1 // Copyright (c) 2011 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/preconnect.h"
6
7 #include "base/logging.h"
8 #include "base/metrics/histogram.h"
9 #include "chrome/browser/profiles/profile.h"
10 #include "content/browser/browser_thread.h"
11 #include "net/base/net_log.h"
12 #include "net/base/ssl_config_service.h"
13 #include "net/http/http_network_session.h"
14 #include "net/http/http_request_info.h"
15 #include "net/http/http_stream_factory.h"
16 #include "net/http/http_transaction_factory.h"
17 #include "net/url_request/url_request_context.h"
18 #include "net/url_request/url_request_context_getter.h"
19
20 namespace chrome_browser_net {
21
PreconnectOnUIThread(const GURL & url,UrlInfo::ResolutionMotivation motivation,int count)22 void PreconnectOnUIThread(
23 const GURL& url,
24 UrlInfo::ResolutionMotivation motivation,
25 int count) {
26 // Prewarm connection to Search URL.
27 BrowserThread::PostTask(
28 BrowserThread::IO,
29 FROM_HERE,
30 NewRunnableFunction(PreconnectOnIOThread, url, motivation,
31 count));
32 return;
33 }
34
35
PreconnectOnIOThread(const GURL & url,UrlInfo::ResolutionMotivation motivation,int count)36 void PreconnectOnIOThread(
37 const GURL& url,
38 UrlInfo::ResolutionMotivation motivation,
39 int count) {
40 net::URLRequestContextGetter* getter = Profile::GetDefaultRequestContext();
41 if (!getter)
42 return;
43 if (!BrowserThread::CurrentlyOn(BrowserThread::IO)) {
44 LOG(DFATAL) << "This must be run only on the IO thread.";
45 return;
46 }
47
48 // We are now commited to doing the async preconnection call.
49 UMA_HISTOGRAM_ENUMERATION("Net.PreconnectMotivation", motivation,
50 UrlInfo::MAX_MOTIVATED);
51
52 net::URLRequestContext* context = getter->GetURLRequestContext();
53 net::HttpTransactionFactory* factory = context->http_transaction_factory();
54 net::HttpNetworkSession* session = factory->GetSession();
55
56 net::HttpRequestInfo request_info;
57 request_info.url = url;
58 request_info.method = "GET";
59 request_info.extra_headers.SetHeader(net::HttpRequestHeaders::kUserAgent,
60 context->GetUserAgent(url));
61 // It almost doesn't matter whether we use net::LOWEST or net::HIGHEST
62 // priority here, as we won't make a request, and will surrender the created
63 // socket to the pool as soon as we can. However, we would like to mark the
64 // speculative socket as such, and IF we use a net::LOWEST priority, and if
65 // a navigation asked for a socket (after us) then it would get our socket,
66 // and we'd get its later-arriving socket, which might make us record that
67 // the speculation didn't help :-/. By using net::HIGHEST, we ensure that
68 // a socket is given to us if "we asked first" and this allows us to mark it
69 // as speculative, and better detect stats (if it gets used).
70 // TODO(jar): histogram to see how often we accidentally use a previously-
71 // unused socket, when a previously used socket was available.
72 request_info.priority = net::HIGHEST;
73
74 // Translate the motivation from UrlRequest motivations to HttpRequest
75 // motivations.
76 switch (motivation) {
77 case UrlInfo::OMNIBOX_MOTIVATED:
78 request_info.motivation = net::HttpRequestInfo::OMNIBOX_MOTIVATED;
79 break;
80 case UrlInfo::LEARNED_REFERAL_MOTIVATED:
81 request_info.motivation = net::HttpRequestInfo::PRECONNECT_MOTIVATED;
82 break;
83 case UrlInfo::SELF_REFERAL_MOTIVATED:
84 case UrlInfo::EARLY_LOAD_MOTIVATED:
85 request_info.motivation = net::HttpRequestInfo::EARLY_LOAD_MOTIVATED;
86 break;
87 default:
88 // Other motivations should never happen here.
89 NOTREACHED();
90 break;
91 }
92
93 // Setup the SSL Configuration.
94 net::SSLConfig ssl_config;
95 session->ssl_config_service()->GetSSLConfig(&ssl_config);
96 if (session->http_stream_factory()->next_protos())
97 ssl_config.next_protos = *session->http_stream_factory()->next_protos();
98
99 // All preconnects should perform EV certificate verification.
100 ssl_config.verify_ev_cert = true;
101
102 net::HttpStreamFactory* http_stream_factory = session->http_stream_factory();
103 http_stream_factory->PreconnectStreams(
104 count, request_info, ssl_config, net::BoundNetLog());
105 }
106
107 } // namespace chrome_browser_net
108