gobblin.service.modules.topology.ConfigBasedTopologySpecFactory.java Source code

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Here is the source code for gobblin.service.modules.topology.ConfigBasedTopologySpecFactory.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 gobblin.service.modules.topology;

import java.lang.reflect.InvocationTargetException;
import java.util.Collection;
import java.util.Collections;

import org.apache.commons.lang3.reflect.ConstructorUtils;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

import com.google.common.base.Optional;
import com.google.common.base.Preconditions;
import com.google.common.base.Splitter;
import com.google.common.collect.Lists;
import com.typesafe.config.Config;

import gobblin.annotation.Alpha;
import gobblin.runtime.api.SpecExecutorInstanceProducer;
import gobblin.runtime.api.TopologySpec;
import gobblin.service.ServiceConfigKeys;
import gobblin.util.ClassAliasResolver;
import gobblin.util.ConfigUtils;

@Alpha
public class ConfigBasedTopologySpecFactory implements TopologySpecFactory {

    private static final Splitter SPLIT_BY_COMMA = Splitter.on(",").omitEmptyStrings().trimResults();
    private final Config _config;
    private final Logger _log;
    private final ClassAliasResolver<SpecExecutorInstanceProducer> _aliasResolver;

    public ConfigBasedTopologySpecFactory(Config config) {
        this(config, Optional.<Logger>absent());
    }

    public ConfigBasedTopologySpecFactory(Config config, Optional<Logger> log) {
        Preconditions.checkNotNull(config, "Config should not be null");
        _log = log.isPresent() ? log.get() : LoggerFactory.getLogger(getClass());
        _config = config;
        _aliasResolver = new ClassAliasResolver<>(SpecExecutorInstanceProducer.class);
    }

    @Override
    public Collection<TopologySpec> getTopologies() {

        if (!_config.hasPath(ServiceConfigKeys.TOPOLOGY_FACTORY_TOPOLOGY_NAMES_KEY)) {
            return Collections.EMPTY_LIST;
        }
        Collection<TopologySpec> topologySpecs = Lists.newArrayList();
        Collection<String> topologyNames = SPLIT_BY_COMMA
                .splitToList(_config.getString(ServiceConfigKeys.TOPOLOGY_FACTORY_TOPOLOGY_NAMES_KEY));

        for (String topologyName : topologyNames) {
            Preconditions.checkArgument(_config.hasPath(ServiceConfigKeys.TOPOLOGY_FACTORY_PREFIX + topologyName),
                    "Config does not contain Topology Factory descriptor for Topology" + topologyName);
            Config topologyConfig = _config.getConfig(ServiceConfigKeys.TOPOLOGY_FACTORY_PREFIX + topologyName);
            String description = ConfigUtils.getString(topologyConfig,
                    ServiceConfigKeys.TOPOLOGYSPEC_DESCRIPTION_KEY, "NA");
            String version = ConfigUtils.getString(topologyConfig, ServiceConfigKeys.TOPOLOGYSPEC_VERSION_KEY,
                    "-1");

            String specExecutorInstanceProducerClass = ServiceConfigKeys.DEFAULT_SPEC_EXECUTOR_INSTANCE_PRODUCER;
            if (topologyConfig.hasPath(ServiceConfigKeys.SPEC_EXECUTOR_INSTANCE_PRODUCER_KEY)) {
                specExecutorInstanceProducerClass = topologyConfig
                        .getString(ServiceConfigKeys.SPEC_EXECUTOR_INSTANCE_PRODUCER_KEY);
            }
            SpecExecutorInstanceProducer specExecutorInstanceProducer;
            try {
                _log.info(
                        "Using SpecExecutorInstanceProducer class name/alias " + specExecutorInstanceProducerClass);
                specExecutorInstanceProducer = (SpecExecutorInstanceProducer) ConstructorUtils.invokeConstructor(
                        Class.forName(_aliasResolver.resolve(specExecutorInstanceProducerClass)), topologyConfig);
            } catch (NoSuchMethodException | IllegalAccessException | InvocationTargetException
                    | InstantiationException | ClassNotFoundException e) {
                throw new RuntimeException(e);
            }

            TopologySpec.Builder topologySpecBuilder = TopologySpec
                    .builder(topologyConfig.getString(ServiceConfigKeys.TOPOLOGYSPEC_URI_KEY))
                    .withConfig(topologyConfig).withDescription(description).withVersion(version)
                    .withSpecExecutorInstanceProducer(specExecutorInstanceProducer);
            topologySpecs.add(topologySpecBuilder.build());
        }

        return topologySpecs;
    }
}