com.facebook.buck.counters.CounterRegistryImpl.java Source code

Introduction

Here is the source code for com.facebook.buck.counters.CounterRegistryImpl.java

Source

/*
 * Copyright 2016-present Facebook, 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 com.facebook.buck.counters;

import com.facebook.buck.event.BuckEventBus;
import com.facebook.buck.util.MoreCollectors;
import com.facebook.buck.util.Optionals;
import com.google.common.base.Preconditions;
import com.google.common.collect.ImmutableList;
import com.google.common.collect.ImmutableMap;
import com.google.common.collect.Lists;
import com.google.common.collect.Sets;
import com.google.common.eventbus.Subscribe;

import java.io.IOException;
import java.util.Collection;
import java.util.List;
import java.util.Optional;
import java.util.Set;
import java.util.concurrent.ScheduledExecutorService;
import java.util.concurrent.ScheduledFuture;
import java.util.concurrent.TimeUnit;

public class CounterRegistryImpl implements CounterRegistry {
    private static final int FIRST_FLUSH_INTERVAL_MILLIS = 5000;
    private static final int FLUSH_INTERVAL_MILLIS = 30000;

    private final BuckEventBus eventBus;
    private final ScheduledFuture<?> flushCountersFuture;
    private final Set<Counter> counters;

    public CounterRegistryImpl(ScheduledExecutorService service, BuckEventBus eventBus) {
        this(service, eventBus, FIRST_FLUSH_INTERVAL_MILLIS, FLUSH_INTERVAL_MILLIS);
    }

    public CounterRegistryImpl(ScheduledExecutorService service, BuckEventBus eventBus,
            long firstFlushIntervalMillis, long flushIntervalMillis) {
        this.counters = Sets.newLinkedHashSet();
        this.eventBus = eventBus;
        flushCountersFuture = service.scheduleAtFixedRate(this::flushCounters,
                /* initialDelay */ firstFlushIntervalMillis, /* period */ flushIntervalMillis,
                /* unit */ TimeUnit.MILLISECONDS);
        eventBus.register(this);
    }

    @Override
    public IntegerCounter newIntegerCounter(String category, String name, ImmutableMap<String, String> tags) {
        return registerCounter(new IntegerCounter(category, name, tags));
    }

    @Override
    public SamplingCounter newSamplingCounter(String category, String name, ImmutableMap<String, String> tags) {
        return registerCounter(new SamplingCounter(category, name, tags));
    }

    @Override
    public TagSetCounter newTagSetCounter(String category, String name, ImmutableMap<String, String> tags) {
        return registerCounter(new TagSetCounter(category, name, tags));
    }

    @Override
    public void registerCounters(Collection<Counter> countersToRegister) {
        synchronized (this) {
            Preconditions.checkState(counters.addAll(countersToRegister), "Duplicate counters=[%s]",
                    countersToRegister);
        }
    }

    @Override
    @Subscribe
    public void registerCounters(AsyncCounterRegistrationEvent event) {
        registerCounters(event.getCounters());
    }

    @Override
    public void close() throws IOException {
        flushCountersFuture.cancel(false);
        flushCounters();
    }

    private <T extends Counter> T registerCounter(T counter) {
        synchronized (this) {
            Preconditions.checkState(counters.add(counter), "Duplicate counter=[%s]", counter);
        }

        return counter;
    }

    private void flushCounters() {
        List<Optional<CounterSnapshot>> snapshots;
        synchronized (this) {
            snapshots = Lists.newArrayListWithCapacity(counters.size());
            for (Counter counter : counters) {
                snapshots.add(counter.flush());
            }
        }

        ImmutableList<CounterSnapshot> presentSnapshots = snapshots.stream().flatMap(Optionals::toStream)
                .collect(MoreCollectors.toImmutableList());
        if (!presentSnapshots.isEmpty()) {
            CountersSnapshotEvent event = new CountersSnapshotEvent(presentSnapshots);
            eventBus.post(event);
        }
    }

}