SessionOutputBufferImpl.java
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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
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* 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
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* <http://www.apache.org/>.
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*/
package org.apache.hc.core5.http.impl.io;
import java.io.IOException;
import java.io.OutputStream;
import java.nio.ByteBuffer;
import java.nio.CharBuffer;
import java.nio.charset.CharsetEncoder;
import java.nio.charset.CoderResult;
import org.apache.hc.core5.http.Chars;
import org.apache.hc.core5.http.impl.BasicHttpTransportMetrics;
import org.apache.hc.core5.http.io.HttpTransportMetrics;
import org.apache.hc.core5.http.io.SessionOutputBuffer;
import org.apache.hc.core5.util.Args;
import org.apache.hc.core5.util.ByteArrayBuffer;
import org.apache.hc.core5.util.CharArrayBuffer;
/**
* Abstract base class for session output buffers that stream data to
* an arbitrary {@link OutputStream}. This class buffers small chunks of
* output data in an internal byte array for optimal output performance.
* <p>
* {@link #writeLine(CharArrayBuffer, OutputStream)} method of this class uses CR-LF
* as a line delimiter.
*
* @since 4.3
*/
public class SessionOutputBufferImpl implements SessionOutputBuffer {
private static final byte[] CRLF = new byte[] {Chars.CR, Chars.LF};
private final BasicHttpTransportMetrics metrics;
private final ByteArrayBuffer buffer;
private final int fragmentSizeHint;
private final CharsetEncoder encoder;
private ByteBuffer bbuf;
/**
* Creates new instance of SessionOutputBufferImpl.
*
* @param metrics HTTP transport metrics.
* @param bufferSize buffer size. Must be a positive number.
* @param fragmentSizeHint fragment size hint defining a minimal size of a fragment
* that should be written out directly to the socket bypassing the session buffer.
* Value {@code 0} disables fragment buffering.
* @param charEncoder charEncoder to be used for encoding HTTP protocol elements.
* If {@code null} simple type cast will be used for char to byte conversion.
*/
public SessionOutputBufferImpl(
final BasicHttpTransportMetrics metrics,
final int bufferSize,
final int fragmentSizeHint,
final CharsetEncoder charEncoder) {
super();
Args.positive(bufferSize, "Buffer size");
Args.notNull(metrics, "HTTP transport metrics");
this.metrics = metrics;
this.buffer = new ByteArrayBuffer(bufferSize);
this.fragmentSizeHint = fragmentSizeHint >= 0 ? fragmentSizeHint : bufferSize;
this.encoder = charEncoder;
}
public SessionOutputBufferImpl(final int bufferSize) {
this(new BasicHttpTransportMetrics(), bufferSize, bufferSize, null);
}
public SessionOutputBufferImpl(final int bufferSize, final CharsetEncoder encoder) {
this(new BasicHttpTransportMetrics(), bufferSize, bufferSize, encoder);
}
@Override
public int capacity() {
return this.buffer.capacity();
}
@Override
public int length() {
return this.buffer.length();
}
@Override
public int available() {
return capacity() - length();
}
private void flushBuffer(final OutputStream outputStream) throws IOException {
final int len = this.buffer.length();
if (len > 0) {
outputStream.write(this.buffer.array(), 0, len);
this.buffer.clear();
this.metrics.incrementBytesTransferred(len);
}
}
@Override
public void flush(final OutputStream outputStream) throws IOException {
Args.notNull(outputStream, "Output stream");
flushBuffer(outputStream);
outputStream.flush();
}
@Override
public void write(final byte[] b, final int off, final int len, final OutputStream outputStream) throws IOException {
if (b == null) {
return;
}
Args.notNull(outputStream, "Output stream");
// Do not want to buffer large-ish chunks
// if the byte array is larger then MIN_CHUNK_LIMIT
// write it directly to the output stream
if (len > this.fragmentSizeHint || len > this.buffer.capacity()) {
// flush the buffer
flushBuffer(outputStream);
// write directly to the out stream
outputStream.write(b, off, len);
this.metrics.incrementBytesTransferred(len);
} else {
// Do not let the buffer grow unnecessarily
final int freecapacity = this.buffer.capacity() - this.buffer.length();
if (len > freecapacity) {
// flush the buffer
flushBuffer(outputStream);
}
// buffer
this.buffer.append(b, off, len);
}
}
@Override
public void write(final byte[] b, final OutputStream outputStream) throws IOException {
if (b == null) {
return;
}
write(b, 0, b.length, outputStream);
}
@Override
public void write(final int b, final OutputStream outputStream) throws IOException {
Args.notNull(outputStream, "Output stream");
if (this.fragmentSizeHint > 0) {
if (this.buffer.isFull()) {
flushBuffer(outputStream);
}
this.buffer.append(b);
} else {
flushBuffer(outputStream);
outputStream.write(b);
}
}
/**
* Writes characters from the specified char array followed by a line
* delimiter to this session buffer.
* <p>
* This method uses CR-LF as a line delimiter.
*
* @param charbuffer the buffer containing chars of the line.
* @throws IOException if an I/O error occurs.
*/
@Override
public void writeLine(final CharArrayBuffer charbuffer, final OutputStream outputStream) throws IOException {
if (charbuffer == null) {
return;
}
Args.notNull(outputStream, "Output stream");
if (this.encoder == null) {
int off = 0;
int remaining = charbuffer.length();
while (remaining > 0) {
int chunk = this.buffer.capacity() - this.buffer.length();
chunk = Math.min(chunk, remaining);
if (chunk > 0) {
this.buffer.append(charbuffer, off, chunk);
}
if (this.buffer.isFull()) {
flushBuffer(outputStream);
}
off += chunk;
remaining -= chunk;
}
} else {
final CharBuffer cbuf = CharBuffer.wrap(charbuffer.array(), 0, charbuffer.length());
writeEncoded(cbuf, outputStream);
}
write(CRLF, outputStream);
}
private void writeEncoded(final CharBuffer cbuf, final OutputStream outputStream) throws IOException {
if (!cbuf.hasRemaining()) {
return;
}
if (this.bbuf == null) {
this.bbuf = ByteBuffer.allocate(1024);
}
this.encoder.reset();
while (cbuf.hasRemaining()) {
final CoderResult result = this.encoder.encode(cbuf, this.bbuf, true);
handleEncodingResult(result, outputStream);
}
final CoderResult result = this.encoder.flush(this.bbuf);
handleEncodingResult(result, outputStream);
this.bbuf.clear();
}
private void handleEncodingResult(final CoderResult result, final OutputStream outputStream) throws IOException {
if (result.isError()) {
result.throwException();
}
this.bbuf.flip();
while (this.bbuf.hasRemaining()) {
write(this.bbuf.get(), outputStream);
}
this.bbuf.compact();
}
@Override
public HttpTransportMetrics getMetrics() {
return this.metrics;
}
}