[call-v3] Convert server-call-tracer filter (#35249)

Closes #35249

COPYBARA_INTEGRATE_REVIEW=https://github.com/grpc/grpc/pull/35249 from ctiller:cg-server-call-tracer ad52acb64f
PiperOrigin-RevId: 588885615

src/core/ext/filters/http/client/http_client_filter.cc

@@ -53,6 +53,7 @@ namespace grpc_core {
 
 const NoInterceptor HttpClientFilter::Call::OnServerToClientMessage;
 const NoInterceptor HttpClientFilter::Call::OnClientToServerMessage;
+const NoInterceptor HttpClientFilter::Call::OnFinalize;
 
 const grpc_channel_filter HttpClientFilter::kFilter =
     MakePromiseBasedFilter<HttpClientFilter, FilterEndpoint::kClient,

src/core/ext/filters/http/client/http_client_filter.h

@@ -45,6 +45,7 @@ class HttpClientFilter : public ImplementChannelFilter<HttpClientFilter> {
     absl::Status OnServerTrailingMetadata(ServerMetadata& md);
     static const NoInterceptor OnClientToServerMessage;
     static const NoInterceptor OnServerToClientMessage;
+    static const NoInterceptor OnFinalize;
   };
 
  private:

src/core/ext/filters/http/server/http_server_filter.cc

@@ -51,6 +51,7 @@ namespace grpc_core {
 
 const NoInterceptor HttpServerFilter::Call::OnClientToServerMessage;
 const NoInterceptor HttpServerFilter::Call::OnServerToClientMessage;
+const NoInterceptor HttpServerFilter::Call::OnFinalize;
 
 const grpc_channel_filter HttpServerFilter::kFilter =
     MakePromiseBasedFilter<HttpServerFilter, FilterEndpoint::kServer,

src/core/ext/filters/http/server/http_server_filter.h

@@ -47,6 +47,7 @@ class HttpServerFilter : public ImplementChannelFilter<HttpServerFilter> {
     void OnServerTrailingMetadata(ServerMetadata& md);
     static const NoInterceptor OnClientToServerMessage;
     static const NoInterceptor OnServerToClientMessage;
+    static const NoInterceptor OnFinalize;
   };
 
  private:

src/core/ext/filters/message_size/message_size_filter.cc

@@ -53,9 +53,11 @@ namespace grpc_core {
 const NoInterceptor ClientMessageSizeFilter::Call::OnClientInitialMetadata;
 const NoInterceptor ClientMessageSizeFilter::Call::OnServerInitialMetadata;
 const NoInterceptor ClientMessageSizeFilter::Call::OnServerTrailingMetadata;
+const NoInterceptor ClientMessageSizeFilter::Call::OnFinalize;
 const NoInterceptor ServerMessageSizeFilter::Call::OnClientInitialMetadata;
 const NoInterceptor ServerMessageSizeFilter::Call::OnServerInitialMetadata;
 const NoInterceptor ServerMessageSizeFilter::Call::OnServerTrailingMetadata;
+const NoInterceptor ServerMessageSizeFilter::Call::OnFinalize;
 
 //
 // MessageSizeParsedConfig

src/core/ext/filters/message_size/message_size_filter.h

@@ -99,6 +99,7 @@ class ServerMessageSizeFilter final
     static const NoInterceptor OnClientInitialMetadata;
     static const NoInterceptor OnServerInitialMetadata;
     static const NoInterceptor OnServerTrailingMetadata;
+    static const NoInterceptor OnFinalize;
     ServerMetadataHandle OnClientToServerMessage(
         const Message& message, ServerMessageSizeFilter* filter);
     ServerMetadataHandle OnServerToClientMessage(
@@ -126,6 +127,7 @@ class ClientMessageSizeFilter final
     static const NoInterceptor OnClientInitialMetadata;
     static const NoInterceptor OnServerInitialMetadata;
     static const NoInterceptor OnServerTrailingMetadata;
+    static const NoInterceptor OnFinalize;
     ServerMetadataHandle OnClientToServerMessage(const Message& message);
     ServerMetadataHandle OnServerToClientMessage(const Message& message);
 

src/core/lib/channel/promise_based_filter.h

@@ -186,6 +186,11 @@ inline constexpr bool HasChannelAccess(R (T::*)(A)) {
   return false;
 }
 
+template <typename T, typename R, typename A>
+inline constexpr bool HasChannelAccess(R (T::*)()) {
+  return false;
+}
+
 template <typename T, typename R, typename A, typename C>
 inline constexpr bool HasChannelAccess(R (T::*)(A, C)) {
   return true;
@@ -208,7 +213,8 @@ inline constexpr bool CallHasChannelAccess() {
                           &Derived::Call::OnClientToServerMessage,
                           &Derived::Call::OnServerInitialMetadata,
                           &Derived::Call::OnServerToClientMessage,
-                          &Derived::Call::OnServerTrailingMetadata);
+                          &Derived::Call::OnServerTrailingMetadata,
+                          &Derived::Call::OnFinalize);
 }
 
 // Given a boolean X export a type:
@@ -642,6 +648,18 @@ inline void InterceptServerTrailingMetadata(
       });
 }
 
+inline void InterceptFinalize(const NoInterceptor*, void*) {}
+
+template <class Call>
+inline void InterceptFinalize(void (Call::*fn)(const grpc_call_final_info*),
+                              Call* call) {
+  GPR_DEBUG_ASSERT(fn == &Call::OnFinalize);
+  GetContext<CallFinalization>()->Add(
+      [call](const grpc_call_final_info* final_info) {
+        call->OnFinalize(final_info);
+      });
+}
+
 template <typename Derived>
 absl::enable_if_t<std::is_empty<FilterCallData<Derived>>::value,
                   FilterCallData<Derived>*>
@@ -674,6 +692,7 @@ MakeFilterCall(Derived* derived) {
 // - OnServerToClientMessage  - $VALUE_TYPE = Message
 // - OnClientToServerMessage  - $VALUE_TYPE = Message
 // - OnServerTrailingMetadata - $VALUE_TYPE = ServerMetadata
+// - OnFinalize               - special, see below
 // These members define an interception point for a particular event in
 // the call lifecycle.
 // The type of these members matters, and is selectable by the class
@@ -706,6 +725,12 @@ MakeFilterCall(Derived* derived) {
 //   the filter can return nullptr for success, or a metadata handle for
 //   failure (in which case the call will be aborted).
 //   useful for cases where the exact metadata returned needs to be customized.
+// Finally, OnFinalize can be added to intecept call finalization.
+// It must have one of the signatures:
+// - static const NoInterceptor OnFinalize:
+//   the filter does not intercept call finalization.
+// - void OnFinalize(const grpc_call_final_info*):
+//   the filter intercepts call finalization.
 template <typename Derived>
 class ImplementChannelFilter : public ChannelFilter {
  public:
@@ -730,6 +755,7 @@ class ImplementChannelFilter : public ChannelFilter {
     promise_filter_detail::InterceptServerTrailingMetadata(
         &Derived::Call::OnServerTrailingMetadata, call,
         static_cast<Derived*>(this), call_spine);
+    promise_filter_detail::InterceptFinalize(&Derived::Call::OnFinalize, call);
   }
 
   // Polyfill for the original promise scheme.
@@ -745,6 +771,9 @@ class ImplementChannelFilter : public ChannelFilter {
         &Derived::Call::OnServerInitialMetadata, call, call_args);
     promise_filter_detail::InterceptServerToClientMessage(
         &Derived::Call::OnServerToClientMessage, call, call_args);
+    promise_filter_detail::InterceptFinalize(
+        &Derived::Call::OnFinalize,
+        static_cast<typename Derived::Call*>(&call->call));
     return promise_filter_detail::MapResult(
         &Derived::Call::OnServerTrailingMetadata,
         promise_filter_detail::RaceAsyncCompletion<

src/core/lib/channel/server_call_tracer_filter.cc

@@ -42,19 +42,55 @@ namespace grpc_core {
 
 namespace {
 
-// TODO(yashykt): This filter is not really needed. We should be able to move
-// this to the connected filter.
-class ServerCallTracerFilter : public ChannelFilter {
+class ServerCallTracerFilter
+    : public ImplementChannelFilter<ServerCallTracerFilter> {
  public:
   static const grpc_channel_filter kFilter;
 
   static absl::StatusOr<ServerCallTracerFilter> Create(
       const ChannelArgs& /*args*/, ChannelFilter::Args /*filter_args*/);
 
-  ArenaPromise<ServerMetadataHandle> MakeCallPromise(
-      CallArgs call_args, NextPromiseFactory next_promise_factory) override;
+  class Call {
+   public:
+    void OnClientInitialMetadata(ClientMetadata& client_initial_metadata) {
+      auto* call_tracer = CallTracer();
+      if (call_tracer == nullptr) return;
+      call_tracer->RecordReceivedInitialMetadata(&client_initial_metadata);
+    }
+
+    void OnServerInitialMetadata(ServerMetadata& server_initial_metadata) {
+      auto* call_tracer = CallTracer();
+      if (call_tracer == nullptr) return;
+      call_tracer->RecordSendInitialMetadata(&server_initial_metadata);
+    }
+
+    void OnFinalize(const grpc_call_final_info* final_info) {
+      auto* call_tracer = CallTracer();
+      if (call_tracer == nullptr) return;
+      call_tracer->RecordEnd(final_info);
+    }
+
+    void OnServerTrailingMetadata(ServerMetadata& server_trailing_metadata) {
+      auto* call_tracer = CallTracer();
+      if (call_tracer == nullptr) return;
+      call_tracer->RecordSendTrailingMetadata(&server_trailing_metadata);
+    }
+
+    static const NoInterceptor OnClientToServerMessage;
+    static const NoInterceptor OnServerToClientMessage;
+
+   private:
+    static ServerCallTracer* CallTracer() {
+      auto* call_context = GetContext<grpc_call_context_element>();
+      return static_cast<ServerCallTracer*>(
+          call_context[GRPC_CONTEXT_CALL_TRACER].value);
+    }
+  };
 };
 
+const NoInterceptor ServerCallTracerFilter::Call::OnClientToServerMessage;
+const NoInterceptor ServerCallTracerFilter::Call::OnServerToClientMessage;
+
 const grpc_channel_filter ServerCallTracerFilter::kFilter =
     MakePromiseBasedFilter<ServerCallTracerFilter, FilterEndpoint::kServer,
                            kFilterExaminesServerInitialMetadata>(
@@ -65,34 +101,6 @@ absl::StatusOr<ServerCallTracerFilter> ServerCallTracerFilter::Create(
   return ServerCallTracerFilter();
 }
 
-ArenaPromise<ServerMetadataHandle> ServerCallTracerFilter::MakeCallPromise(
-    CallArgs call_args, NextPromiseFactory next_promise_factory) {
-  auto* call_context = GetContext<grpc_call_context_element>();
-  auto* call_tracer = static_cast<ServerCallTracer*>(
-      call_context[GRPC_CONTEXT_CALL_TRACER].value);
-  if (call_tracer == nullptr) {
-    return next_promise_factory(std::move(call_args));
-  }
-  call_tracer->RecordReceivedInitialMetadata(
-      call_args.client_initial_metadata.get());
-  call_args.server_initial_metadata->InterceptAndMap(
-      [call_tracer](ServerMetadataHandle metadata) {
-        call_tracer->RecordSendInitialMetadata(metadata.get());
-        return metadata;
-      });
-  GetContext<CallFinalization>()->Add(
-      [call_tracer](const grpc_call_final_info* final_info) {
-        call_tracer->RecordEnd(final_info);
-      });
-  return OnCancel(
-      Map(next_promise_factory(std::move(call_args)),
-          [call_tracer](ServerMetadataHandle md) {
-            call_tracer->RecordSendTrailingMetadata(md.get());
-            return md;
-          }),
-      [call_tracer]() { call_tracer->RecordCancel(absl::CancelledError()); });
-}
-
 }  // namespace
 
 void RegisterServerCallTracerFilter(CoreConfiguration::Builder* builder) {