WIP residPackage

pkg/resid/resid.go

@@ -0,0 +1,148 @@
+/*
+Copyright 2018 The Kubernetes Authors.
+
+Licensed under the Apache License, Version 2.0 (the "License");
+you may not use this file except in compliance with the License.
+You may obtain a copy of the License at
+
+    http://www.apache.org/licenses/LICENSE-2.0
+
+Unless required by applicable law or agreed to in writing, software
+distributed under the License is distributed on an "AS IS" BASIS,
+WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+See the License for the specific language governing permissions and
+limitations under the License.
+*/
+
+package resid
+
+import (
+	"strings"
+
+	"sigs.k8s.io/kustomize/pkg/gvk"
+)
+
+// ResId conflates GroupVersionKind with a textual name to uniquely identify a kubernetes resource (object).
+type ResId struct {
+	// Gvk of the resource.
+	gvKind gvk.Gvk
+	// original name of the resource before transformation.
+	name string
+	// namePrefix of the resource
+	// an untransformed resource has no prefix, fully transformed resource has an arbitrary number of prefixes
+	// concatenated together.
+	prefix string
+	// namespace the resource belongs to
+	// an untransformed resource has no namespace, fully transformed resource has the namespace from
+	// the top most overlay
+	namespace string
+}
+
+// NewResIdWithPrefixNamespace creates new resource identifier with a prefix and a namespace
+func NewResIdWithPrefixNamespace(k gvk.Gvk, n, p, ns string) ResId {
+	return ResId{gvKind: k, name: n, prefix: p, namespace: ns}
+}
+
+// NewResIdWithPrefix creates new resource identifier with a prefix
+func NewResIdWithPrefix(k gvk.Gvk, n, p string) ResId {
+	return ResId{gvKind: k, name: n, prefix: p}
+}
+
+// NewResId creates new resource identifier
+func NewResId(k gvk.Gvk, n string) ResId {
+	return ResId{gvKind: k, name: n}
+}
+
+// NewResIdKindOnly creates new resource identifier
+func NewResIdKindOnly(k string, n string) ResId {
+	return ResId{gvKind: gvk.FromKind(k), name: n}
+}
+
+const (
+	noNamespace = "noNamespace"
+	noPrefix    = "noPrefix"
+	noName      = "noName"
+	separator   = "|"
+)
+
+// String of ResId based on GVK, name and prefix
+func (n ResId) String() string {
+	ns := n.namespace
+	if ns == "" {
+		ns = noNamespace
+	}
+	p := n.prefix
+	if p == "" {
+		p = noPrefix
+	}
+	nm := n.name
+	if nm == "" {
+		nm = noName
+	}
+
+	return strings.Join(
+		[]string{n.gvKind.String(), ns, p, nm}, separator)
+}
+
+// GvknString of ResId based on GVK and name
+func (n ResId) GvknString() string {
+	return n.gvKind.String() + separator + n.name
+}
+
+// GvknEquals return if two ResId have the same Group/Version/Kind and name
+// The comparison excludes prefix
+func (n ResId) GvknEquals(id ResId) bool {
+	return n.gvKind.Equals(id.gvKind) && n.name == id.name
+}
+
+// Gvk returns Group/Version/Kind of the resource.
+func (n ResId) Gvk() gvk.Gvk {
+	return n.gvKind
+}
+
+// Name returns resource name.
+func (n ResId) Name() string {
+	return n.name
+}
+
+// Prefix returns name prefix.
+func (n ResId) Prefix() string {
+	return n.prefix
+}
+
+// Namespace returns resource namespace.
+func (n ResId) Namespace() string {
+	return n.namespace
+}
+
+// CopyWithNewPrefix make a new copy from current ResId and append a new prefix
+func (n ResId) CopyWithNewPrefix(p string) ResId {
+	return ResId{gvKind: n.gvKind, name: n.name, prefix: n.concatPrefix(p), namespace: n.namespace}
+}
+
+// CopyWithNewNamespace make a new copy from current ResId and set a new namespace
+func (n ResId) CopyWithNewNamespace(ns string) ResId {
+	return ResId{gvKind: n.gvKind, name: n.name, prefix: n.prefix, namespace: ns}
+}
+
+// HasSameLeftmostPrefix check if two ResIds have the same
+// left most prefix.
+func (n ResId) HasSameLeftmostPrefix(id ResId) bool {
+	prefixes1 := n.prefixList()
+	prefixes2 := id.prefixList()
+	return prefixes1[0] == prefixes2[0]
+}
+
+func (n ResId) concatPrefix(p string) string {
+	if p == "" {
+		return n.prefix
+	}
+	if n.prefix == "" {
+		return p
+	}
+	return p + ":" + n.prefix
+}
+
+func (n ResId) prefixList() []string {
+	return strings.Split(n.prefix, ":")
+}