[VOL-5291] On demand statistics for ONU and OLT

Change-Id: I4850bb0f0d2235122cb0c1bcf835b3672bb34436
Signed-off-by: Akash Reddy Kankanala <akash.kankanala@radisys.com>
diff --git a/vendor/google.golang.org/grpc/pickfirst.go b/vendor/google.golang.org/grpc/pickfirst.go
index 5168b62..abe266b 100644
--- a/vendor/google.golang.org/grpc/pickfirst.go
+++ b/vendor/google.golang.org/grpc/pickfirst.go
@@ -19,11 +19,15 @@
 package grpc
 
 import (
+	"encoding/json"
 	"errors"
 	"fmt"
 
 	"google.golang.org/grpc/balancer"
 	"google.golang.org/grpc/connectivity"
+	"google.golang.org/grpc/internal/envconfig"
+	"google.golang.org/grpc/internal/grpcrand"
+	"google.golang.org/grpc/serviceconfig"
 )
 
 // PickFirstBalancerName is the name of the pick_first balancer.
@@ -43,90 +47,158 @@
 	return PickFirstBalancerName
 }
 
+type pfConfig struct {
+	serviceconfig.LoadBalancingConfig `json:"-"`
+
+	// If set to true, instructs the LB policy to shuffle the order of the list
+	// of addresses received from the name resolver before attempting to
+	// connect to them.
+	ShuffleAddressList bool `json:"shuffleAddressList"`
+}
+
+func (*pickfirstBuilder) ParseConfig(js json.RawMessage) (serviceconfig.LoadBalancingConfig, error) {
+	cfg := &pfConfig{}
+	if err := json.Unmarshal(js, cfg); err != nil {
+		return nil, fmt.Errorf("pickfirst: unable to unmarshal LB policy config: %s, error: %v", string(js), err)
+	}
+	return cfg, nil
+}
+
 type pickfirstBalancer struct {
-	state connectivity.State
-	cc    balancer.ClientConn
-	sc    balancer.SubConn
+	state   connectivity.State
+	cc      balancer.ClientConn
+	subConn balancer.SubConn
+	cfg     *pfConfig
 }
 
 func (b *pickfirstBalancer) ResolverError(err error) {
-	switch b.state {
-	case connectivity.TransientFailure, connectivity.Idle, connectivity.Connecting:
-		// Set a failing picker if we don't have a good picker.
-		b.cc.UpdateState(balancer.State{ConnectivityState: connectivity.TransientFailure,
-			Picker: &picker{err: fmt.Errorf("name resolver error: %v", err)},
-		})
-	}
 	if logger.V(2) {
-		logger.Infof("pickfirstBalancer: ResolverError called with error %v", err)
+		logger.Infof("pickfirstBalancer: ResolverError called with error: %v", err)
 	}
+	if b.subConn == nil {
+		b.state = connectivity.TransientFailure
+	}
+
+	if b.state != connectivity.TransientFailure {
+		// The picker will not change since the balancer does not currently
+		// report an error.
+		return
+	}
+	b.cc.UpdateState(balancer.State{
+		ConnectivityState: connectivity.TransientFailure,
+		Picker:            &picker{err: fmt.Errorf("name resolver error: %v", err)},
+	})
 }
 
-func (b *pickfirstBalancer) UpdateClientConnState(cs balancer.ClientConnState) error {
-	if len(cs.ResolverState.Addresses) == 0 {
+func (b *pickfirstBalancer) UpdateClientConnState(state balancer.ClientConnState) error {
+	addrs := state.ResolverState.Addresses
+	if len(addrs) == 0 {
+		// The resolver reported an empty address list. Treat it like an error by
+		// calling b.ResolverError.
+		if b.subConn != nil {
+			// Remove the old subConn. All addresses were removed, so it is no longer
+			// valid.
+			b.cc.RemoveSubConn(b.subConn)
+			b.subConn = nil
+		}
 		b.ResolverError(errors.New("produced zero addresses"))
 		return balancer.ErrBadResolverState
 	}
-	if b.sc == nil {
-		var err error
-		b.sc, err = b.cc.NewSubConn(cs.ResolverState.Addresses, balancer.NewSubConnOptions{})
-		if err != nil {
-			if logger.V(2) {
-				logger.Errorf("pickfirstBalancer: failed to NewSubConn: %v", err)
-			}
-			b.state = connectivity.TransientFailure
-			b.cc.UpdateState(balancer.State{ConnectivityState: connectivity.TransientFailure,
-				Picker: &picker{err: fmt.Errorf("error creating connection: %v", err)},
-			})
-			return balancer.ErrBadResolverState
+
+	if state.BalancerConfig != nil {
+		cfg, ok := state.BalancerConfig.(*pfConfig)
+		if !ok {
+			return fmt.Errorf("pickfirstBalancer: received nil or illegal BalancerConfig (type %T): %v", state.BalancerConfig, state.BalancerConfig)
 		}
-		b.state = connectivity.Idle
-		b.cc.UpdateState(balancer.State{ConnectivityState: connectivity.Idle, Picker: &picker{result: balancer.PickResult{SubConn: b.sc}}})
-		b.sc.Connect()
-	} else {
-		b.cc.UpdateAddresses(b.sc, cs.ResolverState.Addresses)
-		b.sc.Connect()
+		b.cfg = cfg
 	}
+
+	if envconfig.PickFirstLBConfig && b.cfg != nil && b.cfg.ShuffleAddressList {
+		grpcrand.Shuffle(len(addrs), func(i, j int) { addrs[i], addrs[j] = addrs[j], addrs[i] })
+	}
+	if b.subConn != nil {
+		b.cc.UpdateAddresses(b.subConn, addrs)
+		return nil
+	}
+
+	subConn, err := b.cc.NewSubConn(addrs, balancer.NewSubConnOptions{})
+	if err != nil {
+		if logger.V(2) {
+			logger.Errorf("pickfirstBalancer: failed to NewSubConn: %v", err)
+		}
+		b.state = connectivity.TransientFailure
+		b.cc.UpdateState(balancer.State{
+			ConnectivityState: connectivity.TransientFailure,
+			Picker:            &picker{err: fmt.Errorf("error creating connection: %v", err)},
+		})
+		return balancer.ErrBadResolverState
+	}
+	b.subConn = subConn
+	b.state = connectivity.Idle
+	b.cc.UpdateState(balancer.State{
+		ConnectivityState: connectivity.Connecting,
+		Picker:            &picker{err: balancer.ErrNoSubConnAvailable},
+	})
+	b.subConn.Connect()
 	return nil
 }
 
-func (b *pickfirstBalancer) UpdateSubConnState(sc balancer.SubConn, s balancer.SubConnState) {
+func (b *pickfirstBalancer) UpdateSubConnState(subConn balancer.SubConn, state balancer.SubConnState) {
 	if logger.V(2) {
-		logger.Infof("pickfirstBalancer: UpdateSubConnState: %p, %v", sc, s)
+		logger.Infof("pickfirstBalancer: UpdateSubConnState: %p, %v", subConn, state)
 	}
-	if b.sc != sc {
+	if b.subConn != subConn {
 		if logger.V(2) {
-			logger.Infof("pickfirstBalancer: ignored state change because sc is not recognized")
+			logger.Infof("pickfirstBalancer: ignored state change because subConn is not recognized")
 		}
 		return
 	}
-	b.state = s.ConnectivityState
-	if s.ConnectivityState == connectivity.Shutdown {
-		b.sc = nil
+	if state.ConnectivityState == connectivity.Shutdown {
+		b.subConn = nil
 		return
 	}
 
-	switch s.ConnectivityState {
+	switch state.ConnectivityState {
 	case connectivity.Ready:
-		b.cc.UpdateState(balancer.State{ConnectivityState: s.ConnectivityState, Picker: &picker{result: balancer.PickResult{SubConn: sc}}})
+		b.cc.UpdateState(balancer.State{
+			ConnectivityState: state.ConnectivityState,
+			Picker:            &picker{result: balancer.PickResult{SubConn: subConn}},
+		})
 	case connectivity.Connecting:
-		b.cc.UpdateState(balancer.State{ConnectivityState: s.ConnectivityState, Picker: &picker{err: balancer.ErrNoSubConnAvailable}})
+		if b.state == connectivity.TransientFailure {
+			// We stay in TransientFailure until we are Ready. See A62.
+			return
+		}
+		b.cc.UpdateState(balancer.State{
+			ConnectivityState: state.ConnectivityState,
+			Picker:            &picker{err: balancer.ErrNoSubConnAvailable},
+		})
 	case connectivity.Idle:
-		b.cc.UpdateState(balancer.State{ConnectivityState: s.ConnectivityState, Picker: &idlePicker{sc: sc}})
+		if b.state == connectivity.TransientFailure {
+			// We stay in TransientFailure until we are Ready. Also kick the
+			// subConn out of Idle into Connecting. See A62.
+			b.subConn.Connect()
+			return
+		}
+		b.cc.UpdateState(balancer.State{
+			ConnectivityState: state.ConnectivityState,
+			Picker:            &idlePicker{subConn: subConn},
+		})
 	case connectivity.TransientFailure:
 		b.cc.UpdateState(balancer.State{
-			ConnectivityState: s.ConnectivityState,
-			Picker:            &picker{err: s.ConnectionError},
+			ConnectivityState: state.ConnectivityState,
+			Picker:            &picker{err: state.ConnectionError},
 		})
 	}
+	b.state = state.ConnectivityState
 }
 
 func (b *pickfirstBalancer) Close() {
 }
 
 func (b *pickfirstBalancer) ExitIdle() {
-	if b.sc != nil && b.state == connectivity.Idle {
-		b.sc.Connect()
+	if b.subConn != nil && b.state == connectivity.Idle {
+		b.subConn.Connect()
 	}
 }
 
@@ -135,18 +207,18 @@
 	err    error
 }
 
-func (p *picker) Pick(info balancer.PickInfo) (balancer.PickResult, error) {
+func (p *picker) Pick(balancer.PickInfo) (balancer.PickResult, error) {
 	return p.result, p.err
 }
 
 // idlePicker is used when the SubConn is IDLE and kicks the SubConn into
 // CONNECTING when Pick is called.
 type idlePicker struct {
-	sc balancer.SubConn
+	subConn balancer.SubConn
 }
 
-func (i *idlePicker) Pick(info balancer.PickInfo) (balancer.PickResult, error) {
-	i.sc.Connect()
+func (i *idlePicker) Pick(balancer.PickInfo) (balancer.PickResult, error) {
+	i.subConn.Connect()
 	return balancer.PickResult{}, balancer.ErrNoSubConnAvailable
 }