/**
* 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.
*/
package org.apache.cxf.transport.http.asyncclient;
import java.io.IOException;
import java.io.InterruptedIOException;
import java.nio.ByteBuffer;
import java.util.concurrent.locks.Condition;
import java.util.concurrent.locks.ReentrantLock;
import org.apache.http.nio.ContentDecoder;
import org.apache.http.nio.IOControl;
import org.apache.http.nio.util.ByteBufferAllocator;
import org.apache.http.nio.util.ExpandableBuffer;
/**
* Content buffer that can be shared by multiple threads, usually the I/O dispatch of
* an I/O reactor and a worker thread.
* <p/>
* The I/O dispatch thread is expect to transfer data from {@link ContentDecoder} to the buffer
* by calling {@link #consumeContent(ContentDecoder)}.
* <p/>
* The worker thread is expected to read the data from the buffer by calling
* {@link #read()} or {@link #read(byte[], int, int)} methods.
* <p/>
* In case of an abnormal situation or when no longer needed the buffer must be shut down
* using {@link #shutdown()} method.
*/
public class SharedInputBuffer extends ExpandableBuffer {
private final ReentrantLock lock;
private final Condition condition;
private final int requestInputSize;
private volatile IOControl ioctrl;
private volatile boolean shutdown;
private volatile boolean endOfStream;
private volatile ByteBuffer waitingBuffer;
//private volatile int waitCnt;
//private volatile int nowaitCnt;
public SharedInputBuffer(int buffersize,
final ByteBufferAllocator allocator) {
super(buffersize, allocator);
this.lock = new ReentrantLock();
this.condition = this.lock.newCondition();
//if the buffer become 3/4 empty, we'll turn on the input
//events again to hopefully get more data before the next
//the buffer fully empties and we have to wait to read
this.requestInputSize = buffersize * 3 / 4;
}
public void reset() {
if (this.shutdown) {
return;
}
this.lock.lock();
try {
clear();
this.endOfStream = false;
} finally {
this.lock.unlock();
}
}
public int consumeContent(final ContentDecoder decoder, final IOControl ioc) throws IOException {
if (this.shutdown) {
//something bad happened, we need to shutdown the connection
//as we're not going to read the data at all and we
//don't want to keep getting read notices and such
ioc.shutdown();
return -1;
}
this.lock.lock();
try {
this.ioctrl = ioc;
setInputMode();
int totalRead = 0;
int bytesRead;
if (waitingBuffer != null && this.buffer.position() == 0) {
while ((bytesRead = decoder.read(this.waitingBuffer)) > 0) {
totalRead += bytesRead;
}
}
//read more
while ((bytesRead = decoder.read(this.buffer)) > 0) {
totalRead += bytesRead;
}
if (bytesRead == -1 || decoder.isCompleted()) {
this.endOfStream = true;
}
if (!this.buffer.hasRemaining() && this.ioctrl != null) {
this.ioctrl.suspendInput();
}
this.condition.signalAll();
if (totalRead > 0) {
return totalRead;
} else {
if (this.endOfStream) {
return -1;
} else {
return 0;
}
}
} finally {
this.lock.unlock();
}
}
@Override
public boolean hasData() {
this.lock.lock();
try {
return super.hasData();
} finally {
this.lock.unlock();
}
}
@Override
public int available() {
this.lock.lock();
try {
return super.length();
} finally {
this.lock.unlock();
}
}
@Override
public int capacity() {
this.lock.lock();
try {
return super.capacity();
} finally {
this.lock.unlock();
}
}
@Override
public int length() {
this.lock.lock();
try {
return super.length();
} finally {
this.lock.unlock();
}
}
protected void waitForData(int waitPos) throws IOException {
this.lock.lock();
try {
try {
while (true) {
if (this.waitingBuffer != null && this.waitingBuffer.position() > waitPos) {
return;
}
if (super.hasData()) {
return;
}
if (this.endOfStream) {
return;
}
if (this.shutdown) {
throw new InterruptedIOException("Input operation aborted");
}
if (this.ioctrl != null) {
this.ioctrl.requestInput();
}
this.condition.await();
}
} catch (InterruptedException ex) {
throw new IOException("Interrupted while waiting for more data");
}
} finally {
this.lock.unlock();
}
}
public void close() {
if (this.shutdown) {
return;
}
this.endOfStream = true;
this.lock.lock();
try {
this.condition.signalAll();
} finally {
this.lock.unlock();
}
}
public void shutdown() {
if (this.shutdown) {
return;
}
this.shutdown = true;
this.lock.lock();
try {
this.condition.signalAll();
} finally {
this.lock.unlock();
}
}
protected boolean isShutdown() {
return this.shutdown;
}
protected boolean isEndOfStream() {
return this.shutdown || (!hasData() && this.endOfStream);
}
public int read() throws IOException {
if (this.shutdown) {
return -1;
}
this.lock.lock();
try {
if (!super.hasData()) {
waitForData(0);
}
if (isEndOfStream()) {
return -1;
}
setOutputMode();
return this.buffer.get() & 0xff;
} finally {
this.lock.unlock();
}
}
public int read(final byte[] b, int off, int len) throws IOException {
if (this.shutdown) {
return -1;
}
if (b == null) {
return 0;
}
this.lock.lock();
try {
if (!hasData()) {
this.waitingBuffer = ByteBuffer.wrap(b, off, len);
waitForData(off);
int i = waitingBuffer.position() - off;
waitingBuffer = null;
if (i > 0) {
//++waitCnt;
return i;
}
}
if (isEndOfStream()) {
//System.out.println(waitCnt + " " + nowaitCnt);
return -1;
}
setOutputMode();
int chunk = len;
if (chunk > this.buffer.remaining()) {
chunk = this.buffer.remaining();
}
this.buffer.get(b, off, chunk);
if (this.buffer.position() >= this.requestInputSize && !this.endOfStream && this.ioctrl != null) {
//we have a significant amount of space empty in the buffer, we'll turn on
//the input so maybe we'll get another chunk by the time the next read happens
//and we can then avoid waiting for input
this.ioctrl.requestInput();
}
//++nowaitCnt;
return chunk;
} finally {
this.lock.unlock();
}
}
public int read(final byte[] b) throws IOException {
if (this.shutdown) {
return -1;
}
if (b == null) {
return 0;
}
return read(b, 0, b.length);
}
}