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; 20 21 import java.io.IOException; 22 import java.util.Collection; 23 import java.util.Iterator; 24 import java.util.List; 25 26 import org.apache.hadoop.classification.InterfaceAudience; 27 import org.apache.hadoop.hbase.KeyValue; 28 import org.apache.hadoop.hbase.KeyValue.KVComparator; 29 30 import com.google.common.collect.ImmutableCollection; 31 32 /** 33 * Manages the store files and basic metadata about that that determines the logical structure 34 * (e.g. what files to return for scan, how to determine split point, and such). 35 * Does NOT affect the physical structure of files in HDFS. 36 * Example alternative structures - the default list of files by seqNum; levelDB one sorted 37 * by level and seqNum. 38 * 39 * Implementations are assumed to be not thread safe. 40 */ 41 @InterfaceAudience.Private 42 public interface StoreFileManager { 43 /** 44 * Loads the initial store files into empty StoreFileManager. 45 * @param storeFiles The files to load. 46 */ 47 void loadFiles(List<StoreFile> storeFiles); 48 49 /** 50 * Adds new file, either for from MemStore flush or bulk insert, into the structure. 51 * @param sf New store file. 52 */ 53 void insertNewFile(StoreFile sf); 54 55 /** 56 * Adds compaction results into the structure. 57 * @param compactedFiles The input files for the compaction. 58 * @param results The resulting files for the compaction. 59 */ 60 void addCompactionResults( 61 Collection<StoreFile> compactedFiles, Collection<StoreFile> results 62 ); 63 64 /** 65 * Clears all the files currently in use and returns them. 66 * @return The files previously in use. 67 */ 68 ImmutableCollection<StoreFile> clearFiles(); 69 70 /** 71 * Gets the snapshot of the store files currently in use. Can be used for things like metrics 72 * and checks; should not assume anything about relations between store files in the list. 73 * @return The list of StoreFiles. 74 */ 75 Collection<StoreFile> getStorefiles(); 76 77 /** 78 * Returns the number of files currently in use. 79 * @return The number of files. 80 */ 81 int getStorefileCount(); 82 83 /** 84 * Gets the store files to scan for a Scan or Get request. 85 * @param isGet Whether it's a get. 86 * @param startRow Start row of the request. 87 * @param stopRow Stop row of the request. 88 * @return The list of files that are to be read for this request. 89 */ 90 Collection<StoreFile> getFilesForScanOrGet( 91 boolean isGet, byte[] startRow, byte[] stopRow 92 ); 93 94 /** 95 * Gets initial, full list of candidate store files to check for row-key-before. 96 * @param targetKey The key that is the basis of the search. 97 * @return The files that may have the key less than or equal to targetKey, in reverse 98 * order of new-ness, and preference for target key. 99 */ 100 Iterator<StoreFile> getCandidateFilesForRowKeyBefore( 101 KeyValue targetKey 102 ); 103 104 /** 105 * Updates the candidate list for finding row key before. Based on the list of candidates 106 * remaining to check from getCandidateFilesForRowKeyBefore, targetKey and current candidate, 107 * may trim and reorder the list to remove the files where a better candidate cannot be found. 108 * @param candidateFiles The candidate files not yet checked for better candidates - return 109 * value from {@link #getCandidateFilesForRowKeyBefore(KeyValue)}, 110 * with some files already removed. 111 * @param targetKey The key to search for. 112 * @param candidate The current best candidate found. 113 * @return The list to replace candidateFiles. 114 */ 115 Iterator<StoreFile> updateCandidateFilesForRowKeyBefore( 116 Iterator<StoreFile> candidateFiles, KeyValue targetKey, KeyValue candidate 117 ); 118 119 120 /** 121 * Gets the split point for the split of this set of store files (approx. middle). 122 * @return The mid-point, or null if no split is possible. 123 * @throws IOException 124 */ 125 byte[] getSplitPoint() throws IOException; 126 127 /** 128 * @return The store compaction priority. 129 */ 130 int getStoreCompactionPriority(); 131 }