| /* |
| * 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.beam.runners.dataflow.worker; |
| |
| import java.io.Closeable; |
| import java.io.IOException; |
| import javax.annotation.concurrent.ThreadSafe; |
| import org.apache.beam.runners.dataflow.worker.util.common.worker.OperationContext; |
| |
| /** |
| * ApplianceShuffleReader reads chunks of data from a shuffle dataset for a position range. |
| * |
| * <p>It is a JNI wrapper of an equivalent C++ class. |
| */ |
| @ThreadSafe |
| @SuppressWarnings({ |
| "nullness" // TODO(https://issues.apache.org/jira/browse/BEAM-10402) |
| }) |
| public final class ApplianceShuffleReader implements ShuffleReader, Closeable { |
| static { |
| ShuffleLibrary.load(); |
| } |
| |
| /** Pointer to the underlying C++ ShuffleReader object. */ |
| private long nativePointer; |
| |
| /** Adapter used to import counterFactory from native code. */ |
| private ApplianceShuffleCounters counters; |
| |
| /** Whether the underlying C++ object was already destroyed. */ |
| private boolean destroyed = false; |
| |
| /** Returns the total number of allocated native ShuffleReader objects. */ |
| public static native int getNumReaders(); |
| |
| /** |
| * @param shuffleReaderConfig opaque configuration for creating a shuffle reader |
| * @param operationContext context of the read operation this shuffle reader is associated with |
| */ |
| public ApplianceShuffleReader(byte[] shuffleReaderConfig, OperationContext operationContext) { |
| this.nativePointer = createFromConfig(shuffleReaderConfig); |
| this.counters = |
| new ApplianceShuffleCounters( |
| operationContext.counterFactory(), operationContext.nameContext(), getDatasetId()); |
| } |
| |
| public native String getDatasetId(); |
| |
| @Override |
| public native ReadChunkResult readIncludingPosition(byte[] startPosition, byte[] endPosition) |
| throws IOException; |
| |
| /** |
| * Releases resources associated with this reader. |
| * |
| * <p>May be called multiple times, but once it's called, no other methods can be called on this |
| * object. |
| */ |
| @Override |
| public void close() { |
| destroySynchronized(); |
| } |
| |
| @Override |
| protected void finalize() { |
| destroySynchronized(); |
| } |
| |
| /** |
| * Native methods for interacting with the underlying native shuffle client code. {@code |
| * createFromConfig()} returns a pointer to a newly created C++ ShuffleReader object. |
| */ |
| private native long createFromConfig(byte[] shuffleReaderConfig); |
| |
| private native void destroy(); |
| |
| /** Destroys the underlying C++ object if it hasn't yet been destroyed. */ |
| private synchronized void destroySynchronized() { |
| if (!destroyed) { |
| destroy(); |
| destroyed = true; |
| nativePointer = 0; |
| } |
| } |
| } |