From c76474a640fa5ab0c91339a264c06cf59f0d5a7f Mon Sep 17 00:00:00 2001
From: Michael Bayne <mdb@threerings.net>
Date: Mon, 24 Sep 2007 20:49:01 +0000
Subject: [PATCH] Drop forced move requests if they come in while we have a
 move pending.  We may have to do some things on the server as well which
 blindly ejects the user from their current place, but now the worst case is
 that a player ends up nowhere in the event of extreme lag and clicks the
 button to go somewhere again rather than having a move half-completed get
 aborted and the code ending up confused and not properly able to clean up
 after itself.

git-svn-id: svn+ssh://src.earth.threerings.net/vilya/trunk@436 c613c5cb-e716-0410-b11b-feb51c14d237
---
 .../whirled/client/SceneDirector.java         | 21 ++++++++++++++++---
 .../whirled/zone/client/ZoneDirector.java     | 13 +++++++++---
 2 files changed, 28 insertions(+), 6 deletions(-)

diff --git a/src/java/com/threerings/whirled/client/SceneDirector.java b/src/java/com/threerings/whirled/client/SceneDirector.java
index 1611077d..d5e42733 100644
--- a/src/java/com/threerings/whirled/client/SceneDirector.java
+++ b/src/java/com/threerings/whirled/client/SceneDirector.java
@@ -119,6 +119,14 @@ public class SceneDirector extends BasicDirector
         return _scene;
     }
 
+    /**
+     * Returns true if there is a pending move request.
+     */
+    public boolean movePending ()
+    {
+        return (_pendingSceneId > 0);
+    }
+
     /**
      * Requests that this client move the specified scene. A request will be made and when the
      * response is received, the location observers will be notified of success or failure.
@@ -167,7 +175,7 @@ public class SceneDirector extends BasicDirector
         boolean refuse = _locdir.checkRepeatMove();
 
         // complain if we're over-writing a pending request
-        if (_pendingSceneId != -1) {
+        if (movePending()) {
             if (refuse) {
                 Log.warning("Refusing moveTo; We have a request outstanding " +
                             "[psid=" + _pendingSceneId + ", nsid=" + sceneId + "].");
@@ -367,11 +375,18 @@ public class SceneDirector extends BasicDirector
     // from interface SceneReceiver
     public void forcedMove (int sceneId)
     {
-        Log.info("Moving at request of server [sceneId=" + sceneId + "].");
+        // if we're in the middle of a move, we can't abort it or we will screw everything up, so
+        // just finish up what we're doing and assume that the repeated move request was the
+        // spurious one as it would be in the case of lag causing rapid-fire repeat requests
+        if (movePending()) {
+            Log.info("Dropping forced move because we have a move pending " +
+                     "[pendId=" + _pendingSceneId + ", reqId=" + sceneId + "].");
+            return;
+        }
 
+        Log.info("Moving at request of server [sceneId=" + sceneId + "].");
         // clear out our old scene and place data
         didLeaveScene();
-
         // move to the new scene
         moveTo(sceneId);
     }
diff --git a/src/java/com/threerings/whirled/zone/client/ZoneDirector.java b/src/java/com/threerings/whirled/zone/client/ZoneDirector.java
index ffdc4a20..0ba43cf5 100644
--- a/src/java/com/threerings/whirled/zone/client/ZoneDirector.java
+++ b/src/java/com/threerings/whirled/zone/client/ZoneDirector.java
@@ -244,12 +244,19 @@ public class ZoneDirector extends BasicDirector
     // documentation inherited from interface
     public void forcedMove (int zoneId, int sceneId)
     {
-        Log.info("Moving at request of server [zoneId=" + zoneId +
-                 ", sceneId=" + sceneId + "].");
+        // if we're in the middle of a move, we can't abort it or we will screw everything up, so
+        // just finish up what we're doing and assume that the repeated move request was the
+        // spurious one as it would be in the case of lag causing rapid-fire repeat requests
+        if (_scdir.movePending()) {
+            Log.info("Dropping forced move because we have a move pending " +
+                     "[pend=" + _scdir.getPendingModel() + ", rzId=" + zoneId +
+                     ", rsId=" + sceneId + "].");
+            return;
+        }
 
+        Log.info("Moving at request of server [zoneId=" + zoneId + ", sceneId=" + sceneId + "].");
         // clear out our old scene and place data
         _scdir.didLeaveScene();
-
         // move to the new zone and scene
         moveTo(zoneId, sceneId, null);
     }