com.facebook.buck.rules.keys.EventPostingRuleKeyCacheScope.java Source code

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Here is the source code for com.facebook.buck.rules.keys.EventPostingRuleKeyCacheScope.java

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/*
 * Copyright 2017-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.rules.keys;

import com.facebook.buck.event.BuckEventBus;
import com.facebook.buck.event.PerfEventId;
import com.facebook.buck.event.SimplePerfEvent;
import com.google.common.cache.CacheStats;

/** A {@link RuleKeyCacheScope} which logs stats on close. */
public class EventPostingRuleKeyCacheScope<V> implements RuleKeyCacheScope<V> {

    private final BuckEventBus buckEventBus;
    private final RuleKeyCache<V> cache;

    private final CacheStats startStats;

    public EventPostingRuleKeyCacheScope(BuckEventBus buckEventBus, RuleKeyCache<V> cache) {
        this.buckEventBus = buckEventBus;
        this.cache = cache;

        try (SimplePerfEvent.Scope scope = SimplePerfEvent.scope(buckEventBus,
                PerfEventId.of("rule_key_cache_setup"))) {

            // Record the initial stats.
            startStats = cache.getStats();

            // Run additional setup.
            setup(scope);
        }
    }

    /** Additional setup. To be implemented by sub-classes. */
    protected void setup(@SuppressWarnings("unused") SimplePerfEvent.Scope scope) {
    }

    /** Additional cleanup. To be implemented by sub-classes. */
    protected void cleanup(@SuppressWarnings("unused") SimplePerfEvent.Scope scope) {
    }

    @Override
    public final RuleKeyCache<V> getCache() {
        return cache;
    }

    @Override
    public final void close() {
        try (SimplePerfEvent.Scope scope = SimplePerfEvent.scope(buckEventBus,
                PerfEventId.of("rule_key_cache_cleanup"))) {

            // Log stats.
            CacheStats stats = cache.getStats().minus(startStats);
            buckEventBus.post(RuleKeyCacheStatsEvent.create(stats));
            scope.update("hitRate", stats.hitRate());
            scope.update("hits", stats.hitCount());
            scope.update("misses", stats.missCount());
            scope.update("requests", stats.requestCount());
            scope.update("load_time_ns", stats.totalLoadTime());

            // Run additional cleanup.
            cleanup(scope);
        }
    }
}