sync: Expose sync functionality as functions

sync/engine/download.cc

+// 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.
+
+#include "sync/engine/download.h"
+
+#include <string>
+
+#include "base/command_line.h"
+#include "sync/engine/process_updates_command.h"
+#include "sync/engine/store_timestamps_command.h"
+#include "sync/engine/syncer.h"
+#include "sync/engine/syncer_proto_util.h"
+#include "sync/internal_api/public/base/model_type_invalidation_map.h"
+#include "sync/sessions/nudge_tracker.h"
+#include "sync/syncable/directory.h"
+#include "sync/syncable/nigori_handler.h"
+#include "sync/syncable/syncable_read_transaction.h"
+
+using sync_pb::DebugInfo;
+
+namespace syncer {
+
+using sessions::StatusController;
+using sessions::SyncSession;
+using sessions::SyncSessionContext;
+using std::string;
+
+namespace {
+
+SyncerError HandleGetEncryptionKeyResponse(
+    const sync_pb::ClientToServerResponse& update_response,
+    syncable::Directory* dir) {
+  bool success = false;
+  if (update_response.get_updates().encryption_keys_size() == 0) {
+    LOG(ERROR) << "Failed to receive encryption key from server.";
+    return SERVER_RESPONSE_VALIDATION_FAILED;
+  }
+  syncable::ReadTransaction trans(FROM_HERE, dir);
+  syncable::NigoriHandler* nigori_handler = dir->GetNigoriHandler();
+  success = nigori_handler->SetKeystoreKeys(
+      update_response.get_updates().encryption_keys(),
+      &trans);
+
+  DVLOG(1) << "GetUpdates returned "
+           << update_response.get_updates().encryption_keys_size()
+           << "encryption keys. Nigori keystore key "
+           << (success ? "" : "not ") << "updated.";
+  return (success ? SYNCER_OK : SERVER_RESPONSE_VALIDATION_FAILED);
+}
+
+sync_pb::SyncEnums::GetUpdatesOrigin ConvertConfigureSourceToOrigin(
+    sync_pb::GetUpdatesCallerInfo::GetUpdatesSource source) {
+  switch (source) {
+    // Configurations:
+    case sync_pb::GetUpdatesCallerInfo::NEWLY_SUPPORTED_DATATYPE:
+      return sync_pb::SyncEnums::NEWLY_SUPPORTED_DATATYPE;
+    case sync_pb::GetUpdatesCallerInfo::MIGRATION:
+      return sync_pb::SyncEnums::MIGRATION;
+    case sync_pb::GetUpdatesCallerInfo::RECONFIGURATION:
+      return sync_pb::SyncEnums::RECONFIGURATION;
+    case sync_pb::GetUpdatesCallerInfo::NEW_CLIENT:
+      return sync_pb::SyncEnums::NEW_CLIENT;
+    default:
+      NOTREACHED();
+      return sync_pb::SyncEnums::UNKNOWN_ORIGIN;
+  }
+}
+
+sync_pb::GetUpdatesMessage* InitDownloadUpdatesRequest(
+    sync_pb::ClientToServerMessage* msg) {
+  msg->set_message_contents(sync_pb::ClientToServerMessage::GET_UPDATES);
+
+  // We want folders for our associated types, always.  If we were to set
+  // this to false, the server would send just the non-container items
+  // (e.g. Bookmark URLs but not their containing folders).
+  sync_pb::GetUpdatesMessage* get_updates = msg->mutable_get_updates();
+  get_updates->set_fetch_folders(true);
+  return get_updates;
+}
+
+bool ShouldRequestEncryptionKey(
+    SyncSessionContext* context) {
+  bool need_encryption_key = false;
+  if (context->keystore_encryption_enabled()) {
+    syncable::Directory* dir = context->directory();
+    syncable::ReadTransaction trans(FROM_HERE, dir);
+    syncable::NigoriHandler* nigori_handler = dir->GetNigoriHandler();
+    need_encryption_key = nigori_handler->NeedKeystoreKey(&trans);
+  }
+  return need_encryption_key;
+}
+
+SyncerError ExecuteDownloadUpdates(
+    bool need_encryption_key,
+    SyncSession* session,
+    sync_pb::ClientToServerMessage* msg) {
+  sync_pb::ClientToServerResponse update_response;
+  StatusController* status = session->mutable_status_controller();
+
+  SyncerError result = SyncerProtoUtil::PostClientToServerMessage(
+      msg,
+      &update_response,
+      session);
+
+  DVLOG(2) << SyncerProtoUtil::ClientToServerResponseDebugString(
+      update_response);
+
+  if (result != SYNCER_OK) {
+    status->mutable_updates_response()->Clear();
+    LOG(ERROR) << "PostClientToServerMessage() failed during GetUpdates";
+  } else {
+    status->mutable_updates_response()->CopyFrom(update_response);
+
+    DVLOG(1) << "GetUpdates "
+             << " returned " << update_response.get_updates().entries_size()
+             << " updates and indicated "
+             << update_response.get_updates().changes_remaining()
+             << " updates left on server.";
+
+    if (need_encryption_key ||
+        update_response.get_updates().encryption_keys_size() > 0) {
+      syncable::Directory* dir = session->context()->directory();
+      status->set_last_get_key_result(
+          HandleGetEncryptionKeyResponse(update_response, dir));
+    }
+  }
+
+  ProcessUpdatesCommand process_updates;
+  process_updates.Execute(session);
+
+  StoreTimestampsCommand store_timestamps;
+  store_timestamps.Execute(session);
+
+  return result;
+}
+
+}  // namespace
+
+SyncerError NormalDownloadUpdates(
+    SyncSession* session,
+    bool create_mobile_bookmarks_folder,
+    ModelTypeSet request_types,
+    const sessions::NudgeTracker& nudge_tracker) {
+  sync_pb::ClientToServerMessage client_to_server_message;
+  client_to_server_message.set_share(session->context()->account_name());
+  sync_pb::GetUpdatesMessage* get_updates =
+      InitDownloadUpdatesRequest(&client_to_server_message);
+
+  DebugInfo* debug_info = client_to_server_message.mutable_debug_info();
+  AppendClientDebugInfoIfNeeded(session, debug_info);
+
+  get_updates->set_create_mobile_bookmarks_folder(
+      create_mobile_bookmarks_folder);
+  bool need_encryption_key = ShouldRequestEncryptionKey(session->context());
+  get_updates->set_need_encryption_key(need_encryption_key);
+
+  // Request updates for all requested types.
+  DVLOG(1) << "Getting updates for types "
+           << ModelTypeSetToString(request_types);
+  DCHECK(!request_types.Empty());

[tim (not reviewing), 2013/06/26 20:26:30]

There's just too much duplicated code here. I think everything up to this point
in this function is copied in the Configure (and Poll?) variant.  Worse, I keep
having to scroll up and down to convince myself they're the same or different
and I'm not even sure if I'm right; the readability isn't great.  Previously all
boilerplate was handled by common code; you should figure out how to make that
work  in this world as well before checking in.

[rlarocque, 2013/06/26 22:00:51]

I've expanded InitDownloadUpdates to include more common code.  

I was reluctant to do this earlier, since it results in a function that doesn't
make a lot of sense.  It performs a handful of trivial tasks that aren't related
to each other, except in that they're common to all three download update
functions.  However, you make a good point about the benefits of making it clear
that these functions do have a few things in common.  

+
+  // Set legacy GetUpdatesMessage.GetUpdatesCallerInfo information.
+  get_updates->mutable_caller_info()->set_source(
+      nudge_tracker.updates_source());

[tim (not reviewing), 2013/06/26 20:26:30]

The GetUpdatesCallerInfo setting seems to be the same as well except in one case
it comes from a nudge tracker.  Depending how you deal with the above code
duplication you might want to parameterize this as well.

[rlarocque, 2013/06/26 22:00:51]

That will change.  The SyncSourceInfo becomes redundant once this patch lands. 
I haven't removed it yet because a lot of unit tests depend on it.

+  get_updates->mutable_caller_info()->set_notifications_enabled(
+      session->context()->notifications_enabled());
+
+  // Set the new and improved version of source, too.
+  get_updates->set_get_updates_origin(sync_pb::SyncEnums::GU_TRIGGER);
+
+  // Set the progress markers and notification hints.
+  syncable::Directory* dir = session->context()->directory();
+  for (ModelTypeSet::Iterator it = request_types.First();
+       it.Good(); it.Inc()) {
+    if (ProxyTypes().Has(it.Get()))
+      continue;
+
+    DCHECK(!nudge_tracker.IsTypeThrottled(it.Get()))
+        << "Throttled types should have been removed from the request_types.";
+
+    sync_pb::DataTypeProgressMarker* progress_marker =
+        get_updates->add_from_progress_marker();
+    dir->GetDownloadProgress(it.Get(), progress_marker);
+    nudge_tracker.SetLegacyNotificationHint(it.Get(), progress_marker);
+    nudge_tracker.FillProtoMessage(
+        it.Get(),
+        progress_marker->mutable_get_update_triggers());
+  }
+
+  StatusController* status = session->mutable_status_controller();
+  status->set_updates_request_types(request_types);
+  return ExecuteDownloadUpdates(
+      need_encryption_key,
+      session,
+      &client_to_server_message);
+}
+
+SyncerError ConfigureDownloadUpdates(
+    SyncSession* session,
+    bool create_mobile_bookmarks_folder,
+    const syncer::sessions::SyncSourceInfo& source,
+    ModelTypeSet request_types) {
+  sync_pb::ClientToServerMessage client_to_server_message;
+  client_to_server_message.set_share(session->context()->account_name());
+  sync_pb::GetUpdatesMessage* get_updates =
+      InitDownloadUpdatesRequest(&client_to_server_message);
+
+  DebugInfo* debug_info = client_to_server_message.mutable_debug_info();
+  AppendClientDebugInfoIfNeeded(session, debug_info);
+
+  get_updates->set_create_mobile_bookmarks_folder(
+      create_mobile_bookmarks_folder);
+  bool need_encryption_key = ShouldRequestEncryptionKey(session->context());
+  get_updates->set_need_encryption_key(need_encryption_key);
+
+  // Request updates for all enabled types.
+  DVLOG(1) << "Initial download for types "
+           << ModelTypeSetToString(request_types);
+  DCHECK(!request_types.Empty());
+
+  syncable::Directory* dir = session->context()->directory();
+  for (ModelTypeSet::Iterator it = request_types.First();
+       it.Good(); it.Inc()) {
+    if (ProxyTypes().Has(it.Get()))
+      continue;
+
+    sync_pb::DataTypeProgressMarker* progress_marker =
+        get_updates->add_from_progress_marker();
+    dir->GetDownloadProgress(it.Get(), progress_marker);
+  }
+
+  // Set legacy GetUpdatesMessage.GetUpdatesCallerInfo information.
+  get_updates->mutable_caller_info()->set_source(source.updates_source);
+  get_updates->mutable_caller_info()->set_notifications_enabled(
+      session->context()->notifications_enabled());
+
+  // Set the new and improved version of source, too.
+  sync_pb::SyncEnums::GetUpdatesOrigin origin =
+      ConvertConfigureSourceToOrigin(source.updates_source);
+  get_updates->set_get_updates_origin(origin);
+
+  StatusController* status = session->mutable_status_controller();
+  status->set_updates_request_types(request_types);
+  return ExecuteDownloadUpdates(
+      need_encryption_key,
+      session,
+      &client_to_server_message);
+}
+
+SyncerError PollDownloadUpdates(
+    SyncSession* session,
+    bool create_mobile_bookmarks_folder,
+    ModelTypeSet request_types) {
+  sync_pb::ClientToServerMessage client_to_server_message;
+  client_to_server_message.set_share(session->context()->account_name());
+  sync_pb::GetUpdatesMessage* get_updates =
+      InitDownloadUpdatesRequest(&client_to_server_message);
+
+  DebugInfo* debug_info = client_to_server_message.mutable_debug_info();
+  AppendClientDebugInfoIfNeeded(session, debug_info);
+
+  get_updates->set_create_mobile_bookmarks_folder(
+      create_mobile_bookmarks_folder);
+  bool need_encryption_key = ShouldRequestEncryptionKey(session->context());
+  get_updates->set_need_encryption_key(need_encryption_key);
+
+  DVLOG(1) << "Polling for types "
+           << ModelTypeSetToString(request_types);
+  DCHECK(!request_types.Empty());
+
+  syncable::Directory* dir = session->context()->directory();
+  for (ModelTypeSet::Iterator it = request_types.First();
+       it.Good(); it.Inc()) {
+    if (ProxyTypes().Has(it.Get()))
+      continue;
+
+    sync_pb::DataTypeProgressMarker* progress_marker =
+        get_updates->add_from_progress_marker();
+    dir->GetDownloadProgress(it.Get(), progress_marker);
+  }
+
+  DCHECK_EQ(sync_pb::GetUpdatesCallerInfo::PERIODIC,
+            session->source().updates_source);
+
+  // Set legacy GetUpdatesMessage.GetUpdatesCallerInfo information.
+  get_updates->mutable_caller_info()->set_source(
+      sync_pb::GetUpdatesCallerInfo::PERIODIC);
+  get_updates->mutable_caller_info()->set_notifications_enabled(
+      session->context()->notifications_enabled());
+
+  // Set the new and improved version of source, too.
+  get_updates->set_get_updates_origin(sync_pb::SyncEnums::PERIODIC);
+
+  StatusController* status = session->mutable_status_controller();
+  status->set_updates_request_types(request_types);
+  return ExecuteDownloadUpdates(
+      need_encryption_key,
+      session,
+      &client_to_server_message);
+}
+
+void AppendClientDebugInfoIfNeeded(
+    SyncSession* session,
+    DebugInfo* debug_info) {
+  // We want to send the debug info only once per sync cycle. Check if it has
+  // already been sent.
+  if (!session->status_controller().debug_info_sent()) {
+    DVLOG(1) << "Sending client debug info ...";
+    // could be null in some unit tests.
+    if (session->context()->debug_info_getter()) {
+      session->context()->debug_info_getter()->GetAndClearDebugInfo(
+          debug_info);
+    }
+    session->mutable_status_controller()->set_debug_info_sent();
+  }
+}
+
+}  // namespace syncer