agents: move text metrics calculation to common

The `Resource` is now updated in `fill_proc_metrics()` so there's no
need for every agent to do it.

PR-URL: #198
Reviewed-By: Trevor Norris <trev.norris@gmail.com>

agents/otlp/src/otlp_common.cc

@@ -46,6 +46,7 @@ using opentelemetry::trace::SpanKind;
 using opentelemetry::trace::TraceFlags;
 using opentelemetry::trace::TraceId;
 using opentelemetry::trace::propagation::detail::HexToBinary;
+using opentelemetry::v1::trace::SemanticConventions::kProcessOwner;
 using opentelemetry::v1::trace::SemanticConventions::kThreadId;
 using opentelemetry::v1::trace::SemanticConventions::kThreadName;
 
@@ -179,7 +180,8 @@ Resource* UpdateResource(ResourceAttributes&& attrs) {
 
 // NOLINTNEXTLINE(runtime/references)
 void fill_proc_metrics(std::vector<MetricData>& metrics,
-                       const ProcessMetrics::MetricsStor& stor) {
+                       const ProcessMetrics::MetricsStor& stor,
+                       const ProcessMetrics::MetricsStor& prev_stor) {
   time_point end{
         duration_cast<time_point::duration>(
           milliseconds(static_cast<uint64_t>(stor.timestamp)))};
@@ -230,6 +232,17 @@ void fill_proc_metrics(std::vector<MetricData>& metrics,
 NSOLID_PROCESS_METRICS_UINT64(V)
 NSOLID_PROCESS_METRICS_DOUBLE(V)
 #undef V
+
+  // Update Resource if needed:
+  // Check if 'user' or 'title' are different from the previous metrics.
+  if (prev_stor.user != stor.user || prev_stor.title != stor.title) {
+    ResourceAttributes attrs = {
+      { kProcessOwner, stor.user },
+      { "process.title", stor.title },
+    };
+
+    USE(UpdateResource(std::move(attrs)));
+  }
 }
 
 // NOLINTNEXTLINE(runtime/references)

agents/otlp/src/otlp_common.h

@@ -48,7 +48,8 @@ OPENTELEMETRY_NAMESPACE::sdk::resource::Resource* UpdateResource(
     OPENTELEMETRY_NAMESPACE::sdk::resource::ResourceAttributes&&);
 
 void fill_proc_metrics(std::vector<opentelemetry::sdk::metrics::MetricData>&,
-                       const ProcessMetrics::MetricsStor& stor);
+                       const ProcessMetrics::MetricsStor& stor,
+                       const ProcessMetrics::MetricsStor& prev_stor);
 
 void fill_env_metrics(std::vector<opentelemetry::sdk::metrics::MetricData>&,
                       const ThreadMetrics::MetricsStor& stor);

agents/otlp/src/otlp_metrics.cc

@@ -39,14 +39,11 @@ using opentelemetry::sdk::metrics::ScopeMetrics;
 using opentelemetry::sdk::metrics::SumPointData;
 using opentelemetry::sdk::metrics::ValueType;
 using opentelemetry::sdk::resource::Resource;
-using opentelemetry::sdk::resource::ResourceAttributes;
 using opentelemetry::v1::exporter::otlp::GetOtlpDefaultHttpMetricsProtocol;
 using opentelemetry::v1::exporter::otlp::OtlpGrpcMetricExporter;
 using opentelemetry::v1::exporter::otlp::OtlpGrpcMetricExporterOptions;
 using opentelemetry::v1::exporter::otlp::OtlpHttpMetricExporter;
 using opentelemetry::v1::exporter::otlp::OtlpHttpMetricExporterOptions;
-using opentelemetry::v1::trace::SemanticConventions::kProcessOwner;
-using opentelemetry::v1::trace::SemanticConventions::kThreadId;
 
 namespace node {
 namespace nsolid {
@@ -104,23 +101,10 @@ OTLPMetrics::~OTLPMetrics() {
 /*virtual*/
 void OTLPMetrics::got_proc_metrics(const ProcessMetricsStor& stor,
                                    const ProcessMetricsStor& prev_stor) {
-  ResourceMetrics data;
-  Resource* resource;
-  // Check if 'user' or 'title' are different from the previous metrics
-  if (prev_stor.user != stor.user || prev_stor.title != stor.title) {
-    ResourceAttributes attrs = {
-      { kProcessOwner, stor.user },
-      { "process.title", stor.title },
-    };
-
-    resource = UpdateResource(std::move(attrs));
-  } else {
-    resource = GetResource();
-  }
-
-  data.resource_ = resource;
   std::vector<MetricData> metrics;
-  fill_proc_metrics(metrics, stor);
+  fill_proc_metrics(metrics, stor, prev_stor);
+  ResourceMetrics data;
+  data.resource_ = GetResource();
   data.scope_metric_data_ = std::vector<ScopeMetrics>{{scope_, metrics}};
   auto result = otlp_metric_exporter_->Export(data);
   Debug("# ProcessMetrics Exported. Result: %d\n", static_cast<int>(result));