1 // Copyright 2023 gRPC authors. 2 // 3 // Licensed under the Apache License, Version 2.0 (the "License"); 4 // you may not use this file except in compliance with the License. 5 // You may obtain a copy of the License at 6 // 7 // http://www.apache.org/licenses/LICENSE-2.0 8 // 9 // Unless required by applicable law or agreed to in writing, software 10 // distributed under the License is distributed on an "AS IS" BASIS, 11 // WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 12 // See the License for the specific language governing permissions and 13 // limitations under the License. 14 15 #ifndef SAMPLER_MAIN_H 16 #define SAMPLER_MAIN_H 17 18 #include <cstdint> 19 #include <string> 20 21 namespace grpc_observability { 22 23 // Returns true or false for sampling based on the given probability. Objects of 24 // this class should be cached between uses because there is a cost to 25 // constructing them. 26 class ProbabilitySampler final { 27 public: 28 static ProbabilitySampler& Get(); 29 30 bool ShouldSample(const std::string& trace_id); 31 32 void SetThreshold(double probability); 33 34 private: 35 ProbabilitySampler() = default; 36 37 // Probability is converted to a value between [0, UINT64_MAX]. 38 uint64_t threshold_; 39 }; 40 41 } // namespace grpc_observability 42 43 #endif // SAMPLER_MAIN_H 44