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.hbase.classification.InterfaceAudience;
27 import org.apache.hadoop.hbase.Cell;
28 import org.apache.hadoop.hbase.KeyValue;
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 files, either for from MemStore flush or bulk insert, into the structure.
51 * @param sfs New store files.
52 */
53 void insertNewFiles(Collection<StoreFile> sfs) throws IOException;
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) throws IOException;
62
63 /**
64 * Clears all the files currently in use and returns them.
65 * @return The files previously in use.
66 */
67 ImmutableCollection<StoreFile> clearFiles();
68
69 /**
70 * Gets the snapshot of the store files currently in use. Can be used for things like metrics
71 * and checks; should not assume anything about relations between store files in the list.
72 * @return The list of StoreFiles.
73 */
74 Collection<StoreFile> getStorefiles();
75
76 /**
77 * Returns the number of files currently in use.
78 * @return The number of files.
79 */
80 int getStorefileCount();
81
82 /**
83 * Gets the store files to scan for a Scan or Get request.
84 * @param isGet Whether it's a get.
85 * @param startRow Start row of the request.
86 * @param stopRow Stop row of the request.
87 * @return The list of files that are to be read for this request.
88 */
89 Collection<StoreFile> getFilesForScanOrGet(
90 boolean isGet, byte[] startRow, byte[] stopRow
91 );
92
93 /**
94 * Gets initial, full list of candidate store files to check for row-key-before.
95 * @param targetKey The key that is the basis of the search.
96 * @return The files that may have the key less than or equal to targetKey, in reverse
97 * order of new-ness, and preference for target key.
98 */
99 Iterator<StoreFile> getCandidateFilesForRowKeyBefore(
100 KeyValue targetKey
101 );
102
103 /**
104 * Updates the candidate list for finding row key before. Based on the list of candidates
105 * remaining to check from getCandidateFilesForRowKeyBefore, targetKey and current candidate,
106 * may trim and reorder the list to remove the files where a better candidate cannot be found.
107 * @param candidateFiles The candidate files not yet checked for better candidates - return
108 * value from {@link #getCandidateFilesForRowKeyBefore(KeyValue)},
109 * with some files already removed.
110 * @param targetKey The key to search for.
111 * @param candidate The current best candidate found.
112 * @return The list to replace candidateFiles.
113 */
114 Iterator<StoreFile> updateCandidateFilesForRowKeyBefore(
115 Iterator<StoreFile> candidateFiles, KeyValue targetKey, Cell candidate
116 );
117
118
119 /**
120 * Gets the split point for the split of this set of store files (approx. middle).
121 * @return The mid-point, or null if no split is possible.
122 * @throws IOException
123 */
124 byte[] getSplitPoint() throws IOException;
125
126 /**
127 * @return The store compaction priority.
128 */
129 int getStoreCompactionPriority();
130
131 /**
132 * @param maxTs Maximum expired timestamp.
133 * @param filesCompacting Files that are currently compacting.
134 * @return The files which don't have any necessary data according to TTL and other criteria.
135 */
136 Collection<StoreFile> getUnneededFiles(long maxTs, List<StoreFile> filesCompacting);
137
138 /**
139 * @return the compaction pressure used for compaction throughput tuning.
140 * @see Store#getCompactionPressure()
141 */
142 double getCompactionPressure();
143 }