-
Notifications
You must be signed in to change notification settings - Fork 2
/
feed.go
71 lines (62 loc) · 1.54 KB
/
feed.go
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
package wtt
import (
"context"
"net/http"
"strings"
"time"
"github.com/NYTimes/gizmo/server/kit"
"github.com/jprobinson/gtfs/mta"
"github.com/jprobinson/gtfs/transit_realtime"
)
const (
timeout = 1 * time.Second
maxAttempts = 10
backoffStep = 50 * time.Millisecond
)
// retries until it hits max attempts or a context timeout
func GetFeed(ctx context.Context, hc *http.Client, key string, ft mta.FeedType) (*transit_realtime.FeedMessage, error) {
var (
feed *transit_realtime.FeedMessage
err error
)
ctx, cancel := context.WithTimeout(ctx, timeout)
defer cancel()
for attempt := 1; attempt <= maxAttempts; attempt++ {
// retry backoff
time.Sleep(time.Duration((attempt - 1)) * backoffStep)
// attempt to get feed
feed, err = mta.GetNYCSubwayFeed(ctx, hc, key, ft)
if err == nil ||
(err != nil && strings.Contains(err.Error(), "deadline exceeded")) {
break
}
kit.LogErrorMsg(ctx, err, "unable to get mta feed")
}
return feed, err
}
func parseFeed(line string) (mta.FeedType, error) {
var ft mta.FeedType
switch line {
case "1", "2", "3", "4", "5", "6":
ft = mta.NumberedFeed
case "N", "Q", "R", "W":
ft = mta.YellowFeed
case "B", "D", "F", "M":
ft = mta.OrangeFeed
case "A", "C", "E":
ft = mta.BlueFeed
case "J", "Z":
ft = mta.BrownFeed
case "L":
ft = mta.LFeed
case "7":
ft = mta.SevenFeed
case "G":
ft = mta.GFeed
default:
return mta.LFeed, errBadRequest
}
return ft, nil
}
var errBadRequest = kit.NewJSONStatusResponse(map[string]string{
"error": "bad request"}, http.StatusBadRequest)