Created the facilities for transmitting distributed objects and derived

classes over the wire (by inspecting their fields and sending those
directly).


git-svn-id: svn+ssh://src.earth.threerings.net/narya/trunk@8 542714f4-19e9-0310-aa3c-eee0fc999fb1

src/java/com/threerings/presents/dobj/io/DObjectFactory.java

@@ -1,12 +1,15 @@
 //
-// $Id: DObjectFactory.java,v 1.1 2001/05/29 03:27:59 mdb Exp $
+// $Id: DObjectFactory.java,v 1.2 2001/05/30 00:16:00 mdb Exp $
 
-package com.samskivert.cocktail.cher.dobj;
+package com.samskivert.cocktail.cher.dobj.net;
 
 import java.io.IOException;
 import java.io.DataInputStream;
 import java.io.DataOutputStream;
+import java.util.HashMap;
 
+import com.samskivert.cocktail.cher.Log;
+import com.samskivert.cocktail.cher.dobj.DObject;
 import com.samskivert.cocktail.cher.io.ObjectStreamException;
 
 /**
@@ -16,22 +19,40 @@ import com.samskivert.cocktail.cher.io.ObjectStreamException;
  */
 public class DObjectFactory
 {
+    /**
+     * Writes the supplied distributed object out to the specified data
+     * output stream.
+     */
     public static void writeTo (DataOutputStream out, DObject dobj)
         throws IOException
     {
-        // first we write the class of the object to the stream
-        out.writeUTF(dobj.getClass().getName());
-        // then we write the object itself
-        dobj.writeTo(out);
+        Log.info("Marshalling object: " + dobj);
+        // look up the marshaller for this object
+        Class clazz = dobj.getClass();
+        Marshaller marsh = getMarshaller(clazz);
+        // then write the class of the object to the stream
+        out.writeUTF(clazz.getName());
+        // then use the marshaller to write the object itself
+        marsh.writeTo(out, dobj);
     }
 
+    /**
+     * Reads a distributed object from the specified input stream.
+     */
     public static DObject readFrom (DataInputStream in)
         throws IOException
     {
         try {
+            // read in the class name and create an instance of that class
             Class clazz = Class.forName(in.readUTF());
             DObject dobj = (DObject)clazz.newInstance();
-            dobj.readFrom(in);
+            Log.info("Unmarshalling object: " + dobj);
+
+            // look up the marshaller for that class
+            Marshaller marsh = getMarshaller(clazz);
+            // use it to reconstitute the object from the stream
+            marsh.readFrom(in, dobj);
+
             return dobj;
 
         } catch (Exception e) {
@@ -39,4 +60,17 @@ public class DObjectFactory
             throw new ObjectStreamException(errmsg);
         }
     }
+
+    protected static Marshaller getMarshaller (Class clazz)
+        throws IOException
+    {
+        Marshaller marsh = (Marshaller)_marshallers.get(clazz);
+        // create a new marshaller if we don't already have one
+        if (marsh == null) {
+            _marshallers.put(clazz, marsh = new Marshaller(clazz));
+        }
+        return marsh;
+    }
+
+    protected static HashMap _marshallers = new HashMap();
 }