function.go

package aliasByTags

import (
	"context"

	"github.com/go-graphite/carbonapi/expr/helper"
	"github.com/go-graphite/carbonapi/expr/interfaces"
	"github.com/go-graphite/carbonapi/expr/types"
	"github.com/go-graphite/carbonapi/pkg/parser"
)

type aliasByTags struct {
	interfaces.FunctionBase
}

func GetOrder() interfaces.Order {
	return interfaces.Any
}

func New(configFile string) []interfaces.FunctionMetadata {
	res := make([]interfaces.FunctionMetadata, 0)
	f := &aliasByTags{}
	for _, n := range []string{"aliasByTags"} {
		res = append(res, interfaces.FunctionMetadata{Name: n, F: f})
	}
	return res
}

func (f *aliasByTags) Do(ctx context.Context, e parser.Expr, from, until int64, values map[parser.MetricRequest][]*types.MetricData) ([]*types.MetricData, error) {
	args, err := helper.GetSeriesArg(e.Args()[0], from, until, values)
	if err != nil {
		return nil, err
	}

	tags, err := e.GetNodeOrTagArgs(1)
	if err != nil {
		return nil, err
	}

	var results []*types.MetricData

	for _, a := range args {
		name := helper.AggKey(a, tags)
		r := *a
		if len(name) > 0 {
			r.Name = name
		}
		results = append(results, &r)
	}

	return results, nil
}

// Description is auto-generated description, based on output of https://github.com/graphite-project/graphite-web
func (f *aliasByTags) Description() map[string]types.FunctionDescription {
	return map[string]types.FunctionDescription{
		"aliasByTags": {
			Description: "Takes a seriesList and applies an alias derived from one or more tags",
			Function:    "aliasByTags(seriesList, *tags)",
			Group:       "Alias",
			Module:      "graphite.render.functions",
			Name:        "aliasByTags",
			Params: []types.FunctionParam{
				{
					Name:     "seriesList",
					Required: true,
					Type:     types.SeriesList,
				},
				{
					Multiple: true,
					Name:     "tags",
					Required: true,
					Type:     types.NodeOrTag,
				},
			},
		},
	}
}