/*
* Copyright 2014 Ben Manes. All Rights Reserved.
*
* 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.github.benmanes.caffeine.profiler;
import java.util.Random;
import com.github.benmanes.caffeine.cache.BasicCache;
import com.github.benmanes.caffeine.cache.CacheType;
import com.yahoo.ycsb.generator.NumberGenerator;
import com.yahoo.ycsb.generator.ScrambledZipfianGenerator;
/**
* A hook for profiling caches.
*
* @author Ben Manes (ben.manes@gmail.com)
*/
public final class CacheProfiler extends ProfilerHook {
static final CacheType cacheType = CacheType.Caffeine;
static final int MAX_SIZE = 10 * NUM_THREADS;
static final int SIZE = (2 << 14);
static final int MASK = SIZE - 1;
static final int ITEMS = SIZE / 4;
final BasicCache<Integer, Boolean> cache;
final Random random = new Random();
final Integer[] ints;
final boolean reads;
CacheProfiler() {
cache = cacheType.create(2 * SIZE);
// Ensure full initialization of internal structures
for (int i = 0; i < 2 * SIZE; i++) {
cache.put(i, Boolean.TRUE);
}
cache.clear();
ints = new Integer[SIZE];
NumberGenerator generator = new ScrambledZipfianGenerator(ITEMS);
for (int i = 0; i < SIZE; i++) {
ints[i] = generator.nextValue().intValue();
cache.put(ints[i], Boolean.TRUE);
}
reads = true;
}
@Override
protected void profile() {
if (reads) {
reads();
} else {
writes();
}
}
/** Spins forever reading from the cache. */
private void reads() {
int index = random.nextInt();
for (;;) {
Integer key = ints[index++ & MASK];
cache.get(key);
calls.increment();
}
}
/** Spins forever writing into the cache. */
private void writes() {
int index = random.nextInt();
for (;;) {
Integer key = ints[index++ & MASK];
cache.put(key, Boolean.TRUE);
calls.increment();
}
}
public static void main(String[] args) {
CacheProfiler profile = new CacheProfiler();
profile.run();
}
}