jjg@106: /*
jjg@839:  * Copyright (c) 2005, 2011, Oracle and/or its affiliates. All rights reserved.
jjg@106:  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
jjg@106:  *
jjg@106:  * This code is free software; you can redistribute it and/or modify it
jjg@106:  * under the terms of the GNU General Public License version 2 only, as
ohair@554:  * published by the Free Software Foundation.  Oracle designates this
jjg@106:  * particular file as subject to the "Classpath" exception as provided
ohair@554:  * by Oracle in the LICENSE file that accompanied this code.
jjg@106:  *
jjg@106:  * This code is distributed in the hope that it will be useful, but WITHOUT
jjg@106:  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
jjg@106:  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
jjg@106:  * version 2 for more details (a copy is included in the LICENSE file that
jjg@106:  * accompanied this code).
jjg@106:  *
jjg@106:  * You should have received a copy of the GNU General Public License version
jjg@106:  * 2 along with this work; if not, write to the Free Software Foundation,
jjg@106:  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
jjg@106:  *
ohair@554:  * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
ohair@554:  * or visit www.oracle.com if you need additional information or have any
ohair@554:  * questions.
jjg@106:  */
jjg@106: 
jjg@106: package com.sun.tools.javac.file;
jjg@106: 
jjg@106: import java.io.File;
jjg@106: import java.io.IOException;
jjg@106: import java.util.List;
jjg@839: import java.util.Map;
jjg@839: import java.util.concurrent.ConcurrentHashMap;
jjg@106: 
jjg@106: import com.sun.tools.javac.util.Context;
jjg@106: 
jjg@106: /**
jjg@333:  * Caching implementation of FSInfo.
jjg@333:  *
jjg@581:  * <p><b>This is NOT part of any supported API.
jjg@333:  * If you write code that depends on this, you do so at your own risk.
jjg@333:  * This code and its internal interfaces are subject to change or
jjg@333:  * deletion without notice.</b>
jjg@106:  */
jjg@106: public class CacheFSInfo extends FSInfo {
jjg@106: 
jjg@106:     /**
jjg@893:      * Register a Context.Factory to create a CacheFSInfo.
jjg@106:      */
jjg@893:     public static void preRegister(Context context) {
jjg@106:         context.put(FSInfo.class, new Context.Factory<FSInfo>() {
jjg@893:             public FSInfo make(Context c) {
jjg@872:                 FSInfo instance = new CacheFSInfo();
jjg@893:                 c.put(FSInfo.class, instance);
jjg@872:                 return instance;
jjg@106:             }
jjg@106:         });
jjg@106:     }
jjg@106: 
jjg@106:     public void clearCache() {
jjg@106:         cache.clear();
jjg@106:     }
jjg@106: 
jjg@106:     @Override
jjg@106:     public File getCanonicalFile(File file) {
jjg@106:         Entry e = getEntry(file);
jjg@106:         return e.canonicalFile;
jjg@106:     }
jjg@106: 
jjg@106:     @Override
jjg@106:     public boolean exists(File file) {
jjg@106:         Entry e = getEntry(file);
jjg@106:         return e.exists;
jjg@106:     }
jjg@106: 
jjg@106:     @Override
jjg@106:     public boolean isDirectory(File file) {
jjg@106:         Entry e = getEntry(file);
jjg@106:         return e.isDirectory;
jjg@106:     }
jjg@106: 
jjg@106:     @Override
jjg@106:     public boolean isFile(File file) {
jjg@106:         Entry e = getEntry(file);
jjg@106:         return e.isFile;
jjg@106:     }
jjg@106: 
jjg@106:     @Override
jjg@106:     public List<File> getJarClassPath(File file) throws IOException {
jjg@106:         // don't bother to lock the cache, because it is thread-safe, and
jjg@106:         // because the worst that can happen would be to create two identical
jjg@106:         // jar class paths together and have one overwrite the other.
jjg@106:         Entry e = getEntry(file);
jjg@106:         if (e.jarClassPath == null)
jjg@106:             e.jarClassPath = super.getJarClassPath(file);
jjg@106:         return e.jarClassPath;
jjg@106:     }
jjg@106: 
jjg@106:     private Entry getEntry(File file) {
jjg@106:         // don't bother to lock the cache, because it is thread-safe, and
jjg@106:         // because the worst that can happen would be to create two identical
jjg@106:         // entries together and have one overwrite the other.
jjg@106:         Entry e = cache.get(file);
jjg@106:         if (e == null) {
jjg@106:             e = new Entry();
jjg@106:             e.canonicalFile = super.getCanonicalFile(file);
jjg@106:             e.exists = super.exists(file);
jjg@106:             e.isDirectory = super.isDirectory(file);
jjg@106:             e.isFile = super.isFile(file);
jjg@106:             cache.put(file, e);
jjg@106:         }
jjg@106:         return e;
jjg@106:     }
jjg@106: 
jjg@106:     // could also be a Map<File,SoftReference<Entry>> ?
jjg@106:     private Map<File,Entry> cache = new ConcurrentHashMap<File,Entry>();
jjg@106: 
jjg@106:     private static class Entry {
jjg@106:         File canonicalFile;
jjg@106:         boolean exists;
jjg@106:         boolean isFile;
jjg@106:         boolean isDirectory;
jjg@106:         List<File> jarClassPath;
jjg@106:     }
jjg@106: }