Seculative resource prefetching for URLs CL.

chrome/browser/net/resource_prefetch_predictor_observer.cc

+// Copyright (c) 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/net/resource_prefetch_predictor_observer.h"
+
+#include "content/public/browser/browser_thread.h"
+#include "net/url_request/url_request.h"
+
+using content::BrowserThread;
+using predictors::ResourcePrefetchPredictor;
+
+namespace chrome_browser_net {
+
+ResourcePrefetchPredictorObserver::ResourcePrefetchPredictorObserver(
+    ResourcePrefetchPredictor* predictor)
+        : predictor_(predictor->AsWeakPtr()) {
+}
+
+ResourcePrefetchPredictorObserver::~ResourcePrefetchPredictorObserver() {
+}
+
+void ResourcePrefetchPredictorObserver::OnRequestStarted(
+    net::URLRequest* request,
+    ResourceType::Type resource_type,
+    int child_id,
+    int route_id) {
+  CHECK(BrowserThread::CurrentlyOn(BrowserThread::IO));
+
+  if (!ResourcePrefetchPredictor::ShouldRecordRequest(request, resource_type))
+    return;
+
+  ResourcePrefetchPredictor::URLRequestSummary summary;

[dominich, 2012/05/30 15:35:01]

I think it's Chromium-style to create and initialize structs like this but it
makes me really nervous. There's no way to catch uninitialized data with this
style initialization. I would prefer a constructor that takes each of the below
as parameters, though I understand that it would make URLRequestSummary non-POD
(at least until C++11...) and you might need the default constructor for STL use
anyway.

This shouldn't block the CL, I just wanted to rant a bit.

[Shishir, 2012/05/30 18:07:15]

Added a todo to NavigationId to use a constructor with arguments that will lead
to this also being rethought.

+  summary.navigation_id_.render_process_id_ = child_id;
+  summary.navigation_id_.render_view_id_ = route_id;
+  summary.navigation_id_.main_frame_url_ = request->first_party_for_cookies();
+  summary.resource_url_ = request->original_url();
+  summary.resource_type_ = resource_type;
+
+  BrowserThread::PostTask(
+      BrowserThread::UI,
+      FROM_HERE,
+      base::Bind(&ResourcePrefetchPredictor::RecordURLRequest,
+                 predictor_,
+                 summary));
+}
+
+void ResourcePrefetchPredictorObserver::OnRequestRedirected(
+    net::URLRequest* request) {
+  CHECK(BrowserThread::CurrentlyOn(BrowserThread::IO));
+
+  if (!ResourcePrefetchPredictor::ShouldRecordRedirect(request))
+    return;
+  ResourcePrefetchPredictor::URLRequestSummary summary;

[dominich, 2012/05/30 15:35:01]

similar to the above - I prefer a constructor that takes a request and a
boolean, though you'd then need an is_valid() method.

[Shishir, 2012/05/30 18:07:15]

As Above.

+  if (!summary.InitFromURLRequest(request, true))
+    return;
+
+  BrowserThread::PostTask(
+      BrowserThread::UI,
+      FROM_HERE,
+      base::Bind(&ResourcePrefetchPredictor::RecordUrlRedirect,
+                 predictor_,
+                 summary));
+}
+
+void ResourcePrefetchPredictorObserver::OnResponseStarted(
+    net::URLRequest* request) {
+  CHECK(BrowserThread::CurrentlyOn(BrowserThread::IO));
+
+  if (!ResourcePrefetchPredictor::ShouldRecordResponse(request))
+    return;
+  ResourcePrefetchPredictor::URLRequestSummary summary;
+  if (!summary.InitFromURLRequest(request, true))
+    return;
+
+  BrowserThread::PostTask(
+      BrowserThread::UI,
+      FROM_HERE,
+      base::Bind(&ResourcePrefetchPredictor::RecordUrlResponse,
+                 predictor_,
+                 summary));
+}
+
+}  // namespace chrome_browser_net