--- /dev/null Thu Jan 01 00:00:00 1970 +0000
+++ b/langtools/src/share/classes/com/sun/tools/javac/file/CacheFSInfo.java Wed Sep 03 10:46:25 2008 -0700
@@ -0,0 +1,122 @@
+/*
+ * Copyright 2005-2008 Sun Microsystems, Inc. All Rights Reserved.
+ * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
+ *
+ * This code is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License version 2 only, as
+ * published by the Free Software Foundation. Sun designates this
+ * particular file as subject to the "Classpath" exception as provided
+ * by Sun in the LICENSE file that accompanied this code.
+ *
+ * This code is distributed in the hope that it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
+ * version 2 for more details (a copy is included in the LICENSE file that
+ * accompanied this code).
+ *
+ * You should have received a copy of the GNU General Public License version
+ * 2 along with this work; if not, write to the Free Software Foundation,
+ * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
+ *
+ * Please contact Sun Microsystems, Inc., 4150 Network Circle, Santa Clara,
+ * CA 95054 USA or visit www.sun.com if you need additional information or
+ * have any questions.
+ */
+
+package com.sun.tools.javac.file;
+
+import java.io.File;
+import java.io.IOException;
+import java.util.List;
+
+import com.sun.tools.javac.util.Context;
+import java.util.Map;
+import java.util.concurrent.ConcurrentHashMap;
+
+/**
+ * Caching implementation of FSInfo
+ */
+public class CacheFSInfo extends FSInfo {
+
+ /**
+ * Register a Context.Factory to create a singleton CacheFSInfo.
+ */
+ public static void preRegister(final Context context) {
+ context.put(FSInfo.class, new Context.Factory<FSInfo>() {
+ public FSInfo make() {
+ if (singleton == null)
+ singleton = new CacheFSInfo();
+ context.put(FSInfo.class, singleton);
+ return singleton;
+ }
+ });
+ }
+
+ static CacheFSInfo singleton;
+
+ public void clearCache() {
+ cache.clear();
+ }
+
+ @Override
+ public File getCanonicalFile(File file) {
+ Entry e = getEntry(file);
+ return e.canonicalFile;
+ }
+
+ @Override
+ public boolean exists(File file) {
+ Entry e = getEntry(file);
+ return e.exists;
+ }
+
+ @Override
+ public boolean isDirectory(File file) {
+ Entry e = getEntry(file);
+ return e.isDirectory;
+ }
+
+ @Override
+ public boolean isFile(File file) {
+ Entry e = getEntry(file);
+ return e.isFile;
+ }
+
+ @Override
+ public List<File> getJarClassPath(File file) throws IOException {
+ // don't bother to lock the cache, because it is thread-safe, and
+ // because the worst that can happen would be to create two identical
+ // jar class paths together and have one overwrite the other.
+ Entry e = getEntry(file);
+ if (e.jarClassPath == null)
+ e.jarClassPath = super.getJarClassPath(file);
+ return e.jarClassPath;
+ }
+
+ private Entry getEntry(File file) {
+ // don't bother to lock the cache, because it is thread-safe, and
+ // because the worst that can happen would be to create two identical
+ // entries together and have one overwrite the other.
+ Entry e = cache.get(file);
+ if (e == null) {
+ e = new Entry();
+ e.canonicalFile = super.getCanonicalFile(file);
+ e.exists = super.exists(file);
+ e.isDirectory = super.isDirectory(file);
+ e.isFile = super.isFile(file);
+ cache.put(file, e);
+ }
+ return e;
+ }
+
+ // could also be a Map<File,SoftReference<Entry>> ?
+ private Map<File,Entry> cache = new ConcurrentHashMap<File,Entry>();
+
+ private static class Entry {
+ File canonicalFile;
+ boolean exists;
+ boolean isFile;
+ boolean isDirectory;
+ List<File> jarClassPath;
+ }
+}