From 057ed9266ddfeb4fecd1531f6aa51255a4003b68 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Kjetil=20=C3=98rbekk?= <kjetil.orbekk@gmail.com>
Date: Tue, 17 Jan 2012 16:57:00 +0100
Subject: Reject old state updates.

Only accept updates from master if revision >= currentRevision.

Client must clear state before joining network.
---
 same/src/main/java/com/orbekk/same/ClientServiceImpl.java |  7 ++++++-
 same/src/main/java/com/orbekk/same/State.java             | 10 +++++++++-
 2 files changed, 15 insertions(+), 2 deletions(-)

(limited to 'same')

diff --git a/same/src/main/java/com/orbekk/same/ClientServiceImpl.java b/same/src/main/java/com/orbekk/same/ClientServiceImpl.java
index 6675c15..36918cf 100644
--- a/same/src/main/java/com/orbekk/same/ClientServiceImpl.java
+++ b/same/src/main/java/com/orbekk/same/ClientServiceImpl.java
@@ -21,7 +21,11 @@ public class ClientServiceImpl implements ClientService, UrlReceiver {
 
     @Override
     public void setState(String component, String data, long revision) {
-        state.forceUpdate(component, data, revision);
+        boolean status = state.update(component, data, revision);
+        if (!status) {
+            logger.warn("Ignoring update: {}",
+                    new State.Component(component, revision, data));
+        }
     }
 
     @Override
@@ -37,6 +41,7 @@ public class ClientServiceImpl implements ClientService, UrlReceiver {
     public void joinNetwork(String masterUrl) {
         if (myUrl != null) {
             MasterService master = connections.getMaster(masterUrl);
+            state.clear();
             master.joinNetworkRequest(myUrl);          
         } else {
             logger.error("Tried to join network at {}, but my url is unknown. " +
diff --git a/same/src/main/java/com/orbekk/same/State.java b/same/src/main/java/com/orbekk/same/State.java
index 4179dcb..c352990 100644
--- a/same/src/main/java/com/orbekk/same/State.java
+++ b/same/src/main/java/com/orbekk/same/State.java
@@ -30,6 +30,12 @@ public class State {
         updateFromObject(".participants", new ArrayList<String>(), 0);
     }
     
+    public synchronized void clear() {
+        logger.info("Clearing state.");
+        updatedComponents.clear();
+        state.clear();
+    }
+    
     public synchronized void forceUpdate(String componentName,
             String data, long revision) {
         Component oldComponent = state.get(componentName);
@@ -48,12 +54,14 @@ public class State {
             component = state.get(componentName);       
         }
         
-        if (revision == component.getRevision()) {
+        if (revision >= component.getRevision()) {
+            Component oldComponent = new Component(component);
             component.setName(componentName);
             component.setRevision(revision + 1);
             component.setData(data);
             state.put(componentName, component);
             updatedComponents.add(componentName);
+            logger.info("Updated state: {} => {}", oldComponent, component);
             return true;
         } else {
             return false;
-- 
cgit v1.2.3