/*
* Copyright 2013 the original author or authors.
*
* 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 org.gradle.api.internal.artifacts.ivyservice.resolveengine.store;
import com.google.common.cache.Cache;
import com.google.common.cache.CacheBuilder;
import org.gradle.api.internal.cache.Store;
import org.gradle.api.logging.Logger;
import org.gradle.api.logging.Logging;
import org.gradle.internal.Factory;
import org.gradle.internal.time.Timer;
import org.gradle.internal.time.Timers;
import java.io.Closeable;
import java.util.concurrent.TimeUnit;
import java.util.concurrent.atomic.AtomicLong;
import static org.gradle.internal.time.Clock.prettyTime;
public class CachedStoreFactory<T> implements Closeable {
private static final Logger LOG = Logging.getLogger(CachedStoreFactory.class);
private final Cache<Object, T> cache;
private final Stats stats;
private String displayName;
public CachedStoreFactory(String displayName) {
this.displayName = displayName;
cache = CacheBuilder.newBuilder().maximumSize(100).expireAfterAccess(10000, TimeUnit.MILLISECONDS).build();
stats = new Stats();
}
public Store<T> createCachedStore(final Object id) {
return new SimpleStore<T>(cache, id, stats);
}
public void close() {
LOG.debug(displayName + " cache closed. Cache reads: "
+ stats.readsFromCache + ", disk reads: "
+ stats.readsFromDisk + " (avg: " + prettyTime(stats.getDiskReadsAvgMs()) + ", total: " + prettyTime(stats.diskReadsTotalMs.get()) + ")");
}
private static class Stats {
private final AtomicLong diskReadsTotalMs = new AtomicLong();
private final AtomicLong readsFromCache = new AtomicLong();
private final AtomicLong readsFromDisk = new AtomicLong();
public void readFromDisk(long duration) {
readsFromDisk.incrementAndGet();
diskReadsTotalMs.addAndGet(duration);
}
public void readFromCache() {
readsFromCache.incrementAndGet();
}
public long getDiskReadsAvgMs() {
if (readsFromDisk.get() == 0) {
return 0;
}
return diskReadsTotalMs.get() / readsFromDisk.get();
}
}
private static class SimpleStore<T> implements Store<T> {
private Cache<Object, T> cache;
private final Object id;
private Stats stats;
public SimpleStore(Cache<Object, T> cache, Object id, Stats stats) {
this.cache = cache;
this.id = id;
this.stats = stats;
}
public T load(Factory<T> createIfNotPresent) {
T out = cache.getIfPresent(id);
if (out != null) {
stats.readFromCache();
return out;
}
Timer timer = Timers.startTimer();
T value = createIfNotPresent.create();
stats.readFromDisk(timer.getElapsedMillis());
cache.put(id, value);
return value;
}
}
}