/*
* Copyright (c) 2005, 2011, Oracle and/or its affiliates. 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. Oracle designates this
* particular file as subject to the "Classpath" exception as provided
* by Oracle 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 Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
* or visit www.oracle.com if you need additional information or have any
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*/
package com.sun.tools.javac.file;
import java.io.File;
import java.io.IOException;
import java.util.List;
import java.util.Map;
import java.util.concurrent.ConcurrentHashMap;
import com.sun.tools.javac.util.Context;
/**
* Caching implementation of FSInfo.
*
* <p><b>This is NOT part of any supported API.
* If you write code that depends on this, you do so at your own risk.
* This code and its internal interfaces are subject to change or
* deletion without notice.</b>
*/
public class CacheFSInfo extends FSInfo {
/**
* Register a Context.Factory to create a CacheFSInfo.
*/
public static void preRegister(Context context) {
context.put(FSInfo.class, new Context.Factory<FSInfo>() {
public FSInfo make(Context c) {
FSInfo instance = new CacheFSInfo();
c.put(FSInfo.class, instance);
return instance;
}
});
}
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;
}
}