| /* |
| * |
| * Copyright 2016 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. |
| * |
| */ |
| |
| /* Functions for manipulating trace contexts as defined in |
| src/proto/census/trace.proto */ |
| #ifndef GRPC_CORE_EXT_CENSUS_TRACE_CONTEXT_H |
| #define GRPC_CORE_EXT_CENSUS_TRACE_CONTEXT_H |
| |
| #include "src/core/ext/census/gen/trace_context.pb.h" |
| |
| /* Span option flags. */ |
| #define SPAN_OPTIONS_IS_SAMPLED 0x01 |
| |
| /* Maximum number of bytes required to encode a TraceContext (31) |
| 1 byte for trace_id field |
| 1 byte for trace_id length |
| 1 byte for trace_id.hi field |
| 8 bytes for trace_id.hi (uint64_t) |
| 1 byte for trace_id.lo field |
| 8 bytes for trace_id.lo (uint64_t) |
| 1 byte for span_id field |
| 8 bytes for span_id (uint64_t) |
| 1 byte for is_sampled field |
| 1 byte for is_sampled (bool) */ |
| #define TRACE_MAX_CONTEXT_SIZE 31 |
| |
| /* Encode a trace context (ctxt) into proto format to the buffer provided. The |
| size of buffer must be at least TRACE_MAX_CONTEXT_SIZE. On success, returns the |
| number of bytes successfully encoded into buffer. On failure, returns 0. */ |
| size_t encode_trace_context(google_trace_TraceContext *ctxt, uint8_t *buffer, |
| const size_t buf_size); |
| |
| /* Decode a proto-encoded TraceContext from the provided buffer into the |
| TraceContext structure (ctxt). The function expects to be supplied the number |
| of bytes to be read from buffer (nbytes). This function will also validate that |
| the TraceContext has a span_id and a trace_id, and will return false if either |
| of these do not exist. On success, returns true and false otherwise. */ |
| bool decode_trace_context(google_trace_TraceContext *ctxt, uint8_t *buffer, |
| const size_t nbytes); |
| |
| #endif /* GRPC_CORE_EXT_CENSUS_TRACE_CONTEXT_H */ |