1 files changed, 30 insertions, 73 deletions

diff --git a/src/mongo/gotools/src/github.com/mongodb/mongo-tools/vendor/go.mongodb.org/mongo-driver/x/mongo/driver/description/topology.go b/src/mongo/gotools/src/github.com/mongodb/mongo-tools/vendor/go.mongodb.org/mongo-driver/x/mongo/driver/description/topology.go
index 07454711511..b6f4e3ea31d 100644
--- a/src/mongo/gotools/src/github.com/mongodb/mongo-tools/vendor/go.mongodb.org/mongo-driver/x/mongo/driver/description/topology.go
+++ b/src/mongo/gotools/src/github.com/mongodb/mongo-tools/vendor/go.mongodb.org/mongo-driver/x/mongo/driver/description/topology.go
@@ -7,9 +7,6 @@
 package description
 
 import (
-	"sort"
-	"strings"
-
 	"go.mongodb.org/mongo-driver/x/mongo/driver/address"
 )
 
@@ -41,39 +38,24 @@ type TopologyDiff struct {
 func DiffTopology(old, new Topology) TopologyDiff {
 	var diff TopologyDiff
 
-	// TODO: do this without sorting...
-	oldServers := serverSorter(old.Servers)
-	newServers := serverSorter(new.Servers)
-
-	sort.Sort(oldServers)
-	sort.Sort(newServers)
-
-	i := 0
-	j := 0
-	for {
-		if i < len(oldServers) && j < len(newServers) {
-			comp := strings.Compare(oldServers[i].Addr.String(), newServers[j].Addr.String())
-			switch comp {
-			case 1:
-				//left is bigger than
-				diff.Added = append(diff.Added, newServers[j])
-				j++
-			case -1:
-				// right is bigger
-				diff.Removed = append(diff.Removed, oldServers[i])
-				i++
-			case 0:
-				i++
-				j++
-			}
-		} else if i < len(oldServers) {
-			diff.Removed = append(diff.Removed, oldServers[i])
-			i++
-		} else if j < len(newServers) {
-			diff.Added = append(diff.Added, newServers[j])
-			j++
+	oldServers := make(map[string]bool)
+	for _, s := range old.Servers {
+		oldServers[s.Addr.String()] = true
+	}
+
+	for _, s := range new.Servers {
+		addr := s.Addr.String()
+		if oldServers[addr] {
+			delete(oldServers, addr)
 		} else {
-			break
+			diff.Added = append(diff.Added, s)
+		}
+	}
+
+	for _, s := range old.Servers {
+		addr := s.Addr.String()
+		if oldServers[addr] {
+			diff.Removed = append(diff.Removed, s)
 		}
 	}
 
@@ -90,47 +72,22 @@ type HostlistDiff struct {
 func (t Topology) DiffHostlist(hostlist []string) HostlistDiff {
 	var diff HostlistDiff
 
-	oldServers := serverSorter(t.Servers)
-	sort.Sort(oldServers)
-	sort.Strings(hostlist)
-
-	i := 0
-	j := 0
-	for {
-		if i < len(oldServers) && j < len(hostlist) {
-			oldServer := oldServers[i].Addr.String()
-			comp := strings.Compare(oldServer, hostlist[j])
-			switch comp {
-			case 1:
-				// oldServers[i] is bigger
-				diff.Added = append(diff.Added, hostlist[j])
-				j++
-			case -1:
-				// hostlist[j] is bigger
-				diff.Removed = append(diff.Removed, oldServer)
-				i++
-			case 0:
-				i++
-				j++
-			}
-		} else if i < len(oldServers) {
-			diff.Removed = append(diff.Removed, oldServers[i].Addr.String())
-			i++
-		} else if j < len(hostlist) {
-			diff.Added = append(diff.Added, hostlist[j])
-			j++
+	oldServers := make(map[string]bool)
+	for _, s := range t.Servers {
+		oldServers[s.Addr.String()] = true
+	}
+
+	for _, addr := range hostlist {
+		if oldServers[addr] {
+			delete(oldServers, addr)
 		} else {
-			break
+			diff.Added = append(diff.Added, addr)
 		}
 	}
 
-	return diff
-}
-
-type serverSorter []Server
+	for addr := range oldServers {
+		diff.Removed = append(diff.Removed, addr)
+	}
 
-func (ss serverSorter) Len() int      { return len(ss) }
-func (ss serverSorter) Swap(i, j int) { ss[i], ss[j] = ss[j], ss[i] }
-func (ss serverSorter) Less(i, j int) bool {
-	return strings.Compare(ss[i].Addr.String(), ss[j].Addr.String()) < 0
+	return diff
 }