| /** |
| * Copyright The Apache Software Foundation |
| * |
| * 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.hbase; |
| |
| import org.apache.hadoop.hbase.classification.InterfaceAudience; |
| import org.apache.hadoop.hbase.util.Bytes; |
| |
| /** |
| * This class is an extension to KeyValue where rowLen and keyLen are cached. |
| * Parsing the backing byte[] every time to get these values will affect the performance. |
| * In read path, we tend to read these values many times in Comparator, SQM etc. |
| * Note: Please do not use these objects in write path as it will increase the heap space usage. |
| * See https://issues.apache.org/jira/browse/HBASE-13448 |
| */ |
| @InterfaceAudience.Private |
| @edu.umd.cs.findbugs.annotations.SuppressWarnings(value="EQ_DOESNT_OVERRIDE_EQUALS") |
| public class SizeCachedKeyValue extends KeyValue { |
| private static final int HEAP_SIZE_OVERHEAD = Bytes.SIZEOF_SHORT + Bytes.SIZEOF_INT; |
| |
| private short rowLen; |
| private int keyLen; |
| |
| public SizeCachedKeyValue(byte[] bytes, int offset, int length, long seqId) { |
| super(bytes, offset, length); |
| // We will read all these cached values at least once. Initialize now itself so that we can |
| // avoid uninitialized checks with every time call |
| rowLen = super.getRowLength(); |
| keyLen = super.getKeyLength(); |
| setSequenceId(seqId); |
| } |
| |
| @Override |
| public short getRowLength() { |
| return rowLen; |
| } |
| |
| @Override |
| public int getKeyLength() { |
| return this.keyLen; |
| } |
| |
| @Override |
| public long heapSize() { |
| return super.heapSize() + HEAP_SIZE_OVERHEAD; |
| } |
| } |