| /* |
| * 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.apex.translation.utils; |
| |
| import java.io.ByteArrayInputStream; |
| import java.io.ByteArrayOutputStream; |
| import java.io.IOException; |
| import java.util.Collections; |
| import java.util.Iterator; |
| import java.util.NoSuchElementException; |
| import javax.annotation.Nullable; |
| import org.apache.beam.sdk.coders.Coder; |
| import org.apache.beam.sdk.coders.Coder.Context; |
| import org.apache.beam.sdk.coders.IterableCoder; |
| import org.apache.beam.sdk.io.UnboundedSource; |
| import org.apache.beam.sdk.options.PipelineOptions; |
| import org.joda.time.Instant; |
| |
| /** |
| * Unbounded source that reads from a Java {@link Iterable}. |
| */ |
| public class ValuesSource<T> extends UnboundedSource<T, UnboundedSource.CheckpointMark> { |
| private static final long serialVersionUID = 1L; |
| |
| private final byte[] codedValues; |
| private final IterableCoder<T> iterableCoder; |
| |
| public ValuesSource(Iterable<T> values, Coder<T> coder) { |
| this.iterableCoder = IterableCoder.of(coder); |
| ByteArrayOutputStream bos = new ByteArrayOutputStream(); |
| try { |
| iterableCoder.encode(values, bos, Context.OUTER); |
| } catch (IOException ex) { |
| throw new RuntimeException(ex); |
| } |
| this.codedValues = bos.toByteArray(); |
| } |
| |
| @Override |
| public java.util.List<? extends UnboundedSource<T, CheckpointMark>> split( |
| int desiredNumSplits, PipelineOptions options) throws Exception { |
| return Collections.singletonList(this); |
| } |
| |
| @Override |
| public UnboundedReader<T> createReader(PipelineOptions options, |
| @Nullable CheckpointMark checkpointMark) { |
| ByteArrayInputStream bis = new ByteArrayInputStream(codedValues); |
| try { |
| Iterable<T> values = this.iterableCoder.decode(bis, Context.OUTER); |
| return new ValuesReader<>(values, this); |
| } catch (IOException ex) { |
| throw new RuntimeException(ex); |
| } |
| } |
| |
| @Nullable |
| @Override |
| public Coder<CheckpointMark> getCheckpointMarkCoder() { |
| return null; |
| } |
| |
| @Override |
| public void validate() { |
| } |
| |
| @Override |
| public Coder<T> getDefaultOutputCoder() { |
| return iterableCoder.getElemCoder(); |
| } |
| |
| private static class ValuesReader<T> extends UnboundedReader<T> { |
| |
| private final Iterable<T> values; |
| private final UnboundedSource<T, CheckpointMark> source; |
| private transient Iterator<T> iterator; |
| private T current; |
| |
| public ValuesReader(Iterable<T> values, UnboundedSource<T, CheckpointMark> source) { |
| this.values = values; |
| this.source = source; |
| } |
| |
| @Override |
| public boolean start() throws IOException { |
| if (null == iterator) { |
| iterator = values.iterator(); |
| } |
| return advance(); |
| } |
| |
| @Override |
| public boolean advance() throws IOException { |
| if (iterator.hasNext()) { |
| current = iterator.next(); |
| return true; |
| } else { |
| return false; |
| } |
| } |
| |
| @Override |
| public T getCurrent() throws NoSuchElementException { |
| return current; |
| } |
| |
| @Override |
| public Instant getCurrentTimestamp() throws NoSuchElementException { |
| return Instant.now(); |
| } |
| |
| @Override |
| public void close() throws IOException { |
| } |
| |
| @Override |
| public Instant getWatermark() { |
| return Instant.now(); |
| } |
| |
| @Override |
| public CheckpointMark getCheckpointMark() { |
| return null; |
| } |
| |
| @Override |
| public UnboundedSource<T, ?> getCurrentSource() { |
| return source; |
| } |
| } |
| } |