go-to-protobuf: generate protobuf IDL and marshalers for Go structs

cmd/libs/go2idl/go-to-protobuf/protobuf/import_tracker.go

@@ -0,0 +1,117 @@
+/*
+Copyright 2015 The Kubernetes Authors All rights reserved.
+
+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 protobuf
+
+import (
+	"fmt"
+	"sort"
+
+	"k8s.io/kubernetes/cmd/libs/go2idl/types"
+)
+
+// ImportTracker handles Protobuf package imports
+//
+// TODO: pay attention to the package name (instead of renaming every package).
+// TODO: Figure out the best way to make names for packages that collide.
+type ImportTracker struct {
+	pathToName map[string]string
+	// forbidden names are in here. (e.g. "go" is a directory in which
+	// there is code, but "go" is not a legal name for a package, so we put
+	// it here to prevent us from naming any package "go")
+	nameToPath map[string]string
+	local      types.Name
+}
+
+func NewImportTracker(local types.Name, types ...*types.Type) *ImportTracker {
+	tracker := &ImportTracker{
+		local:      local,
+		pathToName: map[string]string{},
+		nameToPath: map[string]string{
+		// Add other forbidden keywords that also happen to be
+		// package names here.
+		},
+	}
+	tracker.AddTypes(types...)
+	return tracker
+}
+
+// AddNullable ensures that support for the nullable Gogo-protobuf extension is added.
+func (tracker *ImportTracker) AddNullable() {
+	tracker.AddType(&types.Type{
+		Kind: typesKindProtobuf,
+		Name: types.Name{
+			Name:    "nullable",
+			Package: "gogoproto",
+			Path:    "github.com/gogo/protobuf/gogoproto/gogo.proto",
+		},
+	})
+}
+
+func (tracker *ImportTracker) AddTypes(types ...*types.Type) {
+	for _, t := range types {
+		tracker.AddType(t)
+	}
+}
+func (tracker *ImportTracker) AddType(t *types.Type) {
+	if tracker.local.Package == t.Name.Package {
+		return
+	}
+	// Golang type
+	if t.Kind != typesKindProtobuf {
+		// ignore built in package
+		if t.Kind == types.Builtin {
+			return
+		}
+		if _, ok := tracker.nameToPath[t.Name.Package]; !ok {
+			tracker.nameToPath[t.Name.Package] = ""
+		}
+		return
+	}
+	// ignore default proto package
+	if len(t.Name.Package) == 0 {
+		return
+	}
+	path := t.Name.Path
+	if len(path) == 0 {
+		panic(fmt.Sprintf("imported proto package %s must also have a path", t.Name.Package))
+	}
+	if _, ok := tracker.pathToName[path]; ok {
+		return
+	}
+	tracker.nameToPath[t.Name.Package] = path
+	tracker.pathToName[path] = t.Name.Package
+}
+
+func (tracker *ImportTracker) ImportLines() []string {
+	for k, v := range tracker.nameToPath {
+		if len(v) == 0 {
+			panic(fmt.Sprintf("tracking import Go package %s from %s, but no matching proto path set", k, tracker.local.Package))
+		}
+	}
+	out := []string{}
+	for path := range tracker.pathToName {
+		out = append(out, path)
+	}
+	sort.Sort(sort.StringSlice(out))
+	return out
+}
+
+// LocalNameOf returns the name you would use to refer to the package at the
+// specified path within the body of a file.
+func (tracker *ImportTracker) LocalNameOf(path string) string {
+	return tracker.pathToName[path]
+}