| /** |
| * 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.fs.azurebfs.services; |
| |
| import java.util.concurrent.CountDownLatch; |
| |
| import org.apache.hadoop.fs.azurebfs.contracts.services.ReadBufferStatus; |
| |
| class ReadBufferWorker implements Runnable { |
| |
| protected static final CountDownLatch UNLEASH_WORKERS = new CountDownLatch(1); |
| private int id; |
| |
| ReadBufferWorker(final int id) { |
| this.id = id; |
| } |
| |
| /** |
| * return the ID of ReadBufferWorker. |
| */ |
| public int getId() { |
| return this.id; |
| } |
| |
| /** |
| * Waits until a buffer becomes available in ReadAheadQueue. |
| * Once a buffer becomes available, reads the file specified in it and then posts results back to buffer manager. |
| * Rinse and repeat. Forever. |
| */ |
| public void run() { |
| try { |
| UNLEASH_WORKERS.await(); |
| } catch (InterruptedException ex) { |
| Thread.currentThread().interrupt(); |
| } |
| ReadBufferManager bufferManager = ReadBufferManager.getBufferManager(); |
| ReadBuffer buffer; |
| while (true) { |
| try { |
| buffer = bufferManager.getNextBlockToRead(); // blocks, until a buffer is available for this thread |
| } catch (InterruptedException ex) { |
| Thread.currentThread().interrupt(); |
| return; |
| } |
| if (buffer != null) { |
| try { |
| // do the actual read, from the file. |
| int bytesRead = buffer.getStream().readRemote(buffer.getOffset(), buffer.getBuffer(), 0, buffer.getRequestedLength()); |
| bufferManager.doneReading(buffer, ReadBufferStatus.AVAILABLE, bytesRead); // post result back to ReadBufferManager |
| } catch (Exception ex) { |
| bufferManager.doneReading(buffer, ReadBufferStatus.READ_FAILED, 0); |
| } |
| } |
| } |
| } |
| } |