| /* |
| * 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.common; |
| |
| import org.apache.drill.shaded.guava.com.google.common.base.Preconditions; |
| |
| /** |
| * A helper class used by {@link HashTableTemplate} in order to pre-allocate {@link HashTableTemplate.BatchHolder}s of the appropriate size. |
| * |
| * <b>Note:</b> This class will be obsolete once the key vectors are removed from the hash table. |
| */ |
| class HashTableAllocationTracker |
| { |
| private enum State { |
| NO_ALLOCATION_IN_PROGRESS, |
| ALLOCATION_IN_PROGRESS |
| } |
| |
| private final HashTableConfig config; |
| private State state = State.NO_ALLOCATION_IN_PROGRESS; |
| private int remainingCapacity; |
| |
| protected HashTableAllocationTracker(final HashTableConfig config) |
| { |
| this.config = Preconditions.checkNotNull(config); |
| remainingCapacity = config.getInitialCapacity(); |
| } |
| |
| public int getNextBatchHolderSize(int batchSize) { |
| state = State.ALLOCATION_IN_PROGRESS; |
| |
| if (!config.getInitialSizeIsFinal()) { |
| // We don't know the final size of the hash table, so just return the batch size. |
| return batchSize; |
| } else { |
| // We know the final size of the hash table so we need to compute the next batch holder size. |
| Preconditions.checkState(remainingCapacity > 0); |
| return computeNextBatchHolderSize(batchSize); |
| } |
| } |
| |
| private int computeNextBatchHolderSize(int batchSize) { |
| return Math.min(batchSize, remainingCapacity); |
| } |
| |
| public void commit(int batchSize) { |
| Preconditions.checkState(state.equals(State.ALLOCATION_IN_PROGRESS)); |
| remainingCapacity -= batchSize; |
| state = State.NO_ALLOCATION_IN_PROGRESS; |
| } |
| } |