api/src/main/java/org/apache/iceberg/PartitionField.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.io.Serializable;
import org.apache.iceberg.relocated.com.google.common.base.Objects;
import org.apache.iceberg.transforms.Transform;

/**
 * Represents a single field in a {@link PartitionSpec}.
 */
public class PartitionField implements Serializable {
  private final int sourceId;
  private final int fieldId;
  private final String name;
  private final Transform<?, ?> transform;

  PartitionField(int sourceId, int fieldId, String name, Transform<?, ?> transform) {
    this.sourceId = sourceId;
    this.fieldId = fieldId;
    this.name = name;
    this.transform = transform;
  }

  /**
   * Returns the field id of the source field in the {@link PartitionSpec spec's} table schema.
   */
  public int sourceId() {
    return sourceId;
  }

  /**
   * Returns the partition field id across all the table metadata's partition specs.
   */
  public int fieldId() {
    return fieldId;
  }

  /**
   * Returns the name of this partition field.
   */
  public String name() {
    return name;
  }

  /**
   * Returns the transform used to produce partition values from source values.
   */
  public Transform<?, ?> transform() {
    return transform;
  }

  @Override
  public String toString() {
    return fieldId + ": " + name + ": " + transform + "(" + sourceId + ")";
  }

  @Override
  public boolean equals(Object other) {
    if (this == other) {
      return true;
    } else if (!(other instanceof PartitionField)) {
      return false;
    }

    PartitionField that = (PartitionField) other;
    return sourceId == that.sourceId &&
        fieldId == that.fieldId &&
        name.equals(that.name) &&
        transform.equals(that.transform);
  }

  @Override
  public int hashCode() {
    return Objects.hashCode(sourceId, fieldId, name, transform);
  }
}