| /* |
| * |
| * Copyright 2018 gRPC authors. |
| * |
| * Licensed under the Apache License, Version 2.0 (the "License"); |
| * you may not use this file except in compliance with the License. |
| * You may obtain a copy of the License at |
| * |
| * http://www.apache.org/licenses/LICENSE-2.0 |
| * |
| * Unless required by applicable law or agreed to in writing, software |
| * distributed under the License is distributed on an "AS IS" BASIS, |
| * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. |
| * See the License for the specific language governing permissions and |
| * limitations under the License. |
| * |
| */ |
| |
| #ifndef GRPC_INTERNAL_CPP_EXT_FILTERS_CENSUS_RPC_ENCODING_H |
| #define GRPC_INTERNAL_CPP_EXT_FILTERS_CENSUS_RPC_ENCODING_H |
| |
| #include <grpc/support/port_platform.h> |
| |
| #include <string.h> |
| |
| #include "absl/base/internal/endian.h" |
| #include "absl/strings/string_view.h" |
| #include "opencensus/trace/span_context.h" |
| #include "opencensus/trace/span_id.h" |
| #include "opencensus/trace/trace_id.h" |
| |
| namespace grpc { |
| |
| // TODO(unknown): This may not be needed. Check to see if opencensus requires |
| // a trailing server response. |
| // RpcServerStatsEncoding encapsulates the logic for encoding and decoding of |
| // rpc server stats messages. Rpc server stats consists of a uint64_t time |
| // value (server latency in nanoseconds). |
| class RpcServerStatsEncoding { |
| public: |
| // Size of encoded RPC server stats. |
| static constexpr size_t kRpcServerStatsSize = 10; |
| // Error value. |
| static constexpr size_t kEncodeDecodeFailure = 0; |
| |
| // Deserializes rpc server stats from the incoming 'buf' into *time. Returns |
| // number of bytes decoded. If the buffer is of insufficient size (it must be |
| // at least kRpcServerStatsSize bytes) or the encoding version or field ID are |
| // unrecognized, *time will be set to 0 and it will return |
| // kEncodeDecodeFailure. Inlined for performance reasons. |
| static size_t Decode(absl::string_view buf, uint64_t* time) { |
| if (buf.size() < kRpcServerStatsSize) { |
| *time = 0; |
| return kEncodeDecodeFailure; |
| } |
| |
| uint8_t version = buf[kVersionIdOffset]; |
| uint32_t fieldID = buf[kServerElapsedTimeOffset]; |
| if (version != kVersionId || fieldID != kServerElapsedTimeField) { |
| *time = 0; |
| return kEncodeDecodeFailure; |
| } |
| *time = absl::little_endian::Load64( |
| &buf[kServerElapsedTimeOffset + kFieldIdSize]); |
| return kRpcServerStatsSize; |
| } |
| |
| // Serializes rpc server stats into the provided buffer. It returns the |
| // number of bytes written to the buffer. If the buffer is smaller than |
| // kRpcServerStatsSize bytes it will return kEncodeDecodeFailure. Inlined for |
| // performance reasons. |
| static size_t Encode(uint64_t time, char* buf, size_t buf_size) { |
| if (buf_size < kRpcServerStatsSize) { |
| return kEncodeDecodeFailure; |
| } |
| |
| buf[kVersionIdOffset] = kVersionId; |
| buf[kServerElapsedTimeOffset] = kServerElapsedTimeField; |
| absl::little_endian::Store64(&buf[kServerElapsedTimeOffset + kFieldIdSize], |
| time); |
| return kRpcServerStatsSize; |
| } |
| |
| private: |
| // Size of Version ID. |
| static constexpr size_t kVersionIdSize = 1; |
| // Size of Field ID. |
| static constexpr size_t kFieldIdSize = 1; |
| |
| // Offset and value for currently supported version ID. |
| static constexpr size_t kVersionIdOffset = 0; |
| static constexpr size_t kVersionId = 0; |
| |
| enum FieldIdValue { |
| kServerElapsedTimeField = 0, |
| }; |
| |
| enum FieldSize { |
| kServerElapsedTimeSize = 8, |
| }; |
| |
| enum FieldIdOffset { |
| kServerElapsedTimeOffset = kVersionIdSize, |
| }; |
| |
| RpcServerStatsEncoding() = delete; |
| RpcServerStatsEncoding(const RpcServerStatsEncoding&) = delete; |
| RpcServerStatsEncoding(RpcServerStatsEncoding&&) = delete; |
| RpcServerStatsEncoding operator=(const RpcServerStatsEncoding&) = delete; |
| RpcServerStatsEncoding operator=(RpcServerStatsEncoding&&) = delete; |
| }; |
| |
| } // namespace grpc |
| |
| #endif /* GRPC_INTERNAL_CPP_EXT_FILTERS_CENSUS_RPC_ENCODING_H */ |