Reviewer comments

include/grpcpp/ext/otel_plugin.h

@@ -103,9 +103,9 @@ class OpenTelemetryPluginBuilder {
   // Methods to manipulate which instruments are enabled in the OpenTelemetry
   // Stats Plugin.
   OpenTelemetryPluginBuilder& EnableMetrics(
-      const std::vector<absl::string_view>& metric_names);
+      absl::Span<const absl::string_view> metric_names);
   OpenTelemetryPluginBuilder& DisableMetrics(
-      const std::vector<absl::string_view>& metric_names);
+      absl::Span<const absl::string_view> metric_names);
   OpenTelemetryPluginBuilder& DisableAllMetrics();
   /// Add a plugin option to add to the opentelemetry plugin being built. At
   /// present, this type is an opaque type. Ownership of \a option is

src/cpp/ext/otel/otel_plugin.cc

@@ -151,7 +151,7 @@ OpenTelemetryPluginBuilderImpl::SetMeterProvider(
 }
 
 OpenTelemetryPluginBuilderImpl& OpenTelemetryPluginBuilderImpl::EnableMetrics(
-    const std::vector<absl::string_view>& metric_names) {
+    absl::Span<const absl::string_view> metric_names) {
   for (const auto& metric_name : metric_names) {
     metrics_.emplace(metric_name);
   }
@@ -159,7 +159,7 @@ OpenTelemetryPluginBuilderImpl& OpenTelemetryPluginBuilderImpl::EnableMetrics(
 }
 
 OpenTelemetryPluginBuilderImpl& OpenTelemetryPluginBuilderImpl::DisableMetrics(
-    const std::vector<absl::string_view>& metric_names) {
+    absl::Span<const absl::string_view> metric_names) {
   for (const auto& metric_name : metric_names) {
     metrics_.erase(metric_name);
   }
@@ -612,13 +612,13 @@ OpenTelemetryPluginBuilder::SetGenericMethodAttributeFilter(
 }
 
 OpenTelemetryPluginBuilder& OpenTelemetryPluginBuilder::EnableMetrics(
-    const std::vector<absl::string_view>& metric_names) {
+    absl::Span<const absl::string_view> metric_names) {
   impl_->EnableMetrics(metric_names);
   return *this;
 }
 
 OpenTelemetryPluginBuilder& OpenTelemetryPluginBuilder::DisableMetrics(
-    const std::vector<absl::string_view>& metric_names) {
+    absl::Span<const absl::string_view> metric_names) {
   impl_->DisableMetrics(metric_names);
   return *this;
 }

src/cpp/ext/otel/otel_plugin.h

@@ -136,9 +136,9 @@ class OpenTelemetryPluginBuilderImpl {
   // grpc.server.call.sent_total_compressed_message_size
   // grpc.server.call.rcvd_total_compressed_message_size
   OpenTelemetryPluginBuilderImpl& EnableMetrics(
-      const std::vector<absl::string_view>& metric_name);
+      absl::Span<const absl::string_view> metric_names);
   OpenTelemetryPluginBuilderImpl& DisableMetrics(
-      const std::vector<absl::string_view>& metric_name);
+      absl::Span<const absl::string_view> metric_names);
   OpenTelemetryPluginBuilderImpl& DisableAllMetrics();
   // If set, \a target_selector is called per channel to decide whether to
   // collect metrics on that target or not.

test/cpp/ext/otel/otel_plugin_test.cc

@@ -1355,16 +1355,17 @@ TEST_F(OpenTelemetryPluginNPCMetricsTest,
 
 TEST(OpenTelemetryPluginMetricsEnablingDisablingTest, TestEnableDisableAPIs) {
   grpc::internal::OpenTelemetryPluginBuilderImpl builder;
+  // First disable all metrics
   builder.DisableAllMetrics();
   EXPECT_TRUE(builder.TestOnlyEnabledMetrics().empty());
-
+  // Add in a few metrics
   builder.EnableMetrics(
       {"grpc.test.metric_1", "grpc.test.metric_2", "grpc.test.metric_3"});
   EXPECT_THAT(
       builder.TestOnlyEnabledMetrics(),
       ::testing::UnorderedElementsAre(
           "grpc.test.metric_1", "grpc.test.metric_2", "grpc.test.metric_3"));
-
+  // Now remove a few metrics
   builder.DisableMetrics({"grpc.test.metric_1", "grpc.test.metric_2"});
   EXPECT_THAT(builder.TestOnlyEnabledMetrics(),
               ::testing::UnorderedElementsAre("grpc.test.metric_3"));