/*
* ====================================================================
* 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.apache.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.http.io.
BufferInfo;
import org.apache.http.io.
HttpTransportMetrics;
import org.apache.http.io.
SessionOutputBuffer;
import org.apache.http.protocol.
HTTP;
import org.apache.http.util.
Args;
import org.apache.http.util.
Asserts;
import org.apache.http.util.
ByteArrayBuffer;
import org.apache.http.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)} and {@link #writeLine(String)} methods
* of this class use CR-LF as a line delimiter.
*
* @since 4.3
*/
public class
SessionOutputBufferImpl implements
SessionOutputBuffer,
BufferInfo {
private static final byte[]
CRLF = new byte[] {
HTTP.
CR,
HTTP.
LF};
private final
HttpTransportMetricsImpl metrics;
private final
ByteArrayBuffer buffer;
private final int
fragementSizeHint;
private final
CharsetEncoder encoder;
private
OutputStream outstream;
private
ByteBuffer bbuf;
/**
* Creates new instance of SessionOutputBufferImpl.
*
* @param metrics HTTP transport metrics.
* @param buffersize buffer size. Must be a positive number.
* @param fragementSizeHint 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
HttpTransportMetricsImpl metrics,
final int
buffersize,
final int
fragementSizeHint,
final
CharsetEncoder charencoder) {
super();
Args.
positive(
buffersize, "Buffer size");
Args.
notNull(
metrics, "HTTP transport metrcis");
this.
metrics =
metrics;
this.
buffer = new
ByteArrayBuffer(
buffersize);
this.
fragementSizeHint =
fragementSizeHint >= 0 ?
fragementSizeHint : 0;
this.
encoder =
charencoder;
}
public
SessionOutputBufferImpl(
final
HttpTransportMetricsImpl metrics,
final int
buffersize) {
this(
metrics,
buffersize,
buffersize, null);
}
public void
bind(final
OutputStream outstream) {
this.
outstream =
outstream;
}
public boolean
isBound() {
return this.
outstream != null;
}
@
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
streamWrite(final byte[]
b, final int
off, final int
len) throws
IOException {
Asserts.
notNull(
outstream, "Output stream");
this.
outstream.
write(
b,
off,
len);
}
private void
flushStream() throws
IOException {
if (this.
outstream != null) {
this.
outstream.
flush();
}
}
private void
flushBuffer() throws
IOException {
final int
len = this.
buffer.
length();
if (
len > 0) {
streamWrite(this.
buffer.
buffer(), 0,
len);
this.
buffer.
clear();
this.
metrics.
incrementBytesTransferred(
len);
}
}
@
Override
public void
flush() throws
IOException {
flushBuffer();
flushStream();
}
@
Override
public void
write(final byte[]
b, final int
off, final int
len) throws
IOException {
if (
b == null) {
return;
}
// 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.
fragementSizeHint ||
len > this.
buffer.
capacity()) {
// flush the buffer
flushBuffer();
// write directly to the out stream
streamWrite(
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();
}
// buffer
this.
buffer.
append(
b,
off,
len);
}
}
@
Override
public void
write(final byte[]
b) throws
IOException {
if (
b == null) {
return;
}
write(
b, 0,
b.length);
}
@
Override
public void
write(final int
b) throws
IOException {
if (this.
fragementSizeHint > 0) {
if (this.
buffer.
isFull()) {
flushBuffer();
}
this.
buffer.
append(
b);
} else {
flushBuffer();
this.
outstream.
write(
b);
}
}
/**
* Writes characters from the specified string followed by a line delimiter
* to this session buffer.
* <p>
* This method uses CR-LF as a line delimiter.
*
* @param s the line.
* @throws IOException if an I/O error occurs.
*/
@
Override
public void
writeLine(final
String s) throws
IOException {
if (
s == null) {
return;
}
if (
s.
length() > 0) {
if (this.
encoder == null) {
for (int
i = 0;
i <
s.
length();
i++) {
write(
s.
charAt(
i));
}
} else {
final
CharBuffer cbuf =
CharBuffer.
wrap(
s);
writeEncoded(
cbuf);
}
}
write(
CRLF);
}
/**
* 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) throws
IOException {
if (
charbuffer == null) {
return;
}
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();
}
off +=
chunk;
remaining -=
chunk;
}
} else {
final
CharBuffer cbuf =
CharBuffer.
wrap(
charbuffer.
buffer(), 0,
charbuffer.
length());
writeEncoded(
cbuf);
}
write(
CRLF);
}
private void
writeEncoded(final
CharBuffer cbuf) 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);
}
final
CoderResult result = this.
encoder.
flush(this.
bbuf);
handleEncodingResult(
result);
this.
bbuf.
clear();
}
private void
handleEncodingResult(final
CoderResult result) throws
IOException {
if (
result.
isError()) {
result.
throwException();
}
this.
bbuf.
flip();
while (this.
bbuf.
hasRemaining()) {
write(this.
bbuf.
get());
}
this.
bbuf.
compact();
}
@
Override
public
HttpTransportMetrics getMetrics() {
return this.
metrics;
}
}