Mephimeow
88 lines
1.4 KiB
Go
88 lines
1.4 KiB
Go
package middleware
|
|
|
|
import (
|
|
"net/http"
|
|
"sync"
|
|
"time"
|
|
|
|
"github.com/gin-gonic/gin"
|
|
)
|
|
|
|
type visitor struct {
|
|
count int
|
|
lastSeen time.Time
|
|
}
|
|
|
|
type RateLimiter struct {
|
|
mu sync.Mutex
|
|
visitors map[string]*visitor
|
|
rate int
|
|
window time.Duration
|
|
done chan struct{}
|
|
}
|
|
|
|
func NewRateLimiter(rate int, window time.Duration) *RateLimiter {
|
|
rl := &RateLimiter{
|
|
visitors: make(map[string]*visitor),
|
|
rate: rate,
|
|
window: window,
|
|
done: make(chan struct{}),
|
|
}
|
|
go rl.cleanup()
|
|
return rl
|
|
}
|
|
|
|
func (rl *RateLimiter) Stop() {
|
|
close(rl.done)
|
|
}
|
|
|
|
func (rl *RateLimiter) cleanup() {
|
|
ticker := time.NewTicker(10 * time.Minute)
|
|
defer ticker.Stop()
|
|
for {
|
|
select {
|
|
case <-rl.done:
|
|
return
|
|
case <-ticker.C:
|
|
rl.mu.Lock()
|
|
now := time.Now()
|
|
for ip, v := range rl.visitors {
|
|
if now.Sub(v.lastSeen) > rl.window*2 {
|
|
delete(rl.visitors, ip)
|
|
}
|
|
}
|
|
rl.mu.Unlock()
|
|
}
|
|
}
|
|
}
|
|
|
|
func (rl *RateLimiter) Middleware() gin.HandlerFunc {
|
|
return func(c *gin.Context) {
|
|
ip := c.ClientIP()
|
|
|
|
rl.mu.Lock()
|
|
v, exists := rl.visitors[ip]
|
|
now := time.Now()
|
|
|
|
if !exists || now.Sub(v.lastSeen) > rl.window {
|
|
rl.visitors[ip] = &visitor{count: 1, lastSeen: now}
|
|
rl.mu.Unlock()
|
|
c.Next()
|
|
return
|
|
}
|
|
|
|
v.count++
|
|
v.lastSeen = now
|
|
|
|
if v.count > rl.rate {
|
|
rl.mu.Unlock()
|
|
c.JSON(http.StatusTooManyRequests, gin.H{"error": "too many requests, try again later"})
|
|
c.Abort()
|
|
return
|
|
}
|
|
|
|
rl.mu.Unlock()
|
|
c.Next()
|
|
}
|
|
}
|