/**
* 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.curator.framework.imps;
import org.apache.curator.RetryLoop;
import org.apache.curator.TimeTrace;
import org.apache.curator.framework.api.BackgroundCallback;
import org.apache.curator.framework.api.BackgroundPathable;
import org.apache.curator.framework.api.CuratorEvent;
import org.apache.curator.framework.api.CuratorEventType;
import org.apache.curator.framework.api.CuratorWatcher;
import org.apache.curator.framework.api.ExistsBuilder;
import org.apache.curator.framework.api.Pathable;
import org.apache.zookeeper.AsyncCallback;
import org.apache.zookeeper.Watcher;
import org.apache.zookeeper.data.Stat;
import java.util.concurrent.Callable;
import java.util.concurrent.Executor;
class ExistsBuilderImpl implements ExistsBuilder, BackgroundOperation<String>
{
private final CuratorFrameworkImpl client;
private Backgrounding backgrounding;
private Watching watching;
ExistsBuilderImpl(CuratorFrameworkImpl client)
{
this.client = client;
backgrounding = new Backgrounding();
watching = new Watching();
}
@Override
public BackgroundPathable<Stat> watched()
{
watching = new Watching(true);
return this;
}
@Override
public BackgroundPathable<Stat> usingWatcher(Watcher watcher)
{
watching = new Watching(client, watcher);
return this;
}
@Override
public BackgroundPathable<Stat> usingWatcher(CuratorWatcher watcher)
{
watching = new Watching(client, watcher);
return this;
}
@Override
public Pathable<Stat> inBackground(BackgroundCallback callback, Object context)
{
backgrounding = new Backgrounding(callback, context);
return this;
}
@Override
public Pathable<Stat> inBackground(BackgroundCallback callback, Object context, Executor executor)
{
backgrounding = new Backgrounding(client, callback, context, executor);
return this;
}
@Override
public Pathable<Stat> inBackground(BackgroundCallback callback)
{
backgrounding = new Backgrounding(callback);
return this;
}
@Override
public Pathable<Stat> inBackground(BackgroundCallback callback, Executor executor)
{
backgrounding = new Backgrounding(client, callback, executor);
return this;
}
@Override
public Pathable<Stat> inBackground()
{
backgrounding = new Backgrounding(true);
return this;
}
@Override
public Pathable<Stat> inBackground(Object context)
{
backgrounding = new Backgrounding(context);
return this;
}
@Override
public void performBackgroundOperation(final OperationAndData<String> operationAndData) throws Exception
{
final TimeTrace trace = client.getZookeeperClient().startTracer("ExistsBuilderImpl-Background");
AsyncCallback.StatCallback callback = new AsyncCallback.StatCallback()
{
@Override
public void processResult(int rc, String path, Object ctx, Stat stat)
{
trace.commit();
CuratorEvent event = new CuratorEventImpl(client, CuratorEventType.EXISTS, rc, path, null, ctx, stat, null, null, null, null);
client.processBackgroundOperation(operationAndData, event);
}
};
if ( watching.isWatched() )
{
client.getZooKeeper().exists(operationAndData.getData(), true, callback, backgrounding.getContext());
}
else
{
client.getZooKeeper().exists(operationAndData.getData(), watching.getWatcher(), callback, backgrounding.getContext());
}
}
@Override
public Stat forPath(String path) throws Exception
{
path = client.fixForNamespace(path);
Stat returnStat = null;
if ( backgrounding.inBackground() )
{
client.processBackgroundOperation(new OperationAndData<String>(this, path, backgrounding.getCallback(), null), null);
}
else
{
returnStat = pathInForeground(path);
}
return returnStat;
}
private Stat pathInForeground(final String path) throws Exception
{
TimeTrace trace = client.getZookeeperClient().startTracer("ExistsBuilderImpl-Foreground");
Stat returnStat = RetryLoop.callWithRetry
(
client.getZookeeperClient(),
new Callable<Stat>()
{
@Override
public Stat call() throws Exception
{
Stat returnStat;
if ( watching.isWatched() )
{
returnStat = client.getZooKeeper().exists(path, true);
}
else
{
returnStat = client.getZooKeeper().exists(path, watching.getWatcher());
}
return returnStat;
}
}
);
trace.commit();
return returnStat;
}
}