refactor

pkg/resource/signature.go

@@ -4,12 +4,21 @@ import (
 	"sigs.k8s.io/yaml"
 )
 
+type Resource struct {
+	Path  string
+	Bytes []byte
+	sig   *Signature
+}
+
 type Signature struct {
 	Kind, Version, Namespace, Name string
 }
 
-// SignatureFromBytes returns key identifying elements from a []byte representing the resource
-func SignatureFromBytes(res []byte) (Signature, error) {
+func (res *Resource) Signature() (*Signature, error) {
+	if res.sig != nil {
+		return res.sig, nil
+	}
+
 	resource := struct {
 		APIVersion string `yaml:"apiVersion"`
 		Kind       string `yaml:"kind"`
@@ -19,12 +28,14 @@ func SignatureFromBytes(res []byte) (Signature, error) {
 			GenerateName string `yaml:"generateName"`
 		} `yaml:"Metadata"`
 	}{}
-	err := yaml.Unmarshal(res, &resource)
+	err := yaml.Unmarshal(res.Bytes, &resource)
 
 	name := resource.Metadata.Name
 	if resource.Metadata.GenerateName != "" {
 		name = resource.Metadata.GenerateName + "{{ generateName }}"
 	}
 
-	return Signature{Kind: resource.Kind, Version: resource.APIVersion, Namespace: resource.Metadata.Namespace, Name: name}, err
+	// We cache the result to not unmarshall every time we want to access the signature
+	res.sig = &Signature{Kind: resource.Kind, Version: resource.APIVersion, Namespace: resource.Metadata.Namespace, Name: name}
+	return res.sig, err
 }

pkg/resource/signature_test.go

@@ -35,7 +35,8 @@ spec:
 	}
 
 	for _, testCase := range testCases {
-		sig, err := resource.SignatureFromBytes(testCase.have)
+		res := resource.Resource{Bytes: testCase.have}
+		sig, err := res.Signature()
 		if err != nil && err.Error() != testCase.err.Error() {
 			t.Errorf("test \"%s\" - received error: %s", testCase.name, err)
 		}
@@ -44,6 +45,5 @@ spec:
 			sig.Namespace != testCase.want.Namespace {
 			t.Errorf("test \"%s\": received %+v, expected %+v", testCase.name, sig, testCase.want)
 		}
-
 	}
 }

pkg/resource/stream.go

@@ -0,0 +1,22 @@
+package resource
+
+import (
+	"bytes"
+	"io"
+	"io/ioutil"
+)
+
+func FromStream(path string, r io.Reader) ([]Resource, error) {
+	data, err := ioutil.ReadAll(r)
+	if err != nil {
+		return []Resource{}, err
+	}
+
+	resources := []Resource{}
+	rawResources := bytes.Split(data, []byte("---\n"))
+	for _, rawResource := range rawResources {
+		resources = append(resources, Resource{Path: path, Bytes: rawResource})
+	}
+
+	return resources, nil
+}