1 /* 2 * Copyright 2010 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.regionserver.wal; 21 22 import org.apache.hadoop.fs.Path; 23 import org.apache.hadoop.hbase.HRegionInfo; 24 25 /** 26 * Get notification of {@link HLog}/WAL log events. The invocations are inline 27 * so make sure your implementation is fast else you'll slow hbase. 28 */ 29 public interface WALObserver { 30 /** 31 * The WAL was rolled. 32 * @param newFile the path to the new hlog 33 */ 34 public void logRolled(Path newFile); 35 36 /** 37 * A request was made that the WAL be rolled. 38 */ 39 public void logRollRequested(); 40 41 /** 42 * The WAL is about to close. 43 */ 44 public void logCloseRequested(); 45 46 /** 47 * Called before each write. 48 * @param info 49 * @param logKey 50 * @param logEdit 51 */ 52 public void visitLogEntryBeforeWrite(HRegionInfo info, HLogKey logKey, 53 WALEdit logEdit); 54 }