co.cask.cdap.data.stream.StreamInputFormatProvider.java Source code

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Here is the source code for co.cask.cdap.data.stream.StreamInputFormatProvider.java

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/*
 * Copyright  2015 Cask Data, Inc.
 *
 * Licensed 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 co.cask.cdap.data.stream;

import co.cask.cdap.api.data.batch.InputFormatProvider;
import co.cask.cdap.api.data.format.FormatSpecification;
import co.cask.cdap.api.data.stream.StreamBatchReadable;
import co.cask.cdap.api.stream.StreamEventData;
import co.cask.cdap.api.stream.StreamEventDecoder;
import co.cask.cdap.common.conf.ConfigurationUtil;
import co.cask.cdap.data2.transaction.stream.StreamAdmin;
import co.cask.cdap.data2.transaction.stream.StreamConfig;
import co.cask.cdap.proto.Id;
import com.google.common.base.Throwables;
import org.apache.hadoop.conf.Configuration;
import org.apache.hadoop.mapreduce.InputFormat;
import org.apache.twill.filesystem.Location;

import java.io.IOException;
import java.lang.reflect.Type;
import java.util.Map;

/**
 * A {@link InputFormatProvider} to provide {@link InputFormat} to read from stream.
 */
public class StreamInputFormatProvider implements InputFormatProvider {

    private final Id.Namespace namespaceId;
    private final StreamBatchReadable streamBatchReadable;
    private final StreamAdmin streamAdmin;

    public StreamInputFormatProvider(Id.Namespace namespaceId, StreamBatchReadable streamBatchReadable,
            StreamAdmin streamAdmin) {
        this.namespaceId = namespaceId;
        this.streamBatchReadable = streamBatchReadable;
        this.streamAdmin = streamAdmin;
    }

    /**
     * Returns the stream Id of the stream that will be consumed by InputFormat.
     */
    public Id.Stream getStreamId() {
        return Id.Stream.from(namespaceId, streamBatchReadable.getStreamName());
    }

    /**
     * Sets the {@link StreamEventDecoder} to be used by the InputFormat for the given type. If the
     * {@link StreamBatchReadable} already defined a {@link StreamEventDecoder} or {@link FormatSpecification},
     * this method is a no-op.
     *
     * @param configuration configuration to update
     * @param type type for {@link StreamEventData} to decode to
     * @return the same configuration map as in the argument.
     */
    public Map<String, String> setDecoderType(Map<String, String> configuration, Type type) {
        if (streamBatchReadable.getFormatSpecification() == null && streamBatchReadable.getDecoderType() == null) {
            Configuration hConf = new Configuration();
            hConf.clear();
            StreamInputFormat.inferDecoderClass(hConf, type);
            configuration.putAll(ConfigurationUtil.toMap(hConf));
        }
        return configuration;
    }

    @Override
    public String getInputFormatClassName() {
        return StreamInputFormat.class.getName();
    }

    @Override
    public Map<String, String> getInputFormatConfiguration() {
        Id.Stream streamId = Id.Stream.from(namespaceId, streamBatchReadable.getStreamName());
        try {
            StreamConfig streamConfig = streamAdmin.getConfig(streamId);
            Location streamPath = StreamUtils.createGenerationLocation(streamConfig.getLocation(),
                    StreamUtils.getGeneration(streamConfig));
            Configuration hConf = new Configuration();
            hConf.clear();

            StreamInputFormat.setTTL(hConf, streamConfig.getTTL());
            StreamInputFormat.setStreamPath(hConf, streamPath.toURI());
            StreamInputFormat.setTimeRange(hConf, streamBatchReadable.getStartTime(),
                    streamBatchReadable.getEndTime());
            FormatSpecification formatSpec = streamBatchReadable.getFormatSpecification();
            if (formatSpec != null) {
                StreamInputFormat.setBodyFormatSpecification(hConf, formatSpec);
            } else {
                String decoderType = streamBatchReadable.getDecoderType();
                if (decoderType != null) {
                    StreamInputFormat.setDecoderClassName(hConf, decoderType);
                }
            }

            return ConfigurationUtil.toMap(hConf);
        } catch (IOException e) {
            throw Throwables.propagate(e);
        }
    }
}