status-im/status-go

package topics

import (
    "errors"
    "strconv"
    "strings"

    "github.com/ethereum/go-ethereum/p2p/discv5"

    "github.com/status-im/status-go/params"
)

// TopicFlag used to parse discv5 topics.
type TopicFlag []discv5.Topic

func (f *TopicFlag) String() string {
    return "discv5 topics"
}

// Set parses single topic.
func (f *TopicFlag) Set(value string) error {
    *f = append(*f, discv5.Topic(strings.TrimSpace(value)))
    return nil
}

// TopicLimitsFlag used to parse limits for discv5 topics.
type TopicLimitsFlag map[discv5.Topic]params.Limits

func (f *TopicLimitsFlag) String() string {
    return "disv5 topics to limits map"
}

// Set parses single limit for a topic.
func (f *TopicLimitsFlag) Set(value string) error {
    parts := strings.Split(strings.TrimSpace(value), "=")
    if len(parts) != 2 {
        return errors.New("topic must be separated by '=' from limits, e.g. 'topic1=1,1'")
    }
    limits := strings.Split(parts[1], ",")
    if len(limits) != 2 {
        return errors.New("min and max limit must be set, e.g. 'topic1=1,1'")
    }
    minL, err := strconv.Atoi(limits[0])
    if err != nil {
        return err
    }
    maxL, err := strconv.Atoi(limits[1])
    if err != nil {
        return err
    }
    (*f)[discv5.Topic(parts[0])] = params.NewLimits(minL, maxL)
    return nil
}