001    /*
002     * Copyright 2010-2014 JetBrains s.r.o.
003     *
004     * Licensed under the Apache License, Version 2.0 (the "License");
005     * you may not use this file except in compliance with the License.
006     * You may obtain a copy of the License at
007     *
008     * http://www.apache.org/licenses/LICENSE-2.0
009     *
010     * Unless required by applicable law or agreed to in writing, software
011     * distributed under the License is distributed on an "AS IS" BASIS,
012     * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
013     * See the License for the specific language governing permissions and
014     * limitations under the License.
015     */
016    
017    package org.jetbrains.jet.lang.resolve.kotlin;
018    
019    import com.intellij.openapi.components.ServiceManager;
020    import com.intellij.openapi.vfs.VirtualFile;
021    import com.intellij.util.containers.SLRUCache;
022    import org.jetbrains.annotations.NotNull;
023    import org.jetbrains.jet.storage.LockBasedStorageManager;
024    
025    public final class KotlinBinaryClassCache {
026    
027        // This cache must be small: we only query the same file a few times in a row (from different places)
028        // Since it is on application level we should be careful about this cache. Consider profiling multiple projects indexing simultaneously.
029        private final SLRUCache<VirtualFile, KotlinJvmBinaryClass> cache = new SLRUCache<VirtualFile, KotlinJvmBinaryClass>(2, 2) {
030            @NotNull
031            @Override
032            public KotlinJvmBinaryClass createValue(VirtualFile virtualFile) {
033                // Operations under this lock are not supposed to involve other locks
034                return new VirtualFileKotlinClass(new LockBasedStorageManager(), virtualFile);
035            }
036        };
037    
038        @NotNull
039        public static KotlinJvmBinaryClass getKotlinBinaryClass(@NotNull VirtualFile file) {
040            KotlinBinaryClassCache service = ServiceManager.getService(KotlinBinaryClassCache.class);
041            synchronized (service.cache) {
042                return service.cache.get(file);
043            }
044        }
045    }