Added an asynchronous dictionary service, to perform word lookups

and other dictionary tasks as separate job units on the Invoker thread
(that's because we want to be as lazy as possible about loading 
dictionary files, but those can take a while :).



git-svn-id: svn+ssh://src.earth.threerings.net/vilya/trunk@184 c613c5cb-e716-0410-b11b-feb51c14d237

src/java/com/threerings/ezgame/server/DictionaryService.java

@@ -0,0 +1,164 @@
+//
+// $Id$
+//
+// Vilya library - tools for developing networked games
+// Copyright (C) 2002-2006 Three Rings Design, Inc., All Rights Reserved
+// http://www.threerings.net/code/vilya/
+//
+// This library is free software; you can redistribute it and/or modify it
+// under the terms of the GNU Lesser General Public License as published
+// by the Free Software Foundation; either version 2.1 of the License, or
+// (at your option) any later version.
+//
+// This library 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
+// Lesser General Public License for more details.
+//
+// You should have received a copy of the GNU Lesser General Public
+// License along with this library; if not, write to the Free Software
+// Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
+
+package com.threerings.ezgame.server;
+
+import com.samskivert.util.Invoker;
+import com.samskivert.util.ResultListener;
+
+import com.threerings.crowd.server.CrowdServer;
+
+import com.threerings.presents.client.InvocationService;
+
+import java.lang.reflect.Array;
+
+import java.util.ArrayList;
+import java.util.Random;
+import static com.threerings.ezgame.server.Log.log;
+
+/**
+ * Manages loading and querying word dictionaries in multiple languages.
+ *
+ * NOTE: the service supports lazy loading of language files, but does not
+ * _unload_ them from memory, leading to increasing memory usage. 
+ */
+public class DictionaryService
+{
+    /**
+     * Creates the singleton instance of the dictionary service.
+     */
+    public static void init ()
+    {
+        _singleton = new DictionaryService ();
+    }
+
+    /**
+     * Get an instance of the dictionary service.
+     */
+    public static DictionaryService getInstance ()
+    {
+        return _singleton;
+    }
+
+    /**
+     * Protected constructor.
+     */
+    protected DictionaryService () 
+    {
+        // TODO: set up file paths here
+    }
+
+    /**
+     * Returns true if the language is known to be supported by the
+     * dictionary service (would it be better to return a whole list
+     * of supported languages instead?)
+     */
+    public void isLanguageSupported (
+        final String locale, final InvocationService.ResultListener listener)
+    {
+        // TODO: once we have file paths set up, change this to match
+        // against dictionary files
+        listener.requestProcessed (locale.toLowerCase().startsWith("en"));
+    }
+
+    /**
+     * Retrieves a set of letters from a language definition file,
+     * and returns a random sampling of /count/ elements.
+     */
+    public void getLetterSet (
+        final String locale, final int count, final InvocationService.ResultListener listener)
+    {
+        // Create a new unit of work
+        Invoker.Unit work = new Invoker.Unit ("DictionaryService.getLetterSet") {
+            public boolean invoke ()
+            {
+                if (loadLanguageFile (locale))
+                {
+                    // TODO: actual logic will go here
+                    
+                    Random r = new Random ();
+                    char[] chars = new char[count];
+                    for (int i = 0; i < count; i++)
+                    {
+                        int c = r.nextInt (24) + 65;
+                        chars[i] = (char) (c);
+                    }
+                    StringBuilder sb = new StringBuilder ();
+                    for (char c : chars)
+                    {
+                        sb.append (c);
+                        sb.append (',');
+                    }
+                    sb.deleteCharAt (sb.length() - 1);
+                        
+                    listener.requestProcessed (sb.toString());
+                }
+                return true;
+            }
+        };
+
+        // Do the work!
+        CrowdServer.invoker.postUnit (work);    
+    }
+    
+    /**
+     * Checks if the specified word exists in the given language
+     */
+    public void checkWord (
+        final String locale, final String word, final InvocationService.ResultListener listener)
+    {
+        // Create a new unit of work
+        Invoker.Unit work = new Invoker.Unit ("DictionaryService.checkWord") {
+            public boolean invoke ()
+            {
+                if (loadLanguageFile (locale))
+                {
+                    // TODO: actual logic
+                    listener.requestProcessed (true);
+                }
+                return true;
+            }
+        };
+
+        // ...and off we go.
+        CrowdServer.invoker.postUnit (work);    
+    }
+
+    /**
+     * Loads the language file, if necessary
+     */
+    public boolean loadLanguageFile (String locale)
+    {
+        // this is boring :)
+        try {
+            Thread.sleep (500);
+        } catch (InterruptedException e) { }
+        return true;
+    }
+
+
+
+    // PRIVATE VARIABLES
+
+    /** Singleton instance pointer */
+    private static DictionaryService _singleton;
+
+}

src/java/com/threerings/ezgame/server/EZGameManager.java

@@ -130,9 +130,8 @@ public class EZGameManager extends GameManager
         InvocationService.ResultListener listener)
         throws InvocationException
     {
-        // TODO: real logic here :)
-        String letters = "A,B,C";
-        listener.requestProcessed(letters);
+        DictionaryService dictionary = getDictionaryService ();
+        dictionary.getLetterSet (locale, count, listener);
     }
     
     // from EZGameProvider
@@ -141,8 +140,22 @@ public class EZGameManager extends GameManager
         InvocationService.ResultListener listener)
         throws InvocationException
     {
-        // TODO: real logic here :)
-        listener.requestProcessed (true);
+        DictionaryService dictionary = getDictionaryService ();
+        dictionary.checkWord (locale, word, listener);
+    }  
+
+    /**
+     * Find the dictionary manager
+     */
+    protected DictionaryService getDictionaryService ()
+        throws InvocationException
+    {
+        DictionaryService dictionary = DictionaryService.getInstance ();
+        if (dictionary == null) {
+            log.warning("DictionaryService not initialized.");
+            throw new InvocationException(INTERNAL_ERROR);
+        }
+        return dictionary;
     }
 
     // from EZGameProvider