1   /*
    2    * Copyright (c) 2007, 2011, Oracle and/or its affiliates. All rights reserved.
    3    * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
    4    *
    5    * This code is free software; you can redistribute it and/or modify it
    6    * under the terms of the GNU General Public License version 2 only, as
    7    * published by the Free Software Foundation.  Oracle designates this
    8    * particular file as subject to the "Classpath" exception as provided
    9    * by Oracle in the LICENSE file that accompanied this code.
   10    *
   11    * This code is distributed in the hope that it will be useful, but WITHOUT
   12    * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
   13    * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
   14    * version 2 for more details (a copy is included in the LICENSE file that
   15    * accompanied this code).
   16    *
   17    * You should have received a copy of the GNU General Public License version
   18    * 2 along with this work; if not, write to the Free Software Foundation,
   19    * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
   20    *
   21    * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
   22    * or visit www.oracle.com if you need additional information or have any
   23    * questions.
   24    */
   25   
   26   package com.sun.tools.javac.file;
   27   
   28   import com.sun.tools.javac.file.RelativePath.RelativeDirectory;
   29   import com.sun.tools.javac.util.Context;
   30   import java.io.File;
   31   import java.io.IOException;
   32   import java.util.ArrayList;
   33   import java.util.HashMap;
   34   import java.util.Iterator;
   35   import java.util.List;
   36   import java.util.Map;
   37   
   38   
   39   /** A cache for ZipFileIndex objects. */
   40   public class ZipFileIndexCache {
   41   
   42       private final Map<File, ZipFileIndex> map =
   43               new HashMap<File, ZipFileIndex>();
   44   
   45       /** Get a shared instance of the cache. */
   46       private static ZipFileIndexCache sharedInstance;
   47       public synchronized static ZipFileIndexCache getSharedInstance() {
   48           if (sharedInstance == null)
   49               sharedInstance = new ZipFileIndexCache();
   50           return sharedInstance;
   51       }
   52   
   53       /** Get a context-specific instance of a cache. */
   54       public static ZipFileIndexCache instance(Context context) {
   55           ZipFileIndexCache instance = context.get(ZipFileIndexCache.class);
   56           if (instance == null)
   57               context.put(ZipFileIndexCache.class, instance = new ZipFileIndexCache());
   58           return instance;
   59       }
   60   
   61       /**
   62        * Returns a list of all ZipFileIndex entries
   63        *
   64        * @return A list of ZipFileIndex entries, or an empty list
   65        */
   66       public List<ZipFileIndex> getZipFileIndexes() {
   67           return getZipFileIndexes(false);
   68       }
   69   
   70       /**
   71        * Returns a list of all ZipFileIndex entries
   72        *
   73        * @param openedOnly If true it returns a list of only opened ZipFileIndex entries, otherwise
   74        *                   all ZipFileEntry(s) are included into the list.
   75        * @return A list of ZipFileIndex entries, or an empty list
   76        */
   77       public synchronized List<ZipFileIndex> getZipFileIndexes(boolean openedOnly) {
   78           List<ZipFileIndex> zipFileIndexes = new ArrayList<ZipFileIndex>();
   79   
   80           zipFileIndexes.addAll(map.values());
   81   
   82           if (openedOnly) {
   83               for(ZipFileIndex elem : zipFileIndexes) {
   84                   if (!elem.isOpen()) {
   85                       zipFileIndexes.remove(elem);
   86                   }
   87               }
   88           }
   89   
   90           return zipFileIndexes;
   91       }
   92   
   93       public synchronized ZipFileIndex getZipFileIndex(File zipFile,
   94               RelativeDirectory symbolFilePrefix,
   95               boolean useCache, String cacheLocation,
   96               boolean writeIndex) throws IOException {
   97           ZipFileIndex zi = getExistingZipIndex(zipFile);
   98   
   99           if (zi == null || (zi != null && zipFile.lastModified() != zi.zipFileLastModified)) {
  100               zi = new ZipFileIndex(zipFile, symbolFilePrefix, writeIndex,
  101                       useCache, cacheLocation);
  102               map.put(zipFile, zi);
  103           }
  104           return zi;
  105       }
  106   
  107       public synchronized ZipFileIndex getExistingZipIndex(File zipFile) {
  108           return map.get(zipFile);
  109       }
  110   
  111       public synchronized void clearCache() {
  112           map.clear();
  113       }
  114   
  115       public synchronized void clearCache(long timeNotUsed) {
  116           Iterator<File> cachedFileIterator = map.keySet().iterator();
  117           while (cachedFileIterator.hasNext()) {
  118               File cachedFile = cachedFileIterator.next();
  119               ZipFileIndex cachedZipIndex = map.get(cachedFile);
  120               if (cachedZipIndex != null) {
  121                   long timeToTest = cachedZipIndex.lastReferenceTimeStamp + timeNotUsed;
  122                   if (timeToTest < cachedZipIndex.lastReferenceTimeStamp || // Overflow...
  123                           System.currentTimeMillis() > timeToTest) {
  124                       map.remove(cachedFile);
  125                   }
  126               }
  127           }
  128       }
  129   
  130       public synchronized void removeFromCache(File file) {
  131           map.remove(file);
  132       }
  133   
  134       /** Sets already opened list of ZipFileIndexes from an outside client
  135         * of the compiler. This functionality should be used in a non-batch clients of the compiler.
  136         */
  137       public synchronized void setOpenedIndexes(List<ZipFileIndex>indexes) throws IllegalStateException {
  138           if (map.isEmpty()) {
  139               String msg =
  140                       "Setting opened indexes should be called only when the ZipFileCache is empty. "
  141                       + "Call JavacFileManager.flush() before calling this method.";
  142               throw new IllegalStateException(msg);
  143           }
  144   
  145           for (ZipFileIndex zfi : indexes) {
  146               map.put(zfi.zipFile, zfi);
  147           }
  148       }
  149   }