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package main
import (
"flag"
"fmt"
"log"
"math/rand"
"net/http"
"sync"
"time"
"github.com/garyburd/redigo/redis"
"gopkg.in/throttled/throttled.v1"
"gopkg.in/throttled/throttled.v1/store"
)
var (
requests = flag.Int("requests", 10, "number of requests allowed in the time window")
window = flag.Duration("window", time.Minute, "time window for the limit of requests")
storeType = flag.String("store", "mem", "store to use, one of `mem` or `redis` (on default localhost port)")
delayRes = flag.Duration("delay-response", 0, "delay the response by a random duration between 0 and this value")
output = flag.String("output", "v", "type of output, one of `v`erbose, `q`uiet, `ok`-only, `ko`-only")
)
func main() {
flag.Parse()
var h http.Handler
var ok, ko int
var mu sync.Mutex
var st throttled.Store
// Keep the start time to print since-time
start := time.Now()
// Create the rate-limit store
switch *storeType {
case "mem":
st = store.NewMemStore(0)
case "redis":
st = store.NewRedisStore(setupRedis(), "throttled:", 0)
default:
log.Fatalf("unsupported store: %s", *storeType)
}
// Create the rate-limit throttler, varying on path
t := throttled.RateLimit(throttled.Q{Requests: *requests, Window: *window}, &throttled.VaryBy{
Path: true,
}, st)
// Set its denied handler
t.DeniedHandler = http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
if *output == "v" || *output == "ko" {
log.Printf("KO: %s", time.Since(start))
}
throttled.DefaultDeniedHandler.ServeHTTP(w, r)
mu.Lock()
defer mu.Unlock()
ko++
})
// Throttle the OK handler
rand.Seed(time.Now().Unix())
h = t.Throttle(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
if *output == "v" || *output == "ok" {
log.Printf("ok: %s", time.Since(start))
}
if *delayRes > 0 {
wait := time.Duration(rand.Intn(int(*delayRes)))
time.Sleep(wait)
}
w.WriteHeader(200)
mu.Lock()
defer mu.Unlock()
ok++
}))
// Print stats once in a while
go func() {
for _ = range time.Tick(10 * time.Second) {
mu.Lock()
log.Printf("ok: %d, ko: %d", ok, ko)
mu.Unlock()
}
}()
fmt.Println("server listening on port 9000")
http.ListenAndServe(":9000", h)
}
func setupRedis() *redis.Pool {
pool := &redis.Pool{
MaxIdle: 3,
IdleTimeout: 30 * time.Second,
Dial: func() (redis.Conn, error) {
return redis.Dial("tcp", ":6379")
},
TestOnBorrow: func(c redis.Conn, t time.Time) error {
_, err := c.Do("PING")
return err
},
}
return pool
}
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