refactor Envelope modifiers to provide more flexibility

ctx.go

@@ -17,13 +17,14 @@ type Context struct {
 	utils.SpinLock
 	ctx context.Context //nolint:containedctx
 
-	nb   *northBridge
-	kv   map[string]interface{}
-	hdr  map[string]string
-	conn Conn
-	in   *Envelope
-	wf   WriteFunc
-	err  error
+	nb        *northBridge
+	kv        map[string]interface{}
+	hdr       map[string]string
+	conn      Conn
+	in        *Envelope
+	wf        WriteFunc
+	modifiers []Modifier
+	err       error
 
 	handlers HandlerFuncChain
 	index    int
@@ -54,6 +55,12 @@ func (ctx *Context) StopExecution() {
 	ctx.index = abortIndex
 }
 
+// AddModifier adds one or more modifiers to the context which will be executed on each outgoing
+// Envelope before writing it to the wire.
+func (ctx *Context) AddModifier(modifiers ...Modifier) {
+	ctx.modifiers = append(ctx.modifiers, modifiers...)
+}
+
 // SetUserContext replaces the default context with the provided context.
 func (ctx *Context) SetUserContext(userCtx context.Context) {
 	ctx.ctx = userCtx
@@ -131,5 +138,6 @@ func (ctx *Context) reset() {
 	ctx.in.release()
 	ctx.index = 0
 	ctx.handlers = ctx.handlers[:0]
+	ctx.modifiers = ctx.modifiers[:0]
 	ctx.ctx = nil
 }

desc/desc.go

@@ -4,15 +4,22 @@ import (
 	"github.com/clubpay/ronykit"
 )
 
+type Error struct {
+	Code    int
+	Item    string
+	Message ronykit.Message
+}
+
 // Contract is the description of the ronykit.Contract you are going to create.
 type Contract struct {
-	Name      string
-	Handlers  []ronykit.HandlerFunc
-	Wrappers  []ronykit.ContractWrapper
-	Input     ronykit.Message
-	Output    ronykit.Message
-	Selectors []ronykit.RouteSelector
-	Modifiers []ronykit.Modifier
+	Name           string
+	Handlers       []ronykit.HandlerFunc
+	Wrappers       []ronykit.ContractWrapper
+	Input          ronykit.Message
+	Output         ronykit.Message
+	PossibleErrors []Error
+	Selectors      []ronykit.RouteSelector
+	Modifiers      []ronykit.Modifier
 }
 
 func NewContract() *Contract {
@@ -37,14 +44,26 @@ func (c *Contract) SetInput(m ronykit.Message) *Contract {
 	return c
 }
 
-// SetOutput sets the outgoing message for this Contract. This is an optional parameter, which
-// mostly could be used by external tools such as Swagger generator etc.
+// SetOutput sets the outgoing message for this Contract. This is an OPTIONAL parameter, which
+// mostly could be used by external tools such as Swagger or any other doc generator tools.
 func (c *Contract) SetOutput(m ronykit.Message) *Contract {
 	c.Output = m
 
 	return c
 }
 
+// AddPossibleError sets the possible errors for this Contract. This is OPTIONAL parameter, which
+// mostly could be used by external tools such as Swagger or any other doc generator tools.
+func (c *Contract) AddPossibleError(code int, item string, m ronykit.Message) *Contract {
+	c.PossibleErrors = append(c.PossibleErrors, Error{
+		Code:    code,
+		Item:    item,
+		Message: m,
+	})
+
+	return c
+}
+
 // AddSelector adds a ronykit.RouteSelector for this contract. Selectors are bundle specific.
 func (c *Contract) AddSelector(s ronykit.RouteSelector) *Contract {
 	c.Selectors = append(c.Selectors, s)

envelope.go

@@ -134,6 +134,12 @@ func (e *Envelope) Send() {
 		panic("BUG!! do not call Send on incoming envelope")
 	}
 
+	// run the modifiers in LIFO order
+	modifiersCount := len(e.ctx.modifiers) - 1
+	for idx := range e.ctx.modifiers {
+		e.ctx.modifiers[modifiersCount-idx](e)
+	}
+
 	// Use WriteFunc to write the Envelope into the connection
 	e.ctx.Error(e.ctx.wf(e.conn, e))
 

std/bundle/fasthttp/bundle.go

@@ -194,10 +194,6 @@ func (b *bundle) dispatchWS(in []byte) (ronykit.DispatchFunc, error) {
 	}
 
 	writeFunc := func(conn ronykit.Conn, e *ronykit.Envelope) error {
-		for idx := range routeData.Modifiers {
-			routeData.Modifiers[idx](e)
-		}
-
 		outputMsgContainer := acquireOutgoingMessage()
 		outputMsgContainer.Payload = e.GetMsg()
 		e.WalkHdr(func(key string, val string) bool {
@@ -228,6 +224,8 @@ func (b *bundle) dispatchWS(in []byte) (ronykit.DispatchFunc, error) {
 			Set(ronykit.CtxServiceName, routeData.ServiceName).
 			Set(ronykit.CtxRoute, routeData.Predicate)
 
+		ctx.AddModifier(routeData.Modifiers...)
+
 		// run the execFunc with generated params
 		execFunc(writeFunc, routeData.Handlers...)
 
@@ -265,10 +263,6 @@ func (b *bundle) dispatchHTTP(conn *httpConn, in []byte) (ronykit.DispatchFunc,
 			panic("BUG!! incorrect connection")
 		}
 
-		for idx := range routeData.Modifiers {
-			routeData.Modifiers[idx](e)
-		}
-
 		data, err := e.GetMsg().Marshal()
 		if err != nil {
 			return err
@@ -296,6 +290,8 @@ func (b *bundle) dispatchHTTP(conn *httpConn, in []byte) (ronykit.DispatchFunc,
 			SetHdrWalker(conn).
 			SetMsg(routeData.Decoder(params, in))
 
+		ctx.AddModifier(routeData.Modifiers...)
+
 		// execute handler functions
 		execFunc(writeFunc, routeData.Handlers...)
 

std/bundle/fastws/bundle.go

@@ -96,10 +96,6 @@ func (b *bundle) Dispatch(c ronykit.Conn, in []byte) (ronykit.DispatchFunc, erro
 	}
 
 	writeFunc := func(conn ronykit.Conn, e *ronykit.Envelope) error {
-		for idx := range routeData.Modifiers {
-			routeData.Modifiers[idx](e)
-		}
-
 		outputMsgContainer := acquireOutgoingMessage()
 		outputMsgContainer.Payload = e.GetMsg()
 		e.WalkHdr(func(key string, val string) bool {
@@ -130,6 +126,8 @@ func (b *bundle) Dispatch(c ronykit.Conn, in []byte) (ronykit.DispatchFunc, erro
 			Set(ronykit.CtxServiceName, routeData.ServiceName).
 			Set(ronykit.CtxRoute, routeData.Predicate)
 
+		ctx.AddModifier(routeData.Modifiers...)
+
 		// run the execFunc with generated params
 		execFunc(writeFunc, routeData.Handlers...)