sliding_window_test.go

package ratelimiter_test

import (
	. "github.com/onsi/ginkgo"
	. "github.com/onsi/gomega"
	"ratelimiter"
	"time"
)

var _ = Describe("Sliding window", func() {
	opts := ratelimiter.LimiterOptions{
		Limit:    5,
		Interval: time.Millisecond * 5,
		Tick:     time.Millisecond,
	}

	Describe("Basic tests, sync, one instance", func() {
		var limiter ratelimiter.RateLimiter

		BeforeEach(func() {
			limiter = ratelimiter.NewSlidingWindow(opts)
		})

		It("Get some, no tick advance", func() {
			Expect(limiter.GetTokens(2)).To(Equal(int32(2)))
			Expect(limiter.GetTokens(2)).To(Equal(int32(2)))
			Expect(limiter.GetTokens(2)).To(Equal(int32(1)))
			Expect(limiter.GetTokens(2)).To(Equal(int32(0)))
		})

		It("Get some, with tick advance", func() {
			for i := 0; i < 5; i++ {
				limiter.GetTokens(2)
				limiter.NextTick()
			}
			Expect(limiter.GetTokens(10)).To(Equal(int32(1)))
			limiter.NextTick()
			Expect(limiter.GetTokens(10)).To(Equal(int32(1)))
			limiter.NextTick()
			Expect(limiter.GetTokens(10)).To(Equal(int32(1)))
			limiter.NextTick()
			Expect(limiter.GetTokens(10)).To(Equal(int32(1)))
			limiter.NextTick()
			Expect(limiter.GetTokens(10)).To(Equal(int32(1)))
		})

		It("Get some from end of prev, then from start of next", func() {
			limiter.NextTick()
			limiter.NextTick()
			limiter.NextTick()
			limiter.NextTick()
			limiter.GetTokens(10)
			limiter.NextTick()

			Expect(limiter.GetTokens(10)).To(Equal(int32(1)))
			limiter.NextTick()
			Expect(limiter.GetTokens(10)).To(Equal(int32(1)))
			limiter.NextTick()
			Expect(limiter.GetTokens(10)).To(Equal(int32(1)))
			limiter.NextTick()
			Expect(limiter.GetTokens(10)).To(Equal(int32(1)))
			limiter.NextTick()
			Expect(limiter.GetTokens(10)).To(Equal(int32(1)))
		})
	})

	Describe("Sync test, for race condition checking", func() {
		XIt("Race condition test, run with --race flag", func() {
			limiter := ratelimiter.NewSlidingWindow(opts)

			for i := 0; i < 100000; i++ {
				go func() {
					limiter.GetTokens(10)
					limiter.IsTokenExists()
					limiter.NextTick()
				}()
			}
		})
	})
})