io.vertx.config.zookeeper.ZookeeperConfigStore.java Source code

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Here is the source code for io.vertx.config.zookeeper.ZookeeperConfigStore.java

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/*
 * Copyright (c) 2014 Red Hat, Inc. and others
 *
 * Red Hat 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 io.vertx.config.zookeeper;

import io.vertx.config.spi.ConfigStore;
import io.vertx.core.*;
import io.vertx.core.buffer.Buffer;
import io.vertx.core.json.JsonObject;
import org.apache.curator.framework.CuratorFramework;
import org.apache.curator.framework.CuratorFrameworkFactory;
import org.apache.curator.framework.api.CuratorEvent;
import org.apache.curator.retry.ExponentialBackoffRetry;
import org.apache.zookeeper.KeeperException;

import java.util.Objects;

/**
 * @author <a href="http://escoffier.me">Clement Escoffier</a>
 */
public class ZookeeperConfigStore implements ConfigStore {

    private final CuratorFramework client;
    private final String path;
    private final Vertx vertx;

    public ZookeeperConfigStore(Vertx vertx, JsonObject configuration) {
        String connection = Objects.requireNonNull(configuration.getString("connection"));
        path = Objects.requireNonNull(configuration.getString("path"));
        this.vertx = Objects.requireNonNull(vertx);
        int maxRetries = configuration.getInteger("maxRetries", 3);
        int baseGraceBetweenRetries = configuration.getInteger("baseSleepTimeBetweenRetries", 1000);

        client = CuratorFrameworkFactory.newClient(connection,
                new ExponentialBackoffRetry(baseGraceBetweenRetries, maxRetries));
        client.start();
    }

    @Override
    public void get(Handler<AsyncResult<Buffer>> completionHandler) {
        Context context = Vertx.currentContext();
        vertx.executeBlocking(future -> {
            try {
                client.blockUntilConnected();
                future.complete();
            } catch (InterruptedException e) {
                future.fail(e);
            }

        }, v -> {
            if (v.failed()) {
                completionHandler.handle(Future.failedFuture(v.cause()));
            } else {
                // We are connected.
                try {
                    client.getData().inBackground((client, event) -> {
                        if (context != null) {
                            context.runOnContext(x -> retrieve(event, completionHandler));
                        } else {
                            retrieve(event, completionHandler);
                        }
                    }).withUnhandledErrorListener((message, e) -> {
                        Exception failure = new Exception(message, e);
                        if (context != null) {
                            context.runOnContext(x -> completionHandler.handle(Future.failedFuture(failure)));
                        } else {
                            completionHandler.handle(Future.failedFuture(failure));
                        }
                    }).forPath(path);
                } catch (Exception e) {
                    completionHandler.handle(Future.failedFuture(e));
                }
            }
        });
    }

    private void retrieve(CuratorEvent event, Handler<AsyncResult<Buffer>> completionHandler) {
        KeeperException.Code code = KeeperException.Code.get(event.getResultCode());
        if (code == KeeperException.Code.OK) {
            completionHandler.handle(Future.succeededFuture(Buffer.buffer(event.getData())));
        } else if (code == KeeperException.Code.NONODE) {
            completionHandler.handle(Future.succeededFuture(Buffer.buffer("{}")));
        } else {
            completionHandler.handle(Future.failedFuture(KeeperException.create(code, path)));
        }
    }

    @Override
    public void close(Handler<Void> completionHandler) {
        client.close();
        completionHandler.handle(null);
    }

}