1 // Copyright 2019 CUE Authors 2 // 3 // Licensed under the Apache License, Version 2.0 (the "License"); 4 // you may not use this file except in compliance with the License. 5 // You may obtain a copy of the License at 6 // 7 // http://www.apache.org/licenses/LICENSE-2.0 8 // 9 // Unless required by applicable law or agreed to in writing, software 10 // distributed under the License is distributed on an "AS IS" BASIS, 11 // WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 12 // See the License for the specific language governing permissions and 13 // limitations under the License. 14 15 package time 16 17 import ( 18 "time" 19 ) 20 21 // Common durations. There is no definition for units of Day or larger 22 // to avoid confusion across daylight savings time zone transitions. 23 // 24 // To count the number of units in a Duration, divide: 25 // 26 // second := time.Second 27 // fmt.Print(int64(second/time.Millisecond)) // prints 1000 28 // 29 // To convert an integer number of units to a Duration, multiply: 30 // 31 // seconds := 10 32 // fmt.Print(time.Duration(seconds)*time.Second) // prints 10s 33 const ( 34 Nanosecond = 1 35 Microsecond = 1000 36 Millisecond = 1000000 37 Second = 1000000000 38 Minute = 60000000000 39 Hour = 3600000000000 40 ) 41 42 // Duration validates a duration string. 43 // 44 // Note: this format also accepts strings of the form '1h3m', '2ms', etc. 45 // To limit this to seconds only, as often used in JSON, add the !~"hmuµn" 46 // constraint. 47 func Duration(s string) (bool, error) { 48 if _, err := time.ParseDuration(s); err != nil { 49 return false, err 50 } 51 return true, nil 52 } 53 54 // FormatDuration converts nanoseconds to a string representing the duration in 55 // the form "72h3m0.5s". 56 // 57 // Leading zero units are omitted. As a special case, durations less than 58 // one second use a smaller unit (milli-, micro-, or nanoseconds) to ensure 59 // that the leading digit is non-zero. The zero duration formats as 0s. 60 func FormatDuration(d int64) string { 61 return time.Duration(d).String() 62 } 63 64 // ParseDuration reports the nanoseconds represented by a duration string. 65 // 66 // A duration string is a possibly signed sequence of 67 // decimal numbers, each with optional fraction and a unit suffix, 68 // such as "300ms", "-1.5h" or "2h45m". 69 // Valid time units are "ns", "us" (or "µs"), "ms", "s", "m", "h". 70 func ParseDuration(s string) (int64, error) { 71 d, err := time.ParseDuration(s) 72 if err != nil { 73 return 0, err 74 } 75 return int64(d), nil 76 } 77