1 // Copyright 2023 The Chromium Authors
2 // Use of this source code is governed by a BSD-style license that can be
3 // found in the LICENSE file.
4
5 #ifndef BASE_ALLOCATOR_MIRACLE_PARAMETER_H_
6 #define BASE_ALLOCATOR_MIRACLE_PARAMETER_H_
7
8 #include "base/base_export.h"
9 #include "base/containers/span.h"
10 #include "base/feature_list.h"
11 #include "base/metrics/field_trial_params.h"
12
13 // This is a mirror copy of the //components/miracle_parameter/ to resolve the
14 // dependency cycle of (base->miracle_parameter->base).
15 // Eventually the miracle_parameter component will have a public interface in
16 // //base/ and this could be removed.
17 // TODO(crbug.com/1475915): remove miracle_parameter from
18 // //base/allocator/.
19
20 namespace base {
21
22 namespace miracle_parameter {
23
24 namespace {
25
26 template <typename Enum>
GetFieldTrialParamByFeatureAsEnum(const base::Feature & feature,const std::string & param_name,const Enum default_value,const base::span<const typename base::FeatureParam<Enum>::Option> & options)27 Enum GetFieldTrialParamByFeatureAsEnum(
28 const base::Feature& feature,
29 const std::string& param_name,
30 const Enum default_value,
31 const base::span<const typename base::FeatureParam<Enum>::Option>&
32 options) {
33 std::string string_value =
34 base::GetFieldTrialParamValueByFeature(feature, param_name);
35 if (string_value.empty()) {
36 return default_value;
37 }
38
39 for (const auto& option : options) {
40 if (string_value == option.name) {
41 return option.value;
42 }
43 }
44
45 base::LogInvalidEnumValue(feature, param_name, string_value,
46 static_cast<int>(default_value));
47 return default_value;
48 }
49
50 } // namespace
51
52 constexpr int kMiracleParameterMemory512MB = 512;
53 constexpr int kMiracleParameterMemory1GB = 1024;
54 constexpr int kMiracleParameterMemory2GB = 2 * 1024;
55 constexpr int kMiracleParameterMemory4GB = 4 * 1024;
56 constexpr int kMiracleParameterMemory8GB = 8 * 1024;
57 constexpr int kMiracleParameterMemory16GB = 16 * 1024;
58
59 // GetParamNameWithSuffix put a parameter name suffix based on
60 // the amount of physical memory.
61 //
62 // - "ForLessThan512MB" for less than 512MB memory devices.
63 // - "For512MBTo1GB" for 512MB to 1GB memory devices.
64 // - "For1GBTo2GB" for 1GB to 2GB memory devices.
65 // - "For2GBTo4GB" for 2GB to 4GB memory devices.
66 // - "For4GBTo8GB" for 4GB to 8GB memory devices.
67 // - "For8GBTo16GB" for 8GB to 16GB memory devices.
68 // - "For16GBAndAbove" for 16GB memory and above devices.
69 BASE_EXPORT
70 std::string GetParamNameWithSuffix(const std::string& param_name);
71
72 // Provides a similar behavior with FeatureParam<std::string> except the return
73 // value is determined by the amount of physical memory.
74 BASE_EXPORT
75 std::string GetMiracleParameterAsString(const base::Feature& feature,
76 const std::string& param_name,
77 const std::string& default_value);
78
79 // Provides a similar behavior with FeatureParam<double> except the return value
80 // is determined by the amount of physical memory.
81 BASE_EXPORT
82 double GetMiracleParameterAsDouble(const base::Feature& feature,
83 const std::string& param_name,
84 double default_value);
85
86 // Provides a similar behavior with FeatureParam<int> except the return value is
87 // determined by the amount of physical memory.
88 BASE_EXPORT
89 int GetMiracleParameterAsInt(const base::Feature& feature,
90 const std::string& param_name,
91 int default_value);
92
93 // Provides a similar behavior with FeatureParam<bool> except the return value
94 // is determined by the amount of physical memory.
95 BASE_EXPORT
96 bool GetMiracleParameterAsBool(const base::Feature& feature,
97 const std::string& param_name,
98 bool default_value);
99
100 // Provides a similar behavior with FeatureParam<base::TimeDelta> except the
101 // return value is determined by the amount of physical memory.
102 BASE_EXPORT
103 base::TimeDelta GetMiracleParameterAsTimeDelta(const base::Feature& feature,
104 const std::string& param_name,
105 base::TimeDelta default_value);
106
107 // Provides a similar behavior with FeatureParam<Enum> except the return value
108 // is determined by the amount of physical memory.
109 template <typename Enum>
GetMiracleParameterAsEnum(const base::Feature & feature,const std::string & param_name,const Enum default_value,const base::span<const typename base::FeatureParam<Enum>::Option> options)110 Enum GetMiracleParameterAsEnum(
111 const base::Feature& feature,
112 const std::string& param_name,
113 const Enum default_value,
114 const base::span<const typename base::FeatureParam<Enum>::Option> options) {
115 return GetFieldTrialParamByFeatureAsEnum(
116 feature, GetParamNameWithSuffix(param_name),
117 GetFieldTrialParamByFeatureAsEnum(feature, param_name, default_value,
118 options),
119 options);
120 }
121
122 #define MIRACLE_PARAMETER_FOR_STRING(function_name, feature, param_name, \
123 default_value) \
124 std::string function_name() { \
125 static const std::string value = \
126 miracle_parameter::GetMiracleParameterAsString(feature, param_name, \
127 default_value); \
128 return value; \
129 }
130
131 #define MIRACLE_PARAMETER_FOR_DOUBLE(function_name, feature, param_name, \
132 default_value) \
133 double function_name() { \
134 static const double value = \
135 miracle_parameter::GetMiracleParameterAsDouble(feature, param_name, \
136 default_value); \
137 return value; \
138 }
139
140 #define MIRACLE_PARAMETER_FOR_INT(function_name, feature, param_name, \
141 default_value) \
142 int function_name() { \
143 static const int value = miracle_parameter::GetMiracleParameterAsInt( \
144 feature, param_name, default_value); \
145 return value; \
146 }
147
148 #define MIRACLE_PARAMETER_FOR_BOOL(function_name, feature, param_name, \
149 default_value) \
150 bool function_name() { \
151 static const bool value = miracle_parameter::GetMiracleParameterAsBool( \
152 feature, param_name, default_value); \
153 return value; \
154 }
155
156 #define MIRACLE_PARAMETER_FOR_TIME_DELTA(function_name, feature, param_name, \
157 default_value) \
158 base::TimeDelta function_name() { \
159 static const base::TimeDelta value = \
160 miracle_parameter::GetMiracleParameterAsTimeDelta(feature, param_name, \
161 default_value); \
162 return value; \
163 }
164
165 #define MIRACLE_PARAMETER_FOR_ENUM(function_name, feature, param_name, \
166 default_value, type, options) \
167 type function_name() { \
168 static const type value = miracle_parameter::GetMiracleParameterAsEnum( \
169 feature, param_name, default_value, base::make_span(options)); \
170 return value; \
171 }
172
173 } // namespace miracle_parameter
174
175 } // namespace base
176
177 #endif // BASE_ALLOCATOR_MIRACLE_PARAMETER_H_
178