fix parameter extraction in rust sdk (#3000)

Author: mschuwalow

golem-worker-executor/tests/api.rs

@@ -1497,7 +1497,7 @@ async fn get_worker_metadata(
     )?
     .len();
     assert_eq!(metadata2.component_size, component_file_size);
-    assert_eq!(metadata2.total_linear_memory_size, 1769472);
+    assert_eq!(metadata2.total_linear_memory_size, 1638400);
     Ok(())
 }
 

sdks/rust/golem-rust-macro/src/agentic/agent_implementation_impl.rs

@@ -197,7 +197,6 @@ fn build_match_arms(
 ) -> (Vec<proc_macro2::TokenStream>, Option<&syn::ImplItemFn>) {
     let mut match_arms = Vec::new();
     let mut constructor_method = None;
-    let mut method_index: usize = 0;
 
     for item in &impl_block.items {
         if let syn::ImplItem::Fn(method) = item {
@@ -295,14 +294,10 @@ fn build_match_arms(
                 },
             };
 
-            let current_method_index = method_index;
-            method_index += 1;
-
             let method_param_extraction = generate_method_param_extraction(
                 &param_idents,
                 &agent_type_name,
                 method_name_str.as_str(),
-                current_method_index,
                 post_method_param_extraction_logic,
             );
 
@@ -321,19 +316,18 @@ fn generate_method_param_extraction(
     param_idents: &[syn::Ident],
     agent_type_name: &str,
     method_name: &str,
-    method_index: usize,
     post_method_param_extraction_logic: proc_macro2::TokenStream,
 ) -> proc_macro2::TokenStream {
     let input_param_index_init = quote! {
       let mut input_param_index: usize = 0;
       let __agent_type_name = golem_rust::agentic::AgentTypeName(#agent_type_name.to_string());
-      let __param_schemas = golem_rust::agentic::get_method_parameter_types_by_index(
+      let __param_schemas = golem_rust::agentic::get_method_parameter_types(
           &__agent_type_name,
-          #method_index,
+          #method_name
       ).ok_or_else(|| {
           golem_rust::agentic::custom_error(format!(
-              "Internal Error: Parameter schemas not found for agent: {}, method index: {}",
-              #agent_type_name, #method_index
+              "Internal Error: Parameter schemas not found for agent: {}, method: {}",
+              #agent_type_name, #method_name
           ))
       })?;
     };

sdks/rust/golem-rust/benches/agent_registry_bench.rs

@@ -26,9 +26,8 @@ test_r::enable!();
 mod bench {
     use golem_rust::agentic::{
         get_constructor_parameter_type, get_enriched_agent_type_by_name, get_method_parameter_type,
-        get_method_parameter_types_by_index, register_agent_type, AgentTypeName,
-        EnrichedAgentMethod, EnrichedElementSchema, ExtendedAgentConstructor, ExtendedAgentType,
-        ExtendedDataSchema,
+        register_agent_type, AgentTypeName, EnrichedAgentMethod, EnrichedElementSchema,
+        ExtendedAgentConstructor, ExtendedAgentType, ExtendedDataSchema,
     };
     use golem_rust::golem_agentic::golem::agent::common::{AgentMode, ElementSchema, Snapshotting};
     use golem_wasm::golem_core_1_5_x::types::{NamedWitTypeNode, WitType, WitTypeNode};
@@ -166,27 +165,6 @@ mod bench {
             },
         );
 
-        // --- get_method_parameter_types_by_index (batch, Fix 4a+6) ---
-        println!("\n--- get_method_parameter_types_by_index (batch by method index) ---");
-
-        bench_loop("batch all params by method index", ITERATIONS, || {
-            black_box(get_method_parameter_types_by_index(&agent_type_name, 5));
-        });
-
-        bench_loop(
-            &format!(
-                "batch + index into vec for {} params (new hot path)",
-                PARAMS
-            ),
-            ITERATIONS,
-            || {
-                let schemas = get_method_parameter_types_by_index(&agent_type_name, 5).unwrap();
-                for i in 0..PARAMS {
-                    black_box(schemas.get(i));
-                }
-            },
-        );
-
         // --- get_constructor_parameter_type ---
         println!("\n--- get_constructor_parameter_type ---");
 

sdks/rust/golem-rust/src/agentic/agent_registry.rs

@@ -204,14 +204,14 @@ pub fn get_method_parameter_type(
     extract_parameter_schema(&method.input_schema, parameter_index)
 }
 
-pub fn get_method_parameter_types_by_index(
+pub fn get_method_parameter_types(
     agent_type_name: &AgentTypeName,
-    method_index: usize,
+    method_name: &str,
 ) -> Option<Vec<EnrichedElementSchema>> {
     let state = get_state();
     let agent_types = state.agent_types.borrow();
     let agent_type = agent_types.agent_types.get(agent_type_name.0.as_str())?;
-    let method = agent_type.methods.get(method_index)?;
+    let method = agent_type.methods.iter().find(|m| m.name == method_name)?;
 
     Some(extract_all_parameter_schemas(&method.input_schema))
 }