Files
tasks/common/quotas/delayed_request_rate_limiter_test.go
Michael SnowdenandGitHub 44d5f69cfb Add quotas.DelayedRateLimiter (#4688)
<!-- Describe what has changed in this PR -->
**What changed?**
I added `quotas.DelayedRateLimiter`, which adds a delay before an input
`quotas.RateLimiter` actually takes effect. I also added some utilities
to make its implementation easier. The delayed rate limiter depends on
the new rate limiter delegator and no-op rate limiter structs.

<!-- Tell your future self why have you made these changes -->
**Why?**
In some cases in the history service, we want to delay rate limiters for
a short period after startup.

<!-- How have you verified this change? Tested locally? Added a unit
test? Checked in staging env? -->
**How did you test it?**
There is 100% test coverage for the new code.

<!-- Assuming the worst case, what can be broken when deploying this
change to production? -->
**Potential risks**
None. These are just additions.

<!-- Is this PR a hotfix candidate or require that a notification be
sent to the broader community? (Yes/No) -->
**Is hotfix candidate?**
No.
2023-07-28 01:04:05 +00:00

97 lines
3.8 KiB
Go

// The MIT License
//
// Copyright (c) 2020 Temporal Technologies Inc. All rights reserved.
//
// Copyright (c) 2020 Uber Technologies, Inc.
//
// Permission is hereby granted, free of charge, to any person obtaining a copy
// of this software and associated documentation files (the "Software"), to deal
// in the Software without restriction, including without limitation the rights
// to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
// copies of the Software, and to permit persons to whom the Software is
// furnished to do so, subject to the following conditions:
//
// The above copyright notice and this permission notice shall be included in
// all copies or substantial portions of the Software.
//
// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
// FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
// AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
// LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
// OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
// THE SOFTWARE.
package quotas_test
import (
"testing"
"time"
"github.com/stretchr/testify/assert"
"github.com/stretchr/testify/require"
"go.temporal.io/server/common/clock"
"go.temporal.io/server/common/quotas"
)
// disallowingRateLimiter is a rate limiter whose Allow method always returns false.
type disallowingRateLimiter struct {
// RequestRateLimiter is an embedded field so that disallowingRateLimiter implements that interface. It doesn't
// actually delegate to this rate limiter, and this field should be left nil.
quotas.RequestRateLimiter
}
func (rl disallowingRateLimiter) Allow(time.Time, quotas.Request) bool {
return false
}
func TestNewDelayedRequestRateLimiter_NegativeDelay(t *testing.T) {
t.Parallel()
_, err := quotas.NewDelayedRequestRateLimiter(
quotas.NoopRequestRateLimiter,
-time.Nanosecond,
clock.NewRealTimeSource(),
)
assert.ErrorIs(t, err, quotas.ErrNegativeDelay)
}
func TestNewDelayedRequestRateLimiter_ZeroDelay(t *testing.T) {
t.Parallel()
timeSource := clock.NewEventTimeSource()
drl, err := quotas.NewDelayedRequestRateLimiter(disallowingRateLimiter{}, 0, timeSource)
require.NoError(t, err)
assert.False(t, drl.Allow(time.Time{}, quotas.Request{}), "expected Allow to return false because we "+
"immediately switched to the disallowing rate limiter due to the zero delay")
}
func TestDelayedRequestRateLimiter_Allow(t *testing.T) {
t.Parallel()
timeSource := clock.NewEventTimeSource()
drl, err := quotas.NewDelayedRequestRateLimiter(disallowingRateLimiter{}, time.Second, timeSource)
require.NoError(t, err)
timeSource.Advance(time.Second - time.Nanosecond)
assert.True(t, drl.Allow(time.Time{}, quotas.Request{}), "expected Allow to return true because the "+
"timer hasn't expired yet")
timeSource.Advance(time.Nanosecond)
assert.False(t, drl.Allow(time.Time{}, quotas.Request{}), "expected Allow to return false because the "+
"timer expired, and we switched to the disallowing rate limiter")
}
func TestDelayedRequestRateLimiter_Cancel(t *testing.T) {
t.Parallel()
timeSource := clock.NewEventTimeSource()
drl, err := quotas.NewDelayedRequestRateLimiter(disallowingRateLimiter{}, time.Second, timeSource)
require.NoError(t, err)
timeSource.Advance(time.Second - time.Nanosecond)
assert.True(t, drl.Cancel(), "expected Cancel to return true because the timer was stopped before it "+
"expired")
timeSource.Advance(time.Nanosecond)
assert.True(t, drl.Allow(time.Time{}, quotas.Request{}), "expected Allow to return true because the "+
"timer was stopped before it could expire")
assert.False(t, drl.Cancel(), "expected Cancel to return false because the timer was already stopped")
}