From 9923e0a4f268dce587388f9c3878ba34c095e0b3 Mon Sep 17 00:00:00 2001
From: Julian Kornberger <jk+github@digineo.de>
Date: Sat, 12 Mar 2016 00:59:36 +0100
Subject: [PATCH] Do some magic reflection stuff

---
 main.go                    | 32 +++++++++-----------------------
 respond/collector.go       | 21 ++++++++++++++++-----
 respond/multi_collector.go | 13 ++++++++-----
 3 files changed, 33 insertions(+), 33 deletions(-)

diff --git a/main.go b/main.go
index 1e25f1a..4cdca87 100644
--- a/main.go
+++ b/main.go
@@ -1,7 +1,6 @@
 package main
 
 import (
-	"encoding/json"
 	"flag"
 	"log"
 	"net"
@@ -50,29 +49,16 @@ func main() {
 	}
 
 	if config.Respondd.Enable {
-		multiCollector = respond.NewMultiCollector(collectInterval, func(coll *respond.Collector, res *respond.Response) {
-
-			switch coll.CollectType {
-			case "neighbours":
-				result := &data.NeighbourStruct{}
-				if json.Unmarshal(res.Raw, result) == nil {
-					node := nodes.Get(result.NodeId)
-					node.Neighbours = result
-				}
-			case "nodeinfo":
-				result := &data.NodeInfo{}
-				if json.Unmarshal(res.Raw, result) == nil {
-					node := nodes.Get(result.NodeId)
-					node.Nodeinfo = result
-				}
-			case "statistics":
-				result := &data.StatisticsStruct{}
-				if json.Unmarshal(res.Raw, result) == nil {
-					node := nodes.Get(result.NodeId)
-					node.Statistics = result
-				}
+		multiCollector = respond.NewMultiCollector(collectInterval, func(addr net.UDPAddr, msg interface{}) {
+			switch msg := msg.(type) {
+			case *data.NodeInfo:
+				nodes.Get(msg.NodeId).Nodeinfo = msg
+			case *data.NeighbourStruct:
+				nodes.Get(msg.NodeId).Neighbours = msg
+			case *data.StatisticsStruct:
+				nodes.Get(msg.NodeId).Statistics = msg
 			default:
-				log.Println("unknown CollectType:", coll.CollectType)
+				log.Println("unknown message:", msg)
 			}
 		})
 	}
diff --git a/respond/collector.go b/respond/collector.go
index 9b68710..628b039 100644
--- a/respond/collector.go
+++ b/respond/collector.go
@@ -1,8 +1,10 @@
 package respond
 
 import (
+	"encoding/json"
 	"log"
 	"net"
+	"reflect"
 	"time"
 )
 
@@ -11,17 +13,18 @@ type Collector struct {
 	CollectType string
 	connection  *net.UDPConn   // UDP socket
 	queue       chan *Response // received responses
-	parse       func(coll *Collector, res *Response)
+	onReceive   OnReceive
+	msgType     reflect.Type
 
 	// Ticker and stopper
 	ticker *time.Ticker
 	stop   chan interface{}
 }
 
-type ParseFunc func(coll *Collector, res *Response)
+type OnReceive func(net.UDPAddr, interface{})
 
 //NewCollector creates a Collector struct
-func NewCollector(CollectType string, interval time.Duration, parseFunc ParseFunc) *Collector {
+func NewCollector(CollectType string, interval time.Duration, msgStruct interface{}, onReceive OnReceive) *Collector {
 	// Parse address
 	addr, err := net.ResolveUDPAddr("udp", "[::]:0")
 	if err != nil {
@@ -39,9 +42,10 @@ func NewCollector(CollectType string, interval time.Duration, parseFunc ParseFun
 		CollectType: CollectType,
 		connection:  conn,
 		queue:       make(chan *Response, 400),
-		parse:       parseFunc,
 		ticker:      time.NewTicker(interval),
 		stop:        make(chan interface{}, 1),
+		msgType:     reflect.TypeOf(msgStruct),
+		onReceive:   onReceive,
 	}
 
 	go collector.receiver()
@@ -91,7 +95,14 @@ func (coll *Collector) sender() {
 
 func (coll *Collector) parser() {
 	for obj := range coll.queue {
-		coll.parse(coll, obj)
+		// create new struct instance
+		data := reflect.New(coll.msgType).Interface()
+
+		if err := json.Unmarshal(obj.Raw, data); err == nil {
+			coll.onReceive(obj.Address, data)
+		} else {
+			log.Println("unable to decode response from", obj.Address.String(), err)
+		}
 	}
 }
 
diff --git a/respond/multi_collector.go b/respond/multi_collector.go
index 75a35ae..2e164ed 100644
--- a/respond/multi_collector.go
+++ b/respond/multi_collector.go
@@ -1,6 +1,9 @@
 package respond
 
-import "time"
+import (
+	"github.com/ffdo/node-informant/gluon-collector/data"
+	"time"
+)
 
 //MultiCollector struct
 type MultiCollector struct {
@@ -8,12 +11,12 @@ type MultiCollector struct {
 }
 
 //NewMultiCollector create a list of collectors
-func NewMultiCollector(interval time.Duration, parseFunc ParseFunc) *MultiCollector {
+func NewMultiCollector(interval time.Duration, onReceive OnReceive) *MultiCollector {
 	return &MultiCollector{
 		collectors: []*Collector{
-			NewCollector("statistics", interval, parseFunc),
-			NewCollector("nodeinfo", interval, parseFunc),
-			NewCollector("neighbours", interval, parseFunc),
+			NewCollector("statistics", interval, data.StatisticsStruct{}, onReceive),
+			NewCollector("nodeinfo", interval, data.NodeInfo{}, onReceive),
+			NewCollector("neighbours", interval, data.NeighbourStruct{}, onReceive),
 		},
 	}
 }