boulder/ratelimits/gcra_test.go

226 lines
8.4 KiB
Go

package ratelimits
import (
"testing"
"time"
"github.com/jmhodges/clock"
"github.com/letsencrypt/boulder/config"
"github.com/letsencrypt/boulder/test"
)
func TestDecide(t *testing.T) {
clk := clock.NewFake()
limit := limit{Burst: 10, Count: 1, Period: config.Duration{Duration: time.Second}}
limit.precompute()
// Begin by using 1 of our 10 requests.
d := maybeSpend(clk, limit, clk.Now(), 1)
test.Assert(t, d.Allowed, "should be allowed")
test.AssertEquals(t, d.Remaining, int64(9))
test.AssertEquals(t, d.RetryIn, time.Duration(0))
test.AssertEquals(t, d.ResetIn, time.Second)
// Immediately use another 9 of our remaining requests.
d = maybeSpend(clk, limit, d.newTAT, 9)
test.Assert(t, d.Allowed, "should be allowed")
test.AssertEquals(t, d.Remaining, int64(0))
// We should have to wait 1 second before we can use another request but we
// used 9 so we should have to wait 9 seconds to make an identical request.
test.AssertEquals(t, d.RetryIn, time.Second*9)
test.AssertEquals(t, d.ResetIn, time.Second*10)
// Our new TAT should be 10 seconds (limit.Burst) in the future.
test.AssertEquals(t, d.newTAT, clk.Now().Add(time.Second*10))
// Let's try using just 1 more request without waiting.
d = maybeSpend(clk, limit, d.newTAT, 1)
test.Assert(t, !d.Allowed, "should not be allowed")
test.AssertEquals(t, d.Remaining, int64(0))
test.AssertEquals(t, d.RetryIn, time.Second)
test.AssertEquals(t, d.ResetIn, time.Second*10)
// Let's try being exactly as patient as we're told to be.
clk.Add(d.RetryIn)
d = maybeSpend(clk, limit, d.newTAT, 0)
test.AssertEquals(t, d.Remaining, int64(1))
// We are 1 second in the future, we should have 1 new request.
d = maybeSpend(clk, limit, d.newTAT, 1)
test.Assert(t, d.Allowed, "should be allowed")
test.AssertEquals(t, d.Remaining, int64(0))
test.AssertEquals(t, d.RetryIn, time.Second)
test.AssertEquals(t, d.ResetIn, time.Second*10)
// Let's try waiting (10 seconds) for our whole bucket to refill.
clk.Add(d.ResetIn)
// We should have 10 new requests. If we use 1 we should have 9 remaining.
d = maybeSpend(clk, limit, d.newTAT, 1)
test.Assert(t, d.Allowed, "should be allowed")
test.AssertEquals(t, d.Remaining, int64(9))
test.AssertEquals(t, d.RetryIn, time.Duration(0))
test.AssertEquals(t, d.ResetIn, time.Second)
// Wait just shy of how long we're told to wait for refilling.
clk.Add(d.ResetIn - time.Millisecond)
// We should still have 9 remaining because we're still 1ms shy of the
// refill time.
d = maybeSpend(clk, limit, d.newTAT, 0)
test.Assert(t, d.Allowed, "should be allowed")
test.AssertEquals(t, d.Remaining, int64(9))
test.AssertEquals(t, d.RetryIn, time.Duration(0))
test.AssertEquals(t, d.ResetIn, time.Millisecond)
// Spending 0 simply informed us that we still have 9 remaining, let's see
// what we have after waiting 20 hours.
clk.Add(20 * time.Hour)
// C'mon, big money, no whammies, no whammies, STOP!
d = maybeSpend(clk, limit, d.newTAT, 0)
test.Assert(t, d.Allowed, "should be allowed")
test.AssertEquals(t, d.Remaining, int64(10))
test.AssertEquals(t, d.RetryIn, time.Duration(0))
test.AssertEquals(t, d.ResetIn, time.Duration(0))
// Turns out that the most we can accrue is 10 (limit.Burst). Let's empty
// this bucket out so we can try something else.
d = maybeSpend(clk, limit, d.newTAT, 10)
test.Assert(t, d.Allowed, "should be allowed")
test.AssertEquals(t, d.Remaining, int64(0))
// We should have to wait 1 second before we can use another request but we
// used 10 so we should have to wait 10 seconds to make an identical
// request.
test.AssertEquals(t, d.RetryIn, time.Second*10)
test.AssertEquals(t, d.ResetIn, time.Second*10)
// If you spend 0 while you have 0 you should get 0.
d = maybeSpend(clk, limit, d.newTAT, 0)
test.Assert(t, d.Allowed, "should be allowed")
test.AssertEquals(t, d.Remaining, int64(0))
test.AssertEquals(t, d.RetryIn, time.Duration(0))
test.AssertEquals(t, d.ResetIn, time.Second*10)
// We don't play by the rules, we spend 1 when we have 0.
d = maybeSpend(clk, limit, d.newTAT, 1)
test.Assert(t, !d.Allowed, "should not be allowed")
test.AssertEquals(t, d.Remaining, int64(0))
test.AssertEquals(t, d.RetryIn, time.Second)
test.AssertEquals(t, d.ResetIn, time.Second*10)
// Okay, maybe we should play by the rules if we want to get anywhere.
clk.Add(d.RetryIn)
// Our patience pays off, we should have 1 new request. Let's use it.
d = maybeSpend(clk, limit, d.newTAT, 1)
test.Assert(t, d.Allowed, "should be allowed")
test.AssertEquals(t, d.Remaining, int64(0))
test.AssertEquals(t, d.RetryIn, time.Second)
test.AssertEquals(t, d.ResetIn, time.Second*10)
// Refill from empty to 5.
clk.Add(d.ResetIn / 2)
// Attempt to spend 7 when we only have 5. We should be denied but the
// decision should reflect a retry of 2 seconds, the time it would take to
// refill from 5 to 7.
d = maybeSpend(clk, limit, d.newTAT, 7)
test.Assert(t, !d.Allowed, "should not be allowed")
test.AssertEquals(t, d.Remaining, int64(5))
test.AssertEquals(t, d.RetryIn, time.Second*2)
test.AssertEquals(t, d.ResetIn, time.Second*5)
}
func TestMaybeRefund(t *testing.T) {
clk := clock.NewFake()
limit := limit{Burst: 10, Count: 1, Period: config.Duration{Duration: time.Second}}
limit.precompute()
// Begin by using 1 of our 10 requests.
d := maybeSpend(clk, limit, clk.Now(), 1)
test.Assert(t, d.Allowed, "should be allowed")
test.AssertEquals(t, d.Remaining, int64(9))
test.AssertEquals(t, d.RetryIn, time.Duration(0))
test.AssertEquals(t, d.ResetIn, time.Second)
// Refund back to 10.
d = maybeRefund(clk, limit, d.newTAT, 1)
test.AssertEquals(t, d.Remaining, int64(10))
test.AssertEquals(t, d.RetryIn, time.Duration(0))
test.AssertEquals(t, d.ResetIn, time.Duration(0))
// Refund 0, we should still have 10.
d = maybeRefund(clk, limit, d.newTAT, 0)
test.AssertEquals(t, d.Remaining, int64(10))
test.AssertEquals(t, d.RetryIn, time.Duration(0))
test.AssertEquals(t, d.ResetIn, time.Duration(0))
// Spend 1 more of our 10 requests.
d = maybeSpend(clk, limit, d.newTAT, 1)
test.Assert(t, d.Allowed, "should be allowed")
test.AssertEquals(t, d.Remaining, int64(9))
test.AssertEquals(t, d.RetryIn, time.Duration(0))
test.AssertEquals(t, d.ResetIn, time.Second)
// Wait for our bucket to refill.
clk.Add(d.ResetIn)
// Attempt to refund from 10 to 11.
d = maybeRefund(clk, limit, d.newTAT, 1)
test.Assert(t, !d.Allowed, "should not be allowed")
test.AssertEquals(t, d.Remaining, int64(10))
test.AssertEquals(t, d.RetryIn, time.Duration(0))
test.AssertEquals(t, d.ResetIn, time.Duration(0))
// Spend 10 all 10 of our requests.
d = maybeSpend(clk, limit, d.newTAT, 10)
test.Assert(t, d.Allowed, "should be allowed")
test.AssertEquals(t, d.Remaining, int64(0))
// We should have to wait 1 second before we can use another request but we
// used 10 so we should have to wait 10 seconds to make an identical
// request.
test.AssertEquals(t, d.RetryIn, time.Second*10)
test.AssertEquals(t, d.ResetIn, time.Second*10)
// Attempt a refund of 10.
d = maybeRefund(clk, limit, d.newTAT, 10)
test.AssertEquals(t, d.Remaining, int64(10))
test.AssertEquals(t, d.RetryIn, time.Duration(0))
test.AssertEquals(t, d.ResetIn, time.Duration(0))
// Wait 11 seconds to catching up to TAT.
clk.Add(11 * time.Second)
// Attempt to refund to 11, then ensure it's still 10.
d = maybeRefund(clk, limit, d.newTAT, 1)
test.Assert(t, !d.Allowed, "should be allowed")
test.AssertEquals(t, d.Remaining, int64(10))
test.AssertEquals(t, d.RetryIn, time.Duration(0))
test.AssertEquals(t, d.ResetIn, time.Duration(0))
// Spend 5 of our 10 requests, then refund 1.
d = maybeSpend(clk, limit, d.newTAT, 5)
d = maybeRefund(clk, limit, d.newTAT, 1)
test.Assert(t, d.Allowed, "should be allowed")
test.AssertEquals(t, d.Remaining, int64(6))
test.AssertEquals(t, d.RetryIn, time.Duration(0))
// Wait, a 2.5 seconds to refill to 8.5 requests.
clk.Add(time.Millisecond * 2500)
// Ensure we have 8.5 requests.
d = maybeSpend(clk, limit, d.newTAT, 0)
test.Assert(t, d.Allowed, "should be allowed")
test.AssertEquals(t, d.Remaining, int64(8))
test.AssertEquals(t, d.RetryIn, time.Duration(0))
// Check that ResetIn represents the fractional earned request.
test.AssertEquals(t, d.ResetIn, time.Millisecond*1500)
// Refund 2 requests, we should only have 10, not 10.5.
d = maybeRefund(clk, limit, d.newTAT, 2)
test.AssertEquals(t, d.Remaining, int64(10))
test.AssertEquals(t, d.RetryIn, time.Duration(0))
test.AssertEquals(t, d.ResetIn, time.Duration(0))
}