org.apache.tajo.plan.function.stream.StreamingUtil.java Source code

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Here is the source code for org.apache.tajo.plan.function.stream.StreamingUtil.java

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/*
 * Lisensed 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.tajo.plan.function.stream;

import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;

import java.io.File;
import java.util.ArrayList;
import java.util.List;
import java.util.Map;

public class StreamingUtil {

    private static final Log LOG = LogFactory.getLog(StreamingUtil.class);

    private static final String BASH = "bash";
    private static final String PATH = "PATH";

    /**
     * Create an external process for StreamingCommand command.
     *
     * @param argv process arguments
     * @return
     */
    public static ProcessBuilder createProcess(String[] argv) {
        // Set the actual command to run with 'bash -c exec ...'
        List<String> cmdArgs = new ArrayList<>();

        StringBuffer argBuffer = new StringBuffer();
        for (String arg : argv) {
            argBuffer.append(arg);
            argBuffer.append(" ");
        }
        String argvAsString = argBuffer.toString();

        if (System.getProperty("os.name").toUpperCase().startsWith("WINDOWS")) {
            cmdArgs.add("cmd");
            cmdArgs.add("/c");
            cmdArgs.add(argvAsString);
        } else {
            cmdArgs.add(BASH);
            cmdArgs.add("-c");
            StringBuffer sb = new StringBuffer();
            sb.append("exec ");
            sb.append(argvAsString);
            cmdArgs.add(sb.toString());
        }

        if (LOG.isDebugEnabled()) {
            StringBuffer sb = new StringBuffer("command: ");
            for (String cmd : cmdArgs) {
                sb.append(cmd).append(" ");
            }
            LOG.debug(sb.toString());
        }

        // Start the external process
        ProcessBuilder processBuilder = new ProcessBuilder(cmdArgs.toArray(new String[cmdArgs.size()]));
        setupEnvironment(processBuilder);
        return processBuilder;
    }

    /**
     * Set up the run-time environment of the managed process.
     *
     * @param pb {@link ProcessBuilder} used to exec the process
     */
    private static void setupEnvironment(ProcessBuilder pb) {
        String separator = ":";
        Map<String, String> env = pb.environment();

        // Add the current-working-directory to the $PATH
        File dir = pb.directory();
        String cwd = (dir != null) ? dir.getAbsolutePath() : System.getProperty("user.dir");

        String envPath = env.get(PATH);
        if (envPath == null) {
            envPath = cwd;
        } else {
            envPath = envPath + separator + cwd;
        }
        env.put(PATH, envPath);
    }
}