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