| /** |
| * 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.pulsar.packages.management.storage.bookkeeper; |
| |
| import java.io.IOException; |
| import java.io.OutputStream; |
| import java.util.concurrent.CompletableFuture; |
| import org.apache.distributedlog.DLSN; |
| import org.apache.distributedlog.api.AsyncLogReader; |
| import org.apache.distributedlog.api.DistributedLogManager; |
| import org.apache.distributedlog.exceptions.EndOfStreamException; |
| |
| /** |
| * DistributedLog Input Stream. |
| */ |
| class DLInputStream { |
| |
| private final DistributedLogManager distributedLogManager; |
| private final AsyncLogReader reader; |
| |
| private DLInputStream(DistributedLogManager distributedLogManager, AsyncLogReader reader) { |
| this.distributedLogManager = distributedLogManager; |
| this.reader = reader; |
| } |
| |
| static CompletableFuture<DLInputStream> openReaderAsync(DistributedLogManager distributedLogManager) { |
| return distributedLogManager.openAsyncLogReader(DLSN.InitialDLSN) |
| .thenApply(r -> new DLInputStream(distributedLogManager, r)); |
| } |
| |
| /** |
| * Read data to output stream. |
| * |
| * @param outputStream the data write to |
| * @return |
| */ |
| CompletableFuture<DLInputStream> readAsync(OutputStream outputStream) { |
| CompletableFuture<Void> outputFuture = new CompletableFuture<>(); |
| read(outputStream, outputFuture, 10); |
| return outputFuture.thenApply(ignore -> this); |
| } |
| |
| /** |
| * When reading the end of a stream, it will throw an EndOfStream exception. So we can use this to |
| * check if we read to the end. |
| * |
| * @param outputStream the data write to |
| * @param readFuture a future that wait to read complete |
| * @param num how many entries read in one time |
| */ |
| private void read(OutputStream outputStream, CompletableFuture<Void> readFuture, int num) { |
| reader.readBulk(num) |
| .whenComplete((logRecordWithDLSNS, throwable) -> { |
| if (null != throwable) { |
| if (throwable instanceof EndOfStreamException) { |
| readFuture.complete(null); |
| } else { |
| readFuture.completeExceptionally(throwable); |
| } |
| return; |
| } |
| CompletableFuture.runAsync(() -> logRecordWithDLSNS.forEach(logRecord -> { |
| try { |
| outputStream.write(logRecord.getPayload()); |
| } catch (IOException e) { |
| readFuture.completeExceptionally(e); |
| } |
| })).thenRun(() -> read(outputStream, readFuture, num)); |
| }); |
| } |
| |
| CompletableFuture<Void> closeAsync() { |
| return reader.asyncClose().thenCompose(ignore -> distributedLogManager.asyncClose()); |
| } |
| } |
| |