Basic support for datagram messaging. Hope I haven't fucked

anything up!


git-svn-id: svn+ssh://src.earth.threerings.net/narya/trunk@5090 542714f4-19e9-0310-aa3c-eee0fc999fb1

src/java/com/threerings/io/UnreliableObjectInputStream.java

@@ -0,0 +1,46 @@
+//
+// $Id$
+
+package com.threerings.io;
+
+import java.io.IOException;
+import java.io.InputStream;
+
+/**
+ * The counterpart of {@link UnreliableObjectOutputStream}.
+ */
+public class UnreliableObjectInputStream extends ObjectInputStream
+{
+    /**
+     * Constructs an object input stream which will read its data from the supplied source stream.
+     */
+    public UnreliableObjectInputStream (InputStream source)
+    {
+        super(source);
+    }
+
+    @Override // documentation inherited
+    protected ClassMapping mapClass (short code, String cname)
+        throws IOException, ClassNotFoundException
+    {
+        // see if we already have a mapping
+        ClassMapping cmap = (code < _classmap.size()) ? _classmap.get(code) : null;
+        if (cmap != null) {
+            // sanity check
+            if (!cmap.sclass.getName().equals(cname)) {
+                throw new RuntimeException(
+                    "Received mapping for class that conflicts with existing mapping " +
+                    "[code=" + code + ", oclass=" + cmap.sclass.getName() + ", nclass=" +
+                    cname + "]");
+            }
+            return cmap;
+        }
+        // insert null entries for missing mappings
+        cmap = createClassMapping(code, cname);
+        for (int ii = 0, nn = (code + 1) - _classmap.size(); ii < nn; ii++) {
+            _classmap.add(null);
+        }
+        _classmap.set(code, cmap);
+        return cmap;
+    }
+}