sync/notifier/invalidator_registrar.h

   1 // Copyright 2012 The Chromium Authors. All rights reserved.
   2 // Use of this source code is governed by a BSD-style license that can be
   3 // found in the LICENSE file.
   4
   5 #ifndef SYNC_NOTIFIER_INVALIDATOR_REGISTRAR_H_
   6 #define SYNC_NOTIFIER_INVALIDATOR_REGISTRAR_H_
   7
   8 #include <map>
   9
  10 #include "base/basictypes.h"
  11 #include "base/observer_list.h"
  12 #include "base/threading/thread_checker.h"
  13 #include "sync/base/sync_export.h"
  14 #include "sync/notifier/invalidation_handler.h"
  15 #include "sync/notifier/invalidation_util.h"
  16 #include "sync/notifier/object_id_invalidation_map.h"
  17
  18 namespace invalidation {
  19 class ObjectId;
  20 }  // namespace invalidation
  21
  22 namespace syncer {
  23
  24 // A helper class for implementations of the Invalidator interface.  It helps
  25 // keep track of registered handlers and which object ID registrations are
  26 // associated with which handlers, so implementors can just reuse the logic
  27 // here to dispatch invalidations and other interesting notifications.
  28 class SYNC_EXPORT InvalidatorRegistrar {
  29  public:
  30   InvalidatorRegistrar();
  31
  32   // It is an error to have registered handlers on destruction.
  33   ~InvalidatorRegistrar();
  34
  35   // Starts sending notifications to |handler|.  |handler| must not be NULL,
  36   // and it must already be registered.
  37   void RegisterHandler(InvalidationHandler* handler);
  38
  39   // Updates the set of ObjectIds associated with |handler|.  |handler| must
  40   // not be NULL, and must already be registered.  An ID must be registered for
  41   // at most one handler.
  42   void UpdateRegisteredIds(InvalidationHandler* handler,
  43                            const ObjectIdSet& ids);
  44
  45   // Stops sending notifications to |handler|.  |handler| must not be NULL, and
  46   // it must already be registered.  Note that this doesn't unregister the IDs
  47   // associated with |handler|.
  48   void UnregisterHandler(InvalidationHandler* handler);
  49
  50   ObjectIdSet GetRegisteredIds(InvalidationHandler* handler) const;
  51
  52   // Returns the set of all IDs that are registered to some handler (even
  53   // handlers that have been unregistered).
  54   ObjectIdSet GetAllRegisteredIds() const;
  55
  56   // Sorts incoming invalidations into a bucket for each handler and then
  57   // dispatches the batched invalidations to the corresponding handler.
  58   // Invalidations for IDs with no corresponding handler are dropped, as are
  59   // invalidations for handlers that are not added.
  60   void DispatchInvalidationsToHandlers(
  61       const ObjectIdInvalidationMap& invalidation_map,
  62       IncomingInvalidationSource source);
  63
  64   // Updates the invalidator state to the given one and then notifies
  65   // all handlers.  Note that the order is important; handlers that
  66   // call GetInvalidatorState() when notified will see the new state.
  67   void UpdateInvalidatorState(InvalidatorState state);
  68
  69   // Returns the current invalidator state.  When called from within
  70   // InvalidationHandler::OnInvalidatorStateChange(), this returns the
  71   // updated state.
  72   InvalidatorState GetInvalidatorState() const;
  73
  74   bool IsHandlerRegisteredForTest(InvalidationHandler* handler) const;
  75
  76   // Needed for death tests.
  77   void DetachFromThreadForTest();
  78
  79  private:
  80   typedef std::map<invalidation::ObjectId, InvalidationHandler*,
  81                    ObjectIdLessThan>
  82       IdHandlerMap;
  83
  84   InvalidationHandler* ObjectIdToHandler(const invalidation::ObjectId& id);
  85
  86   base::ThreadChecker thread_checker_;
  87   ObserverList<InvalidationHandler> handlers_;
  88   IdHandlerMap id_to_handler_map_;
  89   InvalidatorState state_;
  90
  91   DISALLOW_COPY_AND_ASSIGN(InvalidatorRegistrar);
  92 };
  93
  94 }  // namespace syncer
  95
  96 #endif  // SYNC_NOTIFIER_INVALIDATOR_REGISTRAR_H_