github.com/go-graphite/carbonapi@v0.17.0/expr/functions/timeFunction/function.go (about)

     1  package timeFunction
     2  
     3  import (
     4  	"context"
     5  	"errors"
     6  
     7  	"github.com/go-graphite/carbonapi/expr/interfaces"
     8  	"github.com/go-graphite/carbonapi/expr/types"
     9  	"github.com/go-graphite/carbonapi/pkg/parser"
    10  	pb "github.com/go-graphite/protocol/carbonapi_v3_pb"
    11  )
    12  
    13  type timeFunction struct{}
    14  
    15  func GetOrder() interfaces.Order {
    16  	return interfaces.Any
    17  }
    18  
    19  func New(configFile string) []interfaces.FunctionMetadata {
    20  	res := make([]interfaces.FunctionMetadata, 0)
    21  	f := &timeFunction{}
    22  	functions := []string{"timeFunction", "time"}
    23  	for _, n := range functions {
    24  		res = append(res, interfaces.FunctionMetadata{Name: n, F: f})
    25  	}
    26  	return res
    27  }
    28  
    29  func (f *timeFunction) Do(ctx context.Context, eval interfaces.Evaluator, e parser.Expr, from, until int64, values map[parser.MetricRequest][]*types.MetricData) ([]*types.MetricData, error) {
    30  	name, err := e.GetStringArg(0)
    31  	if err != nil {
    32  		return nil, err
    33  	}
    34  
    35  	stepInt, err := e.GetIntArgDefault(1, 60)
    36  	if err != nil {
    37  		return nil, err
    38  	}
    39  	if stepInt <= 0 {
    40  		return nil, errors.New("step can't be less than 0")
    41  	}
    42  	step := int64(stepInt)
    43  
    44  	// emulate the behavior of this Python code:
    45  	//   while when < requestContext["endTime"]:
    46  	//     newValues.append(time.mktime(when.timetuple()))
    47  	//     when += delta
    48  
    49  	newValues := make([]float64, (until-from-1+step)/step)
    50  	value := from
    51  	for i := 0; i < len(newValues); i++ {
    52  		newValues[i] = float64(value)
    53  		value += step
    54  	}
    55  
    56  	p := types.MetricData{
    57  		FetchResponse: pb.FetchResponse{
    58  			Name:      name,
    59  			StartTime: from,
    60  			StopTime:  until,
    61  			StepTime:  step,
    62  			Values:    newValues,
    63  		},
    64  		Tags: map[string]string{"name": name},
    65  	}
    66  
    67  	return []*types.MetricData{&p}, nil
    68  }
    69  
    70  // Description is auto-generated description, based on output of https://github.com/graphite-project/graphite-web
    71  func (f *timeFunction) Description() map[string]types.FunctionDescription {
    72  	return map[string]types.FunctionDescription{
    73  		"timeFunction": {
    74  			Description: "Short Alias: time()\n\nJust returns the timestamp for each X value. T\n\nExample:\n\n.. code-block:: none\n\n  &target=time(\"The.time.series\")\n\nThis would create a series named \"The.time.series\" that contains in Y the same\nvalue (in seconds) as X.\nAccepts optional second argument as 'step' parameter (default step is 60 sec)",
    75  			Function:    "timeFunction(name, step=60)",
    76  			Group:       "Transform",
    77  			Module:      "graphite.render.functions",
    78  			Name:        "timeFunction",
    79  			Params: []types.FunctionParam{
    80  				{
    81  					Name:     "name",
    82  					Required: true,
    83  					Type:     types.String,
    84  				},
    85  				{
    86  					Default: types.NewSuggestion(60),
    87  					Name:    "step",
    88  					Type:    types.Integer,
    89  				},
    90  			},
    91  		},
    92  		"time": {
    93  			Description: "Short Alias: time()\n\nJust returns the timestamp for each X value. T\n\nExample:\n\n.. code-block:: none\n\n  &target=time(\"The.time.series\")\n\nThis would create a series named \"The.time.series\" that contains in Y the same\nvalue (in seconds) as X.\nAccepts optional second argument as 'step' parameter (default step is 60 sec)",
    94  			Function:    "time(name, step=60)",
    95  			Group:       "Transform",
    96  			Module:      "graphite.render.functions",
    97  			Name:        "time",
    98  			Params: []types.FunctionParam{
    99  				{
   100  					Name:     "name",
   101  					Required: true,
   102  					Type:     types.String,
   103  				},
   104  				{
   105  					Default: types.NewSuggestion(60),
   106  					Name:    "step",
   107  					Type:    types.Integer,
   108  				},
   109  			},
   110  		},
   111  	}
   112  }