Chore: Remove bus (#47511)

* Chore: Remove bus

* remove unused const

pkg/bus/bus.go

@@ -21,41 +21,17 @@ type Msg interface{}
 // ErrHandlerNotFound defines an error if a handler is not found
 var ErrHandlerNotFound = errors.New("handler not found")
 
-// TransactionManager defines a transaction interface
-type TransactionManager interface {
-	InTransaction(ctx context.Context, fn func(ctx context.Context) error) error
-}
-
 // Bus type defines the bus interface structure
 type Bus interface {
-	Dispatch(ctx context.Context, msg Msg) error
-
 	Publish(ctx context.Context, msg Msg) error
-
-	// InTransaction starts a transaction and store it in the context.
-	// The caller can then pass a function with multiple DispatchCtx calls that
-	// all will be executed in the same transaction. InTransaction will rollback if the
-	// callback returns an error.
-	InTransaction(ctx context.Context, fn func(ctx context.Context) error) error
-
-	AddHandler(handler HandlerFunc)
-
 	AddEventListener(handler HandlerFunc)
-
-	// SetTransactionManager allows the user to replace the internal
-	// noop TransactionManager that is responsible for managing
-	// transactions in `InTransaction`
-	SetTransactionManager(tm TransactionManager)
 }
 
 // InProcBus defines the bus structure
 type InProcBus struct {
 	logger           log.Logger
-	handlers         map[string]HandlerFunc
-	handlersWithCtx  map[string]HandlerFunc
 	listeners        map[string][]HandlerFunc
 	listenersWithCtx map[string][]HandlerFunc
-	txMng            TransactionManager
 	tracer           tracing.Tracer
 }
 
@@ -64,11 +40,6 @@ func ProvideBus(tracer tracing.Tracer) *InProcBus {
 	return globalBus
 }
 
-// InTransaction defines an in transaction function
-func (b *InProcBus) InTransaction(ctx context.Context, fn func(ctx context.Context) error) error {
-	return b.txMng.InTransaction(ctx, fn)
-}
-
 // temp stuff, not sure how to handle bus instance, and init yet
 var globalBus = New()
 
@@ -76,11 +47,8 @@ var globalBus = New()
 func New() *InProcBus {
 	bus := &InProcBus{
 		logger:           log.New("bus"),
-		handlers:         make(map[string]HandlerFunc),
-		handlersWithCtx:  make(map[string]HandlerFunc),
 		listeners:        make(map[string][]HandlerFunc),
 		listenersWithCtx: make(map[string][]HandlerFunc),
-		txMng:            &noopTransactionManager{},
 	}
 	bus.tracer = tracing.InitializeForBus()
 	return bus
@@ -91,46 +59,6 @@ func GetBus() Bus {
 	return globalBus
 }
 
-// SetTransactionManager function assign a transaction manager to the bus.
-func (b *InProcBus) SetTransactionManager(tm TransactionManager) {
-	b.txMng = tm
-}
-
-// DispatchCtx function dispatch a message to the bus context.
-func (b *InProcBus) Dispatch(ctx context.Context, msg Msg) error {
-	var msgName = reflect.TypeOf(msg).Elem().Name()
-
-	ctx, span := b.tracer.Start(ctx, "bus - "+msgName)
-	defer span.End()
-
-	span.SetAttributes("msg", msgName, attribute.Key("msg").String(msgName))
-
-	withCtx := true
-	var handler = b.handlersWithCtx[msgName]
-	if handler == nil {
-		withCtx = false
-		handler = b.handlers[msgName]
-		if handler == nil {
-			return ErrHandlerNotFound
-		}
-	}
-
-	var params = []reflect.Value{}
-	if withCtx {
-		params = append(params, reflect.ValueOf(ctx))
-	} else if setting.Env == setting.Dev {
-		b.logger.Warn("DispatchCtx called with message handler registered using AddHandler and should be changed to use AddHandler", "msgName", msgName)
-	}
-	params = append(params, reflect.ValueOf(msg))
-
-	ret := reflect.ValueOf(handler).Call(params)
-	err := ret[0].Interface()
-	if err == nil {
-		return nil
-	}
-	return err.(error)
-}
-
 // PublishCtx function publish a message to the bus listener.
 func (b *InProcBus) Publish(ctx context.Context, msg Msg) error {
 	var msgName = reflect.TypeOf(msg).Elem().Name()
@@ -176,17 +104,6 @@ func callListeners(listeners []HandlerFunc, params []reflect.Value) error {
 	return nil
 }
 
-func (b *InProcBus) AddHandler(handler HandlerFunc) {
-	handlerType := reflect.TypeOf(handler)
-	queryTypeName := handlerType.In(1).Elem().Name()
-	b.handlersWithCtx[queryTypeName] = handler
-}
-
-// GetHandlerCtx returns the handler function for the given struct name.
-func (b *InProcBus) GetHandlerCtx(name string) HandlerFunc {
-	return b.handlersWithCtx[name]
-}
-
 func (b *InProcBus) AddEventListener(handler HandlerFunc) {
 	handlerType := reflect.TypeOf(handler)
 	eventName := handlerType.In(1).Elem().Name()
@@ -197,36 +114,12 @@ func (b *InProcBus) AddEventListener(handler HandlerFunc) {
 	b.listenersWithCtx[eventName] = append(b.listenersWithCtx[eventName], handler)
 }
 
-// AddHandler attaches a handler function to the global bus context.
-// Package level function.
-func AddHandler(implName string, handler HandlerFunc) {
-	globalBus.AddHandler(handler)
-}
-
 // AddEventListenerCtx attaches a handler function to the event listener.
 // Package level function.
 func AddEventListener(handler HandlerFunc) {
 	globalBus.AddEventListener(handler)
 }
 
-func Dispatch(ctx context.Context, msg Msg) error {
-	return globalBus.Dispatch(ctx, msg)
-}
-
 func Publish(ctx context.Context, msg Msg) error {
 	return globalBus.Publish(ctx, msg)
 }
-
-func GetHandlerCtx(name string) HandlerFunc {
-	return globalBus.GetHandlerCtx(name)
-}
-
-func ClearBusHandlers() {
-	globalBus = New()
-}
-
-type noopTransactionManager struct{}
-
-func (*noopTransactionManager) InTransaction(ctx context.Context, fn func(ctx context.Context) error) error {
-	return fn(ctx)
-}

pkg/bus/bus_test.go

@@ -2,7 +2,6 @@ package bus
 
 import (
 	"context"
-	"errors"
 	"testing"
 
 	"github.com/grafana/grafana/pkg/infra/tracing"
@@ -14,140 +13,6 @@ type testQuery struct {
 	Resp string
 }
 
-func TestDispatch(t *testing.T) {
-	bus := New()
-	tracer, err := tracing.InitializeTracerForTest()
-	require.NoError(t, err)
-	bus.tracer = tracer
-
-	var invoked bool
-
-	bus.AddHandler(func(ctx context.Context, query *testQuery) error {
-		invoked = true
-		return nil
-	})
-
-	require.NoError(t, err)
-	err = bus.Dispatch(context.Background(), &testQuery{})
-	require.NoError(t, err)
-
-	require.True(t, invoked, "expected handler to be called")
-}
-
-func TestDispatch_NoRegisteredHandler(t *testing.T) {
-	bus := New()
-	tracer, err := tracing.InitializeTracerForTest()
-	require.NoError(t, err)
-	bus.tracer = tracer
-
-	err = bus.Dispatch(context.Background(), &testQuery{})
-	require.Equal(t, err, ErrHandlerNotFound,
-		"expected bus to return HandlerNotFound since no handler is registered")
-}
-
-func TestDispatch_ContextHandler(t *testing.T) {
-	bus := New()
-	tracer, err := tracing.InitializeTracerForTest()
-	require.NoError(t, err)
-	bus.tracer = tracer
-
-	var invoked bool
-
-	bus.AddHandler(func(ctx context.Context, query *testQuery) error {
-		invoked = true
-		return nil
-	})
-
-	err = bus.Dispatch(context.Background(), &testQuery{})
-	require.NoError(t, err)
-
-	require.True(t, invoked, "expected handler to be called")
-}
-
-func TestDispatchCtx(t *testing.T) {
-	bus := New()
-	tracer, err := tracing.InitializeTracerForTest()
-	require.NoError(t, err)
-	bus.tracer = tracer
-
-	var invoked bool
-
-	bus.AddHandler(func(ctx context.Context, query *testQuery) error {
-		invoked = true
-		return nil
-	})
-
-	err = bus.Dispatch(context.Background(), &testQuery{})
-	require.NoError(t, err)
-
-	require.True(t, invoked, "expected handler to be called")
-}
-
-func TestDispatchCtx_NoContextHandler(t *testing.T) {
-	bus := New()
-	tracer, err := tracing.InitializeTracerForTest()
-	require.NoError(t, err)
-	bus.tracer = tracer
-
-	var invoked bool
-
-	bus.AddHandler(func(ctx context.Context, query *testQuery) error {
-		invoked = true
-		return nil
-	})
-
-	err = bus.Dispatch(context.Background(), &testQuery{})
-	require.NoError(t, err)
-
-	require.True(t, invoked, "expected handler to be called")
-}
-
-func TestDispatchCtx_NoRegisteredHandler(t *testing.T) {
-	bus := New()
-	tracer, err := tracing.InitializeTracerForTest()
-	require.NoError(t, err)
-	bus.tracer = tracer
-
-	err = bus.Dispatch(context.Background(), &testQuery{})
-	require.Equal(t, err, ErrHandlerNotFound,
-		"expected bus to return HandlerNotFound since no handler is registered")
-}
-
-func TestQuery(t *testing.T) {
-	bus := New()
-	tracer, err := tracing.InitializeTracerForTest()
-	require.NoError(t, err)
-	bus.tracer = tracer
-
-	want := "hello from handler"
-
-	bus.AddHandler(func(ctx context.Context, q *testQuery) error {
-		q.Resp = want
-		return nil
-	})
-
-	q := &testQuery{}
-
-	err = bus.Dispatch(context.Background(), q)
-	require.NoError(t, err, "unable to dispatch query")
-
-	require.Equal(t, want, q.Resp)
-}
-
-func TestQuery_HandlerReturnsError(t *testing.T) {
-	bus := New()
-	tracer, err := tracing.InitializeTracerForTest()
-	require.NoError(t, err)
-	bus.tracer = tracer
-
-	bus.AddHandler(func(ctx context.Context, query *testQuery) error {
-		return errors.New("handler error")
-	})
-
-	err = bus.Dispatch(context.Background(), &testQuery{})
-	require.Error(t, err, "expected error but got none")
-}
-
 func TestEventPublish(t *testing.T) {
 	bus := New()
 	tracer, err := tracing.InitializeTracerForTest()