Implement Invalidator::Acknowledge

sync/notifier/invalidation_state_tracker.h

Index: sync/notifier/invalidation_state_tracker.h
diff --git a/sync/notifier/invalidation_state_tracker.h b/sync/notifier/invalidation_state_tracker.h
index 3105f3a8ac9c08e23a54c7bf6cba04c3d32cd43c..bb8d0fdc8d10936594c4f24c4b450c81b00f9d5a 100644
--- a/sync/notifier/invalidation_state_tracker.h
+++ b/sync/notifier/invalidation_state_tracker.h
@@ -2,28 +2,44 @@
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 //
-// An InvalidationVersionTracker is an interface that handles getting
-// and setting (persisting) max invalidation versions.
+// An InvalidationStateTracker is an interface that handles getting
+// and setting (persisting) max invalidation versions and our local ack
+// handles.
 
 #ifndef SYNC_NOTIFIER_INVALIDATION_STATE_TRACKER_H_
 #define SYNC_NOTIFIER_INVALIDATION_STATE_TRACKER_H_
 
+#include <string>
 #include <map>
 
 #include "base/basictypes.h"
 #include "google/cacheinvalidation/include/types.h"
+#include "sync/internal_api/public/base/invalidation_state.h"
 #include "sync/notifier/invalidation_util.h"
 
 namespace syncer {
 
-typedef std::map<invalidation::ObjectId, int64, ObjectIdLessThan>
-    InvalidationVersionMap;
+// TODO(dcheng): Need a better name.
+struct LocalState {
+  LocalState();
+  ~LocalState();
+
+  int64 version;
+  std::string payload;
+  AckHandle expected;
+  AckHandle current;
+};
+
+typedef std::map<invalidation::ObjectId, LocalState, ObjectIdLessThan>
+    InvalidationStateMap;
+typedef std::map<invalidation::ObjectId, AckHandle, ObjectIdLessThan>
+    AckHandleMap;
 
 class InvalidationStateTracker {
  public:
   InvalidationStateTracker() {}
 
-  virtual InvalidationVersionMap GetAllMaxVersions() const = 0;
+  virtual InvalidationStateMap GetStateMap() const = 0;
 
   // |max_version| should be strictly greater than any existing max
   // version for |model_type|.
@@ -39,6 +55,15 @@ class InvalidationStateTracker {
   virtual void SetInvalidationState(const std::string& state) = 0;
   virtual std::string GetInvalidationState() const = 0;
 
+  // Used for generating our own local ack handles.
+  // Generates a new ack handle for each object id in |ids|. The resulting ack
+  // handles are passed back in the output parameter rather than being returned
+  // directly, since this method is typically used with PostTaskAndReply.
+  virtual void GenerateAckHandles(const ObjectIdSet& ids,
+                                  AckHandleMap* ack_handles) = 0;
+  virtual void Acknowledge(const invalidation::ObjectId& id,
+                           const AckHandle& ack_handle) = 0;
+
  protected:
   virtual ~InvalidationStateTracker() {}
 };