curator-master/curator-framework/src/main/java/org/apache/curator/framework/imps/RemoveWatchesBuilderImpl.java
/*
 * 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 java.util.concurrent.Callable;
import java.util.concurrent.Executor;
import org.apache.curator.RetryLoop;
import org.apache.curator.TimeTrace;
import org.apache.curator.framework.api.*;
import org.apache.curator.utils.DebugUtils;
import org.apache.zookeeper.AsyncCallback;
import org.apache.zookeeper.KeeperException;
import org.apache.zookeeper.Watcher;
import org.apache.zookeeper.Watcher.WatcherType;
import org.apache.zookeeper.ZooKeeper;

public class RemoveWatchesBuilderImpl
        implements RemoveWatchesBuilder,
                RemoveWatchesType,
                RemoveWatchesLocal,
                BackgroundOperation<String>,
                ErrorListenerPathable<Void> {
    private CuratorFrameworkImpl client;
    private Watcher watcher;
    private CuratorWatcher curatorWatcher;
    private WatcherType watcherType;
    private boolean guaranteed;
    private boolean local;
    private boolean quietly;
    private Backgrounding backgrounding;

    public RemoveWatchesBuilderImpl(CuratorFrameworkImpl client) {
        this.client = client;
        this.watcher = null;
        this.curatorWatcher = null;
        this.watcherType = WatcherType.Any;
        this.guaranteed = false;
        this.local = false;
        this.quietly = false;
        this.backgrounding = new Backgrounding();
    }

    public RemoveWatchesBuilderImpl(
            CuratorFrameworkImpl client,
            Watcher watcher,
            CuratorWatcher curatorWatcher,
            WatcherType watcherType,
            boolean guaranteed,
            boolean local,
            boolean quietly,
            Backgrounding backgrounding) {
        this.client = client;
        this.watcher = watcher;
        this.curatorWatcher = curatorWatcher;
        this.watcherType = watcherType;
        this.guaranteed = guaranteed;
        this.local = local;
        this.quietly = quietly;
        this.backgrounding = backgrounding;
    }

    void internalRemoval(Watcher watcher, String path) throws Exception {
        this.watcher = watcher;
        watcherType = WatcherType.Any;
        quietly = true;
        guaranteed = true;
        if (Boolean.getBoolean(DebugUtils.PROPERTY_REMOVE_WATCHERS_IN_FOREGROUND)) {
            this.backgrounding = new Backgrounding();
            pathInForeground(path);
        } else {
            this.backgrounding = new Backgrounding(true);
            pathInBackground(path);
        }
    }

    @Override
    public RemoveWatchesType remove(Watcher watcher) {
        this.watcher = watcher;
        this.curatorWatcher = null;
        return this;
    }

    @Override
    public RemoveWatchesType remove(CuratorWatcher watcher) {
        this.watcher = null;
        this.curatorWatcher = watcher;
        return this;
    }

    @Override
    public RemoveWatchesType removeAll() {
        this.watcher = null;
        this.curatorWatcher = null;
        return this;
    }

    @Override
    public RemoveWatchesLocal ofType(WatcherType watcherType) {
        this.watcherType = watcherType;

        return this;
    }

    @Override
    public ErrorListenerPathable<Void> inBackground(BackgroundCallback callback, Object context) {
        backgrounding = new Backgrounding(callback, context);
        return this;
    }

    @Override
    public ErrorListenerPathable<Void> inBackground(BackgroundCallback callback, Object context, Executor executor) {
        backgrounding = new Backgrounding(client, callback, context, executor);
        return this;
    }

    @Override
    public ErrorListenerPathable<Void> inBackground(BackgroundCallback callback) {
        backgrounding = new Backgrounding(callback);
        return this;
    }

    @Override
    public ErrorListenerPathable<Void> inBackground(BackgroundCallback callback, Executor executor) {
        backgrounding = new Backgrounding(client, callback, executor);
        return this;
    }

    @Override
    public ErrorListenerPathable<Void> inBackground() {
        backgrounding = new Backgrounding(true);
        return this;
    }

    @Override
    public ErrorListenerPathable<Void> inBackground(Object context) {
        backgrounding = new Backgrounding(context);
        return this;
    }

    @Override
    public Pathable<Void> withUnhandledErrorListener(UnhandledErrorListener listener) {
        backgrounding = new Backgrounding(backgrounding, listener);
        return this;
    }

    @Override
    public RemoveWatchesLocal guaranteed() {
        guaranteed = true;
        return this;
    }

    @Override
    public BackgroundPathableQuietlyable<Void> locally() {
        local = true;
        return this;
    }

    @Override
    public BackgroundPathable<Void> quietly() {
        quietly = true;
        return this;
    }

    @Override
    public Void forPath(String path) throws Exception {
        final String adjustedPath = client.fixForNamespace(path);

        if (backgrounding.inBackground()) {
            pathInBackground(adjustedPath);
        } else {
            pathInForeground(adjustedPath);
        }

        return null;
    }

    protected CuratorFrameworkImpl getClient() {
        return client;
    }

    private void pathInBackground(final String path) {
        OperationAndData.ErrorCallback<String> errorCallback = null;

        // Only need an error callback if we're in guaranteed mode
        if (guaranteed) {
            errorCallback = new OperationAndData.ErrorCallback<String>() {
                @Override
                public void retriesExhausted(OperationAndData<String> operationAndData) {
                    client.getFailedRemoveWatcherManager()
                            .addFailedOperation(new FailedRemoveWatchManager.FailedRemoveWatchDetails(path, watcher));
                }
            };
        }

        client.processBackgroundOperation(
                new OperationAndData<String>(
                        this, path, backgrounding.getCallback(), errorCallback, backgrounding.getContext(), !local),
                null);
    }

    private void pathInForeground(final String path) throws Exception {
        NamespaceWatcher namespaceWatcher = makeNamespaceWatcher(path);
        // For the local case we don't want to use the normal retry loop and we don't want to block until a connection
        // is available.
        // We just execute the removeWatch, and if it fails, ZK will just remove local watches.
        if (local) {
            ZooKeeper zkClient = client.getZooKeeper();
            if (namespaceWatcher != null) {
                zkClient.removeWatches(path, namespaceWatcher, watcherType, local);
            } else {
                zkClient.removeAllWatches(path, watcherType, local);
            }
        } else {
            final NamespaceWatcher finalNamespaceWatcher = namespaceWatcher;
            RetryLoop.callWithRetry(client.getZookeeperClient(), new Callable<Void>() {
                @Override
                public Void call() throws Exception {
                    try {
                        ZooKeeper zkClient = client.getZookeeperClient().getZooKeeper();

                        if (finalNamespaceWatcher != null) {
                            zkClient.removeWatches(path, finalNamespaceWatcher, watcherType, false);
                        } else {
                            zkClient.removeAllWatches(path, watcherType, false);
                        }
                    } catch (Exception e) {
                        if (client.getZookeeperClient().getRetryPolicy().allowRetry(e) && guaranteed) {
                            // Setup the guaranteed handler
                            client.getFailedRemoveWatcherManager()
                                    .addFailedOperation(new FailedRemoveWatchManager.FailedRemoveWatchDetails(
                                            path, finalNamespaceWatcher));
                            throw e;
                        } else if (e instanceof KeeperException.NoWatcherException && quietly) {
                            // ignore
                        } else {
                            // Rethrow
                            throw e;
                        }
                    }

                    return null;
                }
            });
        }
    }

    private NamespaceWatcher makeNamespaceWatcher(String path) {
        NamespaceWatcher namespaceWatcher = null;
        if (watcher != null) {
            if (watcher instanceof NamespaceWatcher) {
                namespaceWatcher = (NamespaceWatcher) watcher;
            } else {
                namespaceWatcher = new NamespaceWatcher(client, watcher, path);
            }
        } else if (curatorWatcher != null) {
            namespaceWatcher = new NamespaceWatcher(client, curatorWatcher, path);
        }
        return namespaceWatcher;
    }

    @Override
    public CuratorEventType getBackgroundEventType() {
        return CuratorEventType.REMOVE_WATCHES;
    }

    @Override
    public void performBackgroundOperation(final OperationAndData<String> operationAndData) throws Exception {
        try {
            final TimeTrace trace = client.getZookeeperClient().startTracer("RemoteWatches-Background");

            AsyncCallback.VoidCallback callback = new AsyncCallback.VoidCallback() {
                @Override
                public void processResult(int rc, String path, Object ctx) {
                    trace.commit();
                    CuratorEvent event = new CuratorEventImpl(
                            client,
                            CuratorEventType.REMOVE_WATCHES,
                            rc,
                            path,
                            null,
                            ctx,
                            null,
                            null,
                            null,
                            null,
                            null,
                            null);
                    client.processBackgroundOperation(operationAndData, event);
                }
            };

            ZooKeeper zkClient = client.getZooKeeper();
            NamespaceWatcher namespaceWatcher = makeNamespaceWatcher(operationAndData.getData());
            if (namespaceWatcher == null) {
                zkClient.removeAllWatches(
                        operationAndData.getData(), watcherType, local, callback, operationAndData.getContext());
            } else {
                zkClient.removeWatches(
                        operationAndData.getData(),
                        namespaceWatcher,
                        watcherType,
                        local,
                        callback,
                        operationAndData.getContext());
            }
        } catch (Throwable e) {
            backgrounding.checkError(e, null);
        }
    }
}
