text: // Copyright 2012 The Chromium Authors. All rights reserved.
  // Use of this source code is governed by a BSD-style license that can be
  // found in the LICENSE file.
  //
  // An implementation of Invalidator that wraps an invalidation
  // client.  Handles the details of connecting to XMPP and hooking it
  // up to the invalidation client.
  //
  // You probably don't want to use this directly; use
  // NonBlockingInvalidator.
  
  #ifndef SYNC_NOTIFIER_INVALIDATION_NOTIFIER_H_
  #define SYNC_NOTIFIER_INVALIDATION_NOTIFIER_H_
  
  #include <string>
  
  #include "base/basictypes.h"
  #include "base/compiler_specific.h"
  #include "base/memory/scoped_ptr.h"
  #include "base/threading/non_thread_safe.h"
  #include "base/time/default_tick_clock.h"
  #include "sync/base/sync_export.h"
  #include "sync/internal_api/public/base/model_type.h"
  #include "sync/internal_api/public/util/weak_handle.h"
  #include "sync/notifier/invalidation_state_tracker.h"
  #include "sync/notifier/invalidator.h"
  #include "sync/notifier/invalidator_registrar.h"
  #include "sync/notifier/sync_invalidation_listener.h"
  
  namespace notifier {
  class PushClient;
  }  // namespace notifier
  
  namespace syncer {
  
  // This class must live on the IO thread.
  // TODO(dcheng): Think of a name better than InvalidationInvalidator.
  class SYNC_EXPORT_PRIVATE InvalidationNotifier
      : public Invalidator,
        public SyncInvalidationListener::Delegate,
        public base::NonThreadSafe {
   public:
    // |invalidation_state_tracker| must be initialized.
    InvalidationNotifier(
        scoped_ptr<notifier::PushClient> push_client,
        const std::string& invalidator_client_id,
        const InvalidationStateMap& initial_invalidation_state_map,
        const std::string& invalidation_bootstrap_data,
        const WeakHandle<InvalidationStateTracker>&
            invalidation_state_tracker,
        const std::string& client_info);
  
    virtual ~InvalidationNotifier();
  
    // Invalidator implementation.
    virtual void RegisterHandler(InvalidationHandler* handler) OVERRIDE;
    virtual void UpdateRegisteredIds(InvalidationHandler* handler,
                                     const ObjectIdSet& ids) OVERRIDE;
    virtual void UnregisterHandler(InvalidationHandler* handler) OVERRIDE;
    virtual void Acknowledge(const invalidation::ObjectId& id,
                             const AckHandle& ack_handle) OVERRIDE;
    virtual InvalidatorState GetInvalidatorState() const OVERRIDE;
    virtual void UpdateCredentials(
        const std::string& email, const std::string& token) OVERRIDE;
  
    // SyncInvalidationListener::Delegate implementation.
    virtual void OnInvalidate(
        const ObjectIdInvalidationMap& invalidation_map) OVERRIDE;
    virtual void OnInvalidatorStateChange(InvalidatorState state) OVERRIDE;
  
   private:
    // We start off in the STOPPED state.  When we get our initial
    // credentials, we connect and move to the CONNECTING state.  When
    // we're connected we start the invalidation client and move to the
    // STARTED state.  We never go back to a previous state.
    enum State {
      STOPPED,
      CONNECTING,
      STARTED
    };
    State state_;
  
    InvalidatorRegistrar registrar_;
  
    // Passed to |invalidation_listener_|.
    const InvalidationStateMap initial_invalidation_state_map_;
  
    // Passed to |invalidation_listener_|.
    const WeakHandle<InvalidationStateTracker>
        invalidation_state_tracker_;
  
    // Passed to |invalidation_listener_|.
    const std::string client_info_;
  
    // The client ID to pass to |invalidation_listener_|.
    const std::string invalidator_client_id_;
  
    // The initial bootstrap data to pass to |invalidation_listener_|.
    const std::string invalidation_bootstrap_data_;
  
    // TODO(akalin): Clean up this reference to DefaultTickClock. Ideally, we
    // should simply be using TaskRunner's tick clock. See http://crbug.com/179211
    base::DefaultTickClock tick_clock_;
  
    // The invalidation listener.
    SyncInvalidationListener invalidation_listener_;
  
    DISALLOW_COPY_AND_ASSIGN(InvalidationNotifier);
  };
  
  }  // namespace syncer
  
  #endif  // SYNC_NOTIFIER_INVALIDATION_NOTIFIER_H_
  