separate runtime_id from class SpanDefaults, and introduce class RuntimeID

dgoffredo · dgoffredo · commit 879cfe341515 · 2023-10-12T14:32:11.000-04:00
diff --git a/BUILD.bazel b/BUILD.bazel
@@ -23,6 +23,7 @@ cc_library(
     "src/datadog/propagation_style.cpp",
     "src/datadog/random.cpp",
     "src/datadog/rate.cpp",
+    "src/datadog/runtime_id.cpp",
     "src/datadog/span.cpp",
     "src/datadog/span_data.cpp",
     "src/datadog/span_defaults.cpp",
@@ -75,6 +76,7 @@ cc_library(
     "src/datadog/propagation_style.h",
     "src/datadog/random.h",
     "src/datadog/rate.h",
+    "src/datadog/runtime_id.h",
     "src/datadog/sampling_decision.h",
     "src/datadog/sampling_mechanism.h",
     "src/datadog/sampling_priority.h",
diff --git a/CMakeLists.txt b/CMakeLists.txt
@@ -118,6 +118,7 @@ target_sources(dd_trace_cpp-objects PRIVATE
     src/datadog/propagation_style.cpp
     src/datadog/random.cpp
     src/datadog/rate.cpp
+    src/datadog/runtime_id.cpp
     src/datadog/span.cpp
     src/datadog/span_data.cpp
     src/datadog/span_defaults.cpp
@@ -176,6 +177,7 @@ target_sources(dd_trace_cpp-objects PUBLIC
   src/datadog/propagation_style.h
   src/datadog/random.h
   src/datadog/rate.h
+  src/datadog/runtime_id.h
   src/datadog/sampling_decision.h
   src/datadog/sampling_mechanism.h
   src/datadog/sampling_priority.h
@@ -209,12 +211,12 @@ include_directories(${CMAKE_BINARY_DIR}/include)
 
 # Linking this library requires libcurl and threads.
 find_package(Threads REQUIRED)
-target_link_libraries(dd_trace_cpp-objects 
-  PUBLIC 
-    ${CMAKE_BINARY_DIR}/lib/libcurl.a 
-  PUBLIC 
-    Threads::Threads 
-    ${COVERAGE_LIBRARIES} 
+target_link_libraries(dd_trace_cpp-objects
+  PUBLIC
+    ${CMAKE_BINARY_DIR}/lib/libcurl.a
+  PUBLIC
+    Threads::Threads
+    ${COVERAGE_LIBRARIES}
     ${COREFOUNDATION_LIBRARY}
     ${SYSTEMCONFIGURATION_LIBRARY}
 )
diff --git a/src/datadog/runtime_id.cpp b/src/datadog/runtime_id.cpp
@@ -0,0 +1,17 @@
+#include "runtime_id.h"
+
+#include "random.h"
+
+namespace datadog {
+namespace tracing {
+
+RuntimeID::RuntimeID() {}
+
+RuntimeID RuntimeID::generate() {
+  RuntimeID id;
+  id.uuid_ = uuid();
+  return id;
+}
+
+}  // namespace tracing
+}  // namespace datadog
diff --git a/src/datadog/runtime_id.h b/src/datadog/runtime_id.h
@@ -0,0 +1,24 @@
+#pragma once
+
+// TODO: document
+
+#include <string>
+
+namespace datadog {
+namespace tracing {
+
+class RuntimeID {
+  std::string uuid_;
+  RuntimeID();
+
+ public:
+  // Return the canonical textual representation of this ID.
+  const std::string& string() const { return uuid_; }
+
+  // Return a pseudo-randomly generated runtime ID. The underlying generator is
+  // `random_uint64()` declared in `random.h`.
+  static RuntimeID generate();
+};
+
+}  // namespace tracing
+}  // namespace datadog
diff --git a/src/datadog/span_defaults.cpp b/src/datadog/span_defaults.cpp
@@ -22,7 +22,6 @@ nlohmann::json to_json(const SpanDefaults& defaults) {
   TO_JSON(version);
   TO_JSON(name);
   TO_JSON(tags);
-  TO_JSON(runtime_id);
 #undef TO_JSON
   return result;
 }
diff --git a/src/datadog/span_defaults.h b/src/datadog/span_defaults.h
@@ -8,7 +8,6 @@
 #include <unordered_map>
 
 #include "json_fwd.hpp"
-#include "random.h"
 
 namespace datadog {
 namespace tracing {
@@ -20,7 +19,6 @@ struct SpanDefaults {
   std::string version = "";
   std::string name = "";
   std::unordered_map<std::string, std::string> tags;
-  std::string runtime_id = uuid();
 };
 
 nlohmann::json to_json(const SpanDefaults&);
diff --git a/src/datadog/trace_segment.cpp b/src/datadog/trace_segment.cpp
@@ -83,6 +83,7 @@ TraceSegment::TraceSegment(
     const std::shared_ptr<TraceSampler>& trace_sampler,
     const std::shared_ptr<SpanSampler>& span_sampler,
     const std::shared_ptr<const SpanDefaults>& defaults,
+    const RuntimeID& runtime_id,
     const std::vector<PropagationStyle>& injection_styles,
     const Optional<std::string>& hostname, Optional<std::string> origin,
     std::size_t tags_header_max_size,
@@ -97,6 +98,7 @@ TraceSegment::TraceSegment(
       trace_sampler_(trace_sampler),
       span_sampler_(span_sampler),
       defaults_(defaults),
+      runtime_id_(runtime_id),
       injection_styles_(injection_styles),
       hostname_(hostname),
       origin_(std::move(origin)),
@@ -214,7 +216,7 @@ void TraceSegment::span_finished() {
     }
     span.numeric_tags[tags::internal::process_id] = Cache::process_id;
     span.tags[tags::internal::language] = "cpp";
-    span.tags[tags::internal::runtime_id] = defaults_->runtime_id;
+    span.tags[tags::internal::runtime_id] = runtime_id_.string();
   }
 
   const auto result = collector_->send(std::move(spans_), trace_sampler_);
diff --git a/src/datadog/trace_segment.h b/src/datadog/trace_segment.h
@@ -61,6 +61,7 @@ class TraceSegment {
   std::shared_ptr<SpanSampler> span_sampler_;
 
   std::shared_ptr<const SpanDefaults> defaults_;
+  RuntimeID runtime_id_;
   const std::vector<PropagationStyle> injection_styles_;
   const Optional<std::string> hostname_;
   const Optional<std::string> origin_;
@@ -81,6 +82,7 @@ class TraceSegment {
                const std::shared_ptr<TraceSampler>& trace_sampler,
                const std::shared_ptr<SpanSampler>& span_sampler,
                const std::shared_ptr<const SpanDefaults>& defaults,
+               const RuntimeID& runtime_id,
                const std::vector<PropagationStyle>& injection_styles,
                const Optional<std::string>& hostname,
                Optional<std::string> origin, std::size_t tags_header_max_size,
diff --git a/src/datadog/tracer.cpp b/src/datadog/tracer.cpp
@@ -199,15 +199,16 @@ Expected<ExtractedData> extract_b3(
 
 nlohmann::json make_config_json(
     StringView tracer_version_string, const Collector& collector,
-    const SpanDefaults& defaults, const TraceSampler& trace_sampler,
-    const SpanSampler& span_sampler,
+    const SpanDefaults& defaults, const RuntimeID& runtime_id,
+    const TraceSampler& trace_sampler, const SpanSampler& span_sampler,
     const std::vector<PropagationStyle>& injection_styles,
     const std::vector<PropagationStyle>& extraction_styles,
     const Optional<std::string>& hostname, std::size_t tags_header_max_size) {
   // clang-format off
   auto config = nlohmann::json::object({
     {"version", tracer_version_string},
     {"defaults", to_json(defaults)},
+    {"runtime_id", runtime_id.string()},
     {"collector", collector.config_json()},
     {"trace_sampler", trace_sampler.config_json()},
     {"span_sampler", span_sampler.config_json()},
@@ -244,8 +245,10 @@ Tracer::Tracer(const FinalizedTracerConfig& config,
     : logger_(config.logger),
       collector_(/* see constructor body */),
       defaults_(std::make_shared<SpanDefaults>(config.defaults)),
+      runtime_id_(config.runtime_id ? *config.runtime_id
+                                    : RuntimeID::generate()),
       tracer_telemetry_(std::make_shared<TracerTelemetry>(
-          config.report_telemetry, clock, logger_, defaults_)),
+          config.report_telemetry, clock, logger_, defaults_, runtime_id_)),
       trace_sampler_(
           std::make_shared<TraceSampler>(config.trace_sampler, clock)),
       span_sampler_(std::make_shared<SpanSampler>(config.span_sampler, clock)),
@@ -278,8 +281,9 @@ Tracer::Tracer(const FinalizedTracerConfig& config,
 
 nlohmann::json Tracer::config_json() const {
   return make_config_json(tracer_version_string, *collector_, *defaults_,
-                          *trace_sampler_, *span_sampler_, injection_styles_,
-                          extraction_styles_, hostname_, tags_header_max_size_);
+                          runtime_id_, *trace_sampler_, *span_sampler_,
+                          injection_styles_, extraction_styles_, hostname_,
+                          tags_header_max_size_);
 }
 
 Span Tracer::create_span() { return create_span(SpanConfig{}); }
@@ -300,8 +304,8 @@ Span Tracer::create_span(const SpanConfig& config) {
   tracer_telemetry_->metrics().tracer.trace_segments_created_new.inc();
   const auto segment = std::make_shared<TraceSegment>(
       logger_, collector_, tracer_telemetry_, trace_sampler_, span_sampler_,
-      defaults_, injection_styles_, hostname_, nullopt /* origin */,
-      tags_header_max_size_, std::move(trace_tags),
+      defaults_, runtime_id_, injection_styles_, hostname_,
+      nullopt /* origin */, tags_header_max_size_, std::move(trace_tags),
       nullopt /* sampling_decision */, nullopt /* additional_w3c_tracestate */,
       nullopt /* additional_datadog_w3c_tracestate*/, std::move(span_data));
   Span span{span_data_ptr, segment,
@@ -464,7 +468,7 @@ Expected<Span> Tracer::extract_span(const DictReader& reader,
   tracer_telemetry_->metrics().tracer.trace_segments_created_continued.inc();
   const auto segment = std::make_shared<TraceSegment>(
       logger_, collector_, tracer_telemetry_, trace_sampler_, span_sampler_,
-      defaults_, injection_styles_, hostname_, std::move(origin),
+      defaults_, runtime_id_, injection_styles_, hostname_, std::move(origin),
       tags_header_max_size_, std::move(trace_tags),
       std::move(sampling_decision), std::move(additional_w3c_tracestate),
       std::move(additional_datadog_w3c_tracestate), std::move(span_data));
diff --git a/src/datadog/tracer.h b/src/datadog/tracer.h
@@ -32,6 +32,7 @@ class Tracer {
   std::shared_ptr<Logger> logger_;
   std::shared_ptr<Collector> collector_;
   std::shared_ptr<const SpanDefaults> defaults_;
+  RuntimeID runtime_id_;
   std::shared_ptr<TracerTelemetry> tracer_telemetry_;
   std::shared_ptr<TraceSampler> trace_sampler_;
   std::shared_ptr<SpanSampler> span_sampler_;
diff --git a/src/datadog/tracer_config.cpp b/src/datadog/tracer_config.cpp
@@ -359,6 +359,8 @@ Expected<FinalizedTracerConfig> finalize_config(const TracerConfig &config) {
     result.trace_id_128_bit = config.trace_id_128_bit;
   }
 
+  result.runtime_id = config.runtime_id;
+
   return result;
 }
 
diff --git a/src/datadog/tracer_config.h b/src/datadog/tracer_config.h
@@ -13,7 +13,7 @@
 #include "error.h"
 #include "expected.h"
 #include "propagation_style.h"
-#include "random.h"
+#include "runtime_id.h"
 #include "span_defaults.h"
 #include "span_sampler_config.h"
 #include "trace_sampler_config.h"
@@ -109,6 +109,9 @@ struct TracerConfig {
   // tracer will generate 64-bit trace IDs. `trace_id_128_bit` is overridden by
   // the `DD_TRACE_128_BIT_TRACEID_GENERATION_ENABLED` environment variable.
   bool trace_id_128_bit = false;
+
+  // TODO: document
+  Optional<RuntimeID> runtime_id;
 };
 
 // `FinalizedTracerConfig` contains `Tracer` implementation details derived from
@@ -138,8 +141,7 @@ class FinalizedTracerConfig {
   bool log_on_startup;
   bool trace_id_128_bit;
   bool report_telemetry;
-
-  std::string runtime_id = uuid();
+  Optional<RuntimeID> runtime_id;
 };
 
 // Return a `FinalizedTracerConfig` from the specified `config` and from any
diff --git a/src/datadog/tracer_telemetry.cpp b/src/datadog/tracer_telemetry.cpp
@@ -10,11 +10,13 @@ namespace tracing {
 
 TracerTelemetry::TracerTelemetry(
     bool enabled, const Clock& clock, const std::shared_ptr<Logger>& logger,
-    const std::shared_ptr<const SpanDefaults>& span_defaults)
+    const std::shared_ptr<const SpanDefaults>& span_defaults,
+    const RuntimeID& runtime_id)
     : enabled_(enabled),
       clock_(clock),
       logger_(logger),
       span_defaults_(span_defaults),
+      runtime_id_(runtime_id),
       hostname_(get_hostname().value_or("hostname-unavailable")) {
   if (enabled_) {
     // Register all the metrics that we're tracking by adding them to the
@@ -62,7 +64,7 @@ nlohmann::json TracerTelemetry::generate_telemetry_body(
       {"seq_id", seq_id_},
       {"request_type", request_type},
       {"tracer_time", tracer_time},
-      {"runtime_id", span_defaults_->runtime_id},
+      {"runtime_id", runtime_id_.string()},
       {"debug", debug_},
       {"application", nlohmann::json::object({
                           {"service_name", span_defaults_->service},
diff --git a/src/datadog/tracer_telemetry.h b/src/datadog/tracer_telemetry.h
@@ -30,6 +30,7 @@
 #include "clock.h"
 #include "json.hpp"
 #include "metrics.h"
+#include "runtime_id.h"
 
 namespace datadog {
 namespace tracing {
@@ -43,6 +44,7 @@ class TracerTelemetry {
   Clock clock_;
   std::shared_ptr<Logger> logger_;
   std::shared_ptr<const SpanDefaults> span_defaults_;
+  RuntimeID runtime_id_;
   std::string hostname_;
   uint64_t seq_id_ = 0;
   // Each metric has an associated MetricSnapshot that contains the data points,
@@ -98,7 +100,8 @@ class TracerTelemetry {
  public:
   TracerTelemetry(bool enabled, const Clock& clock,
                   const std::shared_ptr<Logger>& logger,
-                  const std::shared_ptr<const SpanDefaults>& span_defaults);
+                  const std::shared_ptr<const SpanDefaults>& span_defaults,
+                  const RuntimeID& runtime_id);
   bool enabled() { return enabled_; };
   // Provides access to the telemetry metrics for updating the values.
   // This value should not be stored.
diff --git a/test/test_tracer_telemetry.cpp b/test/test_tracer_telemetry.cpp
@@ -23,7 +23,8 @@ TEST_CASE("Tracer telemetry") {
   auto span_defaults = std::make_shared<SpanDefaults>();
   span_defaults->service = "testsvc";
   span_defaults->environment = "test";
-  TracerTelemetry tracer_telemetry = {true, clock, logger, span_defaults};
+  TracerTelemetry tracer_telemetry = {true, clock, logger, span_defaults,
+                                      RuntimeID::generate()};
 
   SECTION("generates app-started message") {
     auto app_started_message =

Original file line number	Diff line number	Diff line change
`@@ -22,7 +22,6 @@ nlohmann::json to_json(const SpanDefaults& defaults) {`
`22`	`22`	`TO_JSON(version);`
`23`	`23`	`TO_JSON(name);`
`24`	`24`	`TO_JSON(tags);`
`25`		`- TO_JSON(runtime_id);`
`26`	`25`	`#undef TO_JSON`
`27`	`26`	`return result;`
`28`	`27`	`}`