chrome/browser/net/connect_interceptor.cc

   1 // Copyright (c) 2013 The Chromium Authors. All rights reserved.
   2 // Use of this source code is governed by a BSD-style license that can be
   3 // found in the LICENSE file.
   4
   5 #include "chrome/browser/net/connect_interceptor.h"
   6
   7 #include "chrome/browser/net/predictor.h"
   8 #include "content/public/browser/resource_request_info.h"
   9 #include "content/public/common/resource_type.h"
  10 #include "net/base/load_flags.h"
  11 #include "net/url_request/url_request.h"
  12
  13 namespace chrome_browser_net {
  14
  15 ConnectInterceptor::ConnectInterceptor(Predictor* predictor)
  16     : timed_cache_(base::TimeDelta::FromSeconds(
  17           Predictor::kMaxUnusedSocketLifetimeSecondsWithoutAGet)),
  18       predictor_(predictor) {
  19   DCHECK(predictor);
  20 }
  21
  22 ConnectInterceptor::~ConnectInterceptor() {
  23 }
  24
  25 void ConnectInterceptor::WitnessURLRequest(net::URLRequest* request) {
  26   GURL request_scheme_host(Predictor::CanonicalizeUrl(request->url()));
  27   if (request_scheme_host == GURL::EmptyGURL())
  28     return;
  29
  30   const content::ResourceRequestInfo* info =
  31       content::ResourceRequestInfo::ForRequest(request);
  32   bool is_main_frame = false;
  33   bool is_sub_frame = false;
  34   // TODO(mmenke):  Should the predictor really be fed requests without a
  35   // ResourceRequestInfo?
  36   if (info) {
  37     content::ResourceType resource_type = info->GetResourceType();
  38     is_main_frame = (resource_type == content::RESOURCE_TYPE_MAIN_FRAME);
  39     is_sub_frame = (resource_type == content::RESOURCE_TYPE_SUB_FRAME);
  40   }
  41
  42   // Learn what URLs are likely to be needed during next startup.
  43   predictor_->LearnAboutInitialNavigation(request_scheme_host);
  44
  45   bool redirected_host = false;
  46   if (request->referrer().empty()) {
  47     if (request->url() != request->original_url()) {
  48       // This request was completed with a redirect.
  49       GURL original_scheme_host(request->original_url().GetWithEmptyPath());
  50       if (request_scheme_host != original_scheme_host) {
  51         redirected_host = true;
  52         // Don't learn from redirects that take path as an argument, but do
  53         // learn from short-hand typing entries, such as "cnn.com" redirects to
  54         // "www.cnn.com".  We can't just check for has_path(), as a mere "/"
  55         // will count as a path, so we check that the path is at most a "/"
  56         // (1 character long) to decide the redirect is "definitive" and has no
  57         // significant path.
  58         // TODO(jar): It may be ok to learn from all redirects, as the adaptive
  59         // system will not respond until several identical redirects have taken
  60         // place.  Hence a use of a path (that changes) wouldn't really be
  61         // learned from anyway.
  62         if (request->original_url().path().length() <= 1 &&
  63             timed_cache_.WasRecentlySeen(original_scheme_host)) {
  64           // TODO(jar): These definite redirects could be learned much faster.
  65           predictor_->LearnFromNavigation(original_scheme_host,
  66                                           request_scheme_host);
  67         }
  68       }
  69     }
  70   } else {
  71     GURL referring_scheme_host = GURL(request->referrer()).GetWithEmptyPath();
  72     // Learn about our referring URL, for use in the future.
  73     if (!is_main_frame && timed_cache_.WasRecentlySeen(referring_scheme_host)) {
  74       predictor_->LearnFromNavigation(referring_scheme_host,
  75                                       request_scheme_host);
  76     }
  77     if (referring_scheme_host == request_scheme_host) {
  78       // We've already made any/all predictions when we navigated to the
  79       // referring host, so we can bail out here.
  80       // We don't update the RecentlySeen() time because any preconnections
  81       // need to be made at the first navigation (i.e., when referer was loaded)
  82       // and wouldn't have waited for this current request navigation.
  83       return;
  84     }
  85   }
  86   timed_cache_.SetRecentlySeen(request_scheme_host);
  87
  88   // Subresources for main frames usually get predicted when we detected the
  89   // main frame request - way back in RenderViewHost::Navigate.  So only handle
  90   // predictions now for subresources or for redirected hosts.
  91   if (is_sub_frame || redirected_host) {
  92     predictor_->PredictFrameSubresources(request_scheme_host,
  93                                          request->first_party_for_cookies());
  94   }
  95   return;
  96 }
  97
  98 }  // namespace chrome_browser_net