VictoriaMetrics/vendor/google.golang.org/grpc/internal/serviceconfig/duration.go
2023-07-07 00:05:50 -07:00

131 lines
3.6 KiB
Go

/*
*
* Copyright 2023 gRPC 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 serviceconfig
import (
"encoding/json"
"fmt"
"math"
"strconv"
"strings"
"time"
)
// Duration defines JSON marshal and unmarshal methods to conform to the
// protobuf JSON spec defined [here].
//
// [here]: https://protobuf.dev/reference/protobuf/google.protobuf/#duration
type Duration time.Duration
func (d Duration) String() string {
return fmt.Sprint(time.Duration(d))
}
// MarshalJSON converts from d to a JSON string output.
func (d Duration) MarshalJSON() ([]byte, error) {
ns := time.Duration(d).Nanoseconds()
sec := ns / int64(time.Second)
ns = ns % int64(time.Second)
var sign string
if sec < 0 || ns < 0 {
sign, sec, ns = "-", -1*sec, -1*ns
}
// Generated output always contains 0, 3, 6, or 9 fractional digits,
// depending on required precision.
str := fmt.Sprintf("%s%d.%09d", sign, sec, ns)
str = strings.TrimSuffix(str, "000")
str = strings.TrimSuffix(str, "000")
str = strings.TrimSuffix(str, ".000")
return []byte(fmt.Sprintf("\"%ss\"", str)), nil
}
// UnmarshalJSON unmarshals b as a duration JSON string into d.
func (d *Duration) UnmarshalJSON(b []byte) error {
var s string
if err := json.Unmarshal(b, &s); err != nil {
return err
}
if !strings.HasSuffix(s, "s") {
return fmt.Errorf("malformed duration %q: missing seconds unit", s)
}
neg := false
if s[0] == '-' {
neg = true
s = s[1:]
}
ss := strings.SplitN(s[:len(s)-1], ".", 3)
if len(ss) > 2 {
return fmt.Errorf("malformed duration %q: too many decimals", s)
}
// hasDigits is set if either the whole or fractional part of the number is
// present, since both are optional but one is required.
hasDigits := false
var sec, ns int64
if len(ss[0]) > 0 {
var err error
if sec, err = strconv.ParseInt(ss[0], 10, 64); err != nil {
return fmt.Errorf("malformed duration %q: %v", s, err)
}
// Maximum seconds value per the durationpb spec.
const maxProtoSeconds = 315_576_000_000
if sec > maxProtoSeconds {
return fmt.Errorf("out of range: %q", s)
}
hasDigits = true
}
if len(ss) == 2 && len(ss[1]) > 0 {
if len(ss[1]) > 9 {
return fmt.Errorf("malformed duration %q: too many digits after decimal", s)
}
var err error
if ns, err = strconv.ParseInt(ss[1], 10, 64); err != nil {
return fmt.Errorf("malformed duration %q: %v", s, err)
}
for i := 9; i > len(ss[1]); i-- {
ns *= 10
}
hasDigits = true
}
if !hasDigits {
return fmt.Errorf("malformed duration %q: contains no numbers", s)
}
if neg {
sec *= -1
ns *= -1
}
// Maximum/minimum seconds/nanoseconds representable by Go's time.Duration.
const maxSeconds = math.MaxInt64 / int64(time.Second)
const maxNanosAtMaxSeconds = math.MaxInt64 % int64(time.Second)
const minSeconds = math.MinInt64 / int64(time.Second)
const minNanosAtMinSeconds = math.MinInt64 % int64(time.Second)
if sec > maxSeconds || (sec == maxSeconds && ns >= maxNanosAtMaxSeconds) {
*d = Duration(math.MaxInt64)
} else if sec < minSeconds || (sec == minSeconds && ns <= minNanosAtMinSeconds) {
*d = Duration(math.MinInt64)
} else {
*d = Duration(sec*int64(time.Second) + ns)
}
return nil
}