fix #14 Avoid too much api call times by creating a file to store last IP address

.gitignore

@@ -32,3 +32,4 @@ vendor/*
 /godns.iml
 /godns.ipr
 /godns.iws
+.current_ip

handler/dnspod_handler.go

@@ -37,7 +37,6 @@ func (handler *DNSPodHandler) DomainLoop(domain *godns.Domain, panicChan chan<-
 	}()
 
 	for {
-
 		domainID := handler.GetDomain(domain.DomainName)
 
 		if domainID == -1 {
@@ -50,7 +49,18 @@ func (handler *DNSPodHandler) DomainLoop(domain *godns.Domain, panicChan chan<-
 			log.Println("get_currentIP:", err)
 			continue
 		}
-		log.Println("currentIp is:", currentIP)
+		log.Println("currentIP is:", currentIP)
+
+		//Compare currentIP with saved IP
+		savedIP := godns.LoadCurrentIP()
+		log.Println("savedIP is:", savedIP)
+
+		if savedIP != "" && strings.TrimRight(currentIP, "\n") == strings.TrimRight(savedIP, "\n") {
+			log.Printf("Current IP is not changed, no need to update...")
+			continue
+		} else {
+			godns.SaveCurrentIP(currentIP)
+		}
 
 		for _, subDomain := range domain.SubDomains {
 

handler/he_handler.go

@@ -46,7 +46,17 @@ func (handler *HEHandler) DomainLoop(domain *godns.Domain, panicChan chan<- godn
 			log.Println("get_currentIP:", err)
 			continue
 		}
-		log.Println("currentIp is:", currentIP)
+		log.Println("currentIP is:", currentIP)
+
+		//Compare currentIP with saved IP
+		savedIP := godns.LoadCurrentIP()
+
+		if savedIP != "" && currentIP == savedIP {
+			log.Printf("Current IP is not changed, no need to update...")
+			continue
+		} else {
+			godns.SaveCurrentIP(currentIP)
+		}
 
 		for _, subDomain := range domain.SubDomains {
 			log.Printf("%s.%s Start to update record IP...\n", subDomain, domain.DomainName)

utils.go

@@ -5,6 +5,8 @@ import (
 	"io/ioutil"
 	"log"
 	"net/http"
+	"os"
+	"strings"
 
 	"golang.org/x/net/proxy"
 )
@@ -67,3 +69,17 @@ func CheckSettings(config *Settings) error {
 
 	return nil
 }
+
+func SaveCurrentIP(currentIP string) {
+	ioutil.WriteFile("./.current_ip", []byte(currentIP), os.FileMode(0644))
+}
+
+func LoadCurrentIP() string {
+	content, err := ioutil.ReadFile("./.current_ip")
+
+	if err != nil {
+		return ""
+	}
+
+	return strings.Replace(string(content), "\n", "", -1)
+}