Decouple the different contexts from each other (#24786)

Replace #16455

Close #21803

Mixing different Gitea contexts together causes some problems:

1. Unable to respond proper content when error occurs, eg: Web should
respond HTML while API should respond JSON
2. Unclear dependency, eg: it's unclear when Context is used in
APIContext, which fields should be initialized, which methods are
necessary.


To make things clear, this PR introduces a Base context, it only
provides basic Req/Resp/Data features.

This PR mainly moves code. There are still many legacy problems and
TODOs in code, leave unrelated changes to future PRs.

1 files changed, 10 insertions, 19 deletions

diff --git a/modules/context/private.go b/modules/context/private.go
index f621dd6839..41ca8a4709 100644
--- a/modules/context/private.go
+++ b/modules/context/private.go
@@ -11,13 +11,14 @@ import (
 
 	"code.gitea.io/gitea/modules/graceful"
 	"code.gitea.io/gitea/modules/process"
-	"code.gitea.io/gitea/modules/web/middleware"
 )
 
 // PrivateContext represents a context for private routes
 type PrivateContext struct {
-	*Context
+	*Base
 	Override context.Context
+
+	Repo *Repository
 }
 
 // Deadline is part of the interface for context.Context and we pass this to the request context
@@ -25,7 +26,7 @@ func (ctx *PrivateContext) Deadline() (deadline time.Time, ok bool) {
 	if ctx.Override != nil {
 		return ctx.Override.Deadline()
 	}
-	return ctx.Req.Context().Deadline()
+	return ctx.Base.Deadline()
 }
 
 // Done is part of the interface for context.Context and we pass this to the request context
@@ -33,7 +34,7 @@ func (ctx *PrivateContext) Done() <-chan struct{} {
 	if ctx.Override != nil {
 		return ctx.Override.Done()
 	}
-	return ctx.Req.Context().Done()
+	return ctx.Base.Done()
 }
 
 // Err is part of the interface for context.Context and we pass this to the request context
@@ -41,16 +42,11 @@ func (ctx *PrivateContext) Err() error {
 	if ctx.Override != nil {
 		return ctx.Override.Err()
 	}
-	return ctx.Req.Context().Err()
+	return ctx.Base.Err()
 }
 
 var privateContextKey interface{} = "default_private_context"
 
-// WithPrivateContext set up private context in request
-func WithPrivateContext(req *http.Request, ctx *PrivateContext) *http.Request {
-	return req.WithContext(context.WithValue(req.Context(), privateContextKey, ctx))
-}
-
 // GetPrivateContext returns a context for Private routes
 func GetPrivateContext(req *http.Request) *PrivateContext {
 	return req.Context().Value(privateContextKey).(*PrivateContext)
@@ -60,16 +56,11 @@ func GetPrivateContext(req *http.Request) *PrivateContext {
 func PrivateContexter() func(http.Handler) http.Handler {
 	return func(next http.Handler) http.Handler {
 		return http.HandlerFunc(func(w http.ResponseWriter, req *http.Request) {
-			ctx := &PrivateContext{
-				Context: &Context{
-					Resp: NewResponse(w),
-					Data: middleware.GetContextData(req.Context()),
-				},
-			}
-			defer ctx.Close()
+			base, baseCleanUp := NewBaseContext(w, req)
+			ctx := &PrivateContext{Base: base}
+			defer baseCleanUp()
+			ctx.Base.AppendContextValue(privateContextKey, ctx)
 
-			ctx.Req = WithPrivateContext(req, ctx)
-			ctx.Data["Context"] = ctx
 			next.ServeHTTP(ctx.Resp, ctx.Req)
 		})
 	}