server: reduce number of path.Clone() call to reduce memory footprint

the result of memory profile (500 route-server-clients each of them
advertises 100 routes)

before:
(pprof) top5
3913.02MB of 3978.69MB total (98.35%)
Dropped 148 nodes (cum <= 19.89MB)
Showing top 10 nodes out of 11 (cum >= 21MB)
flat       flat%   sum%        cum   cum%
2970.30MB 74.66% 74.66%  2975.80MB 74.79% github.com/osrg/gobgp/server.filterpath
810.09MB  20.36% 95.02%   810.59MB 20.37% github.com/osrg/gobgp/table.(*AdjRib).Update
115.60MB   2.91% 97.92%   119.10MB  2.99% github.com/osrg/gobgp/table.createUpdateMsgFromPath
10MB       0.25% 98.17%  1878.02MB 47.20% github.com/osrg/gobgp/server.(*BgpServer).propagateUpdate
4.50MB     0.11% 98.29%   144.60MB  3.63% github.com/osrg/gobgp/table.CreateUpdateMsgFromPaths

after:
(pprof) top5
1259.49MB of 1284.27MB total (98.07%)
Dropped 175 nodes (cum <= 6.42MB)
Showing top 10 nodes out of 26 (cum >= 36.51MB)
flat     flat%  sum%        cum   cum%
975.81MB 75.98% 75.98%   976.31MB 76.02% github.com/osrg/gobgp/table.(*AdjRib).Update
198.67MB 15.47% 91.45%   208.17MB 16.21% github.com/osrg/gobgp/table.createUpdateMsgFromPath
22MB      1.71% 93.16%       22MB  1.71% github.com/osrg/gobgp/packet.(*IPAddrPrefix).Serialize
20MB      1.56% 94.72%   707.19MB 55.07% github.com/osrg/gobgp/server.(*BgpServer).propagateUpdate
13.50MB   1.05% 95.77%    13.50MB  1.05% github.com/osrg/gobgp/table.NewPath

Signed-off-by: ISHIDA Wataru <ishida.wataru@lab.ntt.co.jp>

1 files changed, 10 insertions, 4 deletions

diff --git a/table/policy.go b/table/policy.go
index a8192a58..81010a9d 100644
--- a/table/policy.go
+++ b/table/policy.go
@@ -32,6 +32,7 @@ import (
 )
 
 type PolicyOptions struct {
+	Neighbor net.IP
 }
 
 type DefinedType int
@@ -1152,19 +1153,24 @@ func (c *NeighborCondition) Option() MatchOption {
 // compare neighbor ipaddress of this condition and source address of path
 // and, subsequent comparisons are skipped if that matches the conditions.
 // If NeighborList's length is zero, return true.
-func (c *NeighborCondition) Evaluate(path *Path, _ *PolicyOptions) bool {
+func (c *NeighborCondition) Evaluate(path *Path, options *PolicyOptions) bool {
 
 	if len(c.set.list) == 0 {
 		log.Debug("NeighborList doesn't have elements")
 		return true
 	}
 
-	if path.Owner == nil {
+	neighbor := path.GetSource().Address
+	if options != nil && options.Neighbor != nil {
+		neighbor = options.Neighbor
+	}
+
+	if neighbor == nil {
 		return false
 	}
 	result := false
 	for _, n := range c.set.list {
-		if path.Owner.Equal(n) {
+		if neighbor.Equal(n) {
 			result = true
 			break
 		}
@@ -2094,7 +2100,7 @@ func (s *Statement) Apply(path *Path, options *PolicyOptions) (RouteType, *Path)
 	if result {
 		if len(s.ModActions) != 0 {
 			// apply all modification actions
-			path = path.Clone(path.Owner, path.IsWithdraw)
+			path = path.Clone(path.IsWithdraw)
 			for _, action := range s.ModActions {
 				path = action.Apply(path)
 			}