chrome/browser/sync/glue/history_model_worker.cc

   1 // Copyright (c) 2012 The Chromium Authors. All rights reserved.
   2 // Use of this source code is governed by a BSD-style license that can be
   3 // found in the LICENSE file.
   4
   5 #include "chrome/browser/sync/glue/history_model_worker.h"
   6
   7 #include "base/memory/ref_counted.h"
   8 #include "base/message_loop.h"
   9 #include "base/synchronization/waitable_event.h"
  10 #include "chrome/browser/history/history.h"
  11 #include "content/public/browser/browser_thread.h"
  12
  13 using base::WaitableEvent;
  14 using content::BrowserThread;
  15
  16 namespace browser_sync {
  17
  18 class WorkerTask : public HistoryDBTask {
  19  public:
  20   WorkerTask(
  21       const syncer::WorkCallback& work,
  22       WaitableEvent* done,
  23       syncer::SyncerError* error)
  24     : work_(work), done_(done), error_(error) {}
  25
  26   virtual bool RunOnDBThread(history::HistoryBackend* backend,
  27                              history::HistoryDatabase* db) {
  28     *error_ = work_.Run();
  29     done_->Signal();
  30     return true;
  31   }
  32
  33   // Since the DoWorkAndWaitUntilDone() is syncronous, we don't need to run any
  34   // code asynchronously on the main thread after completion.
  35   virtual void DoneRunOnMainThread() {}
  36
  37  protected:
  38   virtual ~WorkerTask() {}
  39
  40   syncer::WorkCallback work_;
  41   WaitableEvent* done_;
  42   syncer::SyncerError* error_;
  43 };
  44
  45 namespace {
  46
  47 // Post the work task on |history_service|'s DB thread from the UI
  48 // thread.
  49 void PostWorkerTask(const base::WeakPtr<HistoryService>& history_service,
  50                     const syncer::WorkCallback& work,
  51                     CancelableRequestConsumerT<int, 0>* cancelable_consumer,
  52                     WaitableEvent* done,
  53                     syncer::SyncerError* error) {
  54   DCHECK(BrowserThread::CurrentlyOn(BrowserThread::UI));
  55   if (history_service.get()) {
  56     scoped_refptr<WorkerTask> task(new WorkerTask(work, done, error));
  57     history_service->ScheduleDBTask(task.get(), cancelable_consumer);
  58   } else {
  59     *error = syncer::CANNOT_DO_WORK;
  60     done->Signal();
  61   }
  62 }
  63
  64 }  // namespace
  65
  66 HistoryModelWorker::HistoryModelWorker(
  67     const base::WeakPtr<HistoryService>& history_service)
  68   : history_service_(history_service) {
  69   CHECK(history_service.get());
  70 }
  71
  72 syncer::SyncerError HistoryModelWorker::DoWorkAndWaitUntilDone(
  73     const syncer::WorkCallback& work) {
  74   syncer::SyncerError error = syncer::UNSET;
  75   WaitableEvent done(false, false);
  76   if (BrowserThread::PostTask(BrowserThread::UI, FROM_HERE,
  77                               base::Bind(&PostWorkerTask,
  78                                          history_service_, work,
  79                                          &cancelable_consumer_,
  80                                          &done, &error))) {
  81     done.Wait();
  82   } else {
  83     error = syncer::CANNOT_DO_WORK;
  84   }
  85   return error;
  86 }
  87
  88 syncer::ModelSafeGroup HistoryModelWorker::GetModelSafeGroup() {
  89   return syncer::GROUP_HISTORY;
  90 }
  91
  92 HistoryModelWorker::~HistoryModelWorker() {}
  93
  94 }  // namespace browser_sync