gorums: reduce generated-code hooks in server API

AGENTS.md

@@ -37,6 +37,16 @@ Generated `zorums_*_gorums.pb.go` files in `cmd/protoc-gen-gorums/dev/` are outp
 
 Never edit any generated file to satisfy a linter; fix the generator or its inputs and regenerate.
 
+### Versions
+
+Never bump versions on a feature branch, even for a breaking generator or runtime change.
+This covers `internal/version/version.go`, `GenVersion` and `MinVersion` in `runtime/gorumsimpl/version.go`, the gorums requirement in `benchkit/go.mod` and `examples/go.mod`, and the `replace` in `go.work`.
+`gorums-release prepare` changes all of them together at release time; a partial bump breaks the nested modules.
+Instead, state in the PR description which flag the next release needs:
+
+- `-bump-gen`: the generated code needs a new runtime feature.
+- `-bump-min`: code generated by an earlier release no longer compiles against the runtime.
+
 ## Tests
 
 Follow TDD: write a failing test, watch it fail, make it pass, refactor.

benchkit/benchmark/benchmark_test.go

@@ -13,6 +13,7 @@ import (
 	"github.com/relab/gorums"
 	"github.com/relab/gorums/benchkit"
 	"github.com/relab/gorums/gorumstest"
+	proto "google.golang.org/protobuf/proto"
 )
 
 func TestDescriptions(t *testing.T) {
@@ -249,7 +250,7 @@ func TestRunAsyncQCBenchmarkRejectsRateRamp(t *testing.T) {
 // to registerReplyDroppingPeer's silent drop, which instead times out). Call
 // before serving srv, since it registers a service.
 func registerFailingQuorumCallPeer(srv *gorums.Server, errMsg string) {
-	srv.RegisterHandler("benchmark.Benchmark.QuorumCall", func(_ gorums.ServerContext, _ *gorums.Message) (*gorums.Message, error) {
+	srv.RegisterHandler("benchmark.Benchmark.QuorumCall", func(_ gorums.ServerContext, _ *gorums.Message, _ func(proto.Message)) (proto.Message, error) {
 		return nil, errors.New(errMsg)
 	})
 }
@@ -645,11 +646,11 @@ func TestServerMeasuredVerify(t *testing.T) {
 // leak deterministically detectable.
 func TestServerMeasuredWindowExcludesClockSync(t *testing.T) {
 	const clockSyncDelay = 2 * time.Millisecond
-	delayClockSync := func(ctx gorums.ServerContext, in *gorums.Message, next gorums.Handler) (*gorums.Message, error) {
+	delayClockSync := func(ctx gorums.ServerContext, in *gorums.Message, send func(proto.Message), next gorums.Handler) (proto.Message, error) {
 		if in.GetMethod() == "benchkit.Control.ClockSync" {
 			time.Sleep(clockSyncDelay)
 		}
-		return next(ctx, in)
+		return next(ctx, in, send)
 	}
 	target := symmetricServers(t, 3, gorums.WithServerInterceptors(delayClockSync))
 

benchkit/benchmark/symmetric_test.go

@@ -19,6 +19,7 @@ import (
 	"github.com/relab/gorums"
 	"github.com/relab/gorums/benchkit"
 	"github.com/relab/gorums/gorumstest"
+	proto "google.golang.org/protobuf/proto"
 )
 
 // captureDiag redirects the probe-stall self-diagnosis to a buffer for the
@@ -124,11 +125,11 @@ func symmetricServers(t *testing.T, n int, serverOpts ...gorums.ServerOption) *S
 func registerReplyDroppingPeer(srv *gorums.Server, drop int64) {
 	var remaining atomic.Int64
 	remaining.Store(drop)
-	srv.RegisterHandler("benchmark.Benchmark.QuorumCall", func(_ gorums.ServerContext, in *gorums.Message) (*gorums.Message, error) {
+	srv.RegisterHandler("benchmark.Benchmark.QuorumCall", func(_ gorums.ServerContext, in *gorums.Message, _ func(proto.Message)) (proto.Message, error) {
 		if remaining.Add(-1) >= 0 {
 			return nil, nil // no response and no error: nothing is sent back
 		}
-		return gorums.NewResponseMessage(in, gorums.AsProto[*Echo](in)), nil
+		return gorums.AsProto[*Echo](in), nil
 	})
 }
 

call_async_test.go

@@ -10,6 +10,7 @@ import (
 	"github.com/relab/gorums/gorumstest"
 	"github.com/relab/gorums/internal/testutils/mock"
 	"github.com/relab/gorums/internal/testutils/mockcall"
+	"google.golang.org/protobuf/proto"
 	pb "google.golang.org/protobuf/types/known/wrapperspb"
 )
 
@@ -180,9 +181,9 @@ func TestCallAsyncSendsBeforeReturn(t *testing.T) {
 	config := gorumstest.Config(t, numNodes, func(int) gorumstest.ServerIface {
 		srv := gorums.NewServer()
 		echo := gorumstest.EchoHandler("echo")
-		srv.RegisterHandler(mock.TestMethod, func(ctx gorums.ServerContext, in *gorums.Message) (*gorums.Message, error) {
+		srv.RegisterHandler(mock.TestMethod, func(ctx gorums.ServerContext, in *gorums.Message, send func(proto.Message)) (proto.Message, error) {
 			received <- struct{}{}
-			return echo(ctx, in)
+			return echo(ctx, in, send)
 		})
 		return srv
 	})

call_test.go

@@ -18,6 +18,7 @@ import (
 	"google.golang.org/grpc"
 	"google.golang.org/grpc/codes"
 	"google.golang.org/grpc/status"
+	"google.golang.org/protobuf/proto"
 	pb "google.golang.org/protobuf/types/known/wrapperspb"
 )
 
@@ -28,7 +29,7 @@ import (
 func TestOnewayNoResourceLeak(t *testing.T) {
 	servers := gorumstest.LocalServers(t, 3)
 	for _, srv := range servers {
-		srv.RegisterHandler(mock.TestMethod, func(_ gorums.ServerContext, _ *gorums.Message) (*gorums.Message, error) {
+		srv.RegisterHandler(mock.TestMethod, func(_ gorums.ServerContext, _ *gorums.Message, _ func(proto.Message)) (proto.Message, error) {
 			return nil, nil
 		})
 	}
@@ -62,7 +63,7 @@ func TestOnewayDroppedHandleDoesNotDispatch(t *testing.T) {
 	var received atomic.Int32
 	servers := gorumstest.LocalServers(t, 3)
 	for _, srv := range servers {
-		srv.RegisterHandler(mock.TestMethod, func(_ gorums.ServerContext, _ *gorums.Message) (*gorums.Message, error) {
+		srv.RegisterHandler(mock.TestMethod, func(_ gorums.ServerContext, _ *gorums.Message, _ func(proto.Message)) (proto.Message, error) {
 			received.Add(1)
 			return nil, nil
 		})
@@ -86,7 +87,7 @@ func TestOnewayDroppedHandleDoesNotDispatch(t *testing.T) {
 func TestOnewayCallDoubleDispatchPanics(t *testing.T) {
 	servers := gorumstest.LocalServers(t, 3)
 	for _, srv := range servers {
-		srv.RegisterHandler(mock.TestMethod, func(_ gorums.ServerContext, _ *gorums.Message) (*gorums.Message, error) {
+		srv.RegisterHandler(mock.TestMethod, func(_ gorums.ServerContext, _ *gorums.Message, _ func(proto.Message)) (proto.Message, error) {
 			return nil, nil
 		})
 	}
@@ -137,7 +138,7 @@ func TestOnewayCallAsync(t *testing.T) {
 	var received atomic.Int32
 	servers := gorumstest.LocalServers(t, 3)
 	for _, srv := range servers {
-		srv.RegisterHandler(mock.TestMethod, func(_ gorums.ServerContext, _ *gorums.Message) (*gorums.Message, error) {
+		srv.RegisterHandler(mock.TestMethod, func(_ gorums.ServerContext, _ *gorums.Message, _ func(proto.Message)) (proto.Message, error) {
 			received.Add(1)
 			return nil, nil
 		})

cmd/protoc-gen-gorums/gengorums/template_funcs.go

@@ -18,6 +18,7 @@ var importMap = map[string]protogen.GoImportPath{
 	"context":    protogen.GoImportPath("context"),
 	"gorums":     protogen.GoImportPath("github.com/relab/gorums"),
 	"gorumsimpl": protogen.GoImportPath("github.com/relab/gorums/runtime/gorumsimpl"),
+	"proto":      protogen.GoImportPath("google.golang.org/protobuf/proto"),
 }
 
 func addImport(path, ident string, g *protogen.GeneratedFile) string {

cmd/protoc-gen-gorums/gengorums/template_server.go

@@ -73,33 +73,28 @@ var serverInterface = `
 var registerInterface = `
 {{$genFile := .GenFile}}
 {{$gorumsMessage := use "gorums.Message" .GenFile}}
+{{$protoMessage := use "proto.Message" .GenFile}}
 {{$asProto := use "gorums.AsProto" .GenFile}}
-{{$newMessage := use "gorums.NewResponseMessage" $genFile}}
 {{$gorumsServer := use "gorums.Server" $genFile}}
 {{range .Services -}}
 {{$names := .Names}}
-{{$reg := localNames "srv impl" $context $gorumsMessage $asProto $newMessage (methodTypes $genFile .Service)}}
+{{$reg := localNames "srv impl" $context $gorumsMessage $protoMessage $asProto (methodTypes $genFile .Service)}}
 
 func {{$names.Register}}({{$reg.srv}} *{{$gorumsServer}}, {{$reg.impl}} {{$names.Interface}}) {
 	{{- range .Service.Methods}}
-	{{- $local := localNames "ctx in req resp err out" $context $gorumsMessage $asProto $newMessage (in $genFile .) (out $genFile .) $reg.impl}}
-	{{$reg.srv}}.RegisterHandler("{{.Desc.FullName}}", func({{$local.ctx}} {{$context}}, {{$local.in}} *{{$gorumsMessage}}) (*{{$gorumsMessage}}, error) {
+	{{- $local := localNames "ctx in req resp send" $context $gorumsMessage $protoMessage $asProto (in $genFile .) (out $genFile .) $reg.impl}}
+	{{$reg.srv}}.RegisterHandler("{{.Desc.FullName}}", func({{$local.ctx}} {{$context}}, {{$local.in}} *{{$gorumsMessage}}, {{if isStreamingServer .}}{{$local.send}}{{else}}_{{end}} func({{$protoMessage}})) ({{$protoMessage}}, error) {
 		{{$local.req}} := {{$asProto}}[*{{in $genFile .}}]({{$local.in}})
 		{{- if isOneway .}}
 		{{$reg.impl}}.{{.GoName}}({{$local.ctx}}, {{$local.req}})
 		return nil, nil
 		{{- else if isStreamingServer .}}
 		{{$reg.impl}}.{{.GoName}}({{$local.ctx}}, {{$local.req}}, func({{$local.resp}} *{{out $genFile .}}) {
-			{{$local.out}} := {{$newMessage}}({{$local.in}}, {{$local.resp}})
-			{{$local.ctx}}.SendMessage({{$local.out}})
+			{{$local.send}}({{$local.resp}})
 		})
 		return nil, nil
 		{{- else }}
-		{{$local.resp}}, {{$local.err}} := {{$reg.impl}}.{{.GoName}}({{$local.ctx}}, {{$local.req}})
-		if {{$local.err}} != nil {
-			return nil, {{$local.err}}
-		}
-		return {{$newMessage}}({{$local.in}}, {{$local.resp}}), nil
+		return {{$reg.impl}}.{{.GoName}}({{$local.ctx}}, {{$local.req}})
 		{{- end}}
 	})
 	{{- end}}