| /* |
| * Copyright 2000-2013 JetBrains s.r.o. |
| * |
| * 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.intellij.util; |
| |
| import com.intellij.util.containers.IntObjectLinkedMap; |
| import org.jetbrains.annotations.Nullable; |
| |
| /** |
| * @author peter |
| */ |
| public class IntSLRUCache<Entry extends IntObjectLinkedMap.MapEntry> { |
| private static final boolean ourPrintDebugStatistics = false; |
| private final IntObjectLinkedMap<Entry> myProtectedQueue; |
| private final IntObjectLinkedMap<Entry> myProbationalQueue; |
| private int probationalHits = 0; |
| private int protectedHits = 0; |
| private int misses = 0; |
| |
| public IntSLRUCache(int protectedQueueSize, int probationalQueueSize) { |
| myProtectedQueue = new IntObjectLinkedMap<Entry>(protectedQueueSize); |
| myProbationalQueue = new IntObjectLinkedMap<Entry>(probationalQueueSize); |
| } |
| |
| public Entry cacheEntry(final Entry entry) { |
| Entry cached = myProtectedQueue.getEntry(entry.key); |
| if (cached == null) { |
| cached = myProbationalQueue.getEntry(entry.key); |
| } |
| if (cached != null) { |
| return cached; |
| } |
| |
| myProbationalQueue.putEntry(entry); |
| return entry; |
| } |
| |
| @Nullable |
| public Entry getCachedEntry(int id) { |
| return getCachedEntry(id, true); |
| } |
| |
| @Nullable |
| public Entry getCachedEntry(int id, boolean allowMutation) { |
| Entry entry = myProtectedQueue.getEntry(id); |
| if (entry != null) { |
| protectedHits++; |
| return entry; |
| } |
| |
| entry = myProbationalQueue.getEntry(id); |
| if (entry != null) { |
| printStatistics(++probationalHits); |
| |
| if (allowMutation) { |
| myProbationalQueue.removeEntry(entry.key); |
| Entry demoted = myProtectedQueue.putEntry(entry); |
| if (demoted != null) { |
| myProbationalQueue.putEntry(demoted); |
| } |
| } |
| return entry; |
| } |
| |
| printStatistics(++misses); |
| |
| return null; |
| } |
| |
| private void printStatistics(int hits) { |
| //noinspection ConstantConditions |
| if (ourPrintDebugStatistics && hits % 1000 == 0) { |
| //noinspection UseOfSystemOutOrSystemErr |
| System.out.println("IntSLRUCache.getCachedEntry time " + System.currentTimeMillis() + |
| ", prot=" + protectedHits + ", prob=" + probationalHits + ", misses=" + misses); |
| } |
| } |
| |
| } |