gobblin.metrics.MetricReportUtils.java Source code

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Here is the source code for gobblin.metrics.MetricReportUtils.java

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/*
 * (c) 2014 LinkedIn Corp. All rights reserved.
 *
 * 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.
 */

package gobblin.metrics;

import java.io.ByteArrayInputStream;
import java.io.DataInputStream;
import java.io.IOException;

import org.apache.avro.io.Decoder;
import org.apache.avro.io.DecoderFactory;
import org.apache.avro.specific.SpecificDatumReader;

import com.google.common.base.Optional;
import com.google.common.io.Closer;

/**
 * Utilities for {@link gobblin.metrics.MetricReport}.
 */
public class MetricReportUtils {

    public static final int SCHEMA_VERSION = 1;
    private static Optional<SpecificDatumReader<MetricReport>> READER = Optional.absent();

    /**
     * Parses a {@link gobblin.metrics.MetricReport} from a byte array representing a json input.
     * @param reuse MetricReport to reuse.
     * @param bytes Input bytes.
     * @return MetricReport.
     * @throws java.io.IOException
     */
    public synchronized static MetricReport deserializeReportFromJson(MetricReport reuse, byte[] bytes)
            throws IOException {
        if (!READER.isPresent()) {
            READER = Optional.of(new SpecificDatumReader<MetricReport>(MetricReport.class));
        }

        Closer closer = Closer.create();

        try {
            DataInputStream inputStream = closer.register(new DataInputStream(new ByteArrayInputStream(bytes)));

            // Check version byte
            int versionNumber = inputStream.readInt();
            if (versionNumber != SCHEMA_VERSION) {
                throw new IOException(
                        String.format("MetricReport schema version not recognized. Found version %d, expected %d.",
                                versionNumber, SCHEMA_VERSION));
            }

            // Decode the rest
            Decoder decoder = DecoderFactory.get().jsonDecoder(MetricReport.SCHEMA$, inputStream);
            return READER.get().read(reuse, decoder);
        } catch (Throwable t) {
            throw closer.rethrow(t);
        } finally {
            closer.close();
        }
    }

    /**
     * Parses a {@link gobblin.metrics.MetricReport} from a byte array Avro serialization.
     * @param reuse MetricReport to reuse.
     * @param bytes Input bytes.
     * @return MetricReport.
     * @throws java.io.IOException
     */
    public synchronized static MetricReport deserializeReportFromAvroSerialization(MetricReport reuse, byte[] bytes)
            throws IOException {
        if (!READER.isPresent()) {
            READER = Optional.of(new SpecificDatumReader<MetricReport>(MetricReport.class));
        }

        Closer closer = Closer.create();

        try {
            DataInputStream inputStream = closer.register(new DataInputStream(new ByteArrayInputStream(bytes)));

            // Check version byte
            int versionNumber = inputStream.readInt();
            if (versionNumber != SCHEMA_VERSION) {
                throw new IOException(
                        String.format("MetricReport schema version not recognized. Found version %d, expected %d.",
                                versionNumber, SCHEMA_VERSION));
            }

            // Decode the rest
            Decoder decoder = DecoderFactory.get().binaryDecoder(inputStream, null);
            return READER.get().read(reuse, decoder);
        } catch (Throwable t) {
            throw closer.rethrow(t);
        } finally {
            closer.close();
        }
    }
}