1 /**
2 * Copyright 2009 The Apache Software Foundation
3 *
4 * Licensed to the Apache Software Foundation (ASF) under one
5 * or more contributor license agreements. See the NOTICE file
6 * distributed with this work for additional information
7 * regarding copyright ownership. The ASF licenses this file
8 * to you under the Apache License, Version 2.0 (the
9 * "License"); you may not use this file except in compliance
10 * with the License. You may obtain a copy of the License at
11 *
12 * http://www.apache.org/licenses/LICENSE-2.0
13 *
14 * Unless required by applicable law or agreed to in writing, software
15 * distributed under the License is distributed on an "AS IS" BASIS,
16 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
17 * See the License for the specific language governing permissions and
18 * limitations under the License.
19 */
20 package org.apache.hadoop.hbase.io.hfile;
21
22 import java.nio.ByteBuffer;
23
24 /**
25 * Block cache interface.
26 * TODO: Add filename or hash of filename to block cache key.
27 */
28 public interface BlockCache {
29 /**
30 * Add block to cache.
31 * @param blockName Zero-based file block number.
32 * @param buf The block contents wrapped in a ByteBuffer.
33 * @param inMemory Whether block should be treated as in-memory
34 */
35 public void cacheBlock(String blockName, ByteBuffer buf, boolean inMemory);
36
37 /**
38 * Add block to cache (defaults to not in-memory).
39 * @param blockName Zero-based file block number.
40 * @param buf The block contents wrapped in a ByteBuffer.
41 */
42 public void cacheBlock(String blockName, ByteBuffer buf);
43
44 /**
45 * Fetch block from cache.
46 * @param blockName Block number to fetch.
47 * @return Block or null if block is not in the cache.
48 */
49 public ByteBuffer getBlock(String blockName);
50
51 /**
52 * Shutdown the cache.
53 */
54 public void shutdown();
55 }