gobblin.instrumented.qualitychecker.InstrumentedRowLevelPolicyBase.java Source code

Introduction

Here is the source code for gobblin.instrumented.qualitychecker.InstrumentedRowLevelPolicyBase.java

Source

/*
 * 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 gobblin.instrumented.qualitychecker;

import java.io.Closeable;
import java.io.IOException;
import java.util.List;
import java.util.concurrent.TimeUnit;

import com.codahale.metrics.Meter;
import com.codahale.metrics.Timer;

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

import gobblin.configuration.State;
import gobblin.instrumented.Instrumentable;
import gobblin.instrumented.Instrumented;
import gobblin.metrics.GobblinMetrics;
import gobblin.metrics.MetricContext;
import gobblin.metrics.MetricNames;
import gobblin.metrics.Tag;
import gobblin.qualitychecker.row.RowLevelPolicy;

/**
 * package-private implementation of instrumentation for {@link gobblin.qualitychecker.row.RowLevelPolicy}.
 * See {@link gobblin.instrumented.qualitychecker.InstrumentedRowLevelPolicy} for extensible class.
 */
abstract class InstrumentedRowLevelPolicyBase extends RowLevelPolicy implements Instrumentable, Closeable {

    private final boolean instrumentationEnabled;

    private MetricContext metricContext;
    private Optional<Meter> recordsMeter;
    private Optional<Meter> passedRecordsMeter;
    private Optional<Meter> failedRecordsMeter;
    private Optional<Timer> policyTimer;
    protected final Closer closer;

    public InstrumentedRowLevelPolicyBase(State state, Type type) {
        this(state, type, Optional.<Class<?>>absent());
    }

    protected InstrumentedRowLevelPolicyBase(State state, Type type, Optional<Class<?>> classTag) {
        super(state, type);
        this.instrumentationEnabled = GobblinMetrics.isEnabled(state);
        this.closer = Closer.create();
        this.metricContext = this.closer
                .register(Instrumented.getMetricContext(state, classTag.or(this.getClass())));

        regenerateMetrics();
    }

    @Override
    public void switchMetricContext(List<Tag<?>> tags) {
        this.metricContext = this.closer.register(
                Instrumented.newContextFromReferenceContext(this.metricContext, tags, Optional.<String>absent()));

        regenerateMetrics();
    }

    @Override
    public void switchMetricContext(MetricContext context) {
        this.metricContext = context;
        regenerateMetrics();
    }

    /**
     * Generates metrics for the instrumentation of this class.
     */
    protected void regenerateMetrics() {
        if (isInstrumentationEnabled()) {
            this.recordsMeter = Optional
                    .of(this.metricContext.meter(MetricNames.RowLevelPolicyMetrics.RECORDS_IN_METER));
            this.passedRecordsMeter = Optional
                    .of(this.metricContext.meter(MetricNames.RowLevelPolicyMetrics.RECORDS_PASSED_METER));
            this.failedRecordsMeter = Optional
                    .of(this.metricContext.meter(MetricNames.RowLevelPolicyMetrics.RECORDS_FAILED_METER));
            this.policyTimer = Optional
                    .<Timer>of(this.metricContext.timer(MetricNames.RowLevelPolicyMetrics.CHECK_TIMER));
        } else {
            this.recordsMeter = Optional.absent();
            this.passedRecordsMeter = Optional.absent();
            this.failedRecordsMeter = Optional.absent();
            this.policyTimer = Optional.absent();
        }
    }

    /** Default with no additional tags */
    @Override
    public List<Tag<?>> generateTags(State state) {
        return Lists.newArrayList();
    }

    @Override
    public boolean isInstrumentationEnabled() {
        return this.instrumentationEnabled;
    }

    @Override
    public Result executePolicy(Object record) {
        if (!isInstrumentationEnabled()) {
            return executePolicyImpl(record);
        }

        long startTime = System.nanoTime();

        beforeCheck(record);
        Result result = executePolicyImpl(record);
        afterCheck(result, startTime);

        return result;
    }

    /**
     * Called before check is run.
     * @param record
     */
    public void beforeCheck(Object record) {
        Instrumented.markMeter(this.recordsMeter);
    }

    /**
     * Called after check is run.
     * @param result result from check.
     * @param startTimeNanos start time of check.
     */
    public void afterCheck(Result result, long startTimeNanos) {
        switch (result) {
        case FAILED:
            Instrumented.markMeter(this.failedRecordsMeter);
            break;
        case PASSED:
            Instrumented.markMeter(this.passedRecordsMeter);
            break;
        default:
        }

        Instrumented.updateTimer(this.policyTimer, System.nanoTime() - startTimeNanos, TimeUnit.NANOSECONDS);
    }

    /**
     * Subclasses should implement this instead of {@link gobblin.qualitychecker.row.RowLevelPolicy#executePolicy}.
     */
    public abstract Result executePolicyImpl(Object record);

    @Override
    public void close() throws IOException {
        this.closer.close();
    }

    @Override
    public MetricContext getMetricContext() {
        return this.metricContext;
    }
}