Update comments

- updates comments and adds where missing
- updates locks so that unlock is done via defer instead of
at the end of the statement
- extracts timeout variable in two places
- remove makeClient() unused method from metrics package

No-harm changes tested via go build.

Signed-off-by: Alex Ellis (VMware) <alexellis2@gmail.com>

gateway/handlers/alerthandler.go

@@ -14,23 +14,25 @@ import (
 	"github.com/openfaas/faas/gateway/requests"
 )
 
-// DefaultMinReplicas is the minimal amount of replicas for a service.
-const DefaultMinReplicas = 1
+const (
+	// DefaultMinReplicas is the minimal amount of replicas for a service.
+	DefaultMinReplicas = 1
 
-// DefaultMaxReplicas is the amount of replicas a service will auto-scale up to.
-const DefaultMaxReplicas = 20
+	// DefaultMaxReplicas is the amount of replicas a service will auto-scale up to.
+	DefaultMaxReplicas = 20
 
-// DefaultScalingFactor is the defining proportion for the scaling increments.
-const DefaultScalingFactor = 20
+	// DefaultScalingFactor is the defining proportion for the scaling increments.
+	DefaultScalingFactor = 20
 
-// MinScaleLabel label indicating min scale for a function
-const MinScaleLabel = "com.openfaas.scale.min"
+	// MinScaleLabel label indicating min scale for a function
+	MinScaleLabel = "com.openfaas.scale.min"
 
-// MaxScaleLabel label indicating max scale for a function
-const MaxScaleLabel = "com.openfaas.scale.max"
+	// MaxScaleLabel label indicating max scale for a function
+	MaxScaleLabel = "com.openfaas.scale.max"
 
-// ScalingFactorLabel label indicates the scaling factor for a function
-const ScalingFactorLabel = "com.openfaas.scale.factor"
+	// ScalingFactorLabel label indicates the scaling factor for a function
+	ScalingFactorLabel = "com.openfaas.scale.factor"
+)
 
 // MakeAlertHandler handles alerts from Prometheus Alertmanager
 func MakeAlertHandler(service ServiceQuery) http.HandlerFunc {
@@ -130,5 +132,6 @@ func CalculateReplicas(status string, currentReplicas uint64, maxReplicas uint64
 	} else { // Resolved event.
 		newReplicas = minReplicas
 	}
+
 	return newReplicas
 }

gateway/handlers/forwarding_proxy.go

@@ -23,7 +23,7 @@ import (
 // functionMatcher parses out the service name (group 1) and rest of path (group 2).
 var functionMatcher = regexp.MustCompile("^/?(?:async-)?function/([^/?]+)([^?]*)")
 
-// Indicies and meta-data for functionMatcher regex parts
+// Indices and meta-data for functionMatcher regex parts
 const (
 	hasPathCount = 3
 	routeIndex   = 0 // routeIndex corresponds to /function/ or /async-function/

gateway/handlers/function_cache.go

@@ -31,6 +31,7 @@ type FunctionCache struct {
 // Set replica count for functionName
 func (fc *FunctionCache) Set(functionName string, serviceQueryResponse ServiceQueryResponse) {
 	fc.Sync.Lock()
+	defer fc.Sync.Unlock()
 
 	if _, exists := fc.Cache[functionName]; !exists {
 		fc.Cache[functionName] = &FunctionMeta{}
@@ -40,23 +41,23 @@ func (fc *FunctionCache) Set(functionName string, serviceQueryResponse ServiceQu
 	entry.LastRefresh = time.Now()
 	entry.ServiceQueryResponse = serviceQueryResponse
 
-	fc.Sync.Unlock()
 }
 
 // Get replica count for functionName
 func (fc *FunctionCache) Get(functionName string) (ServiceQueryResponse, bool) {
+
+	fc.Sync.Lock()
+	defer fc.Sync.Unlock()
+
 	replicas := ServiceQueryResponse{
 		AvailableReplicas: 0,
 	}
 
 	hit := false
-	fc.Sync.Lock()
-
 	if val, exists := fc.Cache[functionName]; exists {
 		replicas = val.ServiceQueryResponse
 		hit = !val.Expired(fc.Expiry)
 	}
 
-	fc.Sync.Unlock()
 	return replicas, hit
 }