org.apache.hadoop.hive.ql.exec.vector.mapjoin.hashtable.VectorMapJoinHashMapResult Maven / Gradle / Ivy
/**
* 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.hadoop.hive.ql.exec.vector.mapjoin.hashtable;
import org.apache.hadoop.hive.serde2.WriteBuffers.ByteSegmentRef;
/*
* Abstract class for a hash map result. For reading the values, one-by-one.
*/
public abstract class VectorMapJoinHashMapResult extends VectorMapJoinHashTableResult {
/**
* @return Whether there are any rows (i.e. true for match).
*/
public abstract boolean hasRows();
/**
* @return Whether there is 1 value row.
*/
public abstract boolean isSingleRow();
/**
* @return Whether there is a capped count available from cappedCount.
*/
public abstract boolean isCappedCountAvailable();
/**
* @return The count of values, up to a arbitrary cap limit. When available, the capped
* count can be used to make decisions on how to optimally generate join results.
*/
public abstract int cappedCount();
/**
* @return A reference to the first value, or null if there are no values.
*/
public abstract ByteSegmentRef first();
/**
* @return The next value, or null if there are no more values to be read.
*/
public abstract ByteSegmentRef next();
/**
* @return Whether reading is at the end.
*/
public abstract boolean isEof();
}