feat(sidekick/rust): integrate explicit resource name extraction (#4496)

Integrate `google.api.resource_reference` explicit extraction into
tracing telemetry.

When explicit resource annotations are available
(`HasResourceNameFields`), the templates now extract the value directly
from the generated request object and pass it via
`options::internal::set_resource_name`, without having to fall back on
the heuristic.

Depends on:
googleapis/google-cloud-rust#3771
googleapis/google-cloud-rust#4035

Fixes #4440

Author: haphungw

internal/sidekick/api/resource_identification.go

@@ -52,8 +52,6 @@ func identifyTargetResourceForBinding(method *Method, binding *PathBinding, voca
 		return nil
 	}
 
-	// Priority 1: Explicit Identification
-	// Matches google.api.resource_reference annotations.
 	target, err := identifyExplicitTarget(method, binding)
 	if err != nil {
 		return err
@@ -63,10 +61,9 @@ func identifyTargetResourceForBinding(method *Method, binding *PathBinding, voca
 		return nil
 	}
 
-	// Priority 2: Heuristic Identification
 	// Uses path segment patterns to guess the resource.
 	if enableHeuristics {
-		target, err = identifyHeuristicTarget(method, binding, vocabulary)
+		target, err := identifyHeuristicTarget(method, binding, vocabulary)
 		if err != nil {
 			return err
 		}

internal/sidekick/api/resource_identification_test.go

@@ -384,6 +384,7 @@ func TestIdentifyTargetResources_Heuristic(t *testing.T) {
 					PathInfo: &PathInfo{
 						Bindings: []*PathBinding{{PathTemplate: p}},
 					},
+					Service: model.Services[0],
 				}
 				model.Services[0].Methods = append(model.Services[0].Methods, m)
 			}

internal/sidekick/rust/annotate.go

@@ -419,6 +419,7 @@ type pathBindingAnnotation struct {
 	HasResourceNameGeneration bool
 	ResourceNameTemplate      string
 	ResourceNameArgs          []string
+	HasResourceNameArgs       bool
 }
 
 // QueryParamsCanFail returns true if we serialize certain query parameters, which can fail. The code we generate
@@ -1635,9 +1636,11 @@ func (c *codec) annotateResourceNameGeneration(m *api.Method, annotation *method
 					}
 					bAnn.ResourceNameTemplate = tmpl
 					bAnn.ResourceNameArgs = formatResourceNameArgs(b.TargetResource.FieldPaths)
+					bAnn.HasResourceNameArgs = len(bAnn.ResourceNameArgs) > 0
 				} else {
 					bAnn.ResourceNameTemplate = ""
 					bAnn.ResourceNameArgs = nil
+					bAnn.HasResourceNameArgs = false
 				}
 			}
 		}

internal/sidekick/rust/annotate_method_test.go

@@ -387,16 +387,19 @@ func TestAnnotateMethodResourceNameTemplate(t *testing.T) {
 					HasResourceNameGeneration: true,
 					ResourceNameTemplate:      "//Test.googleapis.com/projects/{}/locations/{}/clusters/{}",
 					ResourceNameArgs:          []string{"var_name"},
+					HasResourceNameArgs:       true,
 				},
 				{
 					HasResourceNameGeneration: true,
 					ResourceNameTemplate:      "//Test.googleapis.com/projects/{}/locations/{}/clusters/{}",
 					ResourceNameArgs:          []string{"var_project", "var_location", "var_cluster"},
+					HasResourceNameArgs:       true,
 				},
 				{
 					HasResourceNameGeneration: true,
 					ResourceNameTemplate:      "",
 					ResourceNameArgs:          nil,
+					HasResourceNameArgs:       false,
 				},
 			},
 		},

internal/sidekick/rust/templates/crate/src/transport.rs.mustache

@@ -122,10 +122,10 @@ impl super::stub::{{Codec.Name}} for {{Codec.Name}} {
             {{^Codec.HasVariablePath}}
             let path = "{{Codec.PathFmt}}".to_string();
             {{/Codec.HasVariablePath}}
+            
             {{#Codec.DetailedTracingAttributes}}
             let path_template = "{{Codec.PathTemplate}}";
             {{/Codec.DetailedTracingAttributes}}
-
             {{#Codec.HasResourceNameGeneration}}
             let resource_name = format!(
                 "{{{Codec.ResourceNameTemplate}}}",
@@ -183,6 +183,21 @@ impl super::stub::{{Codec.Name}} for {{Codec.Name}} {
         #[cfg(google_cloud_unstable_tracing)]
         let options = {
             use google_cloud_gax::options::internal::{RequestOptionsExt, PathTemplate};
+            {{#Codec.HasResourceNameFields}}
+            let options = {
+                let resource_name = Option::<&String>::None
+                    {{#Codec.ResourceNameFields}}
+                    .or({{{Accessor}}})
+                    {{/Codec.ResourceNameFields}};
+                if let Some(rn) = resource_name {
+                    use google_cloud_gax::options::internal::ResourceName;
+                    let full_resource_name = format!("//{{DefaultHost}}/{}", rn);
+                    options.insert_extension(ResourceName(full_resource_name))
+                } else {
+                    options
+                }
+            };
+            {{/Codec.HasResourceNameFields}}
             options.insert_extension(PathTemplate(_path_template))
         };
         {{/Codec.DetailedTracingAttributes}}

internal/sidekick/rust/templates/grpc-client/transport.rs.mustache

@@ -122,6 +122,27 @@ impl super::stub::{{Codec.Name}} for {{Codec.Name}} {
             {{PathInfo.Codec.IsIdempotent}},
             {{/HasAutoPopulatedFields}}
         );
+        {{#Codec.DetailedTracingAttributes}}
+        #[cfg(google_cloud_unstable_tracing)]
+        let options = {
+            {{#Codec.HasResourceNameFields}}
+            let resource_name = Option::<&String>::None
+                {{#Codec.ResourceNameFields}}
+                .or({{{Accessor}}})
+                {{/Codec.ResourceNameFields}};
+            if let Some(rn) = resource_name {
+                use google_cloud_gax::options::internal::ResourceName;
+                let full_resource_name = format!("//{{DefaultHost}}/{}", rn);
+                options.insert_extension(ResourceName(full_resource_name))
+            } else {
+                options
+            }
+            {{/Codec.HasResourceNameFields}}
+            {{^Codec.HasResourceNameFields}}
+            options
+            {{/Codec.HasResourceNameFields}}
+        };
+        {{/Codec.DetailedTracingAttributes}}
         let extensions = {
             let mut e = Extensions::new();
             e.insert(GrpcMethod::new("{{SourceService.Package}}.{{SourceService.Name}}", "{{Name}}"));