proxy_advisor.cc revision a02191e04bc25c4935f804f2c080ae28663d096d 
1// Copyright 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/spdyproxy/proxy_advisor.h"
6
7#include "base/command_line.h"
8#include "base/logging.h"
9#include "base/memory/scoped_ptr.h"
10#include "base/prefs/pref_service.h"
11#include "base/stl_util.h"
12#include "chrome/common/chrome_switches.h"
13#include "chrome/common/pref_names.h"
14#include "components/data_reduction_proxy/browser/data_reduction_proxy_settings.h"
15#include "content/public/browser/browser_thread.h"
16#include "net/base/load_flags.h"
17#include "net/base/request_priority.h"
18#include "net/http/http_status_code.h"
19#include "net/proxy/proxy_info.h"
20#include "net/proxy/proxy_service.h"
21#include "net/url_request/url_request_context.h"
22#include "net/url_request/url_request_context_getter.h"
23
24// Ensure data reduction features are available.
25#if !defined(OS_ANDROID) && !defined(OS_IOS)
26#error proxy_advisor should only be included in Android or iOS builds.
27#endif
28
29using content::BrowserThread;
30using data_reduction_proxy::DataReductionProxySettings;
31
32namespace {
33const char kOmniboxMotivation[] = "omnibox";
34const char kLowThresholdOmniboxMotivation[] = "low_threshold_omnibox";
35const char kStartupDNSMotivation[] = "startup_dns";
36const char kEarlyLoadMotivation[] = "early_load";
37const char kLearnedReferralMotivation[] = "learned_referral";
38const char kLowThresholdLearnedReferralMotivation[] =
39    "low_threshold_learned_referral";
40const char kSelfReferralMotivation[] = "self_referral";
41const char kPageScanMotivation[] = "page_scan";
42
43// Maps a ResolutionMotivation to a string for use in the advisory HEAD
44// request.
45const char* MotivationName(
46    chrome_browser_net::UrlInfo::ResolutionMotivation motivation,
47    bool is_preconnect) {
48  switch (motivation) {
49    case chrome_browser_net::UrlInfo::OMNIBOX_MOTIVATED:
50      return
51          is_preconnect ? kOmniboxMotivation : kLowThresholdOmniboxMotivation;
52    case chrome_browser_net::UrlInfo::STARTUP_LIST_MOTIVATED:
53      return kStartupDNSMotivation;
54    case chrome_browser_net::UrlInfo::EARLY_LOAD_MOTIVATED:
55      return kEarlyLoadMotivation;
56    case chrome_browser_net::UrlInfo::LEARNED_REFERAL_MOTIVATED:
57      return is_preconnect ?
58          kLearnedReferralMotivation : kLowThresholdLearnedReferralMotivation;
59    case chrome_browser_net::UrlInfo::SELF_REFERAL_MOTIVATED:
60      return kSelfReferralMotivation;
61    case chrome_browser_net::UrlInfo::PAGE_SCAN_MOTIVATED:
62      return kPageScanMotivation;
63    default:
64      // Other motivations should never be passed to here.
65      NOTREACHED();
66      break;
67  }
68  NOTREACHED();
69  return "";
70}
71
72}  // namespace
73
74ProxyAdvisor::ProxyAdvisor(PrefService* pref_service,
75                           net::URLRequestContextGetter* context_getter)
76    : context_getter_(context_getter) {
77  DCHECK(BrowserThread::CurrentlyOn(BrowserThread::UI));
78
79  // pref_service may be null in mock test subclasses.
80  if (pref_service) {
81    proxy_pref_member_.Init(
82        data_reduction_proxy::prefs::kDataReductionProxyEnabled,
83        pref_service,
84        base::Bind(&ProxyAdvisor::UpdateProxyState, base::Unretained(this)));
85    proxy_pref_member_.MoveToThread(
86        BrowserThread::GetMessageLoopProxyForThread(BrowserThread::IO));
87  }
88}
89
90ProxyAdvisor::~ProxyAdvisor() {
91  STLDeleteElements(&inflight_requests_);
92}
93
94void ProxyAdvisor::OnResponseStarted(net::URLRequest* request) {
95  const net::URLRequestStatus& status(request->status());
96  if (!status.is_success()) {
97    DLOG(WARNING) << "Proxy advisory failed "
98        << "status:" << status.status()
99        << " error:" << status.error();
100  } else if (request->GetResponseCode() != net::HTTP_OK) {
101    DLOG(WARNING) << "Proxy advisory status: " << request->GetResponseCode();
102  }
103  RequestComplete(request);
104}
105
106void ProxyAdvisor::OnReadCompleted(net::URLRequest* request, int bytes_read) {
107  // No-op for now, as we don't care yet.
108}
109
110void ProxyAdvisor::Advise(
111    const GURL& url,
112    chrome_browser_net::UrlInfo::ResolutionMotivation motivation,
113    bool is_preconnect) {
114  DCHECK(BrowserThread::CurrentlyOn(BrowserThread::IO));
115
116  if (!WouldProxyURL(url))
117    return;
118
119  std::string motivation_name(MotivationName(motivation, is_preconnect));
120  std::string header_value = motivation_name + " " + url.spec();
121  net::URLRequestContext* context = context_getter_->GetURLRequestContext();
122  std::string endpoint =
123      DataReductionProxySettings::GetDataReductionProxyOrigin() + "preconnect";
124  scoped_ptr<net::URLRequest> request = context->CreateRequest(
125      GURL(endpoint), net::DEFAULT_PRIORITY, this, NULL);
126  request->set_method("HEAD");
127  request->SetExtraRequestHeaderByName(
128      "Proxy-Host-Advisory", header_value, false);
129  request->SetLoadFlags(net::LOAD_DO_NOT_SEND_COOKIES |
130                        net::LOAD_DO_NOT_SAVE_COOKIES |
131                        net::LOAD_BYPASS_PROXY |
132                        net::LOAD_DISABLE_CACHE);
133  net::URLRequest* raw_request = request.get();
134  inflight_requests_.insert(request.release());
135  raw_request->Start();
136}
137
138// TODO(marq): Move this into DataReductionProxySettings, and add support for
139// inspecting the current proxy configs -- if ResolveProxy on |url| can be
140// done synchronously, then this is no longer an approximation.
141bool ProxyAdvisor::WouldProxyURL(const GURL& url)  {
142  if (!proxy_pref_member_.GetValue())
143    return false;
144
145  if (url.SchemeIsSecure())
146    return false;
147
148  return true;
149}
150
151void ProxyAdvisor::RequestComplete(net::URLRequest* request) {
152  DCHECK_EQ(1u, inflight_requests_.count(request));
153  scoped_ptr<net::URLRequest> scoped_request_for_deletion(request);
154  inflight_requests_.erase(request);
155  // |scoped_request_for_deletion| will delete |request|
156}
157
158void ProxyAdvisor::UpdateProxyState() {
159  DCHECK(BrowserThread::CurrentlyOn(BrowserThread::IO));
160  // Delete all inflight requests. Each request's destructor will call Cancel().
161  STLDeleteElements(&inflight_requests_);
162}
163