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 <string>
+
+#include "content/public/browser/browser_thread.h"
+#include "content/public/browser/resource_request_info.h"
+#include "net/url_request/url_request.h"
+
+using content::BrowserThread;
+using predictors::ResourcePrefetchPredictor;
+
+namespace {
+
+bool SummarizeResponse(net::URLRequest* response,

[willchan no longer on Chromium, 2012/06/05 01:34:46]

It's weird how you name the URLRequest a "response". It's a request. I recommend
you rename strings appropriately.

[Shishir, 2012/06/06 23:55:33]

Done. There are some subtle differences when the UrlRequest is actually a
response (like mime_type being present). I thought it would be clearer with
this.

+                       ResourcePrefetchPredictor::URLRequestSummary* summary) {
+  const content::ResourceRequestInfo* info =
+      content::ResourceRequestInfo::ForRequest(response);
+  if (!info) {
+    LOG(ERROR) << "No ResourceRequestInfo in response";
+    return false;
+  }
+
+  int render_process_id, render_view_id;
+  if (!info->GetAssociatedRenderView(&render_process_id, &render_view_id)) {
+    LOG(ERROR) << "Could not get RenderViewId from response info.";
+    return false;
+  }
+
+  summary->navigation_id.render_process_id = render_process_id;
+  summary->navigation_id.render_view_id = render_view_id;
+  summary->navigation_id.main_frame_url = response->first_party_for_cookies();
+  summary->navigation_id.creation_time = response->creation_time();
+  summary->resource_url = response->original_url();
+  summary->resource_type = info->GetResourceType();
+  response->GetMimeType(&summary->mime_type);
+  summary->was_cached = response->was_cached();
+
+  // We want to rely on the mime_type to determine the resource type since we
+  // dont want types such as PREFETCH, SUB_RESOURCE, etc.
+  summary->resource_type =
+      ResourcePrefetchPredictor::GetResourceTypeFromMimeType(
+          summary->mime_type,
+          summary->resource_type);
+  return true;
+}
+
+} // namespace
+
+namespace chrome_browser_net {
+
+ResourcePrefetchPredictorObserver::ResourcePrefetchPredictorObserver(
+    ResourcePrefetchPredictor* predictor)
+        : predictor_(predictor->AsWeakPtr()) {
+  CHECK(BrowserThread::CurrentlyOn(BrowserThread::UI));
+}
+
+ResourcePrefetchPredictorObserver::~ResourcePrefetchPredictorObserver() {
+  CHECK(BrowserThread::CurrentlyOn(BrowserThread::IO));

[dominich, 2012/06/06 17:09:09]

Constructed on UI but destroyed on IO?

[Shishir, 2012/06/06 23:55:33]

Yes. Constructed during the profile_io_data construction which happens on IO.
Then it is owned by the ResourceDispatcherHostDelegate which lives on the IO
thread.

+}
+
+void ResourcePrefetchPredictorObserver::OnRequestStarted(
+    net::URLRequest* request,
+    ResourceType::Type resource_type,
+    int child_id,
+    int route_id) {
+  DCHECK(BrowserThread::CurrentlyOn(BrowserThread::IO));
+
+  if (!ResourcePrefetchPredictor::ShouldRecordRequest(request, resource_type))
+    return;
+
+  ResourcePrefetchPredictor::URLRequestSummary summary;
+  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) {
+  DCHECK(BrowserThread::CurrentlyOn(BrowserThread::IO));
+
+  if (!ResourcePrefetchPredictor::ShouldRecordRedirect(request))
+    return;
+  ResourcePrefetchPredictor::URLRequestSummary summary;
+  if (!SummarizeResponse(request, &summary))
+    return;
+
+  BrowserThread::PostTask(
+      BrowserThread::UI,
+      FROM_HERE,
+      base::Bind(&ResourcePrefetchPredictor::RecordUrlRedirect,
+                 predictor_,
+                 summary));
+}
+
+void ResourcePrefetchPredictorObserver::OnResponseStarted(
+    net::URLRequest* request) {
+  DCHECK(BrowserThread::CurrentlyOn(BrowserThread::IO));
+
+  if (!ResourcePrefetchPredictor::ShouldRecordResponse(request))
+    return;
+  ResourcePrefetchPredictor::URLRequestSummary summary;
+  if (!SummarizeResponse(request, &summary))
+    return;
+
+  BrowserThread::PostTask(
+      BrowserThread::UI,
+      FROM_HERE,
+      base::Bind(&ResourcePrefetchPredictor::RecordUrlResponse,
+                 predictor_,
+                 summary));
+}
+
+}  // namespace chrome_browser_net