From 8d9887294cfa5e9e9e35899944c74c54834d89af Mon Sep 17 00:00:00 2001
From: Arceliar <Arceliar@users.noreply.github.com>
Date: Thu, 17 May 2018 19:32:29 -0500
Subject: [PATCH] add dht time since last ping to admin socket, some DHT code
 cleanup, bugfix to insertIfNew

---
 src/yggdrasil/admin.go | 30 +++++++++++------------
 src/yggdrasil/dht.go   | 55 +++++++++++++++++++-----------------------
 2 files changed, 39 insertions(+), 46 deletions(-)

diff --git a/src/yggdrasil/admin.go b/src/yggdrasil/admin.go
index c6af34b1..8682f75b 100644
--- a/src/yggdrasil/admin.go
+++ b/src/yggdrasil/admin.go
@@ -10,6 +10,7 @@ import "net/url"
 import "sort"
 import "strings"
 import "strconv"
+import "time"
 
 // TODO? Make all of this JSON
 // TODO: Add authentication
@@ -339,27 +340,24 @@ func (a *admin) getData_getSwitchPeers() []admin_nodeInfo {
 
 func (a *admin) getData_getDHT() []admin_nodeInfo {
 	var infos []admin_nodeInfo
+	now := time.Now()
 	getDHT := func() {
 		for i := 0; i < a.core.dht.nBuckets(); i++ {
 			b := a.core.dht.getBucket(i)
-			for _, v := range b.other {
-				addr := *address_addrForNodeID(v.getNodeID())
-				info := admin_nodeInfo{
-					{"IP", net.IP(addr[:]).String()},
-					{"coords", fmt.Sprint(v.coords)},
-					{"bucket", fmt.Sprint(i)},
+			getInfo := func(vs []*dhtInfo) {
+				for _, v := range vs {
+					addr := *address_addrForNodeID(v.getNodeID())
+					info := admin_nodeInfo{
+						{"IP", net.IP(addr[:]).String()},
+						{"coords", fmt.Sprint(v.coords)},
+						{"bucket", fmt.Sprint(i)},
+						{"lastSeen", fmt.Sprint(now.Sub(v.recv))},
+					}
+					infos = append(infos, info)
 				}
-				infos = append(infos, info)
-			}
-			for _, v := range b.peers {
-				addr := *address_addrForNodeID(v.getNodeID())
-				info := admin_nodeInfo{
-					{"IP", net.IP(addr[:]).String()},
-					{"coords", fmt.Sprint(v.coords)},
-					{"bucket", fmt.Sprint(i)},
-				}
-				infos = append(infos, info)
 			}
+			getInfo(b.other)
+			getInfo(b.peers)
 		}
 	}
 	a.core.router.doAdmin(getDHT)
diff --git a/src/yggdrasil/dht.go b/src/yggdrasil/dht.go
index 2f7c2663..5c7be3cd 100644
--- a/src/yggdrasil/dht.go
+++ b/src/yggdrasil/dht.go
@@ -198,20 +198,12 @@ func (t *dht) nBuckets() int {
 func (t *dht) insertIfNew(info *dhtInfo, isPeer bool) {
 	//fmt.Println("DEBUG: dht insertIfNew:", info.getNodeID(), info.coords)
 	// Insert a peer if and only if the bucket doesn't already contain it
-	nodeID := info.getNodeID()
-	bidx, isOK := t.getBucketIndex(nodeID)
-	if !isOK {
+	if !t.shouldInsert(info) {
 		return
 	}
-	b := t.getBucket(bidx)
-	if !b.contains(info) {
-		// We've never heard this node before
-		// TODO is there a better time than "now" to set send/recv to?
-		// (Is there another "natural" choice that bootstraps faster?)
-		info.send = time.Now()
-		info.recv = info.send
-		t.insert(info, isPeer)
-	}
+	info.send = time.Now()
+	info.recv = info.send
+	t.insert(info, isPeer)
 }
 
 func (t *dht) insert(info *dhtInfo, isPeer bool) {
@@ -459,24 +451,7 @@ func (t *dht) doMaintenance() {
 			// Note that the above is a pointer comparison, and target can be nil
 			// This is only for adding new nodes (learned from other lookups)
 			// It only makes sense to ping if the node isn't already in the table
-			bidx, isOK := t.getBucketIndex(rumor.info.getNodeID())
-			if !isOK {
-				continue
-			}
-			b := t.getBucket(bidx)
-			if b.contains(rumor.info) {
-				// Already know about this node
-				continue
-			}
-			// This is a good spot to check if a node is worth pinging
-			doPing := len(b.other) < dht_bucket_size
-			for _, info := range b.other {
-				if dht_firstCloserThanThird(rumor.info.getNodeID(), &t.nodeID, info.getNodeID()) {
-					// Add the node if they are closer to us than someone in the same bucket
-					doPing = true
-				}
-			}
-			if !doPing {
+			if !t.shouldInsert(rumor.info) {
 				continue
 			}
 		}
@@ -485,6 +460,26 @@ func (t *dht) doMaintenance() {
 	}
 }
 
+func (t *dht) shouldInsert(info *dhtInfo) bool {
+	bidx, isOK := t.getBucketIndex(info.getNodeID())
+	if !isOK {
+		return false
+	}
+	b := t.getBucket(bidx)
+	if b.contains(info) {
+		return false
+	}
+	if len(b.other) < dht_bucket_size {
+		return true
+	}
+	for _, other := range b.other {
+		if dht_firstCloserThanThird(info.getNodeID(), &t.nodeID, other.getNodeID()) {
+			return true
+		}
+	}
+	return false
+}
+
 func dht_firstCloserThanThird(first *NodeID,
 	second *NodeID,
 	third *NodeID) bool {