1 files changed, 135 insertions, 0 deletions
diff --git a/third_party/libwebrtc/rtc_base/experiments/struct_parameters_parser.cc b/third_party/libwebrtc/rtc_base/experiments/struct_parameters_parser.cc
new file mode 100644
index 0000000000..011df3eaba
--- /dev/null
+++ b/third_party/libwebrtc/rtc_base/experiments/struct_parameters_parser.cc
@@ -0,0 +1,135 @@
+/*
+ *  Copyright (c) 2019 The WebRTC project authors. All Rights Reserved.
+ *
+ *  Use of this source code is governed by a BSD-style license
+ *  that can be found in the LICENSE file in the root of the source
+ *  tree. An additional intellectual property rights grant can be found
+ *  in the file PATENTS.  All contributing project authors may
+ *  be found in the AUTHORS file in the root of the source tree.
+ */
+#include "rtc_base/experiments/struct_parameters_parser.h"
+
+#include <algorithm>
+
+#include "absl/strings/string_view.h"
+#include "rtc_base/logging.h"
+
+namespace webrtc {
+namespace {
+size_t FindOrEnd(absl::string_view str, size_t start, char delimiter) {
+  size_t pos = str.find(delimiter, start);
+  pos = (pos == absl::string_view::npos) ? str.length() : pos;
+  return pos;
+}
+}  // namespace
+
+namespace struct_parser_impl {
+namespace {
+inline void StringEncode(std::string* target, bool val) {
+  *target += rtc::ToString(val);
+}
+inline void StringEncode(std::string* target, double val) {
+  *target += rtc::ToString(val);
+}
+inline void StringEncode(std::string* target, int val) {
+  *target += rtc::ToString(val);
+}
+inline void StringEncode(std::string* target, unsigned val) {
+  *target += rtc::ToString(val);
+}
+inline void StringEncode(std::string* target, DataRate val) {
+  *target += webrtc::ToString(val);
+}
+inline void StringEncode(std::string* target, DataSize val) {
+  *target += webrtc::ToString(val);
+}
+inline void StringEncode(std::string* target, TimeDelta val) {
+  *target += webrtc::ToString(val);
+}
+
+template <typename T>
+inline void StringEncode(std::string* sb, absl::optional<T> val) {
+  if (val)
+    StringEncode(sb, *val);
+}
+}  // namespace
+template <typename T>
+bool TypedParser<T>::Parse(absl::string_view src, void* target) {
+  auto parsed = ParseTypedParameter<T>(std::string(src));
+  if (parsed.has_value())
+    *reinterpret_cast<T*>(target) = *parsed;
+  return parsed.has_value();
+}
+template <typename T>
+void TypedParser<T>::Encode(const void* src, std::string* target) {
+  StringEncode(target, *reinterpret_cast<const T*>(src));
+}
+
+template class TypedParser<bool>;
+template class TypedParser<double>;
+template class TypedParser<int>;
+template class TypedParser<unsigned>;
+template class TypedParser<absl::optional<double>>;
+template class TypedParser<absl::optional<int>>;
+template class TypedParser<absl::optional<unsigned>>;
+
+template class TypedParser<DataRate>;
+template class TypedParser<DataSize>;
+template class TypedParser<TimeDelta>;
+template class TypedParser<absl::optional<DataRate>>;
+template class TypedParser<absl::optional<DataSize>>;
+template class TypedParser<absl::optional<TimeDelta>>;
+}  // namespace struct_parser_impl
+
+StructParametersParser::StructParametersParser(
+    std::vector<struct_parser_impl::MemberParameter> members)
+    : members_(std::move(members)) {}
+
+void StructParametersParser::Parse(absl::string_view src) {
+  size_t i = 0;
+  while (i < src.length()) {
+    size_t val_end = FindOrEnd(src, i, ',');
+    size_t colon_pos = FindOrEnd(src, i, ':');
+    size_t key_end = std::min(val_end, colon_pos);
+    size_t val_begin = key_end + 1u;
+    absl::string_view key(src.substr(i, key_end - i));
+    absl::string_view opt_value;
+    if (val_end >= val_begin)
+      opt_value = src.substr(val_begin, val_end - val_begin);
+    i = val_end + 1u;
+    bool found = false;
+    for (auto& member : members_) {
+      if (key == member.key) {
+        found = true;
+        if (!member.parser.parse(opt_value, member.member_ptr)) {
+          RTC_LOG(LS_WARNING) << "Failed to read field with key: '" << key
+                              << "' in trial: \"" << src << "\"";
+        }
+        break;
+      }
+    }
+    // "_" is be used to prefix keys that are part of the string for
+    // debugging purposes but not neccessarily used.
+    // e.g. WebRTC-Experiment/param: value, _DebuggingString
+    if (!found && (key.empty() || key[0] != '_')) {
+      RTC_LOG(LS_INFO) << "No field with key: '" << key
+                       << "' (found in trial: \"" << src << "\")";
+    }
+  }
+}
+
+std::string StructParametersParser::Encode() const {
+  std::string res;
+  bool first = true;
+  for (const auto& member : members_) {
+    if (!first)
+      res += ",";
+    res += member.key;
+    res += ":";
+    member.parser.encode(member.member_ptr, &res);
+    first = false;
+  }
+  return res;
+}
+
+}  // namespace webrtc