Allow to tap multiple function services at one time (#1434)

The router taps function service one by one which is inefficient and
increases the burden of executor. This PR aggregates all requests into
one to solve the problem mentioned above.

pkg/router/functionReferenceResolver.go

@@ -50,7 +50,7 @@ type (
 	// a distribution of requests across two functions.
 	resolveResult struct {
 		resolveResultType
-		functionMetadataMap        map[string]*metav1.ObjectMeta
+		functionMap                map[string]*fv1.Function
 		functionWtDistributionList []FunctionWeightDistribution
 	}
 
@@ -134,12 +134,13 @@ func (frr *functionReferenceResolver) resolveByName(namespace, name string) (*re
 	}
 
 	f := obj.(*fv1.Function)
-	functionMetadataMap := make(map[string]*metav1.ObjectMeta, 1)
-	functionMetadataMap[f.Metadata.Name] = &f.Metadata
+	functionMap := map[string]*fv1.Function{
+		f.Metadata.Name: f,
+	}
 
 	rr := resolveResult{
-		resolveResultType:   resolveResultSingleFunction,
-		functionMetadataMap: functionMetadataMap,
+		resolveResultType: resolveResultSingleFunction,
+		functionMap:       functionMap,
 	}
 
 	return &rr, nil
@@ -147,7 +148,7 @@ func (frr *functionReferenceResolver) resolveByName(namespace, name string) (*re
 
 func (frr *functionReferenceResolver) resolveByFunctionWeights(namespace string, fr *fv1.FunctionReference) (*resolveResult, error) {
 
-	functionMetadataMap := make(map[string]*metav1.ObjectMeta)
+	functionMap := make(map[string]*fv1.Function)
 	fnWtDistrList := make([]FunctionWeightDistribution, 0)
 	sumPrefix := 0
 
@@ -167,19 +168,18 @@ func (frr *functionReferenceResolver) resolveByFunctionWeights(namespace string,
 		}
 
 		f := obj.(*fv1.Function)
-		functionMetadataMap[f.Metadata.Name] = &f.Metadata
+		functionMap[f.Metadata.Name] = f
 		sumPrefix = sumPrefix + functionWeight
 		fnWtDistrList = append(fnWtDistrList, FunctionWeightDistribution{
 			name:      functionName,
 			weight:    functionWeight,
 			sumPrefix: sumPrefix,
 		})
-
 	}
 
 	rr := resolveResult{
 		resolveResultType:          resolveResultMultipleFunctions,
-		functionMetadataMap:        functionMetadataMap,
+		functionMap:                functionMap,
 		functionWtDistributionList: fnWtDistrList,
 	}