--- a/software/mpdl-services/mpiwg-mpdl-lt/src/de/mpg/mpiwg/berlin/mpdl/lt/morph/app/MorphologyCache.java	Wed Dec 14 13:57:09 2011 +0100
+++ b/software/mpdl-services/mpiwg-mpdl-lt/src/de/mpg/mpiwg/berlin/mpdl/lt/morph/app/MorphologyCache.java	Tue Nov 27 12:35:19 2012 +0100
@@ -25,11 +25,13 @@
   private static String DB_DIR_DONATUS = DATA_DIR + "/dataBerkeleyDB/donatus";
   public static int QUERY_MODE = 0;
   public static int DOCUMENT_MODE = 1;
+  private static long MIN_RAM = 500000000;
   private static int MAX_HASHTABLE_SIZE = Constants.MORPHOLOGY_CACHE_SIZE;
+  private Date touchTimer;
   protected int mode = QUERY_MODE;
   private Hashtable<String, Hashtable<String, Lemma>> forms = new Hashtable<String, Hashtable<String, Lemma>>();  // cache of forms: hashKey is formName
   private Hashtable<String, Lemma> lemmas = new Hashtable<String, Lemma>();  // cache of lemmas: hashKey is lemmaName
-  private DBMorphHandler dbMorphHandlerStatic;  // handles static morph data (BerkeleyDB)
+  private DBMorphHandler dbMorphHandler;  // handles morph data (BerkeleyDB)
   private Date beginOfOperation;
   private Date endOfOperation;
   
@@ -42,13 +44,20 @@
   }
 
   private void init() throws ApplicationException {
+    long maxMemory = Runtime.getRuntime().maxMemory();
+    if (maxMemory < MIN_RAM) {
+      String message = "Morphology cache: at least " + MIN_RAM + " is needed as heap space: please start java with parameter -Xmx with more than this value)";
+      LOGGER.severe(message);
+      throw new ApplicationException(message);
+    }
+    touchTimer = new Date();
     instance.beginOperation();
-    dbMorphHandlerStatic = new DBMorphHandler(DB_DIR_DONATUS);
-    dbMorphHandlerStatic.start();
-    dbMorphHandlerStatic.openDatabases();
+    dbMorphHandler = new DBMorphHandler(DB_DIR_DONATUS);
+    dbMorphHandler.startReadOnly();
+    dbMorphHandler.openDatabases();
     instance.endOperation();
     Double elapsedTime = new Util().getSecondWithMillisecondsBetween(instance.beginOfOperation, instance.endOfOperation);
-    LOGGER.info("Morphology db cache: opened (needed " + elapsedTime + " seconds)");
+    LOGGER.info("Morphology cache: morphology db opened read only (needed " + elapsedTime + " seconds, heap space: " + maxMemory + " bytes)");
   }
   
   public int getMode() {
@@ -60,16 +69,14 @@
   }
   
   public void end() throws ApplicationException {
-    dbMorphHandlerStatic.closeDatabases();
-    LOGGER.info("Morphology db cache: closed");
+    dbMorphHandler.closeDatabases();
+    LOGGER.info("Morphology cache: db closed");
+    forms = null;
+    lemmas = null;
+    dbMorphHandler = null;
+    instance = null;
   }
 
-  /*
-  public ArrayList<Lemma> getLemmasByFormName(String lang, String formName, boolean normalize) throws ApplicationException {
-    return getLemmasByFormName(lang, formName, normalize, Normalizer.DISPLAY);
-  }
-  */
-  
   public ArrayList<Lemma> getLemmasByFormName(String lang, String formNameArg, int normMode) throws ApplicationException {
     String language = Language.getInstance().getLanguageId(lang);
     ArrayList<Lemma> retFormLemmas = null;
@@ -84,8 +91,16 @@
       ArrayList<Lemma> dbFormLemmas = readLemmasByFormName(language, formName);
       // put lemmas into local cache
       int localHashTableSize = forms.size();
-      if (localHashTableSize >= MAX_HASHTABLE_SIZE) {
-        clearCache();
+      Date now = new Date();
+      if (now.getTime() - touchTimer.getTime() > 900000) { // is true each 0,25 hours: then free memory is fetched (needs some time)
+        touchTimer = new Date();
+        long freeMemory = Runtime.getRuntime().freeMemory();
+        LOGGER.info(touchTimer + ": Morphology cache: free memory in heap space: " + freeMemory + " bytes");
+        if (freeMemory < MIN_RAM || localHashTableSize >= MAX_HASHTABLE_SIZE) { // if freeMemory is less then MIN_RAM then clear cache to get some new memory
+          clearCache();
+          freeMemory = Runtime.getRuntime().freeMemory();
+          LOGGER.info(touchTimer + ": Morphology cache: cache cleared, free memory in heap space: " + freeMemory + " bytes");
+        }
       }
       if (dbFormLemmas != null && ! dbFormLemmas.isEmpty()) {
         formLemmasHashtable = new Hashtable<String, Lemma>();
@@ -271,13 +286,13 @@
 
   private ArrayList<Lemma> readLemmasByFormName(String lang, String formName) throws ApplicationException {
     String language = Language.getInstance().getLanguageId(lang);
-    ArrayList<Lemma> lemmasStatic = dbMorphHandlerStatic.readLemmas(language, formName);
+    ArrayList<Lemma> lemmasStatic = dbMorphHandler.readLemmas(language, formName);
     return lemmasStatic;
   }
 
   private ArrayList<Form> readFormsByLemmaName(String lang, String lemmaName) throws ApplicationException {
     String language = Language.getInstance().getLanguageId(lang);
-    ArrayList<Form> formsStatic = dbMorphHandlerStatic.readForms(language, lemmaName);
+    ArrayList<Form> formsStatic = dbMorphHandler.readForms(language, lemmaName);
     return formsStatic;
   }