| /** |
| * 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.distributedlog.metadata; |
| |
| import com.google.common.annotations.Beta; |
| import com.google.common.base.Optional; |
| import java.util.concurrent.CompletableFuture; |
| import org.apache.distributedlog.lock.DistributedLock; |
| import org.apache.distributedlog.logsegment.LogSegmentMetadataStore; |
| import org.apache.distributedlog.common.util.PermitManager; |
| import org.apache.distributedlog.util.Transaction; |
| |
| import java.io.Closeable; |
| import java.net.URI; |
| |
| /** |
| * The interface to manage the log stream metadata. The implementation is responsible |
| * for creating the metadata layout. |
| */ |
| @Beta |
| public interface LogStreamMetadataStore extends Closeable { |
| |
| /** |
| * Create a transaction for the metadata operations happening in the metadata store. |
| * |
| * @return transaction for the metadata operations |
| */ |
| Transaction<Object> newTransaction(); |
| |
| /** |
| * Ensure the existence of a log stream |
| * |
| * @param uri the location of the log stream |
| * @param logName the name of the log stream |
| * @return future represents the existence of a log stream. |
| * {@link org.apache.distributedlog.exceptions.LogNotFoundException} is thrown if the log doesn't exist |
| */ |
| CompletableFuture<Void> logExists(URI uri, String logName); |
| |
| /** |
| * Create the read lock for the log stream. |
| * |
| * @param metadata the metadata for a log stream |
| * @param readerId the reader id used for lock |
| * @return the read lock |
| */ |
| CompletableFuture<DistributedLock> createReadLock(LogMetadataForReader metadata, |
| Optional<String> readerId); |
| |
| /** |
| * Create the write lock for the log stream. |
| * |
| * @param metadata the metadata for a log stream |
| * @return the write lock |
| */ |
| DistributedLock createWriteLock(LogMetadataForWriter metadata); |
| |
| /** |
| * Create the metadata of a log. |
| * |
| * @param uri the location to store the metadata of the log |
| * @param streamName the name of the log stream |
| * @param ownAllocator whether to use its own allocator or external allocator |
| * @param createIfNotExists flag to create the stream if it doesn't exist |
| * @return the metadata of the log |
| */ |
| CompletableFuture<LogMetadataForWriter> getLog(URI uri, |
| String streamName, |
| boolean ownAllocator, |
| boolean createIfNotExists); |
| |
| /** |
| * Delete the metadata of a log. |
| * |
| * @param uri the location to store the metadata of the log |
| * @param streamName the name of the log stream |
| * @return future represents the result of the deletion. |
| */ |
| CompletableFuture<Void> deleteLog(URI uri, String streamName); |
| |
| /** |
| * Get the log segment metadata store. |
| * |
| * @return the log segment metadata store. |
| */ |
| LogSegmentMetadataStore getLogSegmentMetadataStore(); |
| |
| /** |
| * Get the permit manager for this metadata store. It can be used for limiting the concurrent |
| * metadata operations. The implementation can disable handing over the permits when the metadata |
| * store is unavailable (for example zookeeper session expired). |
| * |
| * @return the permit manager |
| */ |
| PermitManager getPermitManager(); |
| |
| |
| |
| } |