File: prerender_features.h

package info (click to toggle)
chromium 138.0.7204.183-1~deb12u1
  • links: PTS, VCS
  • area: main
  • in suites: bookworm-proposed-updates
  • size: 6,080,960 kB
  • sloc: cpp: 34,937,079; ansic: 7,176,967; javascript: 4,110,704; python: 1,419,954; asm: 946,768; xml: 739,971; pascal: 187,324; sh: 89,623; perl: 88,663; objc: 79,944; sql: 50,304; cs: 41,786; fortran: 24,137; makefile: 21,811; php: 13,980; tcl: 13,166; yacc: 8,925; ruby: 7,485; awk: 3,720; lisp: 3,096; lex: 1,327; ada: 727; jsp: 228; sed: 36
file content (90 lines) | stat: -rw-r--r-- 3,714 bytes parent folder | download | duplicates (2)
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
// Copyright 2023 The Chromium Authors
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.

#ifndef CONTENT_BROWSER_PRELOADING_PRERENDER_PRERENDER_FEATURES_H_
#define CONTENT_BROWSER_PRELOADING_PRERENDER_PRERENDER_FEATURES_H_

#include "base/feature_list.h"
#include "base/metrics/field_trial_params.h"
#include "content/common/content_export.h"

namespace features {

CONTENT_EXPORT BASE_DECLARE_FEATURE(kPrerender2NewLimitAndScheduler);
CONTENT_EXPORT BASE_DECLARE_FEATURE(kPrerender2AllowActivationInBackground);

CONTENT_EXPORT BASE_DECLARE_FEATURE(kPrerender2FallbackPrefetchSpecRules);

// This allows controlling the behavior of multiple use of `PrefetchContainer`
// if `kPrerender2FallbackPrefetchSpecRules` is enabled and `kPrefetchReusable`
// is disabled. If `kPrefetchReusable` is enabled, the feature flag has
// priority.
//
// TODO(crbug.com/373553133): Remove this control once a behavior is shipped and
// stabilized.
enum class Prerender2FallbackPrefetchReusablePolicy {
  // Do not use `PrefetchReusable` code path.
  kNotUse,
  // Use if a prefetch is started by prerender.
  kUseIfIsLikelyAheadOfPrerender,
  // Use always.
  kUseAlways,
};
CONTENT_EXPORT extern const base::FeatureParam<
    Prerender2FallbackPrefetchReusablePolicy>
    kPrerender2FallbackPrefetchReusablePolicy;

CONTENT_EXPORT extern const base::FeatureParam<size_t>
    kPrerender2FallbackBodySizeLimit;

// Controls whether `PrefetchMatchResolver` use timeout for prefetch ahead of
// prerender. We are going not to use timeout as it makes prerender fail. For
// more details, see
// https://docs.google.com/document/d/1ZP7lYrtqZL9jC2xXieNY_UBMJL1sCrfmzTB8K6v4sD4/edit?resourcekey=0-fkbeQhkT3PhBb9FnnPgnZA&tab=t.wphan8fb23kr
CONTENT_EXPORT extern const base::FeatureParam<bool>
    kPrerender2FallbackPrefetchUseBlockUntilHeadTimetout;

enum class Prerender2FallbackPrefetchSchedulerPolicy {
  // Do not use `PrefetchScheduler` code path.
  kNotUse,
  // Prioritize prefetch ahead of prerender.
  kPrioritize,
  // Burst prefetch ahead of prerender.
  kBurst,
};
CONTENT_EXPORT extern const base::FeatureParam<
    Prerender2FallbackPrefetchSchedulerPolicy>
    kPrerender2FallbackPrefetchSchedulerPolicy;

// This feature was used to launch Prerender2 support for No-Vary-Search header.
// This work has finished and the old implementation was deleted. Now this flag
// is just for injecting parameters through field trials as an umberella
// feature.
CONTENT_EXPORT BASE_DECLARE_FEATURE(kPrerender2NoVarySearch);

// A field trial param that controls the timeout for waiting on headers
// during navigation for the prerender URL matched by No-Vary-Search hint before
// falling back to the default navigation path.
CONTENT_EXPORT extern const base::FeatureParam<int>
    kPrerender2NoVarySearchWaitForHeadersTimeoutEagerPrerender;
CONTENT_EXPORT extern const base::FeatureParam<int>
    kPrerender2NoVarySearchWaitForHeadersTimeoutModeratePrerender;
CONTENT_EXPORT extern const base::FeatureParam<int>
    kPrerender2NoVarySearchWaitForHeadersTimeoutConservativePrerender;
CONTENT_EXPORT extern const base::FeatureParam<int>
    kPrerender2NoVarySearchWaitForHeadersTimeoutForEmbedders;

// If enabled, suppresses prerendering on slow network.
CONTENT_EXPORT BASE_DECLARE_FEATURE(kSuppressesPrerenderingOnSlowNetwork);

CONTENT_EXPORT extern const base::FeatureParam<base::TimeDelta>
    kSuppressesPrerenderingOnSlowNetworkThreshold;

CONTENT_EXPORT BASE_DECLARE_FEATURE(kPrerender2DisallowNonTrustworthyHttp);

CONTENT_EXPORT bool UsePrefetchPrerenderIntegration();

}  // namespace features

#endif  // CONTENT_BROWSER_PRELOADING_PRERENDER_PRERENDER_FEATURES_H_