feat: reusable rule engine to prevent memory reallocation

internal/rule/http/response.go

@@ -1,22 +1,33 @@
 package http
 
 import (
+	"context"
 	"fmt"
-	"net/http"
 	"strconv"
 	"strings"
 	"time"
 
 	"forge.cadoles.com/Cadoles/go-proxy/wildcard"
+	"forge.cadoles.com/cadoles/bouncer/internal/rule"
 	"github.com/expr-lang/expr"
+	"github.com/pkg/errors"
 )
 
-func addResponseHeaderFunc(r *http.Response) expr.Option {
+func addResponseHeaderFunc() expr.Option {
 	return expr.Function(
 		"add_header",
 		func(params ...any) (any, error) {
-			name := params[0].(string)
-			rawValue := params[1]
+			ctx, err := rule.Assert[context.Context](params[0])
+			if err != nil {
+				return nil, errors.WithStack(err)
+			}
+
+			name, err := rule.Assert[string](params[1])
+			if err != nil {
+				return nil, errors.WithStack(err)
+			}
+
+			rawValue := params[2]
 
 			var value string
 			switch v := rawValue.(type) {
@@ -30,20 +41,34 @@ func addResponseHeaderFunc(r *http.Response) expr.Option {
 				value = fmt.Sprintf("%v", rawValue)
 			}
 
+			r, ok := ctxResponse(ctx)
+			if !ok {
+				return nil, errors.New("could not find http response in context")
+			}
+
 			r.Header.Add(name, value)
 
 			return true, nil
 		},
-		new(func(string, string) bool),
+		new(func(context.Context, string, string) bool),
 	)
 }
 
-func setResponseHeaderFunc(r *http.Response) expr.Option {
+func setResponseHeaderFunc() expr.Option {
 	return expr.Function(
 		"set_header",
 		func(params ...any) (any, error) {
-			name := params[0].(string)
-			rawValue := params[1]
+			ctx, err := rule.Assert[context.Context](params[0])
+			if err != nil {
+				return nil, errors.WithStack(err)
+			}
+
+			name, err := rule.Assert[string](params[1])
+			if err != nil {
+				return nil, errors.WithStack(err)
+			}
+
+			rawValue := params[2]
 
 			var value string
 			switch v := rawValue.(type) {
@@ -57,19 +82,38 @@ func setResponseHeaderFunc(r *http.Response) expr.Option {
 				value = fmt.Sprintf("%v", rawValue)
 			}
 
+			r, ok := ctxResponse(ctx)
+			if !ok {
+				return nil, errors.New("could not find http response in context")
+			}
+
 			r.Header.Set(name, value)
 
 			return true, nil
 		},
-		new(func(string, string) bool),
+		new(func(context.Context, string, string) bool),
 	)
 }
 
-func delResponseHeadersFunc(r *http.Response) expr.Option {
+func delResponseHeadersFunc() expr.Option {
 	return expr.Function(
 		"del_headers",
 		func(params ...any) (any, error) {
-			pattern := params[0].(string)
+			ctx, err := rule.Assert[context.Context](params[0])
+			if err != nil {
+				return nil, errors.WithStack(err)
+			}
+
+			pattern, err := rule.Assert[string](params[1])
+			if err != nil {
+				return nil, errors.WithStack(err)
+			}
+
+			r, ok := ctxResponse(ctx)
+			if !ok {
+				return nil, errors.New("could not find http response in context")
+			}
+
 			deleted := false
 
 			for key := range r.Header {
@@ -83,6 +127,6 @@ func delResponseHeadersFunc(r *http.Response) expr.Option {
 
 			return deleted, nil
 		},
-		new(func(string) bool),
+		new(func(context.Context, string) bool),
 	)
 }