69 lines
1.3 KiB
Go
69 lines
1.3 KiB
Go
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package email
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import (
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"sync"
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"time"
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)
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// slidingLimiter is an in-process email send budget (per key).
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// Not shared across API replicas; RATE_LIMIT_REPLICAS does not divide this limiter.
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// Multi-replica hard caps need edge/WAF (or a future shared store).
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type slidingLimiter struct {
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mu sync.Mutex
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window time.Duration
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limit int
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hits map[string][]time.Time
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lastGC time.Time
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}
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func newSlidingLimiter(limit int, window time.Duration) *slidingLimiter {
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if limit <= 0 {
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limit = 30
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}
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if window <= 0 {
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window = time.Minute
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}
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return &slidingLimiter{
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window: window,
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limit: limit,
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hits: make(map[string][]time.Time),
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lastGC: time.Now(),
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}
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}
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func (l *slidingLimiter) allow(key string) bool {
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now := time.Now()
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cutoff := now.Add(-l.window)
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l.mu.Lock()
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defer l.mu.Unlock()
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if now.Sub(l.lastGC) > l.window {
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for k, ts := range l.hits {
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kept := ts[:0]
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for _, t := range ts {
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if t.After(cutoff) {
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kept = append(kept, t)
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}
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}
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if len(kept) == 0 {
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delete(l.hits, k)
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} else {
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l.hits[k] = kept
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}
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}
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l.lastGC = now
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}
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ts := l.hits[key]
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kept := ts[:0]
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for _, t := range ts {
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if t.After(cutoff) {
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kept = append(kept, t)
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}
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}
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if len(kept) >= l.limit {
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l.hits[key] = kept
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return false
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}
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l.hits[key] = append(kept, now)
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return true
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}
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