[folks] Add stamping to LinkedHashSet

[Philip Withnall <pwithnall src gnome org>]

commit 34e89c9fdeba10c52238831cd6303fa7a2e9e2c3
Author: Philip Withnall <philip withnall collabora co uk>
Date:   Thu Mar 24 12:19:32 2011 +0000

    Add stamping to LinkedHashSet
    
    Since we don't have access to the stamps in the LinkedHashSet's linked list
    or hash set, we have to maintain our own. This is necessary for implementing
    our own Iterator. (See next commit.)
    
    Helps: bgo#645684

 folks/linked-hash-set.vala |   11 ++++++++++-
 1 files changed, 10 insertions(+), 1 deletions(-)
---
diff --git a/folks/linked-hash-set.vala b/folks/linked-hash-set.vala
index ffb149d..ab1c8ba 100644
--- a/folks/linked-hash-set.vala
+++ b/folks/linked-hash-set.vala
@@ -33,6 +33,9 @@ public class Folks.LinkedHashSet<G> : AbstractList<G>,
   private HashSet<G> _hash_set;
   /* A linked list that maintains the order of the items. */
   private LinkedList<G> _linked_list;
+  /* A stamp which changes whenever either the hash set or the linked list are
+   * modified. */
+  private int _stamp = 0;
 
   /**
    * Constructs a new empty set.
@@ -93,6 +96,7 @@ public class Folks.LinkedHashSet<G> : AbstractList<G>,
   {
     if (this._hash_set.add (item))
       {
+        this._stamp++;
         this._linked_list.add (item);
         return true;
       }
@@ -114,6 +118,7 @@ public class Folks.LinkedHashSet<G> : AbstractList<G>,
   {
     if (this._hash_set.remove (item))
       {
+        this._stamp++;
         this._linked_list.remove (item);
         return true;
       }
@@ -131,6 +136,7 @@ public class Folks.LinkedHashSet<G> : AbstractList<G>,
    */
   public override void clear ()
   {
+    this._stamp++;
     this._hash_set.clear ();
     this._linked_list.clear ();
   }
@@ -197,7 +203,10 @@ public class Folks.LinkedHashSet<G> : AbstractList<G>,
   {
     G item = this._linked_list.remove_at (index);
     if (item != null)
-      this._hash_set.remove (item);
+      {
+        this._stamp++;
+        this._hash_set.remove (item);
+      }
     return item;
   }