this decoder. Normally this is not necessary
* (the decoder will automatically complete when the underlying channel
* returns EOF). It is useful to mark the decoder as completed if you have
* some other means to know all the necessary data has been read and want to
* reuse the underlying connection for more messages.
*/
public void setCompleted(final boolean completed) {
this.completed = completed;
}
@Override
public int read(final ByteBuffer dst) throws IOException {
Args.notNull(dst, "Byte buffer");
if (this.completed) {
return -1;
}
final int bytesRead;
if (this.buffer.hasData()) {
bytesRead = this.buffer.read(dst);
} else {
bytesRead = readFromChannel(dst);
}
if (bytesRead == -1) {
this.completed = true;
}
return bytesRead;
}
@Override
public long transfer(
final FileChannel dst,
final long position,
final long count) throws IOException {
if (dst == null) {
return 0;
}
if (this.completed) {
return 0;
}
long bytesRead;
if (this.buffer.hasData()) {
dst.position(position);
bytesRead = this.buffer.read(dst);
} else {
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);
if (count > 0 && bytesRead == 0) {
bytesRead = this.buffer.fill(this.channel);
}
} else {
bytesRead = -1;
}
if (bytesRead > 0) {
this.metrics.incrementBytesTransferred(bytesRead);
}
}
if (bytesRead == -1) {
this.completed = true;
}
return bytesRead;
}
@Override
public String toString() {
final StringBuilder sb = new StringBuilder();
sb.append("[identity; completed: ");
sb.append(this.completed);
sb.append("]");
return sb.toString();
}
}