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

     1  package isNotNull
     2  
     3  import (
     4  	"context"
     5  	"math"
     6  
     7  	"github.com/go-graphite/carbonapi/expr/helper"
     8  	"github.com/go-graphite/carbonapi/expr/interfaces"
     9  	"github.com/go-graphite/carbonapi/expr/types"
    10  	"github.com/go-graphite/carbonapi/pkg/parser"
    11  )
    12  
    13  type isNotNull 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 := &isNotNull{}
    22  	functions := []string{"isNotNull", "isNonNull"}
    23  	for _, n := range functions {
    24  		res = append(res, interfaces.FunctionMetadata{Name: n, F: f})
    25  	}
    26  	return res
    27  }
    28  
    29  // isNonNull(seriesList)
    30  // alias: isNotNull(seriesList)
    31  func (f *isNotNull) Do(ctx context.Context, eval interfaces.Evaluator, e parser.Expr, from, until int64, values map[parser.MetricRequest][]*types.MetricData) ([]*types.MetricData, error) {
    32  	e.SetTarget("isNonNull")
    33  
    34  	return helper.ForEachSeriesDo(ctx, eval, e, from, until, values, func(a *types.MetricData, r *types.MetricData) *types.MetricData {
    35  		for i, v := range a.Values {
    36  			if math.IsNaN(v) {
    37  				r.Values[i] = 0
    38  			} else {
    39  				r.Values[i] = 1
    40  			}
    41  
    42  		}
    43  		r.Tags["isNonNull"] = "1"
    44  		return r
    45  	})
    46  }
    47  
    48  // Description is auto-generated description, based on output of https://github.com/graphite-project/graphite-web
    49  func (f *isNotNull) Description() map[string]types.FunctionDescription {
    50  	return map[string]types.FunctionDescription{
    51  		"isNotNull": {
    52  			Description: "Takes a metric or wildcard seriesList and counts up the number of non-null\nvalues.  This is useful for understanding the number of metrics that have data\nat a given point in time (i.e. to count which servers are alive).\n\nExample:\n\n.. code-block:: none\n\n  &target=isNotNull(webapp.pages.*.views)\n\nReturns a seriesList where 1 is specified for non-null values, and\n0 is specified for null values.",
    53  			Function:    "isNotNull(seriesList)",
    54  			Group:       "Combine",
    55  			Module:      "graphite.render.functions",
    56  			Name:        "isNotNull",
    57  			Params: []types.FunctionParam{
    58  				{
    59  					Name:     "seriesList",
    60  					Required: true,
    61  					Type:     types.SeriesList,
    62  				},
    63  			},
    64  			NameChange:   true, // name changed
    65  			ValuesChange: true, // values changed
    66  		},
    67  		"isNonNull": {
    68  			Description: "Takes a metric or wildcard seriesList and counts up the number of non-null\nvalues.  This is useful for understanding the number of metrics that have data\nat a given point in time (i.e. to count which servers are alive).\n\nExample:\n\n.. code-block:: none\n\n  &target=isNonNull(webapp.pages.*.views)\n\nReturns a seriesList where 1 is specified for non-null values, and\n0 is specified for null values.",
    69  			Function:    "isNonNull(seriesList)",
    70  			Group:       "Combine",
    71  			Module:      "graphite.render.functions",
    72  			Name:        "isNonNull",
    73  			Params: []types.FunctionParam{
    74  				{
    75  					Name:     "seriesList",
    76  					Required: true,
    77  					Type:     types.SeriesList,
    78  				},
    79  			},
    80  			NameChange:   true, // name changed
    81  			ValuesChange: true, // values changed
    82  		},
    83  	}
    84  }