Manu Mtz-Almeida
404710eaa4
BenchmarkResponseWriter 1239 1304 +5.25% BenchmarkFullSSE 1469 915 -37.71% BenchmarkNoRetrySSE 1187 785 -33.87% BenchmarkSimpleSSE 961 687 -28.51% benchmark old allocs new allocs delta BenchmarkResponseWriter 9 9 +0.00% BenchmarkFullSSE 12 3 -75.00% BenchmarkNoRetrySSE 11 2 -81.82% BenchmarkSimpleSSE 8 2 -75.00% benchmark old bytes new bytes delta BenchmarkResponseWriter 442 442 +0.00% BenchmarkFullSSE 462 320 -30.74% BenchmarkNoRetrySSE 473 337 -28.75% BenchmarkSimpleSSE 426 314 -26.29%
108 lines
2.3 KiB
Go
108 lines
2.3 KiB
Go
// Copyright 2014 Manu Martinez-Almeida. All rights reserved.
|
|
// Use of this source code is governed by a MIT style
|
|
// license that can be found in the LICENSE file.
|
|
|
|
package sse
|
|
|
|
import (
|
|
"encoding/json"
|
|
"fmt"
|
|
"io"
|
|
"net/http"
|
|
"reflect"
|
|
"strconv"
|
|
"strings"
|
|
)
|
|
|
|
// Server-Sent Events
|
|
// W3C Working Draft 29 October 2009
|
|
// http://www.w3.org/TR/2009/WD-eventsource-20091029/
|
|
|
|
const ContentType = "text/event-stream"
|
|
|
|
var contentType = []string{ContentType}
|
|
var noCache = []string{"no-cache"}
|
|
|
|
type Event struct {
|
|
Event string
|
|
Id string
|
|
Retry uint
|
|
Data interface{}
|
|
}
|
|
|
|
func Encode(writer io.Writer, event Event) error {
|
|
w := checkWriter(writer)
|
|
writeId(w, event.Id)
|
|
writeEvent(w, event.Event)
|
|
writeRetry(w, event.Retry)
|
|
return writeData(w, event.Data)
|
|
}
|
|
|
|
func writeId(w stringWriter, id string) {
|
|
if len(id) > 0 {
|
|
w.WriteString("id: ")
|
|
w.WriteString(escape(id))
|
|
w.WriteString("\n")
|
|
}
|
|
}
|
|
|
|
func writeEvent(w stringWriter, event string) {
|
|
if len(event) > 0 {
|
|
w.WriteString("event: ")
|
|
w.WriteString(escape(event))
|
|
w.WriteString("\n")
|
|
}
|
|
}
|
|
|
|
func writeRetry(w stringWriter, retry uint) {
|
|
if retry > 0 {
|
|
w.WriteString("retry: ")
|
|
w.WriteString(strconv.FormatUint(uint64(retry), 10))
|
|
w.WriteString("\n")
|
|
}
|
|
}
|
|
|
|
func writeData(w stringWriter, data interface{}) error {
|
|
w.WriteString("data: ")
|
|
switch kindOfData(data) {
|
|
case reflect.Struct, reflect.Slice, reflect.Map:
|
|
err := json.NewEncoder(w).Encode(data)
|
|
if err != nil {
|
|
return err
|
|
}
|
|
w.WriteString("\n")
|
|
default:
|
|
text := fmt.Sprint(data)
|
|
w.WriteString(escape(text))
|
|
w.WriteString("\n\n")
|
|
}
|
|
return nil
|
|
}
|
|
|
|
func (r Event) Write(w http.ResponseWriter) error {
|
|
header := w.Header()
|
|
header["Content-Type"] = contentType
|
|
|
|
if _, exist := header["Cache-Control"]; !exist {
|
|
header["Cache-Control"] = noCache
|
|
}
|
|
return Encode(w, r)
|
|
}
|
|
|
|
func kindOfData(data interface{}) reflect.Kind {
|
|
value := reflect.ValueOf(data)
|
|
valueType := value.Kind()
|
|
if valueType == reflect.Ptr {
|
|
valueType = value.Elem().Kind()
|
|
}
|
|
return valueType
|
|
}
|
|
|
|
func escape(str string) string {
|
|
// any-char = %x0000-0009 / %x000B-000C / %x000E-10FFFF
|
|
// ; a Unicode character other than U+000A LINE FEED (LF) or U+000D CARRIAGE RETURN (CR)
|
|
str = strings.Replace(str, "\n", "\\n", -1)
|
|
str = strings.Replace(str, "\r", "\\r", -1)
|
|
return str
|
|
}
|