1.1 --- /dev/null Thu Jan 01 00:00:00 1970 +0000
1.2 +++ b/src/share/classes/com/sun/tools/javac/file/CacheFSInfo.java Wed Sep 03 10:46:25 2008 -0700
1.3 @@ -0,0 +1,122 @@
1.4 +/*
1.5 + * Copyright 2005-2008 Sun Microsystems, Inc. All Rights Reserved.
1.6 + * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
1.7 + *
1.8 + * This code is free software; you can redistribute it and/or modify it
1.9 + * under the terms of the GNU General Public License version 2 only, as
1.10 + * published by the Free Software Foundation. Sun designates this
1.11 + * particular file as subject to the "Classpath" exception as provided
1.12 + * by Sun in the LICENSE file that accompanied this code.
1.13 + *
1.14 + * This code is distributed in the hope that it will be useful, but WITHOUT
1.15 + * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
1.16 + * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
1.17 + * version 2 for more details (a copy is included in the LICENSE file that
1.18 + * accompanied this code).
1.19 + *
1.20 + * You should have received a copy of the GNU General Public License version
1.21 + * 2 along with this work; if not, write to the Free Software Foundation,
1.22 + * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
1.23 + *
1.24 + * Please contact Sun Microsystems, Inc., 4150 Network Circle, Santa Clara,
1.25 + * CA 95054 USA or visit www.sun.com if you need additional information or
1.26 + * have any questions.
1.27 + */
1.28 +
1.29 +package com.sun.tools.javac.file;
1.30 +
1.31 +import java.io.File;
1.32 +import java.io.IOException;
1.33 +import java.util.List;
1.34 +
1.35 +import com.sun.tools.javac.util.Context;
1.36 +import java.util.Map;
1.37 +import java.util.concurrent.ConcurrentHashMap;
1.38 +
1.39 +/**
1.40 + * Caching implementation of FSInfo
1.41 + */
1.42 +public class CacheFSInfo extends FSInfo {
1.43 +
1.44 + /**
1.45 + * Register a Context.Factory to create a singleton CacheFSInfo.
1.46 + */
1.47 + public static void preRegister(final Context context) {
1.48 + context.put(FSInfo.class, new Context.Factory<FSInfo>() {
1.49 + public FSInfo make() {
1.50 + if (singleton == null)
1.51 + singleton = new CacheFSInfo();
1.52 + context.put(FSInfo.class, singleton);
1.53 + return singleton;
1.54 + }
1.55 + });
1.56 + }
1.57 +
1.58 + static CacheFSInfo singleton;
1.59 +
1.60 + public void clearCache() {
1.61 + cache.clear();
1.62 + }
1.63 +
1.64 + @Override
1.65 + public File getCanonicalFile(File file) {
1.66 + Entry e = getEntry(file);
1.67 + return e.canonicalFile;
1.68 + }
1.69 +
1.70 + @Override
1.71 + public boolean exists(File file) {
1.72 + Entry e = getEntry(file);
1.73 + return e.exists;
1.74 + }
1.75 +
1.76 + @Override
1.77 + public boolean isDirectory(File file) {
1.78 + Entry e = getEntry(file);
1.79 + return e.isDirectory;
1.80 + }
1.81 +
1.82 + @Override
1.83 + public boolean isFile(File file) {
1.84 + Entry e = getEntry(file);
1.85 + return e.isFile;
1.86 + }
1.87 +
1.88 + @Override
1.89 + public List<File> getJarClassPath(File file) throws IOException {
1.90 + // don't bother to lock the cache, because it is thread-safe, and
1.91 + // because the worst that can happen would be to create two identical
1.92 + // jar class paths together and have one overwrite the other.
1.93 + Entry e = getEntry(file);
1.94 + if (e.jarClassPath == null)
1.95 + e.jarClassPath = super.getJarClassPath(file);
1.96 + return e.jarClassPath;
1.97 + }
1.98 +
1.99 + private Entry getEntry(File file) {
1.100 + // don't bother to lock the cache, because it is thread-safe, and
1.101 + // because the worst that can happen would be to create two identical
1.102 + // entries together and have one overwrite the other.
1.103 + Entry e = cache.get(file);
1.104 + if (e == null) {
1.105 + e = new Entry();
1.106 + e.canonicalFile = super.getCanonicalFile(file);
1.107 + e.exists = super.exists(file);
1.108 + e.isDirectory = super.isDirectory(file);
1.109 + e.isFile = super.isFile(file);
1.110 + cache.put(file, e);
1.111 + }
1.112 + return e;
1.113 + }
1.114 +
1.115 + // could also be a Map<File,SoftReference<Entry>> ?
1.116 + private Map<File,Entry> cache = new ConcurrentHashMap<File,Entry>();
1.117 +
1.118 + private static class Entry {
1.119 + File canonicalFile;
1.120 + boolean exists;
1.121 + boolean isFile;
1.122 + boolean isDirectory;
1.123 + List<File> jarClassPath;
1.124 + }
1.125 +}
