api/src/main/java/org/apache/iceberg/DistributionMode.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 org.apache.iceberg;

import java.util.Locale;
import org.apache.iceberg.relocated.com.google.common.base.Preconditions;

/**
 * Enum of supported write distribution mode, it defines the write behavior of batch or streaming
 * job:
 *
 * <p>1. none: don't shuffle rows. It is suitable for scenarios where the rows are located in only
 * few partitions, otherwise that may produce too many small files because each task is writing rows
 * into different partitions randomly.
 *
 * <p>2. hash: hash distribute by partition key, which is suitable for the scenarios where the rows
 * are located into different partitions evenly.
 *
 * <p>3. range: range distribute by partition key (or sort key if table has an {@link SortOrder}),
 * which is suitable for the scenarios where rows are located into different partitions with skew
 * distribution.
 */
public enum DistributionMode {
  NONE("none"),
  HASH("hash"),
  RANGE("range");

  private final String modeName;

  DistributionMode(String modeName) {
    this.modeName = modeName;
  }

  public String modeName() {
    return modeName;
  }

  public static DistributionMode fromName(String modeName) {
    Preconditions.checkArgument(null != modeName, "Invalid distribution mode: null");
    try {
      return DistributionMode.valueOf(modeName.toUpperCase(Locale.ENGLISH));
    } catch (IllegalArgumentException e) {
      throw new IllegalArgumentException(String.format("Invalid distribution mode: %s", modeName));
    }
  }
}