1 /** 2 * 3 * Licensed to the Apache Software Foundation (ASF) under one 4 * or more contributor license agreements. See the NOTICE file 5 * distributed with this work for additional information 6 * regarding copyright ownership. The ASF licenses this file 7 * to you under the Apache License, Version 2.0 (the 8 * "License"); you may not use this file except in compliance 9 * with the License. You may obtain a copy of the License at 10 * 11 * http://www.apache.org/licenses/LICENSE-2.0 12 * 13 * Unless required by applicable law or agreed to in writing, software 14 * distributed under the License is distributed on an "AS IS" BASIS, 15 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 16 * See the License for the specific language governing permissions and 17 * limitations under the License. 18 */ 19 package org.apache.hadoop.hbase.regionserver.compactions; 20 21 import java.io.IOException; 22 import java.util.List; 23 24 import org.apache.hadoop.hbase.classification.InterfaceAudience; 25 import org.apache.hadoop.fs.Path; 26 import org.apache.hadoop.hbase.regionserver.StoreFile; 27 28 29 /** 30 * This class holds all "physical" details necessary to run a compaction, 31 * and abstracts away the details specific to a particular compaction. 32 * It also has compaction request with all the logical details. 33 * Hence, this class is basically the compaction. 34 */ 35 @InterfaceAudience.Private 36 public abstract class CompactionContext { 37 protected CompactionRequest request = null; 38 39 /** 40 * Called before coprocessor preCompactSelection and should filter the candidates 41 * for coprocessor; i.e. exclude the files that definitely cannot be compacted at this time. 42 * @param filesCompacting files currently compacting 43 * @return the list of files that can theoretically be compacted. 44 */ 45 public abstract List<StoreFile> preSelect(final List<StoreFile> filesCompacting); 46 47 /** 48 * Called to select files for compaction. Must fill in the request field if successful. 49 * @param filesCompacting Files currently being compacted by other compactions. 50 * @param isUserCompaction Whether this is a user compaction. 51 * @param mayUseOffPeak Whether the underlying policy may assume it's off-peak hours. 52 * @param forceMajor Whether to force major compaction. 53 * @return Whether the selection succeeded. Selection may be empty and lead to no compaction. 54 */ 55 public abstract boolean select( 56 final List<StoreFile> filesCompacting, final boolean isUserCompaction, 57 final boolean mayUseOffPeak, final boolean forceMajor) throws IOException; 58 59 /** 60 * Forces external selection to be applied for this compaction. 61 * @param request The pre-cooked request with selection and other settings. 62 */ 63 public void forceSelect(CompactionRequest request) { 64 this.request = request; 65 } 66 67 /** 68 * Runs the compaction based on current selection. select/forceSelect must have been called. 69 * @return The new file paths resulting from compaction. 70 */ 71 public abstract List<Path> compact(CompactionThroughputController throughputController) 72 throws IOException; 73 74 public CompactionRequest getRequest() { 75 assert hasSelection(); 76 return this.request; 77 } 78 79 public boolean hasSelection() { 80 return this.request != null; 81 } 82 }