Defer syncing TopSites with history until the first tab closure

chrome/browser/win/jumplist.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 "chrome/browser/win/jumplist.h"
 
 #include "base/base_paths.h"
 #include "base/bind.h"
 #include "base/bind_helpers.h"
 #include "base/command_line.h"
@@ skipping 37 matching lines @@
 #include "ui/gfx/image/image_family.h"
 #include "ui/gfx/image/image_skia.h"
 #include "ui/gfx/image/image_skia_rep.h"
 #include "url/gurl.h"
 
 using content::BrowserThread;
 using JumpListData = JumpList::JumpListData;
 
 namespace {
 
+// JumpList "Most Visited" category is forced to sync with the TopSites service
+// only after this number of tabs are closed after Chrome launches.
+constexpr int kTabClosedCountToDelayTopSitesSync = 3;
+
 // The delay before updating the JumpList to prevent update storms.
 constexpr base::TimeDelta kDelayForJumplistUpdate =
     base::TimeDelta::FromMilliseconds(3500);
 
 // The maximum allowed time for JumpListUpdater::BeginUpdate. Updates taking
 // longer than this are discarded to prevent bogging down slow machines.
 constexpr base::TimeDelta kTimeOutForJumplistUpdate =
     base::TimeDelta::FromMilliseconds(500);
 
 // Appends the common switches to each shell link.
@@ skipping 106 matching lines @@
 }  // namespace
 
 JumpList::JumpListData::JumpListData() {}
 
 JumpList::JumpListData::~JumpListData() {}
 
 JumpList::JumpList(Profile* profile)
     : RefcountedKeyedService(content::BrowserThread::GetTaskRunnerForThread(
           content::BrowserThread::UI)),
       profile_(profile),
+      tab_closed_count_(0),
+      initial_most_visited_update_done_(false),
       jumplist_data_(new base::RefCountedData<JumpListData>),
       task_id_(base::CancelableTaskTracker::kBadTaskId),
       update_jumplist_task_runner_(base::CreateCOMSTATaskRunnerWithTraits(
           {base::MayBlock(), base::TaskPriority::USER_VISIBLE,
            base::TaskShutdownBehavior::CONTINUE_ON_SHUTDOWN})),
       delete_jumplisticons_task_runner_(
           base::CreateSequencedTaskRunnerWithTraits(
               {base::MayBlock(), base::TaskPriority::BACKGROUND,
                base::TaskShutdownBehavior::CONTINUE_ON_SHUTDOWN})),
       weak_ptr_factory_(this) {
   DCHECK(Enabled());
   // To update JumpList when a tab is added or removed, we add this object to
   // the observer list of the TabRestoreService class.
   // When we add this object to the observer list, we save the pointer to this
   // TabRestoreService object. This pointer is used when we remove this object
   // from the observer list.
   sessions::TabRestoreService* tab_restore_service =
       TabRestoreServiceFactory::GetForProfile(profile_);
   if (!tab_restore_service)
     return;
 
   app_id_ =
       shell_integration::win::GetChromiumModelIdForProfile(profile_->GetPath());
 
   scoped_refptr<history::TopSites> top_sites =
       TopSitesFactory::GetForProfile(profile_);
   if (top_sites) {
-    // TopSites updates itself after a delay. This is especially noticable when
-    // your profile is empty. Ask TopSites to update itself when jumplist is
-    // initialized.
-    top_sites->SyncWithHistory();
     // Register as TopSitesObserver so that we can update ourselves when the
-    // TopSites changes.
+    // TopSites changes. TopSites updates itself after a delay. This is
+    // especially noticable when your profile is empty.
     top_sites->AddObserver(this);
   }
   tab_restore_service->AddObserver(this);
   pref_change_registrar_.reset(new PrefChangeRegistrar);
   pref_change_registrar_->Init(profile_->GetPrefs());
   pref_change_registrar_->Add(
       prefs::kIncognitoModeAvailability,
       base::Bind(&JumpList::OnIncognitoAvailabilityChanged, this));
 }
 
@@ skipping 36 matching lines @@
 
 void JumpList::ShutdownOnUIThread() {
   DCHECK(CalledOnValidThread());
   Terminate();
 }
 
 void JumpList::OnMostVisitedURLsAvailable(
     const history::MostVisitedURLList& urls) {
   DCHECK(CalledOnValidThread());
 
-  // At most 9 JumpList items can be displayed for the "Most Visited"
+  // At most 5 JumpList items can be displayed for the "Most Visited"
   // category.
-  const int kMostVistedCount = 9;
+  const int kMostVistedCount = 5;
   {
     JumpListData* data = &jumplist_data_->data;
     base::AutoLock auto_lock(data->list_lock_);
     data->most_visited_pages_.clear();
 
     for (size_t i = 0; i < urls.size() && i < kMostVistedCount; i++) {
       const history::MostVisitedURL& url = urls[i];
       scoped_refptr<ShellLinkItem> link = CreateShellLink();
       std::string url_string = url.url.spec();
       base::string16 url_string_wide = base::UTF8ToUTF16(url_string);
@@ skipping 10 matching lines @@
   // Send a query that retrieves the first favicon.
   StartLoadingFavicon();
 }
 
 void JumpList::TabRestoreServiceChanged(sessions::TabRestoreService* service) {
   DCHECK(CalledOnValidThread());
 
   // if we have a pending favicon request, cancel it here (it is out of date).
   CancelPendingUpdate();
 
+  ++tab_closed_count_;
+
   // Initialize the one-shot timer to update the the "Recently Closed" category
   // in a while. If there is already a request queued then cancel it and post
   // the new request. This ensures that JumpList update of the "Recently Closed"
   // category won't happen until there has been a brief quiet period, thus
   // avoiding update storms.
   if (timer_recently_closed_.IsRunning()) {
     timer_recently_closed_.Reset();
   } else {
     timer_recently_closed_.Start(
         FROM_HERE, kDelayForJumplistUpdate,
@@ skipping 191 matching lines @@
   if (timer_most_visited_.IsRunning()) {
     timer_most_visited_.Reset();
   } else {
     timer_most_visited_.Start(
         FROM_HERE, kDelayForJumplistUpdate,
         base::Bind(&JumpList::DeferredTopSitesChanged, base::Unretained(this)));
   }
 }
 
 void JumpList::DeferredTopSitesChanged() {
+  if (tab_closed_count_ < kTabClosedCountToDelayTopSitesSync)
+    return;
+
   scoped_refptr<history::TopSites> top_sites =
       TopSitesFactory::GetForProfile(profile_);
   if (top_sites) {
     top_sites->GetMostVisitedURLs(
         base::Bind(&JumpList::OnMostVisitedURLsAvailable,
                    weak_ptr_factory_.GetWeakPtr()),
         false);
   }
 }
 
 void JumpList::DeferredTabRestoreServiceChanged() {
+  if (tab_closed_count_ < kTabClosedCountToDelayTopSitesSync) {
+    return;
+  } else if (!initial_most_visited_update_done_) {
+    scoped_refptr<history::TopSites> top_sites =
+        TopSitesFactory::GetForProfile(profile_);
+    if (top_sites) {
+      top_sites->SyncWithHistory();
+    }
+    initial_most_visited_update_done_ = true;
+  }
+
   // Create a list of ShellLinkItems from the "Recently Closed" pages.
   // As noted above, we create a ShellLinkItem objects with the following
   // parameters.
   // * arguments
   //   The last URL of the tab object.
   // * title
   //   The title of the last URL.
   // * icon
   //   An empty string. This value is to be updated in OnFaviconDataAvailable().
   const int kRecentlyClosedCount = 3;
@@ skipping 85 matching lines @@
   // For the remaining slots, we allocate 5/8 (i.e., 5 slots if both categories
   // present) to "most-visited" items and 3/8 (i.e., 3 slots if both categories
   // present) to "recently-closed" items, respectively.
   // Nevertheless, if there are not so many items in |recently_closed_pages|,
   // we give the remaining slots to "most-visited" items.
 
   const int kMostVisited = 50;
   const int kRecentlyClosed = 30;
   const int kTotal = kMostVisited + kRecentlyClosed;
 
-  // Adjust the available jumplist slots to account for the category titles.
-  size_t user_max_items_adjusted = jumplist_updater.user_max_items();
-  if (!most_visited_pages.empty())
-    --user_max_items_adjusted;
-  if (!recently_closed_pages.empty())
-    --user_max_items_adjusted;
+  // Adjust the available jumplist slots to account for the two category titles.
+  size_t user_max_items_adjusted = jumplist_updater.user_max_items() - 2;
 
   size_t most_visited_items =
       MulDiv(user_max_items_adjusted, kMostVisited, kTotal);

[gab, 2017/05/12 18:13:35]

Can we just make this 5 and recently closed 3. i.e. stop trying to load-balance?

[chengx, 2017/05/18 00:51:00]

I stopped load-balancing, and limited these two categories to 5 items and 3
items. 

   size_t recently_closed_items = user_max_items_adjusted - most_visited_items;
-  if (recently_closed_pages.size() < recently_closed_items) {
-    most_visited_items += recently_closed_items - recently_closed_pages.size();
-    recently_closed_items = recently_closed_pages.size();
-  }
 
   // Record the desired number of icons to create in this JumpList update.
   int icons_to_create = 0;
 
   // Update the icons for "Most Visisted" category of the JumpList if needed.
   if (most_visited_pages_have_updates) {
     base::FilePath icon_dir_most_visited = GenerateJumplistIconDirName(
         profile_dir, FILE_PATH_LITERAL("MostVisited"));
 
     UpdateIconFiles(icon_dir_most_visited, most_visited_pages,
@@ skipping 85 matching lines @@
           app_id, profile_dir, local_most_visited_pages,
           local_recently_closed_pages, most_visited_pages_have_updates,
           recently_closed_pages_have_updates, incognito_availability)) {
     base::AutoLock auto_lock(data->list_lock_);
     if (most_visited_pages_have_updates)
       data->most_visited_pages_have_updates_ = true;
     if (recently_closed_pages_have_updates)
       data->recently_closed_pages_have_updates_ = true;
   }
 }