Refactor SyncBackendHost

chrome/browser/sync/glue/sync_frontend.h

+// Copyright (c) 2013 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.
+
+#ifndef CHROME_BROWSER_SYNC_GLUE_SYNC_FRONTEND_H_
+#define CHROME_BROWSER_SYNC_GLUE_SYNC_FRONTEND_H_
+
+#include "base/basictypes.h"
+#include "sync/internal_api/public/base/model_type.h"
+#include "sync/internal_api/public/sync_encryption_handler.h"
+#include "sync/internal_api/public/sync_manager.h"
+#include "sync/internal_api/public/util/weak_handle.h"
+#include "sync/protocol/sync_protocol_error.h"
+
+namespace syncer {
+class DataTypeDebugInfoListener;
+class JsBackend;
+}  // namespace syncer
+
+namespace sync_pb {
+class EncryptedData;
+}  // namespace sync_pb
+
+namespace browser_sync {
+
+// SyncFrontend is the interface used by SyncBackendHost to communicate with
+// the entity that created it and, presumably, is interested in sync-related
+// activity.
+// NOTE: All methods will be invoked by a SyncBackendHost on the same thread
+// used to create that SyncBackendHost.
+class SyncFrontend {
+ public:
+  SyncFrontend();
+
+  // The backend has completed initialization and it is now ready to
+  // accept and process changes.  If success is false, initialization
+  // wasn't able to be completed and should be retried.
+  //
+  // |js_backend| is what about:sync interacts with; it's different
+  // from the 'Backend' in 'OnBackendInitialized' (unfortunately).  It
+  // is initialized only if |success| is true.
+  virtual void OnBackendInitialized(
+      const syncer::WeakHandle<syncer::JsBackend>& js_backend,
+      const syncer::WeakHandle<syncer::DataTypeDebugInfoListener>&
+          debug_info_listener,
+      bool success) = 0;
+
+  // The backend queried the server recently and received some updates.
+  virtual void OnSyncCycleCompleted() = 0;
+
+  // Configure ran into some kind of error. But it is scheduled to be
+  // retried.
+  virtual void OnSyncConfigureRetry() = 0;
+
+  // The status of the connection to the sync server has changed.
+  virtual void OnConnectionStatusChange(
+      syncer::ConnectionStatus status) = 0;
+
+  // We are no longer permitted to communicate with the server. Sync should
+  // be disabled and state cleaned up at once.
+  virtual void OnStopSyncingPermanently() = 0;
+
+  // The syncer requires a passphrase to decrypt sensitive updates. This is
+  // called when the first sensitive data type is setup by the user and anytime
+  // the passphrase is changed by another synced client. |reason| denotes why
+  // the passphrase was required. |pending_keys| is a copy of the
+  // cryptographer's pending keys to be passed on to the frontend in order to
+  // be cached.
+  virtual void OnPassphraseRequired(
+      syncer::PassphraseRequiredReason reason,
+      const sync_pb::EncryptedData& pending_keys) = 0;
+
+  // Called when the passphrase provided by the user is
+  // accepted. After this is called, updates to sensitive nodes are
+  // encrypted using the accepted passphrase.
+  virtual void OnPassphraseAccepted() = 0;
+
+  // Called when the set of encrypted types or the encrypt everything
+  // flag has been changed.  Note that encryption isn't complete until
+  // the OnEncryptionComplete() notification has been sent (see
+  // below).
+  //
+  // |encrypted_types| will always be a superset of
+  // syncer::Cryptographer::SensitiveTypes().  If |encrypt_everything| is
+  // true, |encrypted_types| will be the set of all known types.
+  //
+  // Until this function is called, observers can assume that the set
+  // of encrypted types is syncer::Cryptographer::SensitiveTypes() and that
+  // the encrypt everything flag is false.
+  virtual void OnEncryptedTypesChanged(
+      syncer::ModelTypeSet encrypted_types,
+      bool encrypt_everything) = 0;
+
+  // Called after we finish encrypting the current set of encrypted
+  // types.
+  virtual void OnEncryptionComplete() = 0;
+
+  // Called to perform migration of |types|.
+  virtual void OnMigrationNeededForTypes(syncer::ModelTypeSet types) = 0;
+
+  // Inform the Frontend that new datatypes are available for registration.
+  virtual void OnExperimentsChanged(
+      const syncer::Experiments& experiments) = 0;
+
+  // Called when the sync cycle returns there is an user actionable error.
+  virtual void OnActionableError(const syncer::SyncProtocolError& error) = 0;
+
+ protected:
+  // Don't delete through SyncFrontend interface.
+  virtual ~SyncFrontend();

[Nicolas Zea, 2013/11/06 18:03:21]

I don't think this is really necessary (although I know that's how it was
before). 

[rlarocque, 2013/11/06 21:48:47]

I don't see any harm in it.

[Nicolas Zea, 2013/11/06 22:18:25]

Just to keep things consistent with other interfaces. It's weird having this
down here. I don't feel too strongly.

[rlarocque, 2013/11/06 22:48:47]

OK.  I'll remove it.

I was hesitant before, because I thought the person who wrote it might know some
obscure bit of C++ trivia that I don't.  Since no one else can figure out why
this is necessary, I guess it's safe to remove it.

+
+ private:
+  DISALLOW_COPY_AND_ASSIGN(SyncFrontend);

[Nicolas Zea, 2013/11/06 18:03:21]

I think typically we leave the DISALLOW_COPY_AND_ASSIGN in implementation right?

[rlarocque, 2013/11/06 21:48:47]

Done.

+};
+
+}  // namespace browser_sync
+
+#endif  // CHROME_BROWSER_SYNC_GLUE_SYNC_FRONTEND_H_