62 lines
1.2 KiB
Go
62 lines
1.2 KiB
Go
package orders
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import (
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"net"
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"net/http"
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"strings"
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"sync"
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"time"
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"golang.org/x/time/rate"
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)
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type visitor struct {
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lim *rate.Limiter
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seen time.Time
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}
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func Limit(next http.Handler, every time.Duration, burst int) http.Handler {
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var mu sync.Mutex
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visitors := map[string]*visitor{}
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go func() {
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for range time.Tick(10 * time.Minute) {
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mu.Lock()
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for ip, v := range visitors {
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if time.Since(v.seen) > 10*time.Minute {
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delete(visitors, ip)
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}
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}
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mu.Unlock()
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}
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}()
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return http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
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ip := clientIP(r)
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mu.Lock()
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v, ok := visitors[ip]
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if !ok {
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v = &visitor{lim: rate.NewLimiter(rate.Every(every), burst)}
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visitors[ip] = v
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}
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v.seen = time.Now()
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allowed := v.lim.Allow()
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mu.Unlock()
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if !allowed {
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http.Error(w, "Zbyt wiele prób. Spróbuj ponownie za chwilę.", http.StatusTooManyRequests)
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return
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}
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next.ServeHTTP(w, r)
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})
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}
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func clientIP(r *http.Request) string {
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host, _, _ := net.SplitHostPort(r.RemoteAddr)
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if ip := net.ParseIP(host); ip != nil && ip.IsLoopback() {
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if xff := r.Header.Get("X-Forwarded-For"); xff != "" {
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return strings.TrimSpace(strings.Split(xff, ",")[0])
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}
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}
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return host
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}
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