feat: add HTTP migration bridges and extensible API binding

httpx/body.go

@@ -0,0 +1,60 @@
+package httpx
+
+import (
+	"errors"
+	apierrors "git.yuntuo.hk/k2safe/go-omni/errors"
+	"git.yuntuo.hk/k2safe/go-omni/response"
+	"net/http"
+)
+
+// LimitBody is useful for handwritten routes. Built-in App.HandleWithBodyLimit
+// additionally installs the reader cap before global middleware can read it.
+func LimitBody(maxBytes int64) Middleware {
+	if maxBytes <= 0 || maxBytes > 1<<40 {
+		panic("httpx: body limit must be 1..1 TiB")
+	}
+	return func(next Handler) Handler {
+		return func(c *Context) error {
+			r := c.Request()
+			if r.ContentLength > maxBytes {
+				return bodyTooLarge()
+			}
+			if r.Body != nil {
+				r.Body = http.MaxBytesReader(c.Raw(), r.Body, maxBytes)
+			}
+			defer CleanupMultipart(r)
+			err := next(c)
+			var limitErr *http.MaxBytesError
+			if errors.As(err, &limitErr) {
+				return bodyTooLarge()
+			}
+			return err
+		}
+	}
+}
+func bodyTooLarge() error { return apierrors.New(413, "BODY_TOO_LARGE", "request body exceeds limit") }
+
+// CleanupMultipart removes disk spill files created by ParseMultipartForm.
+// Callers still close individual multipart files. Streaming MultipartReader
+// handlers own any files they create themselves.
+func CleanupMultipart(r *http.Request) {
+	if r != nil && r.MultipartForm != nil {
+		_ = r.MultipartForm.RemoveAll()
+	}
+}
+
+type BodyLimitRegistrar interface {
+	HandleWithBodyLimit(string, string, int64, response.Encoder, Handler, ...Middleware)
+}
+
+func HandleWithBodyLimit(router interface {
+	Handle(string, string, Handler, ...Middleware)
+}, method, path string, maxBytes int64, encoder response.Encoder, handler Handler, middleware ...Middleware) {
+	if r, ok := router.(BodyLimitRegistrar); ok {
+		r.HandleWithBodyLimit(method, path, maxBytes, encoder, handler, middleware...)
+		return
+	}
+	// Custom registrars without the early hook cap at route middleware entry.
+	all := append([]Middleware{LimitBody(maxBytes)}, middleware...)
+	HandleWithResponse(router, method, path, encoder, handler, all...)
+}