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

     1  package alias
     2  
     3  import (
     4  	"context"
     5  	"strings"
     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 alias 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 := &alias{}
    22  	for _, n := range []string{"alias"} {
    23  		res = append(res, interfaces.FunctionMetadata{Name: n, F: f})
    24  	}
    25  	return res
    26  }
    27  
    28  func (f *alias) Do(ctx context.Context, eval interfaces.Evaluator, e parser.Expr, from, until int64, values map[parser.MetricRequest][]*types.MetricData) ([]*types.MetricData, error) {
    29  	if e.ArgsLen() < 2 {
    30  		return nil, parser.ErrMissingArgument
    31  	}
    32  
    33  	args, err := helper.GetSeriesArg(ctx, eval, e.Arg(0), from, until, values)
    34  	if err != nil {
    35  		return nil, err
    36  	}
    37  
    38  	alias, err := e.GetStringArg(1)
    39  	if err != nil {
    40  		return nil, err
    41  	}
    42  
    43  	allowFormatStr, err := e.GetBoolArgDefault(2, false)
    44  	if err != nil {
    45  		return nil, err
    46  	}
    47  
    48  	results := make([]*types.MetricData, len(args))
    49  	for i, arg := range args {
    50  		name := alias
    51  		if allowFormatStr {
    52  			name = strings.ReplaceAll(name, "${expr}", arg.Name)
    53  		}
    54  		r := arg.CopyLinkTags()
    55  		r.Name = name
    56  		results[i] = r
    57  	}
    58  
    59  	return results, nil
    60  }
    61  
    62  func (f *alias) Description() map[string]types.FunctionDescription {
    63  	return map[string]types.FunctionDescription{
    64  		"alias": {
    65  			Description: "Takes one metric or a wildcard seriesList and a string in quotes.\n" +
    66  				"Prints the string instead of the metric name in the legend.\n" +
    67  				"If set to True, `allowFormatStr` will replace all occurrences of `${expr}` with name of expression\n\n" +
    68  				".. code-block:: none\n\n" +
    69  				"  &target=alias(Sales.widgets.largeBlue,\"Large Blue Widgets\")",
    70  			Function: "alias(seriesList, newName)",
    71  			Group:    "Alias",
    72  			Module:   "graphite.render.functions",
    73  			Name:     "alias",
    74  			Params: []types.FunctionParam{
    75  				{
    76  					Name:     "seriesList",
    77  					Required: true,
    78  					Type:     types.SeriesList,
    79  				},
    80  				{
    81  					Name:     "newName",
    82  					Required: true,
    83  					Type:     types.String,
    84  				},
    85  				{
    86  					Default:  types.NewSuggestion(false),
    87  					Name:     "allowFormatStr",
    88  					Required: false,
    89  					Type:     types.Boolean,
    90  				},
    91  			},
    92  			NameChange: true, // name changed
    93  			TagsChange: true, // name tag changed
    94  		},
    95  	}
    96  }