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
|
package g8
import (
"sync"
"time"
)
// RateLimiter is a fixed rate limiter
type RateLimiter struct {
maximumExecutionsPerSecond int
executionsLeftInWindow int
windowStartTime time.Time
mutex sync.Mutex
}
// NewRateLimiter creates a RateLimiter
func NewRateLimiter(maximumExecutionsPerSecond int) *RateLimiter {
return &RateLimiter{
windowStartTime: time.Now(),
executionsLeftInWindow: maximumExecutionsPerSecond,
maximumExecutionsPerSecond: maximumExecutionsPerSecond,
}
}
// Try updates the number of executions if the rate limit quota hasn't been reached and returns whether the
// attempt was successful or not.
//
// Returns false if the execution was not successful (rate limit quota has been reached)
// Returns true if the execution was successful (rate limit quota has not been reached)
func (r *RateLimiter) Try() bool {
r.mutex.Lock()
defer r.mutex.Unlock()
if time.Now().Add(-time.Second).After(r.windowStartTime) {
r.windowStartTime = time.Now()
r.executionsLeftInWindow = r.maximumExecutionsPerSecond
}
if r.executionsLeftInWindow == 0 {
return false
}
r.executionsLeftInWindow--
return true
}
|
