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
20namespace chrome_browser_net {
21
22void 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
36void 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