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 "net/base/load_flags.h" 9 #include "net/url_request/url_request.h" 10 11 namespace chrome_browser_net { 12 13 ConnectInterceptor::ConnectInterceptor(Predictor* predictor) 14 : timed_cache_(base::TimeDelta::FromSeconds( 15 Predictor::kMaxUnusedSocketLifetimeSecondsWithoutAGet)), 16 predictor_(predictor) { 17 DCHECK(predictor); 18 } 19 20 ConnectInterceptor::~ConnectInterceptor() { 21 } 22 23 void ConnectInterceptor::WitnessURLRequest(net::URLRequest* request) { 24 GURL request_scheme_host(Predictor::CanonicalizeUrl(request->url())); 25 if (request_scheme_host == GURL::EmptyGURL()) 26 return; 27 28 // Learn what URLs are likely to be needed during next startup. 29 predictor_->LearnAboutInitialNavigation(request_scheme_host); 30 31 bool redirected_host = false; 32 bool is_subresource = !(request->load_flags() & net::LOAD_MAIN_FRAME); 33 if (request->referrer().empty()) { 34 if (request->url() != request->original_url()) { 35 // This request was completed with a redirect. 36 GURL original_scheme_host(request->original_url().GetWithEmptyPath()); 37 if (request_scheme_host != original_scheme_host) { 38 redirected_host = true; 39 // Don't learn from redirects that take path as an argument, but do 40 // learn from short-hand typing entries, such as "cnn.com" redirects to 41 // "www.cnn.com". We can't just check for has_path(), as a mere "/" 42 // will count as a path, so we check that the path is at most a "/" 43 // (1 character long) to decide the redirect is "definitive" and has no 44 // significant path. 45 // TODO(jar): It may be ok to learn from all redirects, as the adaptive 46 // system will not respond until several identical redirects have taken 47 // place. Hence a use of a path (that changes) wouldn't really be 48 // learned from anyway. 49 if (request->original_url().path().length() <= 1 && 50 timed_cache_.WasRecentlySeen(original_scheme_host)) { 51 // TODO(jar): These definite redirects could be learned much faster. 52 predictor_->LearnFromNavigation(original_scheme_host, 53 request_scheme_host); 54 } 55 } 56 } 57 } else { 58 GURL referring_scheme_host = GURL(request->referrer()).GetWithEmptyPath(); 59 // Learn about our referring URL, for use in the future. 60 if (is_subresource && timed_cache_.WasRecentlySeen(referring_scheme_host)) 61 predictor_->LearnFromNavigation(referring_scheme_host, 62 request_scheme_host); 63 if (referring_scheme_host == request_scheme_host) { 64 // We've already made any/all predictions when we navigated to the 65 // referring host, so we can bail out here. 66 // We don't update the RecentlySeen() time because any preconnections 67 // need to be made at the first navigation (i.e., when referer was loaded) 68 // and wouldn't have waited for this current request navigation. 69 return; 70 } 71 } 72 timed_cache_.SetRecentlySeen(request_scheme_host); 73 74 // Subresources for main frames usually get predicted when we detected the 75 // main frame request - way back in RenderViewHost::Navigate. So only handle 76 // predictions now for subresources or for redirected hosts. 77 if ((request->load_flags() & net::LOAD_SUB_FRAME) || redirected_host) 78 predictor_->PredictFrameSubresources(request_scheme_host, 79 request->first_party_for_cookies()); 80 return; 81 } 82 83 } // namespace chrome_browser_net 84