b0697da8e4
- Weighted random routing (math/rand/v2 per-goroutine ChaCha8) - PUT /api/route/mode for runtime mode switch (best / weighted_random) - EWMA score smoothing (configurable smoothing_factor, default 0.3) - Periodic stale node eviction (5 min threshold, 60s interval) - Non-blocking WS broadcast (per-client buffered channel + writePump) - Background rate limiter cleanup goroutine - In-memory trunk gateway cache (zero disk I/O in hot path) - Configurable load_avg multiplier (default 50.0, backward compat) - UI mode indicator + admin Switch button in dashboard - 42 tests: weighted random, mode switching, EWMA, eviction, API integration
118 lines
3.0 KiB
Go
118 lines
3.0 KiB
Go
package api
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import (
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"net"
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"net/http"
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"sync"
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"time"
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)
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// rateLimiter — in-memory token bucket rate limiter.
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type rateLimiter struct {
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mu sync.Mutex
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buckets map[string]*tokenBucket
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rate float64 // токенов в секунду
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burst int // максимальный размер бакета
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cleanupInterval time.Duration
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}
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type tokenBucket struct {
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tokens float64
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lastSeen time.Time
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}
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// newRateLimiter создаёт rate limiter с заданными параметрами.
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// Запускает фоновую горутину очистки устаревших бакетов.
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func newRateLimiter(ratePerSec, burst int) *rateLimiter {
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if burst <= 0 {
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burst = ratePerSec
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}
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rl := &rateLimiter{
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buckets: make(map[string]*tokenBucket),
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rate: float64(ratePerSec),
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burst: burst,
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cleanupInterval: 60 * time.Second,
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}
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// Фоновая горутина очистки — не блокирует hot path
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go rl.cleanupLoop()
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return rl
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}
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// allow проверяет, разрешён ли запрос для данного ключа.
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// Возвращает true если разрешён, false если превышен лимит.
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func (rl *rateLimiter) allow(key string) bool {
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rl.mu.Lock()
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defer rl.mu.Unlock()
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now := time.Now()
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b, exists := rl.buckets[key]
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if !exists {
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b = &tokenBucket{tokens: float64(rl.burst), lastSeen: now}
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rl.buckets[key] = b
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b.tokens--
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return true
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}
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// Пополняем токены
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elapsed := now.Sub(b.lastSeen).Seconds()
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b.tokens += elapsed * rl.rate
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if b.tokens > float64(rl.burst) {
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b.tokens = float64(rl.burst)
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}
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b.lastSeen = now
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if b.tokens >= 1.0 {
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b.tokens--
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return true
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}
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return false
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}
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// cleanupLoop — фоновая очистка устаревших бакетов.
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func (rl *rateLimiter) cleanupLoop() {
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ticker := time.NewTicker(rl.cleanupInterval)
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defer ticker.Stop()
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for range ticker.C {
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rl.mu.Lock()
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for k, b := range rl.buckets {
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if time.Since(b.lastSeen) > rl.cleanupInterval {
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delete(rl.buckets, k)
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}
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}
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rl.mu.Unlock()
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}
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}
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// rateLimitMiddleware создаёт middleware с rate limiting по IP.
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// Ключ — RemoteAddr (или X-Forwarded-For, если за проксей).
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func rateLimitMiddleware(limiter *rateLimiter) func(http.Handler) http.Handler {
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return func(next http.Handler) http.Handler {
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return http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
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key := stripPort(r.RemoteAddr)
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if fwd := r.Header.Get("X-Forwarded-For"); fwd != "" {
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key = fwd
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}
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if !limiter.allow(key) {
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w.Header().Set("Retry-After", "1")
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writeError(w, http.StatusTooManyRequests, "слишком много запросов")
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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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}
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// stripPort убирает порт из адреса (напр. "[::1]:58544" → "::1", "127.0.0.1:1234" → "127.0.0.1").
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func stripPort(addr string) string {
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host, _, err := net.SplitHostPort(addr)
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if err != nil {
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return addr // нет порта
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}
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return host
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}
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