/*
* JBoss, Home of Professional Open Source
*
* Copyright 2008 Red Hat, Inc. and/or its affiliates.
*
* Licensed 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.xnio.streams;
import static org.xnio._private.Messages.msg;
import java.io.OutputStream;
import java.io.IOException;
import java.io.InterruptedIOException;
import java.nio.ByteBuffer;
import java.util.concurrent.TimeUnit;
import java.util.concurrent.atomic.AtomicIntegerFieldUpdater;
import org.xnio.Bits;
import org.xnio.channels.StreamSinkChannel;
/**
* An output stream which writes to a stream sink channel. All write operations are directly
* performed upon the channel, so for optimal performance, a buffering output stream should be
* used to wrap this class.
*
* @apiviz.exclude
*
* @since 1.2
*/
public class ChannelOutputStream extends OutputStream {
protected final StreamSinkChannel channel;
@SuppressWarnings("unused")
private volatile int flags;
private volatile long timeout;
private static final AtomicIntegerFieldUpdater<ChannelOutputStream> flagsUpdater = AtomicIntegerFieldUpdater.newUpdater(ChannelOutputStream.class, "flags");
private static final int FLAG_CLOSED = 2;
private static final int FLAG_ENTERED = 1;
/**
* Construct a new instance. No write timeout is configured.
*
* @param channel the channel to wrap
*/
public ChannelOutputStream(final StreamSinkChannel channel) {
if (channel == null) {
throw msg.nullParameter("channel");
}
this.channel = channel;
}
/**
* Construct a new instance.
*
* @param channel the channel to wrap
* @param timeout the write timeout
* @param unit the write timeout units
*/
public ChannelOutputStream(final StreamSinkChannel channel, final long timeout, final TimeUnit unit) {
if (channel == null) {
throw msg.nullParameter("channel");
}
if (unit == null) {
throw msg.nullParameter("unit");
}
if (timeout < 0L) {
throw msg.parameterOutOfRange("timeout");
}
this.channel = channel;
final long calcTimeout = unit.toNanos(timeout);
this.timeout = timeout == 0L ? 0L : calcTimeout < 1L ? 1L : calcTimeout;
}
private boolean enter() {
int old = flags;
do {
if (Bits.allAreSet(old, FLAG_ENTERED)) {
throw msg.concurrentAccess();
}
} while (! flagsUpdater.compareAndSet(this, old, old | FLAG_ENTERED));
return Bits.allAreSet(old, FLAG_CLOSED);
}
private void exit(boolean setEof) {
int oldFlags, newFlags;
do {
oldFlags = flags;
newFlags = oldFlags &~ FLAG_ENTERED;
if (setEof) {
newFlags |= FLAG_CLOSED;
}
} while (! flagsUpdater.compareAndSet(this, oldFlags, newFlags));
}
/**
* Get the write timeout.
*
* @param unit the time unit
* @return the timeout in the given unit
*/
public long getWriteTimeout(TimeUnit unit) {
if (unit == null) {
throw msg.nullParameter("unit");
}
return unit.convert(timeout, TimeUnit.NANOSECONDS);
}
/**
* Set the write timeout. Does not affect write operations in progress.
*
* @param timeout the write timeout, or 0 for none
* @param unit the time unit
*/
public void setWriteTimeout(long timeout, TimeUnit unit) {
if (timeout < 0L) {
throw msg.parameterOutOfRange("timeout");
}
if (unit == null) {
throw msg.nullParameter("unit");
}
final long calcTimeout = unit.toNanos(timeout);
this.timeout = timeout == 0L ? 0L : calcTimeout < 1L ? 1L : calcTimeout;
}
/** {@inheritDoc} */
public void write(final int b) throws IOException {
boolean closed = enter();
try {
if (closed) throw msg.streamClosed();
final StreamSinkChannel channel = this.channel;
final ByteBuffer buffer = ByteBuffer.wrap(new byte[] { (byte) b });
int res = channel.write(buffer);
if (res == 0) {
long timeout;
long start = System.nanoTime();
long elapsed = 0L;
do {
timeout = this.timeout;
if (timeout == 0L) {
channel.awaitWritable();
} else if (timeout < elapsed) {
throw msg.writeTimeout();
} else {
channel.awaitWritable(timeout - elapsed, TimeUnit.NANOSECONDS);
}
elapsed = System.nanoTime() - start;
res = channel.write(buffer);
} while (res == 0);
}
} finally {
exit(closed);
}
}
/** {@inheritDoc} */
public void write(final byte[] b) throws IOException {
write(b, 0, b.length);
}
/** {@inheritDoc} */
public void write(final byte[] b, final int off, final int len) throws IOException {
if (len < 1) {
return;
}
boolean closed = enter();
try {
if (closed) throw msg.streamClosed();
final StreamSinkChannel channel = this.channel;
final ByteBuffer buffer = ByteBuffer.wrap(b, off, len);
int res;
while (buffer.hasRemaining()) {
res = channel.write(buffer);
if (res == 0) {
long timeout;
long start = System.nanoTime();
long elapsed = 0L;
do {
timeout = this.timeout;
try {
if (timeout == 0L) {
channel.awaitWritable();
} else if (timeout < elapsed) {
throw msg.writeTimeout();
} else {
channel.awaitWritable(timeout - elapsed, TimeUnit.NANOSECONDS);
}
} catch (InterruptedIOException e) {
e.bytesTransferred = buffer.position() - off;
throw e;
}
elapsed = System.nanoTime() - start;
res = channel.write(buffer);
} while (res == 0);
}
}
} finally {
exit(closed);
}
}
/** {@inheritDoc} */
public void flush() throws IOException {
final boolean closed = enter();
try {
final StreamSinkChannel channel = this.channel;
if (! channel.flush()) {
long timeout;
long start = System.nanoTime();
long elapsed = 0L;
do {
timeout = this.timeout;
if (timeout == 0L) {
channel.awaitWritable();
} else if (timeout < elapsed) {
throw msg.writeTimeout();
} else {
channel.awaitWritable(timeout - elapsed, TimeUnit.NANOSECONDS);
}
elapsed = System.nanoTime() - start;
} while (! channel.flush());
}
} finally {
exit(closed);
}
}
/** {@inheritDoc} */
public void close() throws IOException {
final boolean closed = enter();
try {
if (closed) return;
final StreamSinkChannel channel = this.channel;
channel.shutdownWrites();
if (! channel.flush()) {
long timeout;
long start = System.nanoTime();
long elapsed = 0L;
do {
timeout = this.timeout;
if (timeout == 0L) {
channel.awaitWritable();
} else if (timeout < elapsed) {
throw msg.writeTimeout();
} else {
channel.awaitWritable(timeout - elapsed, TimeUnit.NANOSECONDS);
}
elapsed = System.nanoTime() - start;
} while (! channel.flush());
}
} finally {
exit(true);
}
}
}