/*
* ====================================================================
* 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.nio.util;
import java.io.IOException;
import java.io.InterruptedIOException;
import java.util.concurrent.locks.Condition;
import java.util.concurrent.locks.ReentrantLock;
import org.apache.http.annotation.ThreadSafe;
import org.apache.http.nio.ContentDecoder;
import org.apache.http.nio.IOControl;
/**
* Implementation of the {@link ContentInputBuffer} interface 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.
*
* @since 4.0
*/
@ThreadSafe
public class SharedInputBuffer extends ExpandableBuffer implements ContentInputBuffer {
private final ReentrantLock lock;
private final Condition condition;
private volatile IOControl ioctrl;
private volatile boolean shutdown = false;
private volatile boolean endOfStream = false;
/**
* @deprecated (4.3) use {@link SharedInputBuffer#SharedInputBuffer(int, ByteBufferAllocator)}
*/
@Deprecated
public SharedInputBuffer(final int buffersize, final IOControl ioctrl, final ByteBufferAllocator allocator) {
super(buffersize, allocator);
this.ioctrl = ioctrl;
this.lock = new ReentrantLock();
this.condition = this.lock.newCondition();
}
/**
* @since 4.3
*/
public SharedInputBuffer(final int buffersize, final ByteBufferAllocator allocator) {
super(buffersize, allocator);
this.lock = new ReentrantLock();
this.condition = this.lock.newCondition();
}
/**
* @since 4.3
*/
public SharedInputBuffer(final int buffersize) {
this(buffersize, HeapByteBufferAllocator.INSTANCE);
}
@Override
public void reset() {
if (this.shutdown) {
return;
}
this.lock.lock();
try {
clear();
this.endOfStream = false;
} finally {
this.lock.unlock();
}
}
/**
* @deprecated (4.3) use {@link #consumeContent(ContentDecoder, IOControl)}
*/
@Override
@Deprecated
public int consumeContent(final ContentDecoder decoder) throws IOException {
return consumeContent(decoder, null);
}
/**
* @since 4.3
*/
public int consumeContent(final ContentDecoder decoder, final IOControl ioctrl) throws IOException {
if (this.shutdown) {
return -1;
}
this.lock.lock();
try {
if (ioctrl != null) {
this.ioctrl = ioctrl;
}
setInputMode();
int totalRead = 0;
int bytesRead;
while ((bytesRead = decoder.read(this.buffer)) > 0) {
totalRead += bytesRead;
}
if (bytesRead == -1 || decoder.isCompleted()) {
this.endOfStream = true;
}
if (!this.buffer.hasRemaining()) {
if (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.available();
} 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() throws IOException {
this.lock.lock();
try {
try {
while (!super.hasData() && !this.endOfStream) {
if (this.shutdown) {
throw new InterruptedIOException("Input operation aborted");
}
if (this.ioctrl != null) {
this.ioctrl.requestInput();
}
this.condition.await();
}
} catch (final 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);
}
@Override
public int read() throws IOException {
if (this.shutdown) {
return -1;
}
this.lock.lock();
try {
if (!hasData()) {
waitForData();
}
if (isEndOfStream()) {
return -1;
}
return this.buffer.get() & 0xff;
} finally {
this.lock.unlock();
}
}
@Override
public int read(final byte[] b, final int off, final int len) throws IOException {
if (this.shutdown) {
return -1;
}
if (b == null) {
return 0;
}
this.lock.lock();
try {
if (!hasData()) {
waitForData();
}
if (isEndOfStream()) {
return -1;
}
setOutputMode();
int chunk = len;
if (chunk > this.buffer.remaining()) {
chunk = this.buffer.remaining();
}
this.buffer.get(b, off, chunk);
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);
}
}