/*
* 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.ignite.internal.client.impl;
import java.util.concurrent.ConcurrentLinkedQueue;
import java.util.concurrent.TimeUnit;
import java.util.concurrent.locks.AbstractQueuedSynchronizer;
import java.util.logging.Level;
import java.util.logging.Logger;
import org.apache.ignite.internal.client.GridClientException;
import org.apache.ignite.internal.client.GridClientFuture;
import org.apache.ignite.internal.client.GridClientFutureListener;
import org.apache.ignite.internal.client.GridClientFutureTimeoutException;
import org.apache.ignite.internal.util.typedef.internal.A;
import org.jetbrains.annotations.Nullable;
/**
* Future adapter.
*/
public class GridClientFutureAdapter<R> extends AbstractQueuedSynchronizer implements GridClientFuture<R> {
/** */
private static final long serialVersionUID = 0L;
/** Initial state. */
private static final int INIT = 0;
/** Done state. */
private static final int DONE = 1;
/** Logger. */
private static final Logger log = Logger.getLogger(GridClientFutureAdapter.class.getName());
/** This future done callbacks. */
private final ConcurrentLinkedQueue<DoneCallback> cbs = new ConcurrentLinkedQueue<>();
/** Result. */
private R res;
/** Error. */
private Throwable err;
/** */
private volatile boolean done;
/**
* Creates not-finished future without any result.
*/
public GridClientFutureAdapter() {
// No-op.
}
/**
* Creates succeeded finished future with given result.
*
* @param res Future result.
*/
public GridClientFutureAdapter(R res) {
onDone(res, null);
}
/**
* Creates failed finished future with given error.
*
* @param err Future error.
*/
public GridClientFutureAdapter(Throwable err) {
onDone(null, err);
}
/** {@inheritDoc} */
@Override public R get() throws GridClientException {
try {
if (!done)
acquireSharedInterruptibly(0);
return getResult();
}
catch (InterruptedException e) {
Thread.currentThread().interrupt();
throw new GridClientException("Operation was interrupted.", e);
}
}
/** {@inheritDoc} */
@Override public R get(long timeout, TimeUnit unit) throws GridClientException {
A.ensure(timeout >= 0, "timeout >= 0");
try {
if (!done && !tryAcquireSharedNanos(0, unit.toNanos(timeout)))
throw new GridClientFutureTimeoutException("Failed to get future result due to waiting timed out.");
}
catch (InterruptedException e) {
throw new GridClientException("Operation was interrupted.", e);
}
return getResult();
}
/**
* Get future result.
*
* @return Future result.
* @throws GridClientException In case of error.
*/
private R getResult() throws GridClientException {
assert getState() == DONE;
if (err == null)
return res;
if (err instanceof Error)
throw (Error)err;
if (err instanceof GridClientException)
throw (GridClientException)err;
throw new GridClientException(err);
}
/** {@inheritDoc} */
@Override public boolean isDone() {
return getState() != INIT;
}
/**
* Callback to notify that future is finished successfully.
*
* @param res Result (can be {@code null}).
*/
public void onDone(@Nullable R res) {
onDone(res, null);
}
/**
* Callback to notify that future is finished with error.
*
* @param err Error (can't be {@code null}).
*/
public void onDone(Throwable err) {
assert err != null;
onDone(null, err);
}
/**
* @param res Result.
* @param err Error.
* @return {@code True} if result was set by this call.
*/
private boolean onDone(@Nullable R res, @Nullable Throwable err) {
boolean notify = false;
try {
if (compareAndSetState(INIT, DONE)) {
this.res = res;
this.err = err;
notify = true;
releaseShared(0);
return true;
}
return false;
}
finally {
if (notify)
fireDone();
}
}
/** {@inheritDoc} */
@Override protected final int tryAcquireShared(int ignore) {
return done ? 1 : -1;
}
/** {@inheritDoc} */
@Override protected final boolean tryReleaseShared(int ignore) {
done = true;
// Always signal after setting final done status.
return true;
}
/**
* Register new listeners for notification when future completes.
*
* Note that current implementations are calling listeners in
* the completing thread.
*
* @param lsnrs Listeners to be registered.
*/
@Override public void listen(final GridClientFutureListener<R>... lsnrs) {
assert lsnrs != null;
for (GridClientFutureListener<R> lsnr : lsnrs)
cbs.add(new DoneCallback<R>(null, lsnr, null));
if (isDone())
fireDone();
}
/**
* Creates future's chain and completes chained future, when this future finishes.
*
* @param cb Future callback to convert this future result into expected format.
* @param <T> New future format to convert this finished future to.
* @return Chained future with new format.
*/
public <T> GridClientFutureAdapter<T> chain(GridClientFutureCallback<R, T> cb) {
GridClientFutureAdapter<T> fut = new GridClientFutureAdapter<>();
cbs.add(new DoneCallback<>(cb, null, fut));
if (isDone())
fireDone();
return fut;
}
/**
* Fire event this future has been finished.
*/
@SuppressWarnings("ErrorNotRethrown")
private void fireDone() {
assert isDone();
DoneCallback cb;
Error err = null;
while ((cb = cbs.poll()) != null)
try {
cb.proceed();
}
catch (Error e) {
if (err == null)
err = e;
else
log.log(Level.WARNING, "Failed to notify future callback due to unhandled error.", e);
}
if (err != null)
throw err;
}
/** This future finished notification callback. */
private class DoneCallback<T> {
/** Done future callback. */
private final GridClientFutureCallback<R, T> cb;
/** Done future listener. */
private final GridClientFutureListener<R> lsnr;
/** Chained future. */
private final GridClientFutureAdapter<T> chainedFut;
/**
* Constructs future finished notification callback.
*
* @param cb Future finished callback.
* @param chainedFut Chained future to set callback result to.
*/
private DoneCallback(GridClientFutureCallback<R, T> cb, GridClientFutureListener<R> lsnr,
GridClientFutureAdapter<T> chainedFut) {
this.cb = cb;
this.lsnr = lsnr;
this.chainedFut = chainedFut;
}
/**
* Proceed this future callback.
*/
public void proceed() {
GridClientFutureAdapter<R> fut = GridClientFutureAdapter.this;
assert fut.isDone();
try {
if (lsnr != null)
lsnr.onDone(fut);
T res = null;
if (cb != null)
res = cb.onComplete(fut);
if (chainedFut != null)
chainedFut.onDone(res);
}
catch (GridClientException e) {
if (chainedFut != null)
chainedFut.onDone(e);
if (log.isLoggable(Level.FINE)) {
log.log(Level.FINE, "Failed to notify chained callback due to unhandled client exception" +
" [fut=" + fut + ", cb=" + cb + ", chainedFut=" + chainedFut + ']', e);
}
}
catch (RuntimeException e) {
if (chainedFut != null)
chainedFut.onDone(e);
log.log(Level.WARNING, "Failed to notify chained callback due to unhandled runtime exception" +
" [fut=" + fut + ", cb=" + cb + ", chainedFut=" + chainedFut + ']', e);
}
catch (Error e) {
if (chainedFut != null)
chainedFut.onDone(e);
throw e;
}
}
}
}