curator-master/curator-framework/src/main/java/org/apache/curator/framework/imps/GetConfigBuilderImpl.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.zookeeper.AsyncCallback;
import org.apache.zookeeper.KeeperException;
import org.apache.zookeeper.Watcher;
import org.apache.zookeeper.ZooDefs;
import org.apache.zookeeper.data.Stat;

public class GetConfigBuilderImpl
        implements GetConfigBuilder, BackgroundOperation<Void>, ErrorListenerEnsembleable<byte[]> {
    private final CuratorFrameworkImpl client;

    private Backgrounding backgrounding;
    private Watching watching;
    private Stat stat;

    public GetConfigBuilderImpl(CuratorFrameworkImpl client) {
        this.client = client;
        backgrounding = new Backgrounding();
        watching = new Watching(client);
    }

    public GetConfigBuilderImpl(CuratorFrameworkImpl client, Backgrounding backgrounding, Watcher watcher, Stat stat) {
        this.client = client;
        this.backgrounding = backgrounding;
        this.watching = new Watching(client, watcher);
        this.stat = stat;
    }

    @Override
    public WatchBackgroundEnsembleable<byte[]> storingStatIn(Stat stat) {
        this.stat = stat;
        return new WatchBackgroundEnsembleable<byte[]>() {
            @Override
            public ErrorListenerEnsembleable<byte[]> inBackground() {
                return GetConfigBuilderImpl.this.inBackground();
            }

            @Override
            public ErrorListenerEnsembleable<byte[]> inBackground(Object context) {
                return GetConfigBuilderImpl.this.inBackground(context);
            }

            @Override
            public ErrorListenerEnsembleable<byte[]> inBackground(BackgroundCallback callback) {
                return GetConfigBuilderImpl.this.inBackground(callback);
            }

            @Override
            public ErrorListenerEnsembleable<byte[]> inBackground(BackgroundCallback callback, Object context) {
                return GetConfigBuilderImpl.this.inBackground(callback, context);
            }

            @Override
            public ErrorListenerEnsembleable<byte[]> inBackground(BackgroundCallback callback, Executor executor) {
                return GetConfigBuilderImpl.this.inBackground(callback, executor);
            }

            @Override
            public ErrorListenerEnsembleable<byte[]> inBackground(
                    BackgroundCallback callback, Object context, Executor executor) {
                return GetConfigBuilderImpl.this.inBackground(callback, context, executor);
            }

            @Override
            public byte[] forEnsemble() throws Exception {
                return GetConfigBuilderImpl.this.forEnsemble();
            }

            @Override
            public BackgroundEnsembleable<byte[]> watched() {
                return GetConfigBuilderImpl.this.watched();
            }

            @Override
            public BackgroundEnsembleable<byte[]> usingWatcher(Watcher watcher) {
                return GetConfigBuilderImpl.this.usingWatcher(watcher);
            }

            @Override
            public BackgroundEnsembleable<byte[]> usingWatcher(CuratorWatcher watcher) {
                return GetConfigBuilderImpl.this.usingWatcher(watcher);
            }
        };
    }

    @Override
    public BackgroundEnsembleable<byte[]> watched() {
        watching = new Watching(client, true);
        return new InternalBackgroundEnsembleable();
    }

    @Override
    public BackgroundEnsembleable<byte[]> usingWatcher(Watcher watcher) {
        watching = new Watching(client, watcher);
        return new InternalBackgroundEnsembleable();
    }

    @Override
    public BackgroundEnsembleable<byte[]> usingWatcher(CuratorWatcher watcher) {
        watching = new Watching(client, watcher);
        return new InternalBackgroundEnsembleable();
    }

    @Override
    public ErrorListenerEnsembleable<byte[]> inBackground() {
        backgrounding = new Backgrounding(true);
        return this;
    }

    @Override
    public ErrorListenerEnsembleable<byte[]> inBackground(Object context) {
        backgrounding = new Backgrounding(context);
        return this;
    }

    @Override
    public ErrorListenerEnsembleable<byte[]> inBackground(BackgroundCallback callback) {
        backgrounding = new Backgrounding(callback);
        return this;
    }

    @Override
    public ErrorListenerEnsembleable<byte[]> inBackground(BackgroundCallback callback, Object context) {
        backgrounding = new Backgrounding(callback, context);
        return this;
    }

    @Override
    public ErrorListenerEnsembleable<byte[]> inBackground(BackgroundCallback callback, Executor executor) {
        backgrounding = new Backgrounding(callback, executor);
        return this;
    }

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

    @Override
    public Ensembleable<byte[]> withUnhandledErrorListener(UnhandledErrorListener listener) {
        backgrounding = new Backgrounding(backgrounding, listener);
        return this;
    }

    @Override
    public byte[] forEnsemble() throws Exception {
        if (backgrounding.inBackground()) {
            client.processBackgroundOperation(
                    new OperationAndData<Void>(
                            this, null, backgrounding.getCallback(), null, backgrounding.getContext(), watching),
                    null);
            return null;
        } else {
            return configInForeground();
        }
    }

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

    @Override
    public void performBackgroundOperation(final OperationAndData<Void> operationAndData) throws Exception {
        try {
            final TimeTrace trace = client.getZookeeperClient().startTracer("GetDataBuilderImpl-Background");
            AsyncCallback.DataCallback callback = new AsyncCallback.DataCallback() {
                @Override
                public void processResult(int rc, String path, Object ctx, byte[] data, Stat stat) {
                    watching.commitWatcher(rc, false);
                    trace.commit();
                    CuratorEvent event = new CuratorEventImpl(
                            client,
                            CuratorEventType.GET_CONFIG,
                            rc,
                            path,
                            null,
                            ctx,
                            stat,
                            data,
                            null,
                            null,
                            null,
                            null);
                    client.processBackgroundOperation(operationAndData, event);
                }
            };
            if (watching.isWatched()) {
                client.getZooKeeper().getConfig(true, callback, backgrounding.getContext());
            } else {
                client.getZooKeeper()
                        .getConfig(watching.getWatcher(ZooDefs.CONFIG_NODE), callback, backgrounding.getContext());
            }
        } catch (Throwable e) {
            backgrounding.checkError(e, watching);
        }
    }

    private byte[] configInForeground() throws Exception {
        TimeTrace trace = client.getZookeeperClient().startTracer("GetConfigBuilderImpl-Foreground");
        try {
            return RetryLoop.callWithRetry(client.getZookeeperClient(), new Callable<byte[]>() {
                @Override
                public byte[] call() throws Exception {
                    if (watching.isWatched()) {
                        return client.getZooKeeper().getConfig(true, stat);
                    }
                    byte[] config = client.getZooKeeper().getConfig(watching.getWatcher(ZooDefs.CONFIG_NODE), stat);
                    watching.commitWatcher(KeeperException.NoNodeException.Code.OK.intValue(), false);
                    return config;
                }
            });
        } finally {
            trace.commit();
        }
    }

    private class InternalBackgroundEnsembleable implements BackgroundEnsembleable<byte[]> {
        @Override
        public ErrorListenerEnsembleable<byte[]> inBackground() {
            return GetConfigBuilderImpl.this.inBackground();
        }

        @Override
        public ErrorListenerEnsembleable<byte[]> inBackground(Object context) {
            return GetConfigBuilderImpl.this.inBackground(context);
        }

        @Override
        public ErrorListenerEnsembleable<byte[]> inBackground(BackgroundCallback callback) {
            return GetConfigBuilderImpl.this.inBackground(callback);
        }

        @Override
        public ErrorListenerEnsembleable<byte[]> inBackground(BackgroundCallback callback, Object context) {
            return GetConfigBuilderImpl.this.inBackground(callback, context);
        }

        @Override
        public ErrorListenerEnsembleable<byte[]> inBackground(BackgroundCallback callback, Executor executor) {
            return GetConfigBuilderImpl.this.inBackground(callback, executor);
        }

        @Override
        public ErrorListenerEnsembleable<byte[]> inBackground(
                BackgroundCallback callback, Object context, Executor executor) {
            return GetConfigBuilderImpl.this.inBackground(callback, context, executor);
        }

        @Override
        public byte[] forEnsemble() throws Exception {
            return GetConfigBuilderImpl.this.forEnsemble();
        }
    }
}
