Enrich fileBrowserPrivate.onFileTransfersUpdated event to support displaying total number of jobs.

chrome/browser/chromeos/extensions/file_manager/event_router.cc

Index: chrome/browser/chromeos/extensions/file_manager/event_router.cc
diff --git a/chrome/browser/chromeos/extensions/file_manager/event_router.cc b/chrome/browser/chromeos/extensions/file_manager/event_router.cc
index c459ccbbff8b4417e23c7db0156a72c8aac4a85e..284586e0829e7c92a80bc02c4cbdfba7fd5e74ac 100644
--- a/chrome/browser/chromeos/extensions/file_manager/event_router.cc
+++ b/chrome/browser/chromeos/extensions/file_manager/event_router.cc
@@ -10,6 +10,7 @@
 #include "base/prefs/pref_change_registrar.h"
 #include "base/prefs/pref_service.h"
 #include "base/stl_util.h"
+#include "base/thread_task_runner_handle.h"
 #include "base/threading/sequenced_worker_pool.h"
 #include "base/values.h"
 #include "chrome/browser/app_mode/app_mode_utils.h"
@@ -61,6 +62,7 @@ namespace file_browser_private = extensions::api::file_browser_private;
 namespace file_manager {
 namespace {
 // Constants for the "transferState" field of onFileTransferUpdated event.
+const char kFileTransferStateAdded[] = "added";
 const char kFileTransferStateStarted[] = "started";
 const char kFileTransferStateInProgress[] = "in_progress";
 const char kFileTransferStateCompleted[] = "completed";
@@ -74,6 +76,14 @@ const int64 kProgressEventFrequencyInMilliseconds = 1000;
 // is kicked.
 const size_t kDirectoryChangeEventMaxDetailInfoSize = 1000;
 
+// This time(millisecond) is used for confirm following event exists.
+const int64 kFileTransferEventDelayTimeInMilliseconds = 500;
+
+// This time(millisecond) is margin for PostDelayedTask.
+// PostDelayedTask do not ensure the specified time to be elapsed. This time
+// is necessary to avoid unexpected discard.
+const int64 kFileTransferEventMarginTimeForDelay = 20;
+
 // Utility function to check if |job_info| is a file uploading job.
 bool IsUploadJob(drive::JobType type) {
   return (type == drive::TYPE_UPLOAD_NEW_FILE ||
@@ -98,6 +108,10 @@ void JobInfoToTransferStatus(
       IsUploadJob(job_info.job_type) ?
       file_browser_private::TRANSFER_TYPE_UPLOAD :
       file_browser_private::TRANSFER_TYPE_DOWNLOAD;
+  DriveIntegrationService* const integration_service =
+      DriveIntegrationServiceFactory::FindForProfile(profile);
+  status->num_total_jobs =
+      integration_service->job_list()->GetJobInfoList().size();

[kinaba, 2014/09/03 05:42:24]

This includes the number of jobs that is not drive::IsActiveFileTransferJobInfo.
Is it fine for your purpose?

[iseki, 2014/09/03 12:29:00]

Done.

   // JavaScript does not have 64-bit integers. Instead we use double, which
   // is in IEEE 754 formant and accurate up to 52-bits in JS, and in practice
   // in C++. Larger values are rounded.
@@ -620,7 +634,10 @@ void EventRouter::OnFileManagerPrefsChanged() {
 
 void EventRouter::OnJobAdded(const drive::JobInfo& job_info) {
   DCHECK(BrowserThread::CurrentlyOn(BrowserThread::UI));
-  OnJobUpdated(job_info);
+  if (!drive::IsActiveFileTransferJobInfo(job_info))
+    return;
+  ScheduleDriveFileTransferEvent(
+      job_info, kFileTransferStateAdded, false /* immediate */);
 }
 
 void EventRouter::OnJobUpdated(const drive::JobInfo& job_info) {
@@ -630,14 +647,13 @@ void EventRouter::OnJobUpdated(const drive::JobInfo& job_info) {
 
   bool is_new_job = (drive_jobs_.find(job_info.job_id) == drive_jobs_.end());
 
+  const std::string status =
+      is_new_job ? kFileTransferStateStarted : kFileTransferStateInProgress;
+
   // Replace with the latest job info.
-  drive_jobs_[job_info.job_id] = DriveJobInfoWithStatus(
-      job_info,
-      is_new_job ? kFileTransferStateStarted : kFileTransferStateInProgress);
+  drive_jobs_[job_info.job_id] = DriveJobInfoWithStatus(job_info, status);
 
-  // Fire event if needed.
-  bool always = is_new_job;
-  SendDriveFileTransferEvent(always);
+  ScheduleDriveFileTransferEvent(job_info, status, false /* immediate */);
 }
 
 void EventRouter::OnJobDone(const drive::JobInfo& job_info,
@@ -646,43 +662,72 @@ void EventRouter::OnJobDone(const drive::JobInfo& job_info,
   if (!drive::IsActiveFileTransferJobInfo(job_info))
     return;
 
-  // Replace with the latest job info.
-  drive_jobs_[job_info.job_id] = DriveJobInfoWithStatus(
-      job_info,
-      error == drive::FILE_ERROR_OK ? kFileTransferStateCompleted
-      : kFileTransferStateFailed);
+  const std::string status = error == drive::FILE_ERROR_OK
+                                 ? kFileTransferStateCompleted
+                                 : kFileTransferStateFailed;
 
-  // Fire event if needed.
-  bool always = true;
-  SendDriveFileTransferEvent(always);
+  ScheduleDriveFileTransferEvent(job_info, status, true /* immediate */);
 
   // Forget about the job.
   drive_jobs_.erase(job_info.job_id);
 }
 
-void EventRouter::SendDriveFileTransferEvent(bool always) {
-  DCHECK(BrowserThread::CurrentlyOn(BrowserThread::UI));
+void EventRouter::ScheduleDriveFileTransferEvent(const drive::JobInfo& job_info,
+                                                 const std::string& status,
+                                                 bool immediate) {
+  // Update next send time.
+  const base::Time now = base::Time::Now();
+  if (immediate) {
+    next_send_file_transfer_event_ = now;
+  } else if (!drive_job_info_for_scheduled_event_) {
+    // The first job is delayed to confirm whether only job or many jobs.
+    next_send_file_transfer_event_ =
+        std::max(now + base::TimeDelta::FromMilliseconds(
+                           kFileTransferEventDelayTimeInMilliseconds),
+                 next_send_file_transfer_event_);
+  }
+
+  // Update the latest event.
+  drive_job_info_for_scheduled_event_.reset(
+      new DriveJobInfoWithStatus(job_info, status));
+
+  // Schedule event.
+  if (next_send_file_transfer_event_ < now) {

[kinaba, 2014/09/03 05:42:24]

<=, rather than <

("immediate" events should fire right now, I think.)

Or, what about something like this?

void Schedule...(...) {
  const bool no_pending_task = !drive_job_info_for_scheduled_event_;
  drive_job_info_for_scheduled_event_.reset(new ...);
  if(immediate) {
    SendDriveFileTransferEvent();
  } else if(no_pending_task) {
    PostDelayedTask(...);
  }
}

void Send...() {
  if(!drive_job_info_for_scheduled_event_)
    return;
  status_list...
  drive_job_info_for_scheduled_event_.reset();
  BroadCastEvent(...);
}

The point is
* SendDriveFileTransferEvent always sends if there is an unflushed event.
* Only ScheduleDriveFileTransferEvent controls the timing logic, in a way that
non-immediate events are delayed for 100ms.

I think doing Post(next_send_time_ - now) every time during the delay as in the
current patch is not quite useful, since all the posted tasks fire at
|next_send_time_|,
but only the first one of them sees non-null drive_job_info_.

[iseki, 2014/09/03 12:29:00]

Done.

+    SendDriveFileTransferEvent();
+  } else {
+    const base::TimeDelta delta = next_send_file_transfer_event_ - now;
+    base::ThreadTaskRunnerHandle::Get()->PostDelayedTask(
+        FROM_HERE,
+        base::Bind(&EventRouter::SendDriveFileTransferEvent,
+                   weak_factory_.GetWeakPtr()),
+        delta);
+  }
+}
 
-  // When |always| flag is not set, we don't send the event until certain
-  // amount of time passes after the previous one. This is to avoid
-  // flooding the IPC between extensions by many onFileTransferUpdated events.
-  if (!ShouldSendProgressEvent(always, &last_file_transfer_event_))
+void EventRouter::SendDriveFileTransferEvent() {
+  const base::Time now = base::Time::Now();
+  if (now < next_send_file_transfer_event_ -
+                base::TimeDelta::FromMilliseconds(
+                    kFileTransferEventMarginTimeForDelay) ||
+      !drive_job_info_for_scheduled_event_) {
     return;
+  }
 
-  // Convert the current |drive_jobs_| to IDL type.
+  // Convert the drive_job_info_for_scheduled_event_ to IDL type.
   std::vector<linked_ptr<file_browser_private::FileTransferStatus> >
       status_list;
-  for (std::map<drive::JobID, DriveJobInfoWithStatus>::iterator
-           iter = drive_jobs_.begin(); iter != drive_jobs_.end(); ++iter) {
-    linked_ptr<file_browser_private::FileTransferStatus> status(
-        new file_browser_private::FileTransferStatus());
-    JobInfoToTransferStatus(profile_,
-                            kFileManagerAppId,
-                            iter->second.status,
-                            iter->second.job_info,
-                            status.get());
-    status_list.push_back(status);
-  }
+
+  linked_ptr<file_browser_private::FileTransferStatus> status(
+      new file_browser_private::FileTransferStatus());
+  JobInfoToTransferStatus(profile_,
+                          kFileManagerAppId,
+                          drive_job_info_for_scheduled_event_->status,
+                          drive_job_info_for_scheduled_event_->job_info,
+                          status.get());
+  status_list.push_back(status);
+
+  drive_job_info_for_scheduled_event_.reset();
+
   BroadcastEvent(
       profile_,
       file_browser_private::OnFileTransfersUpdated::kEventName,