CompressionConfigParser.java

/*
 * 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.compression;

import java.util.Map;

import com.google.common.collect.ImmutableMap;

import gobblin.configuration.ConfigurationKeys;
import gobblin.configuration.State;
import gobblin.util.ForkOperatorUtils;


/**
 * Functions for parsing compression configuration
 */
public class CompressionConfigParser {
  private static final String COMPRESSION_TYPE_KEY = "type";

  /**
   * Retrieve configuration settings for a given branch.
   * @param taskState Task state
   * @param numBranches # of branches in the state
   * @param branch Branch to retrieve
   * @return Map of properties for compression
   */
  public static Map<String, Object> getConfigForBranch(State taskState, int numBranches, int branch) {
    String typePropertyName =
        ForkOperatorUtils.getPropertyNameForBranch(ConfigurationKeys.WRITER_CODEC_TYPE, numBranches, branch);
    String compressionType = taskState.getProp(typePropertyName);
    if (compressionType == null) {
      return null;
    }

    return ImmutableMap.<String, Object>of(COMPRESSION_TYPE_KEY, compressionType);
  }

  /**
   * Return compression type
   * @param properties Compression config settings
   * @return String representing compression type, null if none exists
   */
  public static String getCompressionType(Map<String, Object> properties) {
    return (String) properties.get(COMPRESSION_TYPE_KEY);
  }

  private CompressionConfigParser() {

  }
}