| /* |
| * 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.sdk.io; |
| |
| import java.nio.ByteBuffer; |
| import java.nio.channels.WritableByteChannel; |
| import java.nio.charset.StandardCharsets; |
| import org.apache.beam.sdk.io.DefaultFilenamePolicy.Params; |
| import org.apache.beam.sdk.io.fs.ResolveOptions.StandardResolveOptions; |
| import org.apache.beam.sdk.io.fs.ResourceId; |
| import org.apache.beam.sdk.options.ValueProvider.StaticValueProvider; |
| import org.apache.beam.sdk.util.MimeTypes; |
| |
| /** |
| * A simple {@link FileBasedSink} that writes {@link String} values as lines with header and footer. |
| */ |
| class SimpleSink<DestinationT> extends FileBasedSink<String, DestinationT, String> { |
| public SimpleSink( |
| ResourceId tempDirectory, |
| DynamicDestinations<String, DestinationT, String> dynamicDestinations, |
| WritableByteChannelFactory writableByteChannelFactory) { |
| super(StaticValueProvider.of(tempDirectory), dynamicDestinations, writableByteChannelFactory); |
| } |
| |
| public SimpleSink( |
| ResourceId tempDirectory, |
| DynamicDestinations<String, DestinationT, String> dynamicDestinations, |
| Compression compression) { |
| super(StaticValueProvider.of(tempDirectory), dynamicDestinations, compression); |
| } |
| |
| public static SimpleSink<Void> makeSimpleSink( |
| ResourceId tempDirectory, FilenamePolicy filenamePolicy) { |
| return new SimpleSink<>( |
| tempDirectory, DynamicFileDestinations.constant(filenamePolicy), Compression.UNCOMPRESSED); |
| } |
| |
| public static SimpleSink<Void> makeSimpleSink( |
| ResourceId baseDirectory, |
| String prefix, |
| String shardTemplate, |
| String suffix, |
| WritableByteChannelFactory writableByteChannelFactory) { |
| DynamicDestinations<String, Void, String> dynamicDestinations = |
| DynamicFileDestinations.constant( |
| DefaultFilenamePolicy.fromParams( |
| new Params() |
| .withBaseFilename( |
| baseDirectory.resolve(prefix, StandardResolveOptions.RESOLVE_FILE)) |
| .withShardTemplate(shardTemplate) |
| .withSuffix(suffix))); |
| return new SimpleSink<>(baseDirectory, dynamicDestinations, writableByteChannelFactory); |
| } |
| |
| public static SimpleSink<Void> makeSimpleSink( |
| ResourceId baseDirectory, |
| String prefix, |
| String shardTemplate, |
| String suffix, |
| Compression compression) { |
| return makeSimpleSink( |
| baseDirectory, |
| prefix, |
| shardTemplate, |
| suffix, |
| FileBasedSink.CompressionType.fromCanonical(compression)); |
| } |
| |
| @Override |
| public SimpleWriteOperation<DestinationT> createWriteOperation() { |
| return new SimpleWriteOperation<>(this); |
| } |
| |
| static final class SimpleWriteOperation<DestinationT> |
| extends WriteOperation<DestinationT, String> { |
| public SimpleWriteOperation(SimpleSink<DestinationT> sink, ResourceId tempOutputDirectory) { |
| super(sink, tempOutputDirectory); |
| } |
| |
| public SimpleWriteOperation(SimpleSink<DestinationT> sink) { |
| super(sink); |
| } |
| |
| @Override |
| public SimpleWriter<DestinationT> createWriter() { |
| return new SimpleWriter<>(this); |
| } |
| } |
| |
| static final class SimpleWriter<DestinationT> extends Writer<DestinationT, String> { |
| static final String HEADER = "header"; |
| static final String FOOTER = "footer"; |
| |
| private WritableByteChannel channel; |
| |
| public SimpleWriter(SimpleWriteOperation<DestinationT> writeOperation) { |
| super(writeOperation, MimeTypes.TEXT); |
| } |
| |
| private static ByteBuffer wrap(String value) { |
| return ByteBuffer.wrap((value + "\n").getBytes(StandardCharsets.UTF_8)); |
| } |
| |
| @Override |
| protected void prepareWrite(WritableByteChannel channel) { |
| this.channel = channel; |
| } |
| |
| @Override |
| protected void writeHeader() throws Exception { |
| channel.write(wrap(HEADER)); |
| } |
| |
| @Override |
| protected void writeFooter() throws Exception { |
| channel.write(wrap(FOOTER)); |
| } |
| |
| @Override |
| public void write(String value) throws Exception { |
| channel.write(wrap(value)); |
| } |
| } |
| } |