| /* |
| * 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.drill.exec.physical.impl.join; |
| |
| import org.apache.commons.lang3.tuple.Pair; |
| import org.apache.drill.exec.record.AbstractRecordBatch.BatchState; |
| import org.apache.drill.exec.vector.ValueVector; |
| |
| /** |
| * Interface for a row key join |
| */ |
| public interface RowKeyJoin { |
| |
| /** |
| * Enum for RowKeyJoin internal state. |
| * Possible states are {INITIAL, PROCESSING, DONE} |
| * |
| * Initially RowKeyJoin will be at INITIAL state. Then the state will be transitioned |
| * by the RestrictedJsonRecordReader to PROCESSING as soon as it processes the rows |
| * related to RowKeys. Then RowKeyJoin algorithm sets to INITIAL state when leftStream has no data. |
| * Basically RowKeyJoin calls leftStream multiple times depending upon the rightStream, hence |
| * this transition from PROCESSING to INITIAL. If there is no data from rightStream or OutOfMemory |
| * condition then the state is transitioned to DONE. |
| */ |
| public enum RowKeyJoinState { |
| INITIAL, PROCESSING, DONE; |
| } |
| |
| /** |
| * Is the next batch of row keys ready to be returned |
| * @return True if ready, false if not |
| */ |
| public boolean hasRowKeyBatch(); |
| |
| /** |
| * Get the next batch of row keys |
| * @return a Pair whose left element is the ValueVector containing the row keys, right |
| * element is the number of row keys in this batch |
| */ |
| public Pair<ValueVector, Integer> nextRowKeyBatch(); |
| |
| |
| /** |
| * Get the current BatchState (this is useful when performing row key join) |
| */ |
| public BatchState getBatchState(); |
| |
| /** |
| * Set the BatchState (this is useful when performing row key join) |
| * @param newState |
| */ |
| public void setBatchState(BatchState newState); |
| |
| /** |
| * Set the RowKeyJoinState (this is useful for maintaining state for row key join algorithm) |
| * @param newState |
| */ |
| public void setRowKeyJoinState(RowKeyJoinState newState); |
| |
| /** |
| * Get the current RowKeyJoinState. |
| */ |
| public RowKeyJoinState getRowKeyJoinState(); |
| } |