github.com/m3db/m3@v1.5.0/src/query/functions/linear/datetime.go (about)

     1  // Copyright (c) 2018 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 linear
    22  
    23  import (
    24  	"fmt"
    25  	"math"
    26  	"time"
    27  
    28  	"github.com/m3db/m3/src/query/block"
    29  	"github.com/m3db/m3/src/query/functions/lazy"
    30  	"github.com/m3db/m3/src/query/parser"
    31  )
    32  
    33  const (
    34  	// DayOfMonthType returns the day of the month for each of the given times
    35  	// in UTC.
    36  	// Returned values are from 1 to 31.
    37  	DayOfMonthType = "day_of_month"
    38  
    39  	// DayOfWeekType returns the day of the week for each of the given times
    40  	// in UTC.
    41  	// Returned values are from 0 to 6, where 0 means Sunday etc.
    42  	DayOfWeekType = "day_of_week"
    43  
    44  	// DaysInMonthType returns number of days in the month for each of the given
    45  	// times in UTC.
    46  	// Returned values are from 28 to 31.
    47  	DaysInMonthType = "days_in_month"
    48  
    49  	// HourType returns the hour of the day for each of the given times in UTC.
    50  	// Returned values are from 0 to 23.
    51  	HourType = "hour"
    52  
    53  	// MinuteType returns the minute of the hour for each of the given times
    54  	// in UTC.
    55  	// Returned values are from 0 to 59.
    56  	MinuteType = "minute"
    57  
    58  	// MonthType returns the month of the year for each of the given times in UTC.
    59  	// Returned values are from 1 to 12, where 1 means January etc.
    60  	MonthType = "month"
    61  
    62  	// YearType returns the year for each of the given times in UTC.
    63  	YearType = "year"
    64  )
    65  
    66  type timeFn func(time.Time) float64
    67  
    68  var (
    69  	datetimeFuncs = map[string]timeFn{
    70  		DayOfMonthType: func(t time.Time) float64 { return float64(t.Day()) },
    71  		DayOfWeekType:  func(t time.Time) float64 { return float64(t.Weekday()) },
    72  		DaysInMonthType: func(t time.Time) float64 {
    73  			return float64(32 - time.Date(t.Year(), t.Month(),
    74  				32, 0, 0, 0, 0, time.UTC).Day())
    75  		},
    76  		HourType:   func(t time.Time) float64 { return float64(t.Hour()) },
    77  		MinuteType: func(t time.Time) float64 { return float64(t.Minute()) },
    78  		MonthType:  func(t time.Time) float64 { return float64(t.Month()) },
    79  		YearType:   func(t time.Time) float64 { return float64(t.Year()) },
    80  	}
    81  )
    82  
    83  func buildTransform(fn timeFn, usingSeries bool) block.ValueTransform {
    84  	if !usingSeries {
    85  		return func(v float64) float64 {
    86  			return fn(time.Now())
    87  		}
    88  	}
    89  
    90  	return func(v float64) float64 {
    91  		if math.IsNaN(v) {
    92  			return v
    93  		}
    94  
    95  		t := time.Unix(int64(v), 0).UTC()
    96  		return fn(t)
    97  	}
    98  }
    99  
   100  // NewDateOp creates a new date op based on the type.
   101  func NewDateOp(opType string, usingSeries bool) (parser.Params, error) {
   102  	if dateFn, ok := datetimeFuncs[opType]; ok {
   103  		fn := buildTransform(dateFn, usingSeries)
   104  		lazyOpts := block.NewLazyOptions().SetValueTransform(fn)
   105  		return lazy.NewLazyOp(opType, lazyOpts)
   106  	}
   107  
   108  	return nil, fmt.Errorf("unknown date type: %s", opType)
   109  }