Moving bits into src/main and src/test. Reinstatement of actual test

workingness coming shortly.


git-svn-id: svn+ssh://src.earth.threerings.net/vilya/trunk@995 c613c5cb-e716-0410-b11b-feb51c14d237

src/main/as/com/threerings/whirled/data/SceneUpdate.as

@@ -0,0 +1,163 @@
+//
+// $Id$
+//
+// Vilya library - tools for developing networked games
+// Copyright (C) 2002-2010 Three Rings Design, Inc., All Rights Reserved
+// http://code.google.com/p/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.whirled.data {
+
+import flash.errors.IllegalOperationError;
+
+import com.threerings.util.Joiner;
+
+import com.threerings.io.ObjectInputStream;
+import com.threerings.io.ObjectOutputStream;
+import com.threerings.io.Streamable;
+
+import com.threerings.util.Cloneable;
+import com.threerings.util.Log;
+
+/**
+ * Used to encapsulate updates to scenes in such a manner that updates can
+ * be stored persistently and sent to clients to update their own local
+ * copies of scenes.
+ */
+public class SceneUpdate
+    implements Streamable, Cloneable
+{
+    public function SceneUpdate ()
+    {
+        // nothing needed
+    }
+
+    /**
+     * Applies this update to the specified scene model. Derived classes
+     * will want to override this method and apply updates of their own,
+     * being sure to call <code>super.apply</code>.
+     */
+    public function apply (model :SceneModel) :void
+    {
+        // increment the version; disallowing integer overflow
+        model.version = Math.max(_targetVersion + 1, model.version);
+
+        // sanity check for the amazing two billion updates
+        if (model.version == _targetVersion) {
+            Log.getLog(this).warning("Egads! This scene has been updated two" +
+                " billion times [model=" + model + ", update=" + this + "].");
+        }
+    }
+
+    /**
+     * Returns the scene id for which this update is appropriate.
+     */
+    public function getSceneId () :int
+    {
+        return _targetId;
+    }
+
+    /**
+     * Returns the scene version for which this update is appropriate.
+     */
+    public function getSceneVersion () :int
+    {
+        return _targetVersion;
+    }
+
+    /**
+     * Generates a string representation of this instance.
+     */
+    public function toString () :String
+    {
+        var j :Joiner = Joiner.createFor(this);
+        toStringJoiner(j);
+        return j.toString();
+    }
+
+    /**
+     * Initializes this scene update such that it will operate on a scene
+     * with the specified target scene and version number.
+     *
+     * @param targetId the id of the scene on which we are to operate.
+     * @param targetVersion the version of the scene on which we are to
+     * operate.
+     */
+    public function init (targetId :int, targetVersion :int) :void
+    {
+        _targetId = targetId;
+        _targetVersion = targetVersion;
+    }
+
+    // from interface Streamable
+    public function writeObject (out :ObjectOutputStream) :void
+    {
+        out.writeInt(_targetId);
+        out.writeInt(_targetVersion);
+    }
+
+    // from interface Streamable
+    public function readObject (ins :ObjectInputStream) :void
+    {
+        _targetId = ins.readInt();
+        _targetVersion = ins.readInt();
+    }
+
+    /**
+     * Called to ensure that the scene is in the appropriate state prior
+     * to applying the update.
+     *
+     * @exception IllegalStateException thrown if the update cannot be
+     * applied to the scene because it is not in a valid state
+     * (appropriate previous updates were not applied, it's the wrong kind
+     * of scene, etc.).
+     */
+    public function validate (model :SceneModel) :void
+        //throws IllegalStateException
+    {
+        if (model.sceneId != _targetId) {
+            throw new IllegalOperationError("Wrong target scene, expected id " +
+                _targetId + " got id " + model.sceneId);
+
+        } else if (model.version != _targetVersion) {
+            throw new IllegalOperationError("Target scene not proper " +
+                "version, expected " + _targetVersion +
+                " got " + model.version);
+        }
+    }
+
+    // from interface Cloneable
+    public function clone () :Object
+    {
+        throw new Error("Not implemented.");
+    }
+
+    /**
+     * An extensible mechanism for generating a string representation of
+     * this instance.
+     */
+    protected function toStringJoiner (j :Joiner) :void
+    {
+        j.add("sceneId", _targetId, "version", _targetVersion);
+    }
+
+    /** The version number of the scene on which we operate. */
+    protected var _targetId :int;
+
+    /** The version number of the scene on which we operate. */
+    protected var _targetVersion :int;
+}
+}