| /** |
| * |
| * Licensed to the Apache Software Foundation (ASF) under one |
| * or more contributor license agreements. See the NOTICE file |
| * distributed with this work for additional information |
| * regarding copyright ownership. The ASF licenses this file |
| * to you under the Apache License, Version 2.0 (the |
| * "License"); you may not use this file except in compliance |
| * with the License. You may obtain a copy of the License at |
| * |
| * http://www.apache.org/licenses/LICENSE-2.0 |
| * |
| * Unless required by applicable law or agreed to in writing, software |
| * distributed under the License is distributed on an "AS IS" BASIS, |
| * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. |
| * See the License for the specific language governing permissions and |
| * limitations under the License. |
| */ |
| package org.apache.hadoop.hbase.wal; |
| |
| import java.io.Closeable; |
| import java.io.IOException; |
| import java.util.List; |
| import java.util.OptionalLong; |
| import java.util.concurrent.CompletableFuture; |
| import org.apache.hadoop.conf.Configuration; |
| import org.apache.hadoop.hbase.client.RegionInfo; |
| import org.apache.hadoop.hbase.regionserver.wal.WALActionsListener; |
| import org.apache.hadoop.hbase.replication.regionserver.WALFileLengthProvider; |
| import org.apache.yetus.audience.InterfaceAudience; |
| |
| /** |
| * The Write Ahead Log (WAL) stores all durable edits to the HRegion. This interface provides the |
| * entry point for all WAL implementors. |
| * <p> |
| * See {@link FSHLogProvider} for an example implementation. A single WALProvider will be used for |
| * retrieving multiple WALs in a particular region server and must be threadsafe. |
| */ |
| @InterfaceAudience.Private |
| public interface WALProvider { |
| |
| /** |
| * Set up the provider to create wals. will only be called once per instance. |
| * @param factory factory that made us may not be null |
| * @param conf may not be null |
| * @param providerId differentiate between providers from one factory. may be null |
| */ |
| void init(WALFactory factory, Configuration conf, String providerId) throws IOException; |
| |
| /** |
| * @param region the region which we want to get a WAL for it. Could be null. |
| * @return a WAL for writing entries for the given region. |
| */ |
| WAL getWAL(RegionInfo region) throws IOException; |
| |
| /** |
| * @return the List of WALs that are used by this server |
| */ |
| List<WAL> getWALs(); |
| |
| /** |
| * persist outstanding WALs to storage and stop accepting new appends. This method serves as |
| * shorthand for sending a sync to every WAL provided by a given implementation. Those WALs will |
| * also stop accepting new writes. |
| */ |
| void shutdown() throws IOException; |
| |
| /** |
| * shutdown utstanding WALs and clean up any persisted state. Call this method only when you will |
| * not need to replay any of the edits to the WALs from this provider. After this call completes, |
| * the underlying resources should have been reclaimed. |
| */ |
| void close() throws IOException; |
| |
| interface WriterBase extends Closeable { |
| long getLength(); |
| } |
| |
| // Writers are used internally. Users outside of the WAL should be relying on the |
| // interface provided by WAL. |
| interface Writer extends WriterBase { |
| void sync(boolean forceSync) throws IOException; |
| |
| void append(WAL.Entry entry) throws IOException; |
| } |
| |
| interface AsyncWriter extends WriterBase { |
| CompletableFuture<Long> sync(); |
| |
| void append(WAL.Entry entry); |
| } |
| |
| /** |
| * Get number of the log files this provider is managing |
| */ |
| long getNumLogFiles(); |
| |
| /** |
| * Get size of the log files this provider is managing |
| */ |
| long getLogFileSize(); |
| |
| /** |
| * Add a {@link WALActionsListener}. |
| * <p> |
| * Notice that you must call this method before calling {@link #getWAL(RegionInfo)} as this method |
| * will not effect the {@link WAL} which has already been created. And as long as we can only it |
| * when initialization, it is not thread safe. |
| */ |
| void addWALActionsListener(WALActionsListener listener); |
| |
| default WALFileLengthProvider getWALFileLengthProvider() { |
| return path -> getWALs().stream().map(w -> w.getLogFileSizeIfBeingWritten(path)) |
| .filter(o -> o.isPresent()).findAny().orElse(OptionalLong.empty()); |
| } |
| } |