2005-10-17 jrandom

* Allow an env prop to configure whether we want to use the backwards
      compatible (but not standards compliant) HMAC-MD5, or whether we want
      to use the not-backwards compatible (but standards compliant) one.  No
      one should touch this setting, unless your name is toad or jrandom ;)
    * Added some new dummy facades
    * Be more aggressive on loading up the router.config before building the
      router context
    * Added new hooks for apps to deal with previously undefined I2NP message
      types without having to modify any code.
    * Demo code for using a castrated router for SSU comm (SSUDemo.java)

router/java/src/net/i2p/data/i2np/I2NPMessageImpl.java

@@ -12,6 +12,9 @@ import java.io.IOException;
 import java.io.InputStream;
 import java.io.OutputStream;
 
+import java.util.HashMap;
+import java.util.Map;
+
 import net.i2p.I2PAppContext;
 import net.i2p.data.DataFormatException;
 import net.i2p.data.DataHelper;
@@ -36,6 +39,15 @@ public abstract class I2NPMessageImpl extends DataStructureImpl implements I2NPM
     
     private static final boolean RAW_FULL_SIZE = false;
     
+    /** unsynchronized as its pretty much read only (except at startup) */
+    private static final Map _builders = new HashMap(8);
+    public static final void registerBuilder(Builder builder, int type) { _builders.put(new Integer(type), builder); }
+    /** interface for extending the types of messages handled */
+    public interface Builder {
+        /** instantiate a new I2NPMessage to be populated shortly */
+        public I2NPMessage build(I2PAppContext ctx);
+    }
+    
     public I2NPMessageImpl(I2PAppContext context) {
         _context = context;
         _log = context.logManager().getLog(I2NPMessageImpl.class);
@@ -334,7 +346,11 @@ public abstract class I2NPMessageImpl extends DataStructureImpl implements I2NPM
             case TunnelCreateStatusMessage.MESSAGE_TYPE:
                 return new TunnelCreateStatusMessage(context);
             default:
-                return null;
+                Builder builder = (Builder)_builders.get(new Integer(type));
+                if (builder == null)
+                    return null;
+                else
+                    return builder.build(context);
         }
     }
 }