Optimizations for statsclient

- this dramatically improves performance for stats data collection
- memory allocation is now done only when stat dirs change
- updating prepared stat dir does not need to allocate memory
- created integration test for testing stats client
- added NumWorkerThreads and VectorRatePerWorker to SystemStats
- added ReduceSimpleCounterStatIndex, ReduceCombinedCounterStatIndex for
  aggregating specific index

Change-Id: I702731a69024ab5dd0832bb5cfe2773a987359e5
Signed-off-by: Ondrej Fabry <ofabry@cisco.com>

1 files changed, 3 insertions, 3 deletions

diff --git a/core/connection.go b/core/connection.go
index 8b8c7b1..6f82616 100644
--- a/core/connection.go
+++ b/core/connection.go
@@ -89,7 +89,6 @@ type ConnectionEvent struct {
 // Connection represents a shared memory connection to VPP via vppAdapter.
 type Connection struct {
 	vppClient adapter.VppAPI // VPP binary API client
-	//statsClient adapter.StatsAPI // VPP stats API client
 
 	maxAttempts int           // interval for reconnect attempts
 	recInterval time.Duration // maximum number of reconnect attempts
@@ -177,7 +176,9 @@ func (c *Connection) connectVPP() error {
 	log.Debugf("Connected to VPP")
 
 	if err := c.retrieveMessageIDs(); err != nil {
-		c.vppClient.Disconnect()
+		if err := c.vppClient.Disconnect(); err != nil {
+			log.Debugf("disconnecting vpp client failed: %v", err)
+		}
 		return fmt.Errorf("VPP is incompatible: %v", err)
 	}
 
@@ -192,7 +193,6 @@ func (c *Connection) Disconnect() {
 	if c == nil {
 		return
 	}
-
 	if c.vppClient != nil {
 		c.disconnectVPP()
 	}