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 * @param caching Whether this request has caching enabled (used for stats) 48 * @return Block or null if block is not in the cache. 49 */ 50 public ByteBuffer getBlock(String blockName, boolean caching); 51 52 /** 53 * Shutdown the cache. 54 */ 55 public void shutdown(); 56 }