org.apache.drill.common.config.DrillConfig.java Source code

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Here is the source code for org.apache.drill.common.config.DrillConfig.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
 * 
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 * distributed under the License is distributed on an "AS IS" BASIS,
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package org.apache.drill.common.config;

import java.net.URL;
import java.util.Collection;
import java.util.List;
import java.util.Queue;
import java.util.concurrent.CopyOnWriteArrayList;

import org.apache.drill.common.expression.LogicalExpression;
import org.apache.drill.common.logical.StorageEngineConfigBase;
import org.apache.drill.common.logical.data.LogicalOperatorBase;
import org.apache.drill.common.util.PathScanner;

import com.fasterxml.jackson.core.JsonParser.Feature;
import com.fasterxml.jackson.databind.ObjectMapper;
import com.fasterxml.jackson.databind.SerializationFeature;
import com.fasterxml.jackson.databind.module.SimpleModule;
import com.typesafe.config.Config;
import com.typesafe.config.ConfigFactory;

public final class DrillConfig extends NestedConfig {

    static final org.slf4j.Logger logger = org.slf4j.LoggerFactory.getLogger(DrillConfig.class);
    private final ObjectMapper mapper;

    @SuppressWarnings("unchecked")
    private volatile List<Queue<Object>> sinkQueues = new CopyOnWriteArrayList<Queue<Object>>(new Queue[1]);

    private DrillConfig(Config config) {
        super(config);
        mapper = new ObjectMapper();
        SimpleModule deserModule = new SimpleModule("LogicalExpressionDeserializationModule")
                .addDeserializer(LogicalExpression.class, new LogicalExpression.De(this));
        mapper.registerModule(deserModule);
        mapper.enable(SerializationFeature.INDENT_OUTPUT);
        mapper.configure(Feature.ALLOW_UNQUOTED_FIELD_NAMES, true);
        mapper.configure(Feature.ALLOW_COMMENTS, true);
        mapper.registerSubtypes(LogicalOperatorBase.getSubTypes(this));
        mapper.registerSubtypes(StorageEngineConfigBase.getSubTypes(this));

    };

    /**
     * <p>
     * DrillConfig loads up Drill configuration information. It does this utilizing a combination of classpath scanning
     * and Configuration fallbacks provided by the TypeSafe configuration library. The order of precedence is as
     * follows:
     * </p>
     * <p>
     * Configuration values are retrieved as follows:
     * <ul>
     * <li>Check a single copy of "drill-override.conf". If multiple copies are on the classpath, behavior is
     * indeterminate.</li>
     * <li>Check all copies of "drill-module.conf". Loading order is indeterminate.</li>
     * <li>Check a single copy of "drill-default.conf". If multiple copies are on the classpath, behavior is
     * indeterminate.</li>
     * </ul>
     * 
     * </p>
     * * @return A merged Config object.
     */
    public static DrillConfig create() {
        // first we load defaults.
        Config fallback = ConfigFactory.load(CommonConstants.CONFIG_DEFAULT);
        Collection<URL> urls = PathScanner.getConfigURLs();
        logger.debug("Loading configs at the following URLs {}", urls);
        for (URL url : urls) {
            fallback = ConfigFactory.parseURL(url).withFallback(fallback);
        }

        Config c = ConfigFactory.load(CommonConstants.CONFIG_OVERRIDE).withFallback(fallback).resolve();
        return new DrillConfig(c);
    }

    public void setSinkQueues(int number, Queue<Object> queue) {
        sinkQueues.set(number, queue);
    }

    public Queue<Object> getQueue(int number) {
        if (sinkQueues.size() <= number || number < 0 || sinkQueues == null)
            throw new IllegalArgumentException(String.format("Queue %d is not available.", number));
        return sinkQueues.get(number);
    }

    public ObjectMapper getMapper() {
        return mapper;
    }
}