/*
* Copyright 2012 The Netty Project
*
* The Netty Project 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 io.netty.channel;
import java.util.ArrayDeque;
import java.util.Queue;
/**
* This implementation allows to register {@link ChannelFuture} instances which will get notified once some amount of
* data was written and so a checkpoint was reached.
*/
public final class ChannelFlushPromiseNotifier {
private long writeCounter;
private final Queue<FlushCheckpoint> flushCheckpoints = new ArrayDeque<FlushCheckpoint>();
private final boolean tryNotify;
/**
* Create a new instance
*
* @param tryNotify if {@code true} the {@link ChannelPromise}s will get notified with
* {@link ChannelPromise#trySuccess()} and {@link ChannelPromise#tryFailure(Throwable)}.
* Otherwise {@link ChannelPromise#setSuccess()} and {@link ChannelPromise#setFailure(Throwable)}
* is used
*/
public ChannelFlushPromiseNotifier(boolean tryNotify) {
this.tryNotify = tryNotify;
}
/**
* Create a new instance which will use {@link ChannelPromise#setSuccess()} and
* {@link ChannelPromise#setFailure(Throwable)} to notify the {@link ChannelPromise}s.
*/
public ChannelFlushPromiseNotifier() {
this(false);
}
/**
* @deprecated use {@link #add(ChannelPromise, long)}
*/
@Deprecated
public ChannelFlushPromiseNotifier add(ChannelPromise promise, int pendingDataSize) {
return add(promise, (long) pendingDataSize);
}
/**
* Add a {@link ChannelPromise} to this {@link ChannelFlushPromiseNotifier} which will be notified after the given
* {@code pendingDataSize} was reached.
*/
public ChannelFlushPromiseNotifier add(ChannelPromise promise, long pendingDataSize) {
if (promise == null) {
throw new NullPointerException("promise");
}
if (pendingDataSize < 0) {
throw new IllegalArgumentException("pendingDataSize must be >= 0 but was " + pendingDataSize);
}
long checkpoint = writeCounter + pendingDataSize;
if (promise instanceof FlushCheckpoint) {
FlushCheckpoint cp = (FlushCheckpoint) promise;
cp.flushCheckpoint(checkpoint);
flushCheckpoints.add(cp);
} else {
flushCheckpoints.add(new DefaultFlushCheckpoint(checkpoint, promise));
}
return this;
}
/**
* Increase the current write counter by the given delta
*/
public ChannelFlushPromiseNotifier increaseWriteCounter(long delta) {
if (delta < 0) {
throw new IllegalArgumentException("delta must be >= 0 but was " + delta);
}
writeCounter += delta;
return this;
}
/**
* Return the current write counter of this {@link ChannelFlushPromiseNotifier}
*/
public long writeCounter() {
return writeCounter;
}
/**
* Notify all {@link ChannelFuture}s that were registered with {@link #add(ChannelPromise, int)} and
* their pendingDatasize is smaller after the the current writeCounter returned by {@link #writeCounter()}.
*
* After a {@link ChannelFuture} was notified it will be removed from this {@link ChannelFlushPromiseNotifier} and
* so not receive anymore notification.
*/
public ChannelFlushPromiseNotifier notifyPromises() {
notifyPromises0(null);
return this;
}
/**
* @deprecated use {@link #notifyPromises()}
*/
@Deprecated
public ChannelFlushPromiseNotifier notifyFlushFutures() {
return notifyPromises();
}
/**
* Notify all {@link ChannelFuture}s that were registered with {@link #add(ChannelPromise, int)} and
* their pendingDatasize isis smaller then the current writeCounter returned by {@link #writeCounter()}.
*
* After a {@link ChannelFuture} was notified it will be removed from this {@link ChannelFlushPromiseNotifier} and
* so not receive anymore notification.
*
* The rest of the remaining {@link ChannelFuture}s will be failed with the given {@link Throwable}.
*
* So after this operation this {@link ChannelFutureListener} is empty.
*/
public ChannelFlushPromiseNotifier notifyPromises(Throwable cause) {
notifyPromises();
for (;;) {
FlushCheckpoint cp = flushCheckpoints.poll();
if (cp == null) {
break;
}
if (tryNotify) {
cp.promise().tryFailure(cause);
} else {
cp.promise().setFailure(cause);
}
}
return this;
}
/**
* @deprecated use {@link #notifyPromises(Throwable)}
*/
@Deprecated
public ChannelFlushPromiseNotifier notifyFlushFutures(Throwable cause) {
return notifyPromises(cause);
}
/**
* Notify all {@link ChannelFuture}s that were registered with {@link #add(ChannelPromise, int)} and
* their pendingDatasize is smaller then the current writeCounter returned by {@link #writeCounter()} using
* the given cause1.
*
* After a {@link ChannelFuture} was notified it will be removed from this {@link ChannelFlushPromiseNotifier} and
* so not receive anymore notification.
*
* The rest of the remaining {@link ChannelFuture}s will be failed with the given {@link Throwable}.
*
* So after this operation this {@link ChannelFutureListener} is empty.
*
* @param cause1 the {@link Throwable} which will be used to fail all of the {@link ChannelFuture}s whichs
* pendingDataSize is smaller then the current writeCounter returned by {@link #writeCounter()}
* @param cause2 the {@link Throwable} which will be used to fail the remaining {@link ChannelFuture}s
*/
public ChannelFlushPromiseNotifier notifyPromises(Throwable cause1, Throwable cause2) {
notifyPromises0(cause1);
for (;;) {
FlushCheckpoint cp = flushCheckpoints.poll();
if (cp == null) {
break;
}
if (tryNotify) {
cp.promise().tryFailure(cause2);
} else {
cp.promise().setFailure(cause2);
}
}
return this;
}
/**
* @deprecated use {@link #notifyPromises(Throwable, Throwable)}
*/
@Deprecated
public ChannelFlushPromiseNotifier notifyFlushFutures(Throwable cause1, Throwable cause2) {
return notifyPromises(cause1, cause2);
}
private void notifyPromises0(Throwable cause) {
if (flushCheckpoints.isEmpty()) {
writeCounter = 0;
return;
}
final long writeCounter = this.writeCounter;
for (;;) {
FlushCheckpoint cp = flushCheckpoints.peek();
if (cp == null) {
// Reset the counter if there's nothing in the notification list.
this.writeCounter = 0;
break;
}
if (cp.flushCheckpoint() > writeCounter) {
if (writeCounter > 0 && flushCheckpoints.size() == 1) {
this.writeCounter = 0;
cp.flushCheckpoint(cp.flushCheckpoint() - writeCounter);
}
break;
}
flushCheckpoints.remove();
ChannelPromise promise = cp.promise();
if (cause == null) {
if (tryNotify) {
promise.trySuccess();
} else {
promise.setSuccess();
}
} else {
if (tryNotify) {
promise.tryFailure(cause);
} else {
promise.setFailure(cause);
}
}
}
// Avoid overflow
final long newWriteCounter = this.writeCounter;
if (newWriteCounter >= 0x8000000000L) {
// Reset the counter only when the counter grew pretty large
// so that we can reduce the cost of updating all entries in the notification list.
this.writeCounter = 0;
for (FlushCheckpoint cp: flushCheckpoints) {
cp.flushCheckpoint(cp.flushCheckpoint() - newWriteCounter);
}
}
}
interface FlushCheckpoint {
long flushCheckpoint();
void flushCheckpoint(long checkpoint);
ChannelPromise promise();
}
private static class DefaultFlushCheckpoint implements FlushCheckpoint {
private long checkpoint;
private final ChannelPromise future;
DefaultFlushCheckpoint(long checkpoint, ChannelPromise future) {
this.checkpoint = checkpoint;
this.future = future;
}
@Override
public long flushCheckpoint() {
return checkpoint;
}
@Override
public void flushCheckpoint(long checkpoint) {
this.checkpoint = checkpoint;
}
@Override
public ChannelPromise promise() {
return future;
}
}
}