first-commit

services/context/response.go

@@ -0,0 +1,93 @@
+// Copyright 2021 The Gitea Authors. All rights reserved.
+// SPDX-License-Identifier: MIT
+
+package context
+
+import (
+	"net/http"
+
+	web_types "code.gitea.io/gitea/modules/web/types"
+)
+
+// ResponseWriter represents a response writer for HTTP
+type ResponseWriter interface {
+	http.ResponseWriter              // provides Header/Write/WriteHeader
+	http.Flusher                     // provides Flush
+	web_types.ResponseStatusProvider // provides WrittenStatus
+
+	Before(fn func(ResponseWriter))
+	WrittenSize() int
+}
+
+var _ ResponseWriter = (*Response)(nil)
+
+// Response represents a response
+type Response struct {
+	http.ResponseWriter
+	written        int
+	status         int
+	beforeFuncs    []func(ResponseWriter)
+	beforeExecuted bool
+}
+
+// Write writes bytes to HTTP endpoint
+func (r *Response) Write(bs []byte) (int, error) {
+	if !r.beforeExecuted {
+		for _, before := range r.beforeFuncs {
+			before(r)
+		}
+		r.beforeExecuted = true
+	}
+	size, err := r.ResponseWriter.Write(bs)
+	r.written += size
+	if err != nil {
+		return size, err
+	}
+	if r.status == 0 {
+		r.status = http.StatusOK
+	}
+	return size, nil
+}
+
+func (r *Response) WrittenSize() int {
+	return r.written
+}
+
+// WriteHeader write status code
+func (r *Response) WriteHeader(statusCode int) {
+	if !r.beforeExecuted {
+		for _, before := range r.beforeFuncs {
+			before(r)
+		}
+		r.beforeExecuted = true
+	}
+	if r.status == 0 {
+		r.status = statusCode
+		r.ResponseWriter.WriteHeader(statusCode)
+	}
+}
+
+// Flush flushes cached data
+func (r *Response) Flush() {
+	if f, ok := r.ResponseWriter.(http.Flusher); ok {
+		f.Flush()
+	}
+}
+
+// WrittenStatus returned status code written
+func (r *Response) WrittenStatus() int {
+	return r.status
+}
+
+// Before allows for a function to be called before the ResponseWriter has been written to. This is
+// useful for setting headers or any other operations that must happen before a response has been written.
+func (r *Response) Before(fn func(ResponseWriter)) {
+	r.beforeFuncs = append(r.beforeFuncs, fn)
+}
+
+func WrapResponseWriter(resp http.ResponseWriter) *Response {
+	if v, ok := resp.(*Response); ok {
+		return v
+	}
+	return &Response{ResponseWriter: resp}
+}