1 /*
2 * Copyright (c) 2019 The WebRTC project authors. All Rights Reserved.
3 *
4 * Use of this source code is governed by a BSD-style license
5 * that can be found in the LICENSE file in the root of the source
6 * tree. An additional intellectual property rights grant can be found
7 * in the file PATENTS. All contributing project authors may
8 * be found in the AUTHORS file in the root of the source tree.
9 */
10 #include "rtc_base/experiments/struct_parameters_parser.h"
11
12 #include <algorithm>
13
14 #include "absl/strings/string_view.h"
15 #include "rtc_base/logging.h"
16
17 namespace webrtc {
18 namespace {
FindOrEnd(absl::string_view str,size_t start,char delimiter)19 size_t FindOrEnd(absl::string_view str, size_t start, char delimiter) {
20 size_t pos = str.find(delimiter, start);
21 pos = (pos == absl::string_view::npos) ? str.length() : pos;
22 return pos;
23 }
24 } // namespace
25
26 namespace struct_parser_impl {
27 namespace {
StringEncode(std::string * target,bool val)28 inline void StringEncode(std::string* target, bool val) {
29 *target += rtc::ToString(val);
30 }
StringEncode(std::string * target,double val)31 inline void StringEncode(std::string* target, double val) {
32 *target += rtc::ToString(val);
33 }
StringEncode(std::string * target,int val)34 inline void StringEncode(std::string* target, int val) {
35 *target += rtc::ToString(val);
36 }
StringEncode(std::string * target,unsigned val)37 inline void StringEncode(std::string* target, unsigned val) {
38 *target += rtc::ToString(val);
39 }
StringEncode(std::string * target,DataRate val)40 inline void StringEncode(std::string* target, DataRate val) {
41 *target += webrtc::ToString(val);
42 }
StringEncode(std::string * target,DataSize val)43 inline void StringEncode(std::string* target, DataSize val) {
44 *target += webrtc::ToString(val);
45 }
StringEncode(std::string * target,TimeDelta val)46 inline void StringEncode(std::string* target, TimeDelta val) {
47 *target += webrtc::ToString(val);
48 }
49
50 template <typename T>
StringEncode(std::string * sb,absl::optional<T> val)51 inline void StringEncode(std::string* sb, absl::optional<T> val) {
52 if (val)
53 StringEncode(sb, *val);
54 }
55 } // namespace
56 template <typename T>
Parse(absl::string_view src,void * target)57 bool TypedParser<T>::Parse(absl::string_view src, void* target) {
58 auto parsed = ParseTypedParameter<T>(std::string(src));
59 if (parsed.has_value())
60 *reinterpret_cast<T*>(target) = *parsed;
61 return parsed.has_value();
62 }
63 template <typename T>
Encode(const void * src,std::string * target)64 void TypedParser<T>::Encode(const void* src, std::string* target) {
65 StringEncode(target, *reinterpret_cast<const T*>(src));
66 }
67
68 template class TypedParser<bool>;
69 template class TypedParser<double>;
70 template class TypedParser<int>;
71 template class TypedParser<unsigned>;
72 template class TypedParser<absl::optional<double>>;
73 template class TypedParser<absl::optional<int>>;
74 template class TypedParser<absl::optional<unsigned>>;
75
76 template class TypedParser<DataRate>;
77 template class TypedParser<DataSize>;
78 template class TypedParser<TimeDelta>;
79 template class TypedParser<absl::optional<DataRate>>;
80 template class TypedParser<absl::optional<DataSize>>;
81 template class TypedParser<absl::optional<TimeDelta>>;
82 } // namespace struct_parser_impl
83
StructParametersParser(std::vector<struct_parser_impl::MemberParameter> members)84 StructParametersParser::StructParametersParser(
85 std::vector<struct_parser_impl::MemberParameter> members)
86 : members_(std::move(members)) {}
87
Parse(absl::string_view src)88 void StructParametersParser::Parse(absl::string_view src) {
89 size_t i = 0;
90 while (i < src.length()) {
91 size_t val_end = FindOrEnd(src, i, ',');
92 size_t colon_pos = FindOrEnd(src, i, ':');
93 size_t key_end = std::min(val_end, colon_pos);
94 size_t val_begin = key_end + 1u;
95 absl::string_view key(src.substr(i, key_end - i));
96 absl::string_view opt_value;
97 if (val_end >= val_begin)
98 opt_value = src.substr(val_begin, val_end - val_begin);
99 i = val_end + 1u;
100 bool found = false;
101 for (auto& member : members_) {
102 if (key == member.key) {
103 found = true;
104 if (!member.parser.parse(opt_value, member.member_ptr)) {
105 RTC_LOG(LS_WARNING) << "Failed to read field with key: '" << key
106 << "' in trial: \"" << src << "\"";
107 }
108 break;
109 }
110 }
111 // "_" is be used to prefix keys that are part of the string for
112 // debugging purposes but not neccessarily used.
113 // e.g. WebRTC-Experiment/param: value, _DebuggingString
114 if (!found && (key.empty() || key[0] != '_')) {
115 RTC_LOG(LS_INFO) << "No field with key: '" << key
116 << "' (found in trial: \"" << src << "\")";
117 }
118 }
119 }
120
Encode() const121 std::string StructParametersParser::Encode() const {
122 std::string res;
123 bool first = true;
124 for (const auto& member : members_) {
125 if (!first)
126 res += ",";
127 res += member.key;
128 res += ":";
129 member.parser.encode(member.member_ptr, &res);
130 first = false;
131 }
132 return res;
133 }
134
135 } // namespace webrtc
136