75 lines
1.3 KiB
Go
75 lines
1.3 KiB
Go
package middleware
|
|
|
|
import (
|
|
"net/http"
|
|
"sync"
|
|
"time"
|
|
|
|
"github.com/gin-gonic/gin"
|
|
"golang.org/x/time/rate"
|
|
)
|
|
|
|
type client struct {
|
|
limiter *rate.Limiter
|
|
lastSeen time.Time
|
|
}
|
|
|
|
type RateLimiter struct {
|
|
clients map[string]*client
|
|
mu sync.Mutex
|
|
rps rate.Limit
|
|
burst int
|
|
}
|
|
|
|
func NewRateLimiter(requestsPerSecond float64, burst int) *RateLimiter {
|
|
rl := &RateLimiter{
|
|
clients: make(map[string]*client),
|
|
rps: rate.Limit(requestsPerSecond),
|
|
burst: burst,
|
|
}
|
|
go rl.cleanup()
|
|
return rl
|
|
}
|
|
|
|
func (rl *RateLimiter) getClient(ip string) *rate.Limiter {
|
|
rl.mu.Lock()
|
|
defer rl.mu.Unlock()
|
|
|
|
if c, exists := rl.clients[ip]; exists {
|
|
c.lastSeen = time.Now()
|
|
return c.limiter
|
|
}
|
|
|
|
limiter := rate.NewLimiter(rl.rps, rl.burst)
|
|
rl.clients[ip] = &client{limiter: limiter, lastSeen: time.Now()}
|
|
return limiter
|
|
}
|
|
|
|
func (rl *RateLimiter) cleanup() {
|
|
for {
|
|
time.Sleep(time.Minute)
|
|
rl.mu.Lock()
|
|
for ip, c := range rl.clients {
|
|
if time.Since(c.lastSeen) > 3*time.Minute {
|
|
delete(rl.clients, ip)
|
|
}
|
|
}
|
|
rl.mu.Unlock()
|
|
}
|
|
}
|
|
|
|
func (rl *RateLimiter) Middleware() gin.HandlerFunc {
|
|
return func(c *gin.Context) {
|
|
ip := c.ClientIP()
|
|
limiter := rl.getClient(ip)
|
|
if !limiter.Allow() {
|
|
c.AbortWithStatusJSON(http.StatusTooManyRequests, gin.H{
|
|
"error": "failed",
|
|
"message": "rate limit exceeded",
|
|
})
|
|
return
|
|
}
|
|
c.Next()
|
|
}
|
|
}
|