Split scheduler framework implementation into new runtime package

pkg/scheduler/framework/runtime/registry.go

@@ -0,0 +1,88 @@
+/*
+Copyright 2019 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 runtime
+
+import (
+	"fmt"
+
+	"k8s.io/apimachinery/pkg/runtime"
+	"k8s.io/apimachinery/pkg/util/json"
+	"k8s.io/kubernetes/pkg/scheduler/framework/v1alpha1"
+	"sigs.k8s.io/yaml"
+)
+
+// PluginFactory is a function that builds a plugin.
+type PluginFactory = func(configuration runtime.Object, f v1alpha1.FrameworkHandle) (v1alpha1.Plugin, error)
+
+// DecodeInto decodes configuration whose type is *runtime.Unknown to the interface into.
+func DecodeInto(obj runtime.Object, into interface{}) error {
+	if obj == nil {
+		return nil
+	}
+	configuration, ok := obj.(*runtime.Unknown)
+	if !ok {
+		return fmt.Errorf("want args of type runtime.Unknown, got %T", obj)
+	}
+	if configuration.Raw == nil {
+		return nil
+	}
+
+	switch configuration.ContentType {
+	// If ContentType is empty, it means ContentTypeJSON by default.
+	case runtime.ContentTypeJSON, "":
+		return json.Unmarshal(configuration.Raw, into)
+	case runtime.ContentTypeYAML:
+		return yaml.Unmarshal(configuration.Raw, into)
+	default:
+		return fmt.Errorf("not supported content type %s", configuration.ContentType)
+	}
+}
+
+// Registry is a collection of all available plugins. The framework uses a
+// registry to enable and initialize configured plugins.
+// All plugins must be in the registry before initializing the framework.
+type Registry map[string]PluginFactory
+
+// Register adds a new plugin to the registry. If a plugin with the same name
+// exists, it returns an error.
+func (r Registry) Register(name string, factory PluginFactory) error {
+	if _, ok := r[name]; ok {
+		return fmt.Errorf("a plugin named %v already exists", name)
+	}
+	r[name] = factory
+	return nil
+}
+
+// Unregister removes an existing plugin from the registry. If no plugin with
+// the provided name exists, it returns an error.
+func (r Registry) Unregister(name string) error {
+	if _, ok := r[name]; !ok {
+		return fmt.Errorf("no plugin named %v exists", name)
+	}
+	delete(r, name)
+	return nil
+}
+
+// Merge merges the provided registry to the current one.
+func (r Registry) Merge(in Registry) error {
+	for name, factory := range in {
+		if err := r.Register(name, factory); err != nil {
+			return err
+		}
+	}
+	return nil
+}