/*
* Copyright (c) 2015 Cisco Systems, Inc. and others. All rights reserved.
*
* This program and the accompanying materials are made available under the
* terms of the Eclipse Public License v1.0 which accompanies this distribution,
* and is available at http://www.eclipse.org/legal/epl-v10.html
*/
package org.opendaylight.controller.cluster.datastore;
import com.codahale.metrics.Timer;
import com.google.common.annotations.VisibleForTesting;
import com.google.common.base.Preconditions;
import com.google.common.base.Ticker;
import java.util.concurrent.TimeUnit;
import org.opendaylight.controller.cluster.datastore.utils.ActorContext;
/**
* TransactionRateLimitingCallback computes the new transaction rate limit on the successful completion of a
* transaction.
*/
public class TransactionRateLimitingCallback implements OperationCallback {
private static Ticker TICKER = Ticker.systemTicker();
private enum State {
STOPPED,
RUNNING,
PAUSED
}
private final Timer commitTimer;
private long startTime;
private long elapsedTime;
private volatile State state = State.STOPPED;
TransactionRateLimitingCallback(ActorContext actorContext) {
commitTimer = actorContext.getOperationTimer(ActorContext.COMMIT);
}
@Override
public void run() {
Preconditions.checkState(state == State.STOPPED, "state is not STOPPED");
resume();
}
@Override
public void pause() {
if (state == State.RUNNING) {
elapsedTime += TICKER.read() - startTime;
state = State.PAUSED;
}
}
@Override
public void resume() {
if (state != State.RUNNING) {
startTime = TICKER.read();
state = State.RUNNING;
}
}
@Override
public void success() {
Preconditions.checkState(state != State.STOPPED, "state is STOPPED");
pause();
commitTimer.update(elapsedTime, TimeUnit.NANOSECONDS);
state = State.STOPPED;
}
@Override
public void failure() {
// This would mean we couldn't get a transaction completed in 30 seconds which is
// the default transaction commit timeout. Using the timeout information to figure out the rate limit is
// not going to be useful - so we leave it as it is
}
@VisibleForTesting
static void setTicker(Ticker ticker) {
TICKER = ticker;
}
}