limiter_sliding.go — fiber Source File

Source Code

package limiter

import (
	"fmt"
	"math"
	"strconv"
	"sync"
	"time"

	"github.com/gofiber/fiber/v3"
	"github.com/gofiber/utils/v2"
)

// SlidingWindow implements the sliding-window rate limiting strategy.
type SlidingWindow struct{}

// New creates a new sliding window middleware handler
func (SlidingWindow) New(cfg *Config) fiber.Handler {
	if cfg == nil {
		defaultCfg := configDefault()
		cfg = &defaultCfg
	}

	// Limiter variables
	mux := &sync.RWMutex{}

	// Create manager to simplify storage operations ( see manager.go )
	manager := newManager(cfg.Storage, !cfg.DisableValueRedaction)

	// Update timestamp every second
	utils.StartTimeStampUpdater()

	// Return new handler
	return func(c fiber.Ctx) error {
		// Generate maxRequests from generator, if no generator was provided the default value returned is 5
		maxRequests := cfg.MaxFunc(c)

		// Don't execute middleware if Next returns true or if the max is 0
		if (cfg.Next != nil && cfg.Next(c)) || maxRequests == 0 {
			return c.Next()
		}

		// Generate expiration from generator
		expirationDuration := cfg.ExpirationFunc(c)
		if expirationDuration <= 0 {
			expirationDuration = ConfigDefault.Expiration
		}
		expiration := uint64(expirationDuration.Seconds())

		// Get key from request
		key := cfg.KeyGenerator(c)

		// Lock entry
		mux.Lock()

		reqCtx := c.Context()

		// Get entry from pool and release when finished
		e, err := manager.get(reqCtx, key)
		if err != nil {
// ... (170 more lines)