44 lines
804 B
Go
44 lines
804 B
Go
package policies
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import (
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"sync/atomic"
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"time"
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"github.com/puzpuzpuz/xsync/v3"
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)
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func startRateLimitSystem[K comparable](
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tokensPerInterval int,
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interval time.Duration,
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maxTokens int,
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) func(key K) (ratelimited bool) {
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negativeBuckets := xsync.NewMapOf[K, *atomic.Int32]()
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maxTokensInt32 := int32(maxTokens)
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go func() {
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for {
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time.Sleep(interval)
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negativeBuckets.Range(func(key K, bucket *atomic.Int32) bool {
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newv := bucket.Add(int32(-tokensPerInterval))
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if newv <= 0 {
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negativeBuckets.Delete(key)
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}
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return true
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})
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}
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}()
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return func(key K) bool {
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nb, _ := negativeBuckets.LoadOrStore(key, &atomic.Int32{})
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if nb.Load() < maxTokensInt32 {
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nb.Add(1)
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// rate limit not reached yet
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return false
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}
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// rate limit reached
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return true
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}
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}
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