forked from reactjs/react-tutorial
-
Notifications
You must be signed in to change notification settings - Fork 0
Expand file tree
/
Copy pathserver.go
More file actions
85 lines (71 loc) · 2.4 KB
/
server.go
File metadata and controls
85 lines (71 loc) · 2.4 KB
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
package main
import (
"encoding/json"
"fmt"
"io"
"log"
"net/http"
"os"
"sync"
)
type comment struct {
Author string `json:"author"`
Text string `json:"text"`
}
const dataFile = "./_comments.json"
var commentMutex = new(sync.Mutex)
// Handle comments
func handleComments(w http.ResponseWriter, r *http.Request) {
// Since multiple requests could come in at once, ensure we have a lock
// around all file operations
commentMutex.Lock()
defer commentMutex.Unlock()
// Stat the file, so we can find it's current permissions
fi, err := os.Stat(dataFile)
if err != nil {
http.Error(w, fmt.Sprintf("Unable to stat data file (%s): %s", dataFile, err), http.StatusInternalServerError)
return
}
// Open the file Read/Write
cFile, err := os.OpenFile(dataFile, os.O_RDWR, fi.Mode())
if err != nil {
http.Error(w, fmt.Sprintf("Unable to open data file (%s): %s", dataFile, err), http.StatusInternalServerError)
return
}
defer cFile.Close() //Ensure the file is closed when we are done.
switch r.Method {
case "POST":
// Decode the JSON data
comments := make([]comment, 0)
commentsDecoder := json.NewDecoder(cFile)
if err := commentsDecoder.Decode(&comments); err != nil {
http.Error(w, fmt.Sprintf("Unable to read comments from data file (%s): %s", dataFile, err), http.StatusInternalServerError)
return
}
// Add a new comment to the in memory slice of comments
comments = append(comments, comment{Author: r.FormValue("author"), Text: r.FormValue("text")})
// Truncate the file and Seek to the beginning of it
if err := cFile.Truncate(0); err != nil {
http.Error(w, fmt.Sprintf("Unable to truncate data file (%s): %s", dataFile, err), http.StatusInternalServerError)
return
}
if r, err := cFile.Seek(0, 0); r != 0 && err != nil {
http.Error(w, fmt.Sprintf("Unable to seek to beginning of data file (%s): %s", dataFile, err), http.StatusInternalServerError)
return
}
// Write out the json response
commentsEncoder := json.NewEncoder(cFile)
commentsEncoder.Encode(comments)
case "GET":
// stream the contents of the file to the response
io.Copy(w, cFile)
default:
// Don't know the method, so error
http.Error(w, fmt.Sprintf("Unsupported method: %s", r.Method), http.StatusMethodNotAllowed)
}
}
func main() {
http.HandleFunc("/comments.json", handleComments)
http.Handle("/", http.FileServer(http.Dir("./public")))
log.Fatal(http.ListenAndServe(":3000", nil))
}