chrome/browser/sync/glue/frontend_data_type_controller.cc

// Copyright (c) 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 "chrome/browser/sync/glue/frontend_data_type_controller.h"

#include "base/logging.h"
#include "chrome/browser/profiles/profile.h"
#include "chrome/browser/sync/glue/change_processor.h"
#include "chrome/browser/sync/glue/chrome_report_unrecoverable_error.h"
#include "chrome/browser/sync/glue/model_associator.h"
#include "chrome/browser/sync/profile_sync_components_factory.h"
#include "chrome/browser/sync/profile_sync_service.h"
#include "content/public/browser/browser_thread.h"
#include "sync/api/sync_error.h"
#include "sync/internal_api/public/base/model_type.h"
#include "sync/util/data_type_histogram.h"

using content::BrowserThread;

namespace browser_sync {

FrontendDataTypeController::FrontendDataTypeController(
    ProfileSyncComponentsFactory* profile_sync_factory,
    Profile* profile,
    ProfileSyncService* sync_service)
    : profile_sync_factory_(profile_sync_factory),
      profile_(profile),
      sync_service_(sync_service),
      state_(NOT_RUNNING) {
  DCHECK(BrowserThread::CurrentlyOn(BrowserThread::UI));
  DCHECK(profile_sync_factory);
  DCHECK(profile);
  DCHECK(sync_service);
}

void FrontendDataTypeController::LoadModels(
    const ModelLoadCallback& model_load_callback) {
  DCHECK(BrowserThread::CurrentlyOn(BrowserThread::UI));
  DCHECK(!model_load_callback.is_null());

  if (state_ != NOT_RUNNING) {
    model_load_callback.Run(type(),
                            syncer::SyncError(FROM_HERE,
                                              syncer::SyncError::DATATYPE_ERROR,
                                              "Model already running",
                                              type()));
    return;
  }

  DCHECK(model_load_callback_.is_null());

  model_load_callback_ = model_load_callback;
  state_ = MODEL_STARTING;
  if (!StartModels()) {
    // If we are waiting for some external service to load before associating
    // or we failed to start the models, we exit early. state_ will control
    // what we perform next.
    DCHECK(state_ == NOT_RUNNING || state_ == MODEL_STARTING);
    return;
  }

  OnModelLoaded();
}

void FrontendDataTypeController::OnModelLoaded() {
  DCHECK(BrowserThread::CurrentlyOn(BrowserThread::UI));
  DCHECK(!model_load_callback_.is_null());
  DCHECK_EQ(state_, MODEL_STARTING);

  state_ = MODEL_LOADED;
  ModelLoadCallback model_load_callback = model_load_callback_;
  model_load_callback_.Reset();
  model_load_callback.Run(type(), syncer::SyncError());
}

void FrontendDataTypeController::StartAssociating(
    const StartCallback& start_callback) {
  DCHECK(BrowserThread::CurrentlyOn(BrowserThread::UI));
  DCHECK(!start_callback.is_null());
  DCHECK(start_callback_.is_null());
  DCHECK_EQ(state_, MODEL_LOADED);

  start_callback_ = start_callback;
  state_ = ASSOCIATING;
  if (!Associate()) {
    // We failed to associate and are aborting.
    DCHECK(state_ == DISABLED || state_ == NOT_RUNNING);
    return;
  }
  DCHECK_EQ(state_, RUNNING);
}

void FrontendDataTypeController::Stop() {
  DCHECK(BrowserThread::CurrentlyOn(BrowserThread::UI));

  State prev_state = state_;
  state_ = STOPPING;

  // If Stop() is called while Start() is waiting for the datatype model to
  // load, abort the start.
  if (prev_state == MODEL_STARTING) {
    AbortModelLoad();
    // We can just return here since we haven't performed association if we're
    // still in MODEL_STARTING.
    return;
  }
  DCHECK(start_callback_.is_null());

  CleanUpState();

  sync_service_->DeactivateDataType(type());

  if (model_associator()) {
    syncer::SyncError error;  // Not used.
    error = model_associator()->DisassociateModels();
  }

  set_model_associator(NULL);
  change_processor_.reset();

  state_ = NOT_RUNNING;
}

syncer::ModelSafeGroup FrontendDataTypeController::model_safe_group()
    const {
  return syncer::GROUP_UI;
}

std::string FrontendDataTypeController::name() const {
  // For logging only.
  return syncer::ModelTypeToString(type());
}

DataTypeController::State FrontendDataTypeController::state() const {
  return state_;
}

void FrontendDataTypeController::OnSingleDatatypeUnrecoverableError(
    const tracked_objects::Location& from_here, const std::string& message) {
  RecordUnrecoverableError(from_here, message);
  sync_service_->DisableBrokenDatatype(type(), from_here, message);
}

FrontendDataTypeController::FrontendDataTypeController()
    : profile_sync_factory_(NULL),
      profile_(NULL),
      sync_service_(NULL),
      state_(NOT_RUNNING) {
}

FrontendDataTypeController::~FrontendDataTypeController() {
  DCHECK(BrowserThread::CurrentlyOn(BrowserThread::UI));
}

bool FrontendDataTypeController::StartModels() {
  DCHECK_EQ(state_, MODEL_STARTING);
  // By default, no additional services need to be started before we can proceed
  // with model association.
  return true;
}

bool FrontendDataTypeController::Associate() {
  DCHECK_EQ(state_, ASSOCIATING);
  syncer::SyncMergeResult local_merge_result(type());
  syncer::SyncMergeResult syncer_merge_result(type());
  CreateSyncComponents();
  if (!model_associator()->CryptoReadyIfNecessary()) {
    StartDone(NEEDS_CRYPTO, local_merge_result, syncer_merge_result);
    return false;
  }

  bool sync_has_nodes = false;
  if (!model_associator()->SyncModelHasUserCreatedNodes(&sync_has_nodes)) {
    syncer::SyncError error(FROM_HERE,
                            syncer::SyncError::UNRECOVERABLE_ERROR,
                            "Failed to load sync nodes",
                            type());
    local_merge_result.set_error(error);
    StartDone(UNRECOVERABLE_ERROR, local_merge_result, syncer_merge_result);
    return false;
  }

  // TODO(zea): Have AssociateModels fill the local and syncer merge results.
  base::TimeTicks start_time = base::TimeTicks::Now();
  syncer::SyncError error;
  error = model_associator()->AssociateModels(
      &local_merge_result,
      &syncer_merge_result);
  // TODO(lipalani): crbug.com/122690 - handle abort.
  RecordAssociationTime(base::TimeTicks::Now() - start_time);
  if (error.IsSet()) {
    local_merge_result.set_error(error);
    StartDone(ASSOCIATION_FAILED, local_merge_result, syncer_merge_result);
    return false;
  }

  sync_service_->ActivateDataType(type(), model_safe_group(),
                                  change_processor());
  state_ = RUNNING;
  // FinishStart() invokes the DataTypeManager callback, which can lead to a
  // call to Stop() if one of the other data types being started generates an
  // error.
  StartDone(!sync_has_nodes ? OK_FIRST_RUN : OK,
            local_merge_result,
            syncer_merge_result);
  // Return false if we're not in the RUNNING state (due to Stop() being called
  // from FinishStart()).
  // TODO(zea/atwilson): Should we maybe move the call to FinishStart() out of
  // Associate() and into Start(), so we don't need this logic here? It seems
  // cleaner to call FinishStart() from Start().
  return state_ == RUNNING;
}

void FrontendDataTypeController::CleanUpState() {
  // Do nothing by default.
}

void FrontendDataTypeController::CleanUp() {
  CleanUpState();
  set_model_associator(NULL);
  change_processor_.reset();
}

void FrontendDataTypeController::AbortModelLoad() {
  DCHECK(BrowserThread::CurrentlyOn(BrowserThread::UI));
  CleanUp();
  state_ = NOT_RUNNING;
  ModelLoadCallback model_load_callback = model_load_callback_;
  model_load_callback_.Reset();
  model_load_callback.Run(type(),
                          syncer::SyncError(FROM_HERE,
                                            syncer::SyncError::DATATYPE_ERROR,
                                            "Aborted",
                                            type()));
}

void FrontendDataTypeController::StartDone(
    StartResult start_result,
    const syncer::SyncMergeResult& local_merge_result,
    const syncer::SyncMergeResult& syncer_merge_result) {
  DCHECK(BrowserThread::CurrentlyOn(BrowserThread::UI));
  if (!IsSuccessfulResult(start_result)) {
    if (IsUnrecoverableResult(start_result))
      RecordUnrecoverableError(FROM_HERE, "StartFailed");

    CleanUp();
    if (start_result == ASSOCIATION_FAILED) {
      state_ = DISABLED;
    } else {
      state_ = NOT_RUNNING;
    }
    RecordStartFailure(start_result);
  }

  // We have to release the callback before we call it, since it's possible
  // invoking the callback will trigger a call to STOP(), which will get
  // confused by the non-NULL start_callback_.
  StartCallback callback = start_callback_;
  start_callback_.Reset();
  callback.Run(start_result, local_merge_result, syncer_merge_result);
}

void FrontendDataTypeController::RecordAssociationTime(base::TimeDelta time) {
  DCHECK(BrowserThread::CurrentlyOn(BrowserThread::UI));
#define PER_DATA_TYPE_MACRO(type_str) \
    UMA_HISTOGRAM_TIMES("Sync." type_str "AssociationTime", time);
  SYNC_DATA_TYPE_HISTOGRAM(type());
#undef PER_DATA_TYPE_MACRO
}

void FrontendDataTypeController::RecordStartFailure(StartResult result) {
  DCHECK(BrowserThread::CurrentlyOn(BrowserThread::UI));
  UMA_HISTOGRAM_ENUMERATION("Sync.DataTypeStartFailures",
                            ModelTypeToHistogramInt(type()),
                            syncer::MODEL_TYPE_COUNT);
#define PER_DATA_TYPE_MACRO(type_str) \
    UMA_HISTOGRAM_ENUMERATION("Sync." type_str "StartFailure", result, \
                              MAX_START_RESULT);
  SYNC_DATA_TYPE_HISTOGRAM(type());
#undef PER_DATA_TYPE_MACRO
}

AssociatorInterface* FrontendDataTypeController::model_associator() const {
  return model_associator_.get();
}

void FrontendDataTypeController::set_model_associator(
    AssociatorInterface* model_associator) {
  model_associator_.reset(model_associator);
}

ChangeProcessor* FrontendDataTypeController::change_processor() const {
  return change_processor_.get();
}

void FrontendDataTypeController::set_change_processor(
    ChangeProcessor* change_processor) {
  change_processor_.reset(change_processor);
}

}  // namespace browser_sync