com.cloudera.livy.rsc.RSCClientFactory.java Source code

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Here is the source code for com.cloudera.livy.rsc.RSCClientFactory.java

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/*
 * 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 com.cloudera.livy.rsc;

import java.io.IOException;
import java.net.URI;
import java.util.Properties;
import java.util.concurrent.atomic.AtomicInteger;

import io.netty.util.concurrent.ImmediateEventExecutor;
import io.netty.util.concurrent.Promise;

import com.cloudera.livy.LivyClient;
import com.cloudera.livy.LivyClientFactory;
import com.cloudera.livy.rsc.rpc.RpcServer;

/**
 * Factory for RSC clients.
 */
public final class RSCClientFactory implements LivyClientFactory {

    private final AtomicInteger refCount = new AtomicInteger();
    private RpcServer server = null;

    /**
     * Creates a local Livy client if the URI has the "rsc" scheme.
     * <p>
     * If the URI contains user information, host and port, the library will try to connect to an
     * existing RSC instance with the provided information, and most of the provided configuration
     * will be ignored.
     * <p>
     * Otherwise, a new Spark context will be started with the given configuration.
     */
    @Override
    public LivyClient createClient(URI uri, Properties config) {
        if (!"rsc".equals(uri.getScheme())) {
            return null;
        }

        RSCConf lconf = new RSCConf(config);

        boolean needsServer = false;
        try {
            Promise<ContextInfo> info;
            if (uri.getUserInfo() != null && uri.getHost() != null && uri.getPort() > 0) {
                info = createContextInfo(uri);
            } else {
                needsServer = true;
                ref(lconf);
                info = ContextLauncher.create(this, lconf);
            }
            return new RSCClient(lconf, info);
        } catch (Exception e) {
            if (needsServer) {
                unref();
            }
            throw Utils.propagate(e);
        }
    }

    RpcServer getServer() {
        return server;
    }

    private synchronized void ref(RSCConf config) throws IOException {
        if (refCount.get() != 0) {
            refCount.incrementAndGet();
            return;
        }

        Utils.checkState(server == null, "Server already running but ref count is 0.");
        if (server == null) {
            try {
                server = new RpcServer(config);
            } catch (InterruptedException ie) {
                throw Utils.propagate(ie);
            }
        }

        refCount.incrementAndGet();
    }

    synchronized void unref() {
        if (refCount.decrementAndGet() == 0) {
            server.close();
            server = null;
        }
    }

    private static Promise<ContextInfo> createContextInfo(final URI uri) {
        String[] userInfo = uri.getUserInfo().split(":", 2);
        ImmediateEventExecutor executor = ImmediateEventExecutor.INSTANCE;
        Promise<ContextInfo> promise = executor.newPromise();
        promise.setSuccess(new ContextInfo(uri.getHost(), uri.getPort(), userInfo[0], userInfo[1]));
        return promise;
    }

}