Draft datatype for seat-seconds

This commit is contained in:
Mike Spreitzer 2021-10-01 13:29:35 -07:00
parent e414cf7641
commit d866f94458
2 changed files with 83 additions and 0 deletions

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@ -0,0 +1,45 @@
/*
Copyright 2021 The Kubernetes Authors.
Licensed under the Apache License, Version 2.0 (the "License");
you may not use this file except in compliance with the License.
You may obtain a copy of the License at
http://www.apache.org/licenses/LICENSE-2.0
Unless required by applicable law or agreed to in writing, software
distributed under the License is distributed on an "AS IS" BASIS,
WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
See the License for the specific language governing permissions and
limitations under the License.
*/
package queueset
import (
"fmt"
"math"
"testing"
"time"
)
func TestSeatSecondsString(t *testing.T) {
digits := math.Log10(ssScale)
expectFmt := fmt.Sprintf("%%%d.%dfss", int(digits+2), int(digits))
testCases := []struct {
ss SeatSeconds
expect string
}{
{ss: SeatSeconds(1), expect: fmt.Sprintf(expectFmt, 1.0/ssScale)},
{ss: 0, expect: "0.00000000ss"},
{ss: SeatsTimesDuration(1, time.Second), expect: "1.00000000ss"},
{ss: SeatsTimesDuration(123, 100*time.Millisecond), expect: "12.30000000ss"},
{ss: SeatsTimesDuration(1203, 10*time.Millisecond), expect: "12.03000000ss"},
}
for _, testCase := range testCases {
actualStr := testCase.ss.String()
if actualStr != testCase.expect {
t.Errorf("SeatSeonds(%d) formatted as %q rather than expected %q", uint64(testCase.ss), actualStr, testCase.expect)
}
}
}

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@ -18,6 +18,8 @@ package queueset
import (
"context"
"fmt"
"math"
"time"
genericrequest "k8s.io/apiserver/pkg/endpoints/request"
@ -134,3 +136,39 @@ func (q *queue) dump(includeDetails bool) debug.QueueDump {
SeatsInUse: q.seatsInUse,
}
}
// SeatSeconds is a measure of work, in units of seat-seconds, using a fixed-point representation.
// `SeatSeconds(n)` represents `n/ssScale` seat-seconds.
// The constants `ssScale` and `ssScaleDigits` are private to the implementation here,
// no other code should use them.
type SeatSeconds uint64
// MaxSeatsSeconds is the maximum representable value of SeatSeconds
const MaxSeatSeconds = SeatSeconds(math.MaxUint64)
// MinSeatSeconds is the lowest representable value of SeatSeconds
const MinSeatSeconds = SeatSeconds(0)
// SeatsTimeDuration produces the SeatSeconds value for the given factors.
// This is intended only to produce small values, increments in work
// rather than amount of work done since process start.
func SeatsTimesDuration(seats float64, duration time.Duration) SeatSeconds {
return SeatSeconds(math.Round(seats * float64(duration/time.Nanosecond) / (1e9 / ssScale)))
}
// ToFloat converts to a floating-point representation.
// This conversion may lose precision.
func (ss SeatSeconds) ToFloat() float64 {
return float64(ss) / ssScale
}
// String converts to a string.
// This is suitable for large as well as small values.
func (ss SeatSeconds) String() string {
const div = SeatSeconds(ssScale)
quo := ss / div
rem := ss - quo*div
return fmt.Sprintf("%d.%08dss", quo, rem)
}
const ssScale = 1e8