1package ratelimit_test

2

3import (

4 "fmt"

5 "net"

6 "time"

7

8 "github.com/mjl-/mox/ratelimit"

9)

10

11func ExampleLimiter() {

12 // Make a new rate limit that has maxima per minute, hour and day. The maxima are

13 // tracked per ipmasked1 (ipv4 /32 or ipv6 /64), ipmasked2 (ipv4 /26 or ipv6 /48)

14 // and ipmasked3 (ipv4 /21 or ipv6 /32).

15 //

16 // It is common to allow short bursts (with a narrow window), but not allow a high

17 // sustained rate (with wide window).

18 limit := ratelimit.Limiter{

19 WindowLimits: []ratelimit.WindowLimit{

20 {Window: time.Minute, Limits: [...]int64{2, 3, 4}},

21 {Window: time.Hour, Limits: [...]int64{4, 6, 8}},

22 {Window: 24 * time.Hour, Limits: [...]int64{20, 40, 60}},

23 },

24 }

25

26 tm, _ := time.Parse(time.RFC3339, "2006-01-02T15:04:05Z")

27

28 fmt.Println("1:", limit.Add(net.ParseIP("127.0.0.1"), tm, 1)) // Success.

29 fmt.Println("2:", limit.Add(net.ParseIP("127.0.0.1"), tm, 1)) // Success.

30 fmt.Println("3:", limit.Add(net.ParseIP("127.0.0.1"), tm, 1)) // Failure, too many from same ip.

31 fmt.Println("4:", limit.Add(net.ParseIP("127.0.0.2"), tm, 1)) // Success, different IP, though nearby.

32 fmt.Println("5:", limit.Add(net.ParseIP("127.0.0.2"), tm, 1)) // Failure, hits ipmasked2 check.

33 fmt.Println("6:", limit.Add(net.ParseIP("127.0.0.1"), tm.Add(time.Minute), 1)) // Success, in next minute.

34 fmt.Println("7:", limit.Add(net.ParseIP("127.0.0.1"), tm.Add(2*time.Minute), 1)) // Success, in another minute.

35 fmt.Println("8:", limit.Add(net.ParseIP("127.0.0.1"), tm.Add(3*time.Minute), 1)) // Failure, hitting hourly window for ipmasked1.

36 limit.Reset(net.ParseIP("127.0.0.1"), tm.Add(3*time.Minute))

37 fmt.Println("9:", limit.Add(net.ParseIP("127.0.0.1"), tm.Add(3*time.Minute), 1)) // Success.

38

39 // Output:

40 // 1: true

41 // 2: true

42 // 3: false

43 // 4: true

44 // 5: false

45 // 6: true

46 // 7: true

47 // 8: false

48 // 9: true

49}

50