org.apache.http.impl.nio.codecs.LengthDelimitedEncoder 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.
* ====================================================================
*
* 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
*
* This decoder is optimized to transfer data directly from
* a {@link FileChannel} to the underlying I/O session's channel whenever
* possible avoiding intermediate buffering in the session buffer.
*
* @since 4.0
*/
public class LengthDelimitedEncoder extends AbstractContentEncoder
implements FileContentEncoder {
private final long contentLength;
private final int fragHint;
private long remaining;
/**
* @since 4.3
*
* @param channel underlying channel.
* @param buffer session buffer.
* @param metrics transport metrics.
* @param contentLength content length.
* @param fragementSizeHint fragment size hint defining an minimal size of a fragment
* that should be written out directly to the channel bypassing the session buffer.
* Value {@code 0} disables fragment buffering.
*/
public LengthDelimitedEncoder(
final WritableByteChannel channel,
final SessionOutputBuffer buffer,
final HttpTransportMetricsImpl metrics,
final long contentLength,
final int fragementSizeHint) {
super(channel, buffer, metrics);
Args.notNegative(contentLength, "Content length");
this.contentLength = contentLength;
this.fragHint = fragementSizeHint > 0 ? fragementSizeHint : 0;
this.remaining = contentLength;
}
public LengthDelimitedEncoder(
final WritableByteChannel channel,
final SessionOutputBuffer buffer,
final HttpTransportMetricsImpl metrics,
final long contentLength) {
this(channel, buffer, metrics, contentLength, 0);
}
private int nextChunk(final ByteBuffer src) {
return (int) Math.min(Math.min(this.remaining, Integer.MAX_VALUE), src.remaining());
}
@Override
public int write(final ByteBuffer src) throws IOException {
if (src == null) {
return 0;
}
assertNotCompleted();
int total = 0;
while (src.hasRemaining() && this.remaining > 0) {
if (this.buffer.hasData() || this.fragHint > 0) {
final int chunk = nextChunk(src);
if (chunk <= this.fragHint) {
final int capacity = this.fragHint - this.buffer.length();
if (capacity > 0) {
final int limit = Math.min(capacity, chunk);
final int bytesWritten = writeToBuffer(src, limit);
this.remaining -= bytesWritten;
total += bytesWritten;
}
}
}
if (this.buffer.hasData()) {
final int chunk = nextChunk(src);
if (this.buffer.length() >= this.fragHint || chunk > 0) {
final int bytesWritten = flushToChannel();
if (bytesWritten == 0) {
break;
}
}
}
if (!this.buffer.hasData()) {
final int chunk = nextChunk(src);
if (chunk > this.fragHint) {
final int bytesWritten = writeToChannel(src, chunk);
this.remaining -= bytesWritten;
total += bytesWritten;
if (bytesWritten == 0) {
break;
}
}
}
}
if (this.remaining <= 0) {
super.complete();
}
return total;
}
@Override
public long transfer(
final FileChannel src,
final long position,
final long count) throws IOException {
if (src == null) {
return 0;
}
assertNotCompleted();
flushToChannel();
if (this.buffer.hasData()) {
return 0;
}
final long chunk = Math.min(this.remaining, count);
final long bytesWritten = src.transferTo(position, chunk, this.channel);
if (bytesWritten > 0) {
this.metrics.incrementBytesTransferred(bytesWritten);
}
this.remaining -= bytesWritten;
if (this.remaining <= 0) {
super.complete();
}
return bytesWritten;
}
@Override
public String toString() {
final StringBuilder sb = new StringBuilder();
sb.append("[content length: ");
sb.append(this.contentLength);
sb.append("; pos: ");
sb.append(this.contentLength - this.remaining);
sb.append("; completed: ");
sb.append(isCompleted());
sb.append("]");
return sb.toString();
}
}