1 /*
2 *
3 * Copyright 2018 gRPC authors.
4 *
5 * Licensed under the Apache License, Version 2.0 (the "License");
6 * you may not use this file except in compliance with the License.
7 * You may obtain a copy of the License at
8 *
9 * http://www.apache.org/licenses/LICENSE-2.0
10 *
11 * Unless required by applicable law or agreed to in writing, software
12 * distributed under the License is distributed on an "AS IS" BASIS,
13 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
14 * See the License for the specific language governing permissions and
15 * limitations under the License.
16 *
17 */
18
19 #ifndef GRPC_INTERNAL_CPP_EXT_FILTERS_CENSUS_CONTEXT_H
20 #define GRPC_INTERNAL_CPP_EXT_FILTERS_CENSUS_CONTEXT_H
21
22 #include <grpc/support/port_platform.h>
23
24 #include <grpc/status.h>
25 #include "absl/memory/memory.h"
26 #include "absl/strings/string_view.h"
27 #include "absl/strings/strip.h"
28 #include "opencensus/trace/span.h"
29 #include "opencensus/trace/span_context.h"
30 #include "opencensus/trace/trace_params.h"
31 #include "src/core/lib/slice/slice_internal.h"
32 #include "src/cpp/common/channel_filter.h"
33 #include "src/cpp/ext/filters/census/rpc_encoding.h"
34
35 // This is needed because grpc has hardcoded CensusContext with a
36 // forward declaration of 'struct census_context;'
37 struct census_context;
38
39 namespace grpc {
40
41 // Thread compatible.
42 class CensusContext {
43 public:
CensusContext()44 CensusContext() : span_(::opencensus::trace::Span::BlankSpan()) {}
45
CensusContext(absl::string_view name)46 explicit CensusContext(absl::string_view name)
47 : span_(::opencensus::trace::Span::StartSpan(name)) {}
48
CensusContext(absl::string_view name,const::opencensus::trace::Span * parent)49 CensusContext(absl::string_view name, const ::opencensus::trace::Span* parent)
50 : span_(::opencensus::trace::Span::StartSpan(name, parent)) {}
51
CensusContext(absl::string_view name,const::opencensus::trace::SpanContext & parent_ctxt)52 CensusContext(absl::string_view name,
53 const ::opencensus::trace::SpanContext& parent_ctxt)
54 : span_(::opencensus::trace::Span::StartSpanWithRemoteParent(
55 name, parent_ctxt)) {}
56
Context()57 ::opencensus::trace::SpanContext Context() const { return span_.context(); }
Span()58 ::opencensus::trace::Span Span() const { return span_; }
EndSpan()59 void EndSpan() { span_.End(); }
60
61 private:
62 ::opencensus::trace::Span span_;
63 };
64
65 // Serializes the outgoing trace context. Field IDs are 1 byte followed by
66 // field data. A 1 byte version ID is always encoded first.
67 size_t TraceContextSerialize(const ::opencensus::trace::SpanContext& context,
68 char* tracing_buf, size_t tracing_buf_size);
69
70 // Serializes the outgoing stats context. Field IDs are 1 byte followed by
71 // field data. A 1 byte version ID is always encoded first. Tags are directly
72 // serialized into the given grpc_slice.
73 size_t StatsContextSerialize(size_t max_tags_len, grpc_slice* tags);
74
75 // Serialize outgoing server stats. Returns the number of bytes serialized.
76 size_t ServerStatsSerialize(uint64_t server_elapsed_time, char* buf,
77 size_t buf_size);
78
79 // Deserialize incoming server stats. Returns the number of bytes deserialized.
80 size_t ServerStatsDeserialize(const char* buf, size_t buf_size,
81 uint64_t* server_elapsed_time);
82
83 // Deserialize the incoming SpanContext and generate a new server context based
84 // on that. This new span will never be a root span. This should only be called
85 // with a blank CensusContext as it overwrites it.
86 void GenerateServerContext(absl::string_view tracing, absl::string_view stats,
87 absl::string_view primary_role,
88 absl::string_view method, CensusContext* context);
89
90 // Creates a new client context that is by default a new root context.
91 // If the current context is the default context then the newly created
92 // span automatically becomes a root span. This should only be called with a
93 // blank CensusContext as it overwrites it.
94 void GenerateClientContext(absl::string_view method, CensusContext* ctxt,
95 CensusContext* parent_ctx);
96
97 // Returns the incoming data size from the grpc call final info.
98 uint64_t GetIncomingDataSize(const grpc_call_final_info* final_info);
99
100 // Returns the outgoing data size from the grpc call final info.
101 uint64_t GetOutgoingDataSize(const grpc_call_final_info* final_info);
102
103 // These helper functions return the SpanContext and Span, respectively
104 // associated with the census_context* stored by grpc. The user will need to
105 // call this for manual propagation of tracing data.
106 ::opencensus::trace::SpanContext SpanContextFromCensusContext(
107 const census_context* ctxt);
108 ::opencensus::trace::Span SpanFromCensusContext(const census_context* ctxt);
109
110 // Returns a string representation of the StatusCode enum.
111 absl::string_view StatusCodeToString(grpc_status_code code);
112
GetMethod(const grpc_slice * path)113 inline absl::string_view GetMethod(const grpc_slice* path) {
114 if (GRPC_SLICE_IS_EMPTY(*path)) {
115 return "";
116 }
117 // Check for leading '/' and trim it if present.
118 return absl::StripPrefix(absl::string_view(reinterpret_cast<const char*>(
119 GRPC_SLICE_START_PTR(*path)),
120 GRPC_SLICE_LENGTH(*path)),
121 "/");
122 }
123
124 } // namespace grpc
125
126 #endif /* GRPC_INTERNAL_CPP_EXT_FILTERS_CENSUS_CONTEXT_H */
127