sync: Expose sync functionality as functions

sync/engine/syncer.cc

Index: sync/engine/syncer.cc
diff --git a/sync/engine/syncer.cc b/sync/engine/syncer.cc
index c4ef67155019cf359358022bc5a2071179b96eff..9b1adb3791e0c84f5ea4a0c26d54a5f88a91cb5b 100644
--- a/sync/engine/syncer.cc
+++ b/sync/engine/syncer.cc
@@ -15,13 +15,13 @@
 #include "sync/engine/build_commit_command.h"
 #include "sync/engine/commit.h"
 #include "sync/engine/conflict_resolver.h"
-#include "sync/engine/download_updates_command.h"
+#include "sync/engine/download.h"
 #include "sync/engine/net/server_connection_manager.h"
 #include "sync/engine/process_commit_response_command.h"
-#include "sync/engine/process_updates_command.h"
-#include "sync/engine/store_timestamps_command.h"
 #include "sync/engine/syncer_types.h"
 #include "sync/internal_api/public/base/unique_position.h"
+#include "sync/internal_api/public/util/syncer_error.h"
+#include "sync/sessions/nudge_tracker.h"
 #include "sync/syncable/mutable_entry.h"
 #include "sync/syncable/syncable-inl.h"
 
@@ -31,35 +31,17 @@ using sync_pb::ClientCommand;
 
 namespace syncer {
 
+// TODO(akalin): We may want to propagate this switch up
+// eventually.
+#if defined(OS_ANDROID) || defined(OS_IOS)
+static const bool kCreateMobileBookmarksFolder = true;
+#else
+static const bool kCreateMobileBookmarksFolder = false;
+#endif
+
 using sessions::StatusController;
 using sessions::SyncSession;
-using syncable::IS_UNAPPLIED_UPDATE;
-using syncable::SERVER_CTIME;
-using syncable::SERVER_IS_DEL;
-using syncable::SERVER_IS_DIR;
-using syncable::SERVER_MTIME;
-using syncable::SERVER_NON_UNIQUE_NAME;
-using syncable::SERVER_PARENT_ID;
-using syncable::SERVER_SPECIFICS;
-using syncable::SERVER_UNIQUE_POSITION;
-using syncable::SERVER_VERSION;
-
-#define ENUM_CASE(x) case x: return #x
-const char* SyncerStepToString(const SyncerStep step)
-{
-  switch (step) {
-    ENUM_CASE(SYNCER_BEGIN);
-    ENUM_CASE(DOWNLOAD_UPDATES);
-    ENUM_CASE(PROCESS_UPDATES);
-    ENUM_CASE(STORE_TIMESTAMPS);
-    ENUM_CASE(APPLY_UPDATES);
-    ENUM_CASE(COMMIT);
-    ENUM_CASE(SYNCER_END);
-  }
-  NOTREACHED();
-  return "";
-}
-#undef ENUM_CASE
+using sessions::NudgeTracker;
 
 Syncer::Syncer()
     : early_exit_requested_(false) {
@@ -77,121 +59,100 @@ void Syncer::RequestEarlyExit() {
   early_exit_requested_ = true;
 }
 
-bool Syncer::SyncShare(sessions::SyncSession* session,
-                       SyncerStep first_step,
-                       SyncerStep last_step) {
+bool Syncer::NormalSyncShare(ModelTypeSet request_types,
+                             const NudgeTracker& nudge_tracker,
+                             SyncSession* session) {
+  HandleCycleBegin(session);
+  VLOG(1) << "Downloading types " << ModelTypeSetToString(request_types);
+  if (!DownloadAndApplyUpdates(
+          session,
+          base::Bind(&NormalDownloadUpdates,
+                     session,
+                     kCreateMobileBookmarksFolder,
+                     request_types,
+                     base::ConstRef(nudge_tracker)))) {
+    return HandleCycleEnd(session);
+  }
+
+  VLOG(1) << "Committing from types " << ModelTypeSetToString(request_types);
+  SyncerError commit_result = BuildAndPostCommits(request_types, this, session);
+  session->mutable_status_controller()->set_commit_result(commit_result);
+
+  return HandleCycleEnd(session);
+}
+
+bool Syncer::ConfigureSyncShare(ModelTypeSet request_types,
+                                SyncSession* session) {
+  HandleCycleBegin(session);
+  VLOG(1) << "Configuring types " << ModelTypeSetToString(request_types);
+  DownloadAndApplyUpdates(
+      session,
+      base::Bind(&DownloadUpdatesForConfigure,
+                 session,
+                 kCreateMobileBookmarksFolder,
+                 session->source(),
+                 request_types));
+  return HandleCycleEnd(session);
+}
+
+bool Syncer::PollSyncShare(ModelTypeSet request_types,
+                           SyncSession* session) {
+  HandleCycleBegin(session);
+  VLOG(1) << "Polling types " << ModelTypeSetToString(request_types);
+  DownloadAndApplyUpdates(
+      session,
+      base::Bind(&DownloadUpdatesForPoll,
+                 session,
+                 kCreateMobileBookmarksFolder,
+                 request_types));
+  return HandleCycleEnd(session);
+}
+
+void Syncer::ApplyUpdates(SyncSession* session) {
+  TRACE_EVENT0("sync", "ApplyUpdates");
+
+  ApplyControlDataUpdates(session);
+
+  ApplyUpdatesAndResolveConflictsCommand apply_updates;
+  apply_updates.Execute(session);
+
+  session->context()->set_hierarchy_conflict_detected(
+      session->status_controller().num_hierarchy_conflicts() > 0);
+
+  session->SendEventNotification(SyncEngineEvent::STATUS_CHANGED);
+}
+
+bool Syncer::DownloadAndApplyUpdates(
+    SyncSession* session,
+    base::Callback<SyncerError(void)> download_fn) {
+  while (!session->status_controller().ServerSaysNothingMoreToDownload()) {
+    SyncerError download_result = download_fn.Run();
+    session->mutable_status_controller()->set_last_download_updates_result(
+        download_result);
+    if (download_result != SYNCER_OK) {
+      return false;
+    }
+  }
+  if (ExitRequested())
+    return false;
+  ApplyUpdates(session);
+  if (ExitRequested())
+    return false;
+  return true;
+}
+
+void Syncer::HandleCycleBegin(SyncSession* session) {
   session->mutable_status_controller()->UpdateStartTime();
-  SyncerStep current_step = first_step;
-
-  SyncerStep next_step = current_step;
-  while (!ExitRequested()) {
-    TRACE_EVENT1("sync", "SyncerStateMachine",
-                 "state", SyncerStepToString(current_step));
-    DVLOG(1) << "Syncer step:" << SyncerStepToString(current_step);
-
-    switch (current_step) {
-      case SYNCER_BEGIN:
-        session->SendEventNotification(SyncEngineEvent::SYNC_CYCLE_BEGIN);
-
-        next_step = DOWNLOAD_UPDATES;
-        break;
-      case DOWNLOAD_UPDATES: {
-        // TODO(akalin): We may want to propagate this switch up
-        // eventually.
-#if defined(OS_ANDROID) || defined(OS_IOS)
-        const bool kCreateMobileBookmarksFolder = true;
-#else
-        const bool kCreateMobileBookmarksFolder = false;
-#endif
-        DownloadUpdatesCommand download_updates(kCreateMobileBookmarksFolder);
-        session->mutable_status_controller()->set_last_download_updates_result(
-            download_updates.Execute(session));
-        next_step = PROCESS_UPDATES;
-        break;
-      }
-      case PROCESS_UPDATES: {
-        ProcessUpdatesCommand process_updates;
-        process_updates.Execute(session);
-        next_step = STORE_TIMESTAMPS;
-        break;
-      }
-      case STORE_TIMESTAMPS: {
-        StoreTimestampsCommand store_timestamps;
-        store_timestamps.Execute(session);
-        session->SendEventNotification(SyncEngineEvent::STATUS_CHANGED);
-        // We download all of the updates before attempting to apply them.
-        if (!session->status_controller().download_updates_succeeded()) {
-          // We may have downloaded some updates, but if the latest download
-          // attempt failed then we don't have all the updates.  We'll leave
-          // it to a retry job to pick up where we left off.
-          last_step = SYNCER_END; // Necessary for CONFIGURATION mode.
-          next_step = SYNCER_END;
-          DVLOG(1) << "Aborting sync cycle due to download updates failure";
-        } else if (!session->status_controller()
-                       .ServerSaysNothingMoreToDownload()) {
-          next_step = DOWNLOAD_UPDATES;
-        } else {
-          next_step = APPLY_UPDATES;
-        }
-        break;
-      }
-      case APPLY_UPDATES: {
-        // These include encryption updates that should be applied early.
-        ApplyControlDataUpdates(session);
-
-        ApplyUpdatesAndResolveConflictsCommand apply_updates;
-        apply_updates.Execute(session);
-
-        session->context()->set_hierarchy_conflict_detected(
-            session->status_controller().num_hierarchy_conflicts() > 0);
-
-        session->SendEventNotification(SyncEngineEvent::STATUS_CHANGED);
-        if (last_step == APPLY_UPDATES) {
-          // We're in configuration mode, but we still need to run the
-          // SYNCER_END step.
-          last_step = SYNCER_END;
-          next_step = SYNCER_END;
-        } else {
-          next_step = COMMIT;
-        }
-        break;
-      }
-      case COMMIT: {
-        session->mutable_status_controller()->set_commit_result(
-            BuildAndPostCommits(this, session));
-        next_step = SYNCER_END;
-        break;
-      }
-      case SYNCER_END: {
-        session->SendEventNotification(SyncEngineEvent::SYNC_CYCLE_ENDED);
-        next_step = SYNCER_END;
-        break;
-      }
-      default:
-        LOG(ERROR) << "Unknown command: " << current_step;
-    }  // switch
-    DVLOG(2) << "last step: " << SyncerStepToString(last_step) << ", "
-             << "current step: " << SyncerStepToString(current_step) << ", "
-             << "next step: " << SyncerStepToString(next_step) << ", "
-             << "snapshot: " << session->TakeSnapshot().ToString();
-    if (last_step == current_step)
-      return true;
-    current_step = next_step;
-  }  // while
-  return false;
+  session->SendEventNotification(SyncEngineEvent::SYNC_CYCLE_BEGIN);
 }
 
-void CopyServerFields(syncable::Entry* src, syncable::MutableEntry* dest) {
-  dest->Put(SERVER_NON_UNIQUE_NAME, src->Get(SERVER_NON_UNIQUE_NAME));
-  dest->Put(SERVER_PARENT_ID, src->Get(SERVER_PARENT_ID));
-  dest->Put(SERVER_MTIME, src->Get(SERVER_MTIME));
-  dest->Put(SERVER_CTIME, src->Get(SERVER_CTIME));
-  dest->Put(SERVER_VERSION, src->Get(SERVER_VERSION));
-  dest->Put(SERVER_IS_DIR, src->Get(SERVER_IS_DIR));
-  dest->Put(SERVER_IS_DEL, src->Get(SERVER_IS_DEL));
-  dest->Put(IS_UNAPPLIED_UPDATE, src->Get(IS_UNAPPLIED_UPDATE));
-  dest->Put(SERVER_SPECIFICS, src->Get(SERVER_SPECIFICS));
-  dest->Put(SERVER_UNIQUE_POSITION, src->Get(SERVER_UNIQUE_POSITION));
+bool Syncer::HandleCycleEnd(SyncSession* session) {
+  if (!ExitRequested()) {
+    session->SendEventNotification(SyncEngineEvent::SYNC_CYCLE_ENDED);
+    return true;
+  } else {
+    return false;
+  }
 }
 
 }  // namespace syncer