| /* |
| * |
| * Copyright 2016, Google Inc. |
| * All rights reserved. |
| * |
| * Redistribution and use in source and binary forms, with or without |
| * modification, are permitted provided that the following conditions are |
| * met: |
| * |
| * * Redistributions of source code must retain the above copyright |
| * notice, this list of conditions and the following disclaimer. |
| * * Redistributions in binary form must reproduce the above |
| * copyright notice, this list of conditions and the following disclaimer |
| * in the documentation and/or other materials provided with the |
| * distribution. |
| * * Neither the name of Google Inc. nor the names of its |
| * contributors may be used to endorse or promote products derived from |
| * this software without specific prior written permission. |
| * |
| * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS |
| * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT |
| * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR |
| * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT |
| * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, |
| * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT |
| * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, |
| * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY |
| * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT |
| * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE |
| * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. |
| * |
| */ |
| |
| /* 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 */ |