// Copyright 2020 The Gitea Authors. All rights reserved.// SPDX-License-Identifier: MIT package eventsource import (	"bytes"	"fmt"	"io"	"strings"	"time" 	"forgejo.org/modules/json") func wrapNewlines(w io.Writer, prefix, value []byte) (sum int64, err error) {	if len(value) == 0 {		return 0, nil	}	var n int	last := 0	for j := bytes.IndexByte(value, '\n'); j > -1; j = bytes.IndexByte(value[last:], '\n') {		n, err = w.Write(prefix)		sum += int64(n)		if err != nil {			return sum, err		}		n, err = w.Write(value[last : last+j+1])		sum += int64(n)		if err != nil {			return sum, err		}		last += j + 1	}	n, err = w.Write(prefix)	sum += int64(n)	if err != nil {		return sum, err	}	n, err = w.Write(value[last:])	sum += int64(n)	if err != nil {		return sum, err	}	n, err = w.Write([]byte("\n"))	sum += int64(n)	return sum, err} // Event is an eventsource event, not all fields need to be settype Event struct {	// Name represents the value of the event: tag in the stream	Name string	// Data is either JSONified []byte or any that can be JSONd	Data any	// ID represents the ID of an event	ID string	// Retry tells the receiver only to attempt to reconnect to the source after this time	Retry time.Duration} // WriteTo writes data to w until there's no more data to write or when an error occurs.// The return value n is the number of bytes written. Any error encountered during the write is also returned.func (e *Event) WriteTo(w io.Writer) (int64, error) {	sum := int64(0)	var nint int	n, err := wrapNewlines(w, []byte("event: "), []byte(e.Name))	sum += n	if err != nil {		return sum, err	} 	if e.Data != nil {		var data []byte		switch v := e.Data.(type) {		case []byte:			data = v		case string:			data = []byte(v)		default:			var err error			data, err = json.Marshal(e.Data)			if err != nil {				return sum, err			}		}		n, err := wrapNewlines(w, []byte("data: "), data)		sum += n		if err != nil {			return sum, err		}	} 	n, err = wrapNewlines(w, []byte("id: "), []byte(e.ID))	sum += n	if err != nil {		return sum, err	} 	if e.Retry != 0 {		nint, err = fmt.Fprintf(w, "retry: %d\n", int64(e.Retry/time.Millisecond))		sum += int64(nint)		if err != nil {			return sum, err		}	} 	nint, err = w.Write([]byte("\n"))	sum += int64(nint) 	return sum, err} func (e *Event) String() string {	buf := new(strings.Builder)	_, _ = e.WriteTo(buf)	return buf.String()}