godns/hosts/hosts.go

package hosts

import (
	"time"
)

var (
	zeroDuration = time.Duration(0)
)

type Hosts interface {
	Get(queryType uint16, domain string) ([]string, time.Duration, bool)
}

type ProviderList struct {
	providers       []Provider
}

type Provider interface {
	Get(queryType uint16, domain string) ([]string, time.Duration, bool)
	Set(t, domain, value string) (bool, error)
}

func NewHosts(providers []Provider) Hosts {
	return &ProviderList{providers}
}

/*
Match local /etc/hosts file first, remote redis records second
*/
func (h *ProviderList) Get(queryType uint16, domain string) ([]string, time.Duration, bool) {
	var vals []string
	var ok bool
	var ttl time.Duration

	for _, provider := range h.providers {
		vals, ttl, ok = provider.Get(queryType, domain)

		if ok {
			break
		}
	}

	if vals == nil {
		return nil, zeroDuration, false
	}

	return vals, ttl, true
}