Use a monotonic clock (TimeTicks) to report network times to WebCore.

webkit/glue/weburlloader_impl.cc

Index: webkit/glue/weburlloader_impl.cc
diff --git a/webkit/glue/weburlloader_impl.cc b/webkit/glue/weburlloader_impl.cc
index ad28f41c5bcd7392aa054ca950e2b151e24d6a99..30b0aacceec8e855db0b4d1dd746363a8aa366d1 100644
--- a/webkit/glue/weburlloader_impl.cc
+++ b/webkit/glue/weburlloader_impl.cc
@@ -34,6 +34,7 @@
 
 using base::Time;
 using base::TimeDelta;
+using base::TimeTicks;
 using WebKit::WebData;
 using WebKit::WebHTTPBody;
 using WebKit::WebHTTPHeaderVisitor;
@@ -112,7 +113,8 @@ class HeaderFlattener : public WebHTTPHeaderVisitor {
 bool GetInfoFromDataURL(const GURL& url,
                         ResourceResponseInfo* info,
                         std::string* data,
-                        net::URLRequestStatus* status) {
+                        net::URLRequestStatus* status,
+                        TimeTicks* response_time) {
   std::string mime_type;
   std::string charset;
   if (net::DataURL::Parse(url, &mime_type, &charset, data)) {
@@ -120,6 +122,7 @@ bool GetInfoFromDataURL(const GURL& url,
     // Assure same time for all time fields of data: URLs.
     Time now = Time::Now();
     info->load_timing.base_time = now;
+    info->load_timing.base_ticks = *response_time = TimeTicks::Now();
     info->request_time = now;
     info->response_time = now;
     info->headers = NULL;
@@ -142,6 +145,10 @@ typedef ResourceDevToolsInfo::HeadersVector HeadersVector;
 void PopulateURLResponse(
     const GURL& url,
     const ResourceResponseInfo& info,
+    const TimeTicks& initiation_time,
+    const TimeTicks& start_time,
+    const TimeTicks& end_time,
+    const TimeTicks& callback_time,
     WebURLResponse* response) {
   response->setURL(url);
   response->setResponseTime(info.response_time.ToDoubleT());
@@ -167,20 +174,8 @@ void PopulateURLResponse(
 
   const ResourceLoadTimingInfo& timing_info = info.load_timing;
   if (!timing_info.base_time.is_null()) {
-    WebURLLoadTiming timing;
-    timing.initialize();
-    timing.setRequestTime(timing_info.base_time.ToDoubleT());
-    timing.setProxyStart(timing_info.proxy_start);
-    timing.setProxyEnd(timing_info.proxy_end);
-    timing.setDNSStart(timing_info.dns_start);
-    timing.setDNSEnd(timing_info.dns_end);
-    timing.setConnectStart(timing_info.connect_start);
-    timing.setConnectEnd(timing_info.connect_end);
-    timing.setSSLStart(timing_info.ssl_start);
-    timing.setSSLEnd(timing_info.ssl_end);
-    timing.setSendStart(timing_info.send_start);
-    timing.setSendEnd(timing_info.send_end);
-    timing.setReceiveHeadersEnd(timing_info.receive_headers_end);
+    WebURLLoadTiming timing = PopulateWebURLLoadTiming(
+        timing_info, initiation_time, start_time, end_time, callback_time);
     response->setLoadTiming(timing);
   }
 
@@ -269,9 +264,13 @@ class WebURLLoaderImpl::Context : public base::RefCounted<Context>,
   virtual bool OnReceivedRedirect(
       const GURL& new_url,
       const ResourceResponseInfo& info,
+      const TimeTicks& start_time,
+      const TimeTicks& end_time,
       bool* has_new_first_party_for_cookies,
       GURL* new_first_party_for_cookies);
-  virtual void OnReceivedResponse(const ResourceResponseInfo& info);
+  virtual void OnReceivedResponse(const ResourceResponseInfo& info,
+                                  const TimeTicks& start_time,
+                                  const TimeTicks& end_time);
   virtual void OnDownloadedData(int len);
   virtual void OnReceivedData(const char* data,
                               int data_length,
@@ -279,7 +278,7 @@ class WebURLLoaderImpl::Context : public base::RefCounted<Context>,
   virtual void OnReceivedCachedMetadata(const char* data, int len);
   virtual void OnCompletedRequest(const net::URLRequestStatus& status,
                                   const std::string& security_info,
-                                  const base::Time& completion_time);
+                                  const TimeTicks& completion_time);
 
  private:
   friend class base::RefCounted<Context>;
@@ -292,6 +291,7 @@ class WebURLLoaderImpl::Context : public base::RefCounted<Context>,
   WebURLLoaderImpl* loader_;
   WebURLRequest request_;
   WebURLLoaderClient* client_;
+  TimeTicks initiation_time_;
   scoped_ptr<ResourceLoaderBridge> bridge_;
   scoped_ptr<FtpDirectoryListingResponseDelegate> ftp_listing_delegate_;
   scoped_ptr<MultipartResponseDelegate> multipart_delegate_;
@@ -342,9 +342,12 @@ void WebURLLoaderImpl::Context::Start(
       // This is a sync load. Do the work now.
       sync_load_response->url = url;
       std::string data;
+      TimeTicks response_time;
       GetInfoFromDataURL(sync_load_response->url, sync_load_response,
                          &sync_load_response->data,
-                         &sync_load_response->status);
+                         &sync_load_response->status, &response_time);
+      sync_load_response->start_time = response_time;
+      sync_load_response->end_time = response_time;
     } else {
       AddRef();  // Balanced in OnCompletedRequest
       MessageLoop::current()->PostTask(FROM_HERE,
@@ -452,6 +455,7 @@ void WebURLLoaderImpl::Context::Start(
     bridge_->SetUploadIdentifier(request.httpBody().identifier());
   }
 
+  initiation_time_ = TimeTicks::Now();
   if (sync_load_response) {
     bridge_->SyncLoad(sync_load_response);
     return;
@@ -472,14 +476,18 @@ void WebURLLoaderImpl::Context::OnUploadProgress(uint64 position, uint64 size) {
 bool WebURLLoaderImpl::Context::OnReceivedRedirect(
     const GURL& new_url,
     const ResourceResponseInfo& info,
+    const TimeTicks& start_time,
+    const TimeTicks& end_time,
     bool* has_new_first_party_for_cookies,
     GURL* new_first_party_for_cookies) {
   if (!client_)
     return false;
 
+  TimeTicks callback_time = TimeTicks::Now();
   WebURLResponse response;
   response.initialize();
-  PopulateURLResponse(request_.url(), info, &response);
+  PopulateURLResponse(request_.url(), info, initiation_time_, start_time,
+                      end_time, callback_time, &response);
 
   // TODO(darin): We lack sufficient information to construct the actual
   // request that resulted from the redirect.
@@ -511,13 +519,17 @@ bool WebURLLoaderImpl::Context::OnReceivedRedirect(
 }
 
 void WebURLLoaderImpl::Context::OnReceivedResponse(
-    const ResourceResponseInfo& info) {
+    const ResourceResponseInfo& info,
+    const TimeTicks& start_time,
+    const TimeTicks& end_time) {
   if (!client_)
     return;
 
+  TimeTicks callback_time = TimeTicks::Now();
   WebURLResponse response;
   response.initialize();
-  PopulateURLResponse(request_.url(), info, &response);
+  PopulateURLResponse(request_.url(), info, initiation_time_, start_time,
+                      end_time, callback_time, &response);
 
   bool show_raw_listing = (GURL(request_.url()).query() == "raw");
 
@@ -594,7 +606,9 @@ void WebURLLoaderImpl::Context::OnReceivedCachedMetadata(
 void WebURLLoaderImpl::Context::OnCompletedRequest(
     const net::URLRequestStatus& status,
     const std::string& security_info,
-    const base::Time& completion_time) {
+    const TimeTicks& completion_time) {
+  TimeTicks monotonic_completion_time = std::min(completion_time,
+                                                 TimeTicks::Now());
   if (ftp_listing_delegate_.get()) {
     ftp_listing_delegate_->OnCompletedRequest();
     ftp_listing_delegate_.reset(NULL);
@@ -626,7 +640,9 @@ void WebURLLoaderImpl::Context::OnCompletedRequest(
       error.unreachableURL = request_.url();
       client_->didFail(loader_, error);
     } else {
-      client_->didFinishLoading(loader_, completion_time.ToDoubleT());
+      client_->didFinishLoading(
+          loader_, completion_time.ToInternalValue() /
+          static_cast<double>(base::Time::kMicrosecondsPerSecond));
     }
   }
 
@@ -664,13 +680,15 @@ void WebURLLoaderImpl::Context::HandleDataURL() {
   net::URLRequestStatus status;
   std::string data;
 
-  if (GetInfoFromDataURL(request_.url(), &info, &data, &status)) {
-    OnReceivedResponse(info);
+  TimeTicks response_time;
+  if (GetInfoFromDataURL(request_.url(), &info, &data, &status,
+                         &response_time)) {
+    OnReceivedResponse(info, response_time, response_time);
     if (!data.empty())
       OnReceivedData(data.data(), data.size(), 0);
   }
 
-  OnCompletedRequest(status, info.security_info, base::Time::Now());
+  OnCompletedRequest(status, info.security_info, TimeTicks::Now());
 }
 
 // WebURLLoaderImpl -----------------------------------------------------------
@@ -687,8 +705,10 @@ void WebURLLoaderImpl::loadSynchronously(const WebURLRequest& request,
                                          WebURLResponse& response,
                                          WebURLError& error,
                                          WebData& data) {
+  TimeTicks initiation_time = TimeTicks::Now();
   ResourceLoaderBridge::SyncLoadResponse sync_load_response;
   context_->Start(request, &sync_load_response);
+  TimeTicks completion_time = TimeTicks::Now();
 
   const GURL& final_url = sync_load_response.url;
 
@@ -705,7 +725,9 @@ void WebURLLoaderImpl::loadSynchronously(const WebURLRequest& request,
     return;
   }
 
-  PopulateURLResponse(final_url, sync_load_response, &response);
+  PopulateURLResponse(final_url, sync_load_response, initiation_time,
+                      sync_load_response.start_time,
+                      sync_load_response.end_time, completion_time, &response);
 
   data.assign(sync_load_response.data.data(),
               sync_load_response.data.size());
@@ -731,4 +753,73 @@ void WebURLLoaderImpl::UpdateRoutingId(int new_routing_id) {
   context_->UpdateRoutingId(new_routing_id);
 }
 
+int64 CorrectTime(int64 raw_time, int64 numerator, int64 denominator) {
+  if (raw_time <= 0) {
+    return raw_time;
+  }
+  return numerator * raw_time / denominator;
+}
+
+WebURLLoadTiming PopulateWebURLLoadTiming(

[jar (doing other things), 2011/10/12 01:07:38]

Could you add comments to explain what you are trying to achieve here?

I would expect a lengthy block comment.

[James Simonsen, 2011/10/12 02:57:46]

Done.

+    const ResourceLoadTimingInfo& timing_info,
+    const TimeTicks& initiation_time,
+    const TimeTicks& start_time,
+    const TimeTicks& end_time,
+    const TimeTicks& callback_time) {
+  int64 lower_bound = start_time.ToInternalValue();
+  if (start_time < initiation_time) {
+    lower_bound = initiation_time.ToInternalValue();
+  }
+  int64 upper_bound = end_time.ToInternalValue();
+  if (end_time > callback_time) {
+    upper_bound = callback_time.ToInternalValue();
+  }
+  if (lower_bound > upper_bound) {
+    lower_bound = upper_bound;
+  }
+
+  int64 numerator = upper_bound - lower_bound;
+  int64 denominator = (end_time - start_time).ToInternalValue();
+  if (denominator == 0) {
+    numerator = 0;
+    denominator = 1;
+  }
+
+  int64 adjusted_base =
+      lower_bound +
+      numerator *
+      (timing_info.base_ticks - start_time).ToInternalValue() /
+      denominator;
+
+  WebURLLoadTiming timing;
+  timing.initialize();
+  timing.setRequestTime(
+      adjusted_base /
+      static_cast<double>(base::Time::kMicrosecondsPerSecond));
+  timing.setProxyStart(
+      CorrectTime(timing_info.proxy_start, numerator, denominator));
+  timing.setProxyEnd(
+      CorrectTime(timing_info.proxy_end, numerator, denominator));
+  timing.setDNSStart(
+      CorrectTime(timing_info.dns_start, numerator, denominator));
+  timing.setDNSEnd(
+      CorrectTime(timing_info.dns_end, numerator, denominator));
+  timing.setConnectStart(
+      CorrectTime(timing_info.connect_start, numerator, denominator));
+  timing.setConnectEnd(
+      CorrectTime(timing_info.connect_end, numerator, denominator));
+  timing.setSSLStart(
+      CorrectTime(timing_info.ssl_start, numerator, denominator));
+  timing.setSSLEnd(
+      CorrectTime(timing_info.ssl_end, numerator, denominator));
+  timing.setSendStart(
+      CorrectTime(timing_info.send_start, numerator, denominator));
+  timing.setSendEnd(
+      CorrectTime(timing_info.send_end, numerator, denominator));
+  timing.setReceiveHeadersEnd(
+      CorrectTime(timing_info.receive_headers_end, numerator, denominator));
+
+  return timing;
+}
+
 }  // namespace webkit_glue