Added expiration timer to sessions. Sessions will now last up to 10 minutes (by default) before removed, so you can quickly disconnect (or crash) and come back and still maintain your history.

src/main/java/com/sk89q/worldedit/WorldEdit.java

@@ -129,42 +129,46 @@ public class WorldEdit {
      * @return
      */
     public LocalSession getSession(LocalPlayer player) {
-        if (sessions.containsKey(player.getName())) {
-            return sessions.get(player.getName());
-        }
+        LocalSession session;
         
-        LocalSession session = new LocalSession(config);
-        
-        // Set the limit on the number of blocks that an operation can
-        // change at once, or don't if the player has an override or there
-        // is no limit. There is also a default limit
-        if (!player.hasPermission("worldedit.limit.unrestricted")
-                && config.maxChangeLimit > -1) {
-            
-            // If the default limit is infinite but there is a maximum
-            // limit, make sure to not have it be overridden
-            if (config.defaultChangeLimit < 0) {
-                session.setBlockChangeLimit(config.maxChangeLimit);
-            } else {
-                // Bound the change limit
-                int limit = Math.min(config.defaultChangeLimit,
-                        config.maxChangeLimit);
-                session.setBlockChangeLimit(limit);
+        synchronized (sessions) {
+            if (sessions.containsKey(player.getName())) {
+                return sessions.get(player.getName());
             }
-        } else {
-            // No change limit or override
-            session.setBlockChangeLimit(config.defaultChangeLimit);
+            
+            session = new LocalSession(config);
+            
+            // Set the limit on the number of blocks that an operation can
+            // change at once, or don't if the player has an override or there
+            // is no limit. There is also a default limit
+            if (!player.hasPermission("worldedit.limit.unrestricted")
+                    && config.maxChangeLimit > -1) {
+                
+                // If the default limit is infinite but there is a maximum
+                // limit, make sure to not have it be overridden
+                if (config.defaultChangeLimit < 0) {
+                    session.setBlockChangeLimit(config.maxChangeLimit);
+                } else {
+                    // Bound the change limit
+                    int limit = Math.min(config.defaultChangeLimit,
+                            config.maxChangeLimit);
+                    session.setBlockChangeLimit(limit);
+                }
+            } else {
+                // No change limit or override
+                session.setBlockChangeLimit(config.defaultChangeLimit);
+            }
+            
+            // Have the session use inventory if it's enabled and the player
+            // doesn't have an override
+            session.setUseInventory(config.useInventory
+                    && (!config.useInventoryOverride
+                            || !player.hasPermission("worldedit.inventory.unrestricted")));
+            
+            // Remember the session
+            sessions.put(player.getName(), session);
         }
         
-        // Have the session use inventory if it's enabled and the player
-        // doesn't have an override
-        session.setUseInventory(config.useInventory
-                && (!config.useInventoryOverride
-                        || !player.hasPermission("worldedit.inventory.unrestricted")));
-        
-        // Remember the session
-        sessions.put(player.getName(), session);
-        
         return session;
     }
 
@@ -175,7 +179,9 @@ public class WorldEdit {
      * @return
      */
     public boolean hasSession(LocalPlayer player) {
-        return sessions.containsKey(player.getName());
+        synchronized (sessions) {
+            return sessions.containsKey(player.getName());
+        }
     }
 
     /**
@@ -726,14 +732,18 @@ public class WorldEdit {
      * @param player
      */
     public void removeSession(LocalPlayer player) {
-        sessions.remove(player.getName());
+        synchronized (sessions) {
+            sessions.remove(player.getName());
+        }
     }
 
     /**
      * Remove all sessions.
      */
     public void clearSessions() {
-        sessions.clear();
+        synchronized (sessions) {
+            sessions.clear();
+        }
     }
     
     /**
@@ -788,9 +798,49 @@ public class WorldEdit {
      *
      * @param player
      */
+    @Deprecated
     public void handleDisconnect(LocalPlayer player) {
+        forgetPlayer(player);
+    }
+    
+    /**
+     *
+     * @param player
+     */
+    public void markExpire(LocalPlayer player) {
+        synchronized (sessions) {
+            LocalSession session = sessions.get(player.getName());
+            if (session != null) {
+                session.update();
+            }
+        }
+    }
+    
+    /**
+     * Forget a player.
+     *
+     * @param player
+     */
+    public void forgetPlayer(LocalPlayer player) {
         removeSession(player);
     }
+    
+    /*
+     * Flush expired sessions.
+     */
+    public void flushExpiredSessions(SessionCheck checker) {
+        synchronized (sessions) {
+            Iterator<Map.Entry<String, LocalSession>> it = sessions.entrySet().iterator();
+            
+            while (it.hasNext()) {
+                Map.Entry<String, LocalSession> entry = it.next();
+                if (entry.getValue().hasExpired()
+                        && !checker.isOnlinePlayer(entry.getKey())) {
+                    it.remove();
+                }
+            }
+        }
+    }
 
     /**
      * Called on arm swing.