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

     1  package toLowerCase
     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 toLowerCase 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 := &toLowerCase{}
    22  	functions := []string{"lower", "toLowerCase"}
    23  	for _, n := range functions {
    24  		res = append(res, interfaces.FunctionMetadata{Name: n, F: f})
    25  	}
    26  	return res
    27  }
    28  
    29  // toLowerCase(seriesList, *pos)
    30  func (f *toLowerCase) Do(ctx context.Context, eval interfaces.Evaluator, e parser.Expr, from, until int64, values map[parser.MetricRequest][]*types.MetricData) ([]*types.MetricData, error) {
    31  	args, err := helper.GetSeriesArg(ctx, eval, e.Arg(0), from, until, values)
    32  	if err != nil {
    33  		return nil, err
    34  	}
    35  
    36  	pos, err := e.GetIntArgs(1)
    37  	if err != nil {
    38  		return nil, err
    39  	}
    40  
    41  	results := make([]*types.MetricData, 0, len(args)+1)
    42  
    43  	for _, a := range args {
    44  		r := a.CopyLink()
    45  
    46  		if len(pos) == 0 {
    47  			r.Name = strings.ToLower(a.Name)
    48  		} else {
    49  			for _, i := range pos {
    50  				if i < 0 { // Handle negative indices by indexing backwards
    51  					i = len(r.Name) + i
    52  				}
    53  				lowered := strings.ToLower(string(r.Name[i]))
    54  				r.Name = r.Name[:i] + lowered + r.Name[i+1:]
    55  			}
    56  		}
    57  		r.Tags["name"] = r.Name
    58  
    59  		results = append(results, r)
    60  	}
    61  
    62  	return results, nil
    63  }
    64  
    65  // Description is auto-generated description, based on output of https://github.com/graphite-project/graphite-web
    66  func (f *toLowerCase) Description() map[string]types.FunctionDescription {
    67  	return map[string]types.FunctionDescription{
    68  		"lower": {
    69  			Description: "Takes one metric or a wildcard seriesList and lowers the case of each letter. \n Optionally, a letter position to lower case can be specified, in which case only the letter at the specified position gets lower-cased.\n The position parameter may be given multiple times. The position parameter may be negative to define a position relative to the end of the metric name.",
    70  			Function:    "lower(seriesList, *pos)",
    71  			Group:       "Alias",
    72  			Module:      "graphite.render.functions",
    73  			Name:        "lower",
    74  			Params: []types.FunctionParam{
    75  				{
    76  					Name:     "seriesList",
    77  					Required: true,
    78  					Type:     types.SeriesList,
    79  				},
    80  				{
    81  					Multiple: true,
    82  					Name:     "pos",
    83  					Type:     types.Node,
    84  					Required: false,
    85  				},
    86  			},
    87  			NameChange:   true, // name changed
    88  			ValuesChange: true, // values changed
    89  		},
    90  		"toLowerCase": {
    91  			Description: "Takes one metric or a wildcard seriesList and lowers the case of each letter. \n Optionally, a letter position to lower case can be specified, in which case only the letter at the specified position gets lower-cased.\n The position parameter may be given multiple times. The position parameter may be negative to define a position relative to the end of the metric name.",
    92  			Function:    "toLowerCase(seriesList, *pos)",
    93  			Group:       "Alias",
    94  			Module:      "graphite.render.functions",
    95  			Name:        "toLowerCase",
    96  			Params: []types.FunctionParam{
    97  				{
    98  					Name:     "seriesList",
    99  					Required: true,
   100  					Type:     types.SeriesList,
   101  				},
   102  				{
   103  					Multiple: true,
   104  					Name:     "pos",
   105  					Type:     types.Node,
   106  					Required: false,
   107  				},
   108  			},
   109  			NameChange:   true, // name changed
   110  			ValuesChange: true, // values changed
   111  		},
   112  	}
   113  }