95 lines
1.6 KiB
Go
95 lines
1.6 KiB
Go
package middleware
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import (
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"net/http"
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"sync"
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"time"
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"github.com/gin-gonic/gin"
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)
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type RateLimitConfig struct {
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Enabled bool
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Requests int
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Window int
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}
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type rateLimitEntry struct {
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count int
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expiresAt time.Time
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}
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type rateLimiter struct {
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entries map[string]*rateLimitEntry
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mu sync.Mutex
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config RateLimitConfig
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}
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func newRateLimiter(config RateLimitConfig) *rateLimiter {
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rl := &rateLimiter{
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entries: make(map[string]*rateLimitEntry),
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config: config,
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}
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go rl.cleanup()
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return rl
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}
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func (rl *rateLimiter) cleanup() {
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ticker := time.NewTicker(time.Minute)
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for range ticker.C {
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rl.mu.Lock()
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now := time.Now()
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for key, entry := range rl.entries {
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if now.After(entry.expiresAt) {
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delete(rl.entries, key)
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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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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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entry, exists := rl.entries[key]
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if !exists || now.After(entry.expiresAt) {
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rl.entries[key] = &rateLimitEntry{
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count: 1,
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expiresAt: now.Add(time.Duration(rl.config.Window) * time.Second),
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}
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return true
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}
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entry.count++
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return entry.count <= rl.config.Requests
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}
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func RateLimit(config RateLimitConfig) gin.HandlerFunc {
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if !config.Enabled {
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return func(c *gin.Context) {
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c.Next()
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}
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}
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limiter := newRateLimiter(config)
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return func(c *gin.Context) {
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clientIP := c.ClientIP()
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if !limiter.allow(clientIP) {
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c.JSON(http.StatusTooManyRequests, gin.H{
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"error": "リクエスト数が制限を超えました。しばらくしてからお試しください。",
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})
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c.Abort()
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return
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}
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c.Next()
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}
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}
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