csi: refactor CSIVolume Copy for clarity

nomad/structs/csi.go

@@ -305,25 +305,14 @@ func NewCSIVolume(volumeID string, index uint64) *CSIVolume {
 }
 
 func (v *CSIVolume) newStructs() {
-	if v.Topologies == nil {
-		v.Topologies = []*CSITopology{}
-	}
-	if v.Context == nil {
-		v.Context = map[string]string{}
-	}
-	if v.Parameters == nil {
-		v.Parameters = map[string]string{}
-	}
-	if v.MountOptions == nil {
-		v.MountOptions = &CSIMountOptions{}
-	}
-	if v.Secrets == nil {
-		v.Secrets = CSISecrets{}
-	}
+	v.Topologies = []*CSITopology{}
+	v.MountOptions = new(CSIMountOptions)
+	v.Secrets = CSISecrets{}
+	v.Parameters = map[string]string{}
+	v.Context = map[string]string{}
 
 	v.ReadAllocs = map[string]*Allocation{}
 	v.WriteAllocs = map[string]*Allocation{}
-
 	v.ReadClaims = map[string]*CSIVolumeClaim{}
 	v.WriteClaims = map[string]*CSIVolumeClaim{}
 	v.PastClaims = map[string]*CSIVolumeClaim{}
@@ -407,38 +396,31 @@ func (v *CSIVolume) InUse() bool {
 
 // Copy returns a copy of the volume, which shares only the Topologies slice
 func (v *CSIVolume) Copy() *CSIVolume {
-	copy := *v
-	out := &copy
-	out.newStructs()
+	out := new(CSIVolume)
+	*out = *v
+	out.newStructs() // zero-out the non-primitive structs
+
+	for _, t := range v.Topologies {
+		out.Topologies = append(out.Topologies, t.Copy())
+	}
+	if v.MountOptions != nil {
+		*out.MountOptions = *v.MountOptions
+	}
+	for k, v := range v.Secrets {
+		out.Secrets[k] = v
+	}
 	for k, v := range v.Parameters {
 		out.Parameters[k] = v
 	}
 	for k, v := range v.Context {
 		out.Context[k] = v
 	}
-	for k, v := range v.Secrets {
-		out.Secrets[k] = v
-	}
-	mo := *v.MountOptions
-	out.MountOptions = &mo
 
-	for k, v := range v.ReadAllocs {
-		if v != nil {
-			a := *v
-			out.ReadAllocs[k] = &a
-		} else {
-			out.ReadAllocs[k] = nil
-		}
+	for k, alloc := range v.ReadAllocs {
+		out.ReadAllocs[k] = alloc.Copy()
 	}
-
-	for k, v := range v.WriteAllocs {
-		if v != nil {
-			a := *v
-			out.WriteAllocs[k] = &a
-		} else {
-			out.WriteAllocs[k] = nil
-		}
-
+	for k, alloc := range v.WriteAllocs {
+		out.WriteAllocs[k] = alloc.Copy()
 	}
 
 	for k, v := range v.ReadClaims {
@@ -784,19 +766,19 @@ func (p *CSIPlugin) Copy() *CSIPlugin {
 	out.newStructs()
 
 	for k, v := range p.Controllers {
-		out.Controllers[k] = v
+		out.Controllers[k] = v.Copy()
 	}
 
 	for k, v := range p.Nodes {
-		out.Nodes[k] = v
+		out.Nodes[k] = v.Copy()
 	}
 
 	for k, v := range p.ControllerJobs {
-		out.ControllerJobs[k] = v
+		out.ControllerJobs[k] = v.Copy()
 	}
 
 	for k, v := range p.NodeJobs {
-		out.NodeJobs[k] = v
+		out.NodeJobs[k] = v.Copy()
 	}
 
 	return out
@@ -998,6 +980,14 @@ type JobDescription struct {
 // JobNamespacedDescriptions maps Job.ID to JobDescription
 type JobNamespacedDescriptions map[string]JobDescription
 
+func (j JobNamespacedDescriptions) Copy() JobNamespacedDescriptions {
+	copy := JobNamespacedDescriptions{}
+	for k, v := range j {
+		copy[k] = v
+	}
+	return copy
+}
+
 // JobDescriptions maps Namespace to a mapping of Job.ID to JobDescription
 type JobDescriptions map[string]JobNamespacedDescriptions