/*
* 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;
/**
* 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(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();
}
}