io.micrometer.core.instrument.binder.cache.GuavaCacheMetrics Maven / Gradle / Ivy

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Core module of Micrometer containing instrumentation API and implementation
There is a newer version: 1.13.2
/*
 * Copyright 2017 VMware, 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
 *
 * https://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 io.micrometer.core.instrument.binder.cache;

import com.google.common.cache.Cache;
import com.google.common.cache.CacheBuilder;
import com.google.common.cache.LoadingCache;
import io.micrometer.core.instrument.*;
import io.micrometer.core.lang.NonNullApi;
import io.micrometer.core.lang.NonNullFields;

import java.util.concurrent.TimeUnit;

/**
 * @author Jon Schneider
 */
@NonNullApi
@NonNullFields
public class GuavaCacheMetrics extends CacheMeterBinder {

    private final Cache cache;

    /**
     * Record metrics on a Guava cache. You must call {@link CacheBuilder#recordStats()}
     * prior to building the cache for metrics to be recorded.
     * @param registry The registry to bind metrics to.
     * @param cache The cache to instrument.
     * @param cacheName Will be used to tag metrics with "cache".
     * @param tags Tags to apply to all recorded metrics. Must be an even number of
     * arguments representing key/value pairs of tags.
     * @param  The cache type.
     * @return The instrumented cache, unchanged. The original cache is not wrapped or
     * proxied in any way.
     * @see com.google.common.cache.CacheStats
     */
    public static > C monitor(MeterRegistry registry, C cache, String cacheName, String... tags) {
        return monitor(registry, cache, cacheName, Tags.of(tags));
    }

    /**
     * Record metrics on a Guava cache. You must call {@link CacheBuilder#recordStats()}
     * prior to building the cache for metrics to be recorded.
     * @param registry The registry to bind metrics to.
     * @param cache The cache to instrument.
     * @param cacheName The name prefix of the metrics.
     * @param tags Tags to apply to all recorded metrics.
     * @param  The cache type.
     * @return The instrumented cache, unchanged. The original cache is not wrapped or
     * proxied in any way.
     * @see com.google.common.cache.CacheStats
     */
    public static > C monitor(MeterRegistry registry, C cache, String cacheName,
            Iterable tags) {
        new GuavaCacheMetrics(cache, cacheName, tags).bindTo(registry);
        return cache;
    }

    public GuavaCacheMetrics(Cache cache, String cacheName, Iterable tags) {
        super(cache, cacheName, tags);
        this.cache = cache;
    }

    @Override
    protected Long size() {
        return cache.size();
    }

    @Override
    protected long hitCount() {
        return cache.stats().hitCount();
    }

    @Override
    protected Long missCount() {
        return cache.stats().missCount();
    }

    @Override
    protected Long evictionCount() {
        return cache.stats().evictionCount();
    }

    @Override
    protected long putCount() {
        return cache.stats().loadCount();
    }

    @Override
    protected void bindImplementationSpecificMetrics(MeterRegistry registry) {
        if (cache instanceof LoadingCache) {
            // dividing these gives you a measure of load latency
            TimeGauge.builder("cache.load.duration", cache, TimeUnit.NANOSECONDS, c -> c.stats().totalLoadTime())
                    .tags(getTagsWithCacheName()).description("The time the cache has spent loading new values")
                    .register(registry);

            FunctionCounter.builder("cache.load", cache, c -> c.stats().loadSuccessCount()).tags(getTagsWithCacheName())
                    .tags("result", "success")
                    .description("The number of times cache lookup methods have successfully loaded a new value")
                    .register(registry);

            FunctionCounter.builder("cache.load", cache, c -> c.stats().loadExceptionCount())
                    .tags(getTagsWithCacheName()).tags("result", "failure")
                    .description(
                            "The number of times cache lookup methods threw an exception while loading a new value")
                    .register(registry);
        }
    }

}