github.com/m3db/m3@v1.5.0/src/x/time/time.go (about)

     1  // Copyright (c) 2016 Uber Technologies, Inc.
     2  //
     3  // Permission is hereby granted, free of charge, to any person obtaining a copy
     4  // of this software and associated documentation files (the "Software"), to deal
     5  // in the Software without restriction, including without limitation the rights
     6  // to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
     7  // copies of the Software, and to permit persons to whom the Software is
     8  // furnished to do so, subject to the following conditions:
     9  //
    10  // The above copyright notice and this permission notice shall be included in
    11  // all copies or substantial portions of the Software.
    12  //
    13  // THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
    14  // IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
    15  // FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
    16  // AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
    17  // LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
    18  // OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
    19  // THE SOFTWARE.
    20  
    21  // Package time implement facilities for working with time.
    22  package time
    23  
    24  import (
    25  	"time"
    26  )
    27  
    28  const (
    29  	nanosPerMillis = int64(time.Millisecond)
    30  )
    31  
    32  // Now returns the current local time, in nanoseconds elapsed since January 1,
    33  // 1970 UTC. NB: This is independent of location.
    34  func Now() UnixNano {
    35  	return ToUnixNano(time.Now())
    36  }
    37  
    38  // Since returns the time elapsed since t.
    39  // It is shorthand for time.Now().Sub(t).
    40  func Since(t UnixNano) time.Duration {
    41  	return Now().Sub(t)
    42  }
    43  
    44  // ToNormalizedTime returns the normalized units of time given a time unit.
    45  func ToNormalizedTime(t time.Time, u time.Duration) int64 {
    46  	return t.UnixNano() / u.Nanoseconds()
    47  }
    48  
    49  // FromNormalizedTime returns the time given the normalized time units and the time unit.
    50  func FromNormalizedTime(nt int64, u time.Duration) UnixNano {
    51  	return UnixNano(int64(u/time.Nanosecond) * nt)
    52  }
    53  
    54  // ToNormalizedDuration returns the normalized units of duration given a time unit.
    55  func ToNormalizedDuration(d time.Duration, u time.Duration) int64 {
    56  	return int64(d / u)
    57  }
    58  
    59  // FromNormalizedDuration returns the duration given the normalized time duration and a time unit.
    60  func FromNormalizedDuration(nd int64, u time.Duration) time.Duration {
    61  	return time.Duration(nd) * u
    62  }
    63  
    64  // ToNanoseconds converts a time to nanoseconds.
    65  func ToNanoseconds(t time.Time) int64 {
    66  	return t.UnixNano()
    67  }
    68  
    69  // FromNanoseconds converts nanoseconds to a time.
    70  func FromNanoseconds(nsecs int64) time.Time {
    71  	return time.Unix(0, nsecs)
    72  }
    73  
    74  // ToUnixMillis converts a time to milliseconds since Unix epoch
    75  func ToUnixMillis(t time.Time) int64 {
    76  	return t.UnixNano() / nanosPerMillis
    77  }
    78  
    79  // FromUnixMillis converts milliseconds since Unix epoch to a time
    80  func FromUnixMillis(ms int64) time.Time {
    81  	return time.Unix(0, ms*nanosPerMillis)
    82  }
    83  
    84  // Ceil returns the result of rounding t up to a multiple of d since
    85  // the zero time.
    86  func Ceil(t time.Time, d time.Duration) time.Time {
    87  	res := t.Truncate(d)
    88  	if res.Before(t) {
    89  		res = res.Add(d)
    90  	}
    91  	return res
    92  }
    93  
    94  // MinTime returns the earlier one of t1 and t2.
    95  func MinTime(t1, t2 time.Time) time.Time {
    96  	if t1.Before(t2) {
    97  		return t1
    98  	}
    99  	return t2
   100  }
   101  
   102  // MinUnixNano returns the earlier one of t1 and t2.
   103  func MinUnixNano(t1, t2 UnixNano) UnixNano {
   104  	if t1.Before(t2) {
   105  		return t1
   106  	}
   107  	return t2
   108  }
   109  
   110  // MaxTime returns the later one of t1 and t2.
   111  func MaxTime(t1, t2 time.Time) time.Time {
   112  	if t1.After(t2) {
   113  		return t1
   114  	}
   115  	return t2
   116  }
   117  
   118  // MaxUnixNano returns the later one of t1 and t2.
   119  func MaxUnixNano(t1, t2 UnixNano) UnixNano {
   120  	if t1.After(t2) {
   121  		return t1
   122  	}
   123  	return t2
   124  }