content: /*
   * 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.beam.sdk.transforms.join;
  
  import java.io.Serializable;
  import java.util.HashMap;
  import java.util.List;
  import org.apache.beam.sdk.values.TupleTag;
  import org.apache.beam.sdk.values.TupleTagList;
  import org.checkerframework.checker.nullness.qual.Nullable;
  
  /**
   * A schema for the results of a {@link CoGroupByKey}. This maintains the full set of {@link
   * TupleTag}s for the results of a {@link CoGroupByKey} and facilitates mapping between {@link
   * TupleTag}s and {@link RawUnionValue} tags (which are used as secondary keys in the {@link
   * CoGroupByKey}).
   */
  public class CoGbkResultSchema implements Serializable {
  
    private final TupleTagList tupleTagList;
  
    public static CoGbkResultSchema of(List<TupleTag<?>> tags) {
      TupleTagList tupleTags = TupleTagList.empty();
      for (TupleTag<?> tag : tags) {
        tupleTags = tupleTags.and(tag);
      }
      return new CoGbkResultSchema(tupleTags);
    }
  
    /** Maps TupleTags to union tags. This avoids needing to encode the tags themselves. */
    private final HashMap<TupleTag<?>, Integer> tagMap = new HashMap<>();
  
    /** Builds a schema from a tuple of {@code TupleTag<?>}s. */
    public CoGbkResultSchema(TupleTagList tupleTagList) {
      this.tupleTagList = tupleTagList;
      int index = -1;
      for (TupleTag<?> tag : tupleTagList.getAll()) {
        index++;
        tagMap.put(tag, index);
      }
    }
  
    /**
     * Returns the index for the given tuple tag, if the tag is present in this schema, -1 if it
     * isn't.
     */
    public int getIndex(TupleTag<?> tag) {
      Integer index = tagMap.get(tag);
      return index == null ? -1 : index;
    }
  
    /** Returns the tuple tag at the given index. */
    public TupleTag<?> getTag(int index) {
      return tupleTagList.get(index);
    }
  
    /** Returns the number of columns for this schema. */
    public int size() {
      return tupleTagList.getAll().size();
    }
  
    /** Returns the TupleTagList tuple associated with this schema. */
    public TupleTagList getTupleTagList() {
      return tupleTagList;
    }
  
    @Override
    public boolean equals(@Nullable Object obj) {
      if (obj == this) {
        return true;
      }
      if (!(obj instanceof CoGbkResultSchema)) {
        return false;
      }
      CoGbkResultSchema other = (CoGbkResultSchema) obj;
      return tupleTagList.getAll().equals(other.tupleTagList.getAll());
    }
  
    @Override
    public int hashCode() {
      return tupleTagList.getAll().hashCode();
    }
  
    @Override
    public String toString() {
      return "CoGbkResultSchema: " + tupleTagList.getAll();
    }
  }
  