Offline pages using NQE 2G Slow

chrome/browser/android/offline_pages/offline_page_tab_helper.cc

 // Copyright 2016 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/android/offline_pages/offline_page_tab_helper.h"
 
 #include "base/bind.h"
 #include "base/logging.h"
 #include "base/memory/ptr_util.h"
 #include "base/metrics/histogram.h"
 #include "base/strings/string_number_conversions.h"
 #include "base/threading/thread_task_runner_handle.h"
+#include "base/time/clock.h"
+#include "base/time/default_clock.h"
+#include "base/time/time.h"
 #include "chrome/browser/android/offline_pages/offline_page_model_factory.h"
 #include "chrome/browser/android/offline_pages/offline_page_utils.h"
+#include "chrome/browser/net/nqe/ui_network_quality_estimator_service.h"
+#include "chrome/browser/net/nqe/ui_network_quality_estimator_service_factory.h"
+#include "chrome/browser/profiles/profile.h"
 #include "components/offline_pages/client_namespace_constants.h"
 #include "components/offline_pages/offline_page_model.h"
+#include "components/previews/previews_experiments.h"
 #include "content/public/browser/browser_thread.h"
 #include "content/public/browser/navigation_controller.h"
 #include "content/public/browser/navigation_entry.h"
 #include "content/public/browser/navigation_handle.h"
 #include "content/public/browser/render_frame_host.h"
 #include "content/public/browser/web_contents.h"
 #include "net/base/net_errors.h"
 #include "net/base/network_change_notifier.h"
+#include "net/nqe/network_quality_estimator.h"
 #include "ui/base/page_transition_types.h"
 
 DEFINE_WEB_CONTENTS_USER_DATA_KEY(offline_pages::OfflinePageTabHelper);
 
 namespace offline_pages {
 namespace {
 
 void ReportAccessedOfflinePage(content::BrowserContext* browser_context,
                                const GURL& navigated_url,
                                const GURL& online_url) {
   // If there is a valid online URL for this navigated URL, then we are looking
   // at an offline page.
   if (online_url.is_valid())
     OfflinePageUtils::MarkPageAccessed(browser_context, navigated_url);
 }
 
+// Whether using offline pages for slow networks is allowed and the network is
+// currently estimated to be prohibitivley slow.
+bool ShouldUseOfflineForSlowNetwork(content::BrowserContext* context) {
+  if (!previews::IsIncludedInOfflinePagesSlowConnectionFieldTrial()) {

[tbansal1, 2016/07/26 20:12:48]

braces not needed :)

[RyanSturm, 2016/07/26 21:48:12]

Done.

+    return false;
+  }
+  Profile* profile = Profile::FromBrowserContext(context);
+  UINetworkQualityEstimatorService* nqe_service =
+      UINetworkQualityEstimatorServiceFactory::GetForProfile(profile);
+  if (!nqe_service)
+    return false;
+  net::NetworkQualityEstimator::EffectiveConnectionType
+      effective_connection_type = nqe_service->GetEffectiveConnectionType();
+  if (effective_connection_type >

[tbansal1, 2016/07/26 20:12:48]

s/>/>=/

[RyanSturm, 2016/07/26 21:48:12]

I'll make the change, but does this differ from NCN::IsOffline?

+          net::NetworkQualityEstimator::EFFECTIVE_CONNECTION_TYPE_OFFLINE &&
+      effective_connection_type <=
+          net::NetworkQualityEstimator::EFFECTIVE_CONNECTION_TYPE_SLOW_2G) {
+    return true;
+  }
+  return false;
+}
+
 class DefaultDelegate : public OfflinePageTabHelper::Delegate {
  public:
   DefaultDelegate() {}
   // offline_pages::OfflinePageTabHelper::Delegate implementation:
   bool GetTabId(content::WebContents* web_contents,
                 std::string* tab_id) const override {
     int temp_tab_id;
     if (!OfflinePageUtils::GetTabId(web_contents, &temp_tab_id))
       return false;
     *tab_id = base::IntToString(temp_tab_id);
     return true;
   }
 };
 }  // namespace
 
 OfflinePageTabHelper::OfflinePageTabHelper(content::WebContents* web_contents)
     : content::WebContentsObserver(web_contents),
       delegate_(new DefaultDelegate()),
+      clock_(new base::DefaultClock),
       weak_ptr_factory_(this) {
   DCHECK(content::BrowserThread::CurrentlyOn(content::BrowserThread::UI));
 }
 
 OfflinePageTabHelper::~OfflinePageTabHelper() {}
 
 void OfflinePageTabHelper::SetDelegateForTesting(
     std::unique_ptr<OfflinePageTabHelper::Delegate> delegate) {
   DCHECK(delegate);
   delegate_ = std::move(delegate);
@@ skipping 19 matching lines @@
   // which are not at the head of the stack.
   // TODO(dimich): Not sure this is needed. Clarify and remove. Bug 624216.
   const content::NavigationController& controller =
       web_contents()->GetController();
   if (controller.GetEntryCount() > 0 &&
       controller.GetCurrentEntryIndex() != -1 &&
       controller.GetCurrentEntryIndex() < controller.GetEntryCount() - 1) {
     return;
   }
 
-  content::BrowserContext* context = web_contents()->GetBrowserContext();
   if (net::NetworkChangeNotifier::IsOffline()) {
     GetPagesForRedirectToOffline(
         RedirectResult::REDIRECTED_ON_DISCONNECTED_NETWORK, navigated_url);
     return;
   }
 
+  content::BrowserContext* context = web_contents()->GetBrowserContext();
+  if (ShouldUseOfflineForSlowNetwork(context)) {
+    GetPagesForRedirectToOffline(
+        RedirectResult::REDIRECTED_ON_PROHIBITVELY_SLOW_NETWORK, navigated_url);
+    return;
+  }
+
   OfflinePageModel* offline_page_model =
       OfflinePageModelFactory::GetForBrowserContext(context);
   if (!offline_page_model)
     return;
 
   offline_page_model->GetPageByOfflineURL(
       navigated_url, base::Bind(&OfflinePageTabHelper::RedirectToOnline,
                                 weak_ptr_factory_.GetWeakPtr(), navigated_url));
 }
 
@@ skipping 77 matching lines @@
       online_url,
       base::Bind(&OfflinePageTabHelper::SelectBestPageForRedirectToOffline,
                  weak_ptr_factory_.GetWeakPtr(), result, online_url));
 }
 
 void OfflinePageTabHelper::SelectBestPageForRedirectToOffline(
     RedirectResult result,
     const GURL& online_url,
     const MultipleOfflinePageItemResult& pages) {
   DCHECK(result == RedirectResult::REDIRECTED_ON_FLAKY_NETWORK ||
-         result == RedirectResult::REDIRECTED_ON_DISCONNECTED_NETWORK);
+         result == RedirectResult::REDIRECTED_ON_DISCONNECTED_NETWORK ||
+         result == RedirectResult::REDIRECTED_ON_PROHIBITVELY_SLOW_NETWORK);
 
   // When there is no valid tab android there is nowhere to show the offline
   // page, so we can leave.
   std::string tab_id;
   if (!delegate_->GetTabId(web_contents(), &tab_id)) {
     ReportRedirectResultUMA(RedirectResult::NO_TAB_ID);
     return;
   }
 
   const OfflinePageItem* selected_page = nullptr;
   for (const auto& offline_page : pages) {
     if ((offline_page.client_id.name_space == kBookmarkNamespace) ||
         (offline_page.client_id.name_space == kAsyncNamespace) ||
         (offline_page.client_id.name_space == kLastNNamespace &&
          offline_page.client_id.id == tab_id)) {
       if (!selected_page ||
           offline_page.creation_time > selected_page->creation_time) {
         selected_page = &offline_page;
       }
     }
   }
 
   if (!selected_page) {
+    switch (result) {
+      case RedirectResult::REDIRECTED_ON_FLAKY_NETWORK:
+        ReportRedirectResultUMA(
+            RedirectResult::PAGE_NOT_FOUND_ON_FLAKY_NETWORK);
+        return;
+      case RedirectResult::REDIRECTED_ON_PROHIBITVELY_SLOW_NETWORK:
+        ReportRedirectResultUMA(
+            RedirectResult::PAGE_NOT_FOUND_ON_PROHIBITVELY_SLOW_NETWORK);
+        return;
+      case RedirectResult::REDIRECTED_ON_DISCONNECTED_NETWORK:
+        ReportRedirectResultUMA(
+            RedirectResult::PAGE_NOT_FOUND_ON_DISCONNECTED_NETWORK);
+        return;
+      default:
+        NOTREACHED();
+        return;
+    }
+  }
+
+  // If the page is being loaded on a slow network, only use the offline page
+  // if it was created within the past day.
+  if (result == RedirectResult::REDIRECTED_ON_PROHIBITVELY_SLOW_NETWORK &&
+      clock_->Now() - selected_page->creation_time >
+          base::TimeDelta::FromDays(1)) {

[tbansal1, 2016/07/26 20:12:48]

Where else is this being "freshness test" done?  Would it make sense to move
"base::TimeDelta::FromDays(1)" to a common const to ensure every body is using
the same duration?

[RyanSturm, 2016/07/26 21:48:12]

We are using 1 day for freshness based on different requirements for slow
networks. The database keeps entries for weeks before evicting them. This is the
only place that 1 day is used for freshness.

[tbansal1, 2016/07/26 21:52:43]

Acknowledged.

     ReportRedirectResultUMA(
-        result == RedirectResult::REDIRECTED_ON_FLAKY_NETWORK ?
-        RedirectResult::PAGE_NOT_FOUND_ON_FLAKY_NETWORK :
-        RedirectResult::PAGE_NOT_FOUND_ON_DISCONNECTED_NETWORK);
+        RedirectResult::PAGE_NOT_FRESH_ON_PROHIBITVELY_SLOW_NETWORK);
     return;
   }
 
   TryRedirectToOffline(result, online_url, *selected_page);
 }
 
 void OfflinePageTabHelper::TryRedirectToOffline(
     RedirectResult result,
     const GURL& from_url,
     const OfflinePageItem& offline_page) {
@@ skipping 26 matching lines @@
   return entry &&
          !entry->GetRedirectChain().empty() &&
          entry->GetRedirectChain().back() == to_url;
 }
 
 void OfflinePageTabHelper::ReportRedirectResultUMA(RedirectResult result) {
   UMA_HISTOGRAM_ENUMERATION("OfflinePages.RedirectResult",
       static_cast<int>(result),
       static_cast<int>(RedirectResult::REDIRECT_RESULT_MAX));
 }
+
+void OfflinePageTabHelper::SetClockForTesting(
+    std::unique_ptr<base::Clock> clock) {
+  clock_ = std::move(clock);
+}
+
 }  // namespace offline_pages