| /* |
| * Copyright (C) 2011 The Guava 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 com.google.common.cache; |
| |
| import static com.google.common.base.Preconditions.checkState; |
| |
| import com.google.caliper.BeforeExperiment; |
| import com.google.caliper.Benchmark; |
| import com.google.caliper.Param; |
| import com.google.common.cache.LocalCache.Segment; |
| import java.util.concurrent.atomic.AtomicReferenceArray; |
| |
| /** |
| * Benchmark for {@code LocalCache.Segment.expand()}. |
| * |
| * @author Charles Fry |
| */ |
| public class SegmentBenchmark { |
| |
| @Param({"16", "32", "64", "128", "256", "512", "1024", "2048", "4096", "8192"}) |
| int capacity; |
| |
| private Segment<Object, Object> segment; |
| |
| @BeforeExperiment |
| void setUp() { |
| LocalCache<Object, Object> cache = |
| new LocalCache<>( |
| CacheBuilder.newBuilder().concurrencyLevel(1).initialCapacity(capacity), null); |
| checkState(cache.segments.length == 1); |
| segment = cache.segments[0]; |
| checkState(segment.table.length() == capacity); |
| for (int i = 0; i < segment.threshold; i++) { |
| cache.put(new Object(), new Object()); |
| } |
| checkState(segment.table.length() == capacity); |
| } |
| |
| @Benchmark |
| int time(int reps) { |
| int dummy = 0; |
| AtomicReferenceArray<ReferenceEntry<Object, Object>> oldTable = segment.table; |
| for (int i = 0; i < reps; i++) { |
| segment.expand(); |
| segment.table = oldTable; |
| dummy += segment.count; |
| } |
| return dummy; |
| } |
| } |