factory.go

/*
Copyright 2016 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 generators

import (
	"io"
	"path"

	clientgentypes "k8s.io/code-generator/cmd/client-gen/types"
	"k8s.io/gengo/generator"
	"k8s.io/gengo/namer"
	"k8s.io/gengo/types"

	"k8s.io/klog/v2"
)

// factoryGenerator produces a file of listers for a given GroupVersion and
// type.
type factoryGenerator struct {
	generator.DefaultGen
	outputPackage             string
	imports                   namer.ImportTracker
	groupVersions             map[string]clientgentypes.GroupVersions
	gvGoNames                 map[string]string
	clientSetPackage          string
	internalInterfacesPackage string
	filtered                  bool
}

var _ generator.Generator = &factoryGenerator{}

func (g *factoryGenerator) Filter(c *generator.Context, t *types.Type) bool {
	if !g.filtered {
		g.filtered = true
		return true
	}
	return false
}

func (g *factoryGenerator) Namers(c *generator.Context) namer.NameSystems {
	return namer.NameSystems{
		"raw": namer.NewRawNamer(g.outputPackage, g.imports),
	}
}

func (g *factoryGenerator) Imports(c *generator.Context) (imports []string) {
	imports = append(imports, "github.com/maistra/xns-informer/pkg/internal/sets")
	imports = append(imports, g.imports.ImportLines()...)
	return
}

func (g *factoryGenerator) GenerateType(c *generator.Context, t *types.Type, w io.Writer) error {
	sw := generator.NewSnippetWriter(w, c, "{{", "}}")

	klog.V(5).Infof("processing type %v", t)

	gvInterfaces := make(map[string]*types.Type)
	gvNewFuncs := make(map[string]*types.Type)
	for groupPkgName := range g.groupVersions {
		gvInterfaces[groupPkgName] = c.Universe.Type(types.Name{Package: path.Join(g.outputPackage, groupPkgName), Name: "Interface"})
		gvNewFuncs[groupPkgName] = c.Universe.Function(types.Name{Package: path.Join(g.outputPackage, groupPkgName), Name: "New"})
	}
	m := map[string]interface{}{
		"cacheSharedIndexInformer":       c.Universe.Type(cacheSharedIndexInformer),
		"groupVersions":                  g.groupVersions,
		"gvInterfaces":                   gvInterfaces,
		"gvNewFuncs":                     gvNewFuncs,
		"gvGoNames":                      g.gvGoNames,
		"interfacesNewInformerFunc":      c.Universe.Type(types.Name{Package: g.internalInterfacesPackage, Name: "NewInformerFunc"}),
		"interfacesTweakListOptionsFunc": c.Universe.Type(types.Name{Package: g.internalInterfacesPackage, Name: "TweakListOptionsFunc"}),
		"informerFactoryInterface":       c.Universe.Type(types.Name{Package: g.internalInterfacesPackage, Name: "SharedInformerFactory"}),
		"clientSetInterface":             c.Universe.Type(types.Name{Package: g.clientSetPackage, Name: "Interface"}),
		"reflectType":                    c.Universe.Type(reflectType),
		"runtimeObject":                  c.Universe.Type(runtimeObject),
		"schemaGroupVersionResource":     c.Universe.Type(schemaGroupVersionResource),
		"syncMutex":                      c.Universe.Type(syncMutex),
		"timeDuration":                   c.Universe.Type(timeDuration),
		"namespaceAll":                   c.Universe.Type(metav1NamespaceAll),
		"object":                         c.Universe.Type(metav1Object),
		"xnsNamespaceSet":                c.Universe.Type(xnsNamespaceSet),
		"xnsNewNamespaceSet":             c.Universe.Type(xnsNewNamespaceSet),
	}

	sw.Do(sharedInformerFactoryStruct, m)
	sw.Do(sharedInformerFactoryInterface, m)

	return sw.Error()
}

var sharedInformerFactoryStruct = `
// SharedInformerOption defines the functional option type for SharedInformerFactory.
type SharedInformerOption func(*sharedInformerFactory) *sharedInformerFactory

type sharedInformerFactory struct {
	client {{.clientSetInterface|raw}}
    namespaces {{.xnsNamespaceSet|raw}}
	tweakListOptions {{.interfacesTweakListOptionsFunc|raw}}
	lock {{.syncMutex|raw}}
	defaultResync {{.timeDuration|raw}}
	customResync map[{{.reflectType|raw}}]{{.timeDuration|raw}}

	informers map[{{.reflectType|raw}}]{{.cacheSharedIndexInformer|raw}}
	// startedInformers is used for tracking which informers have been started.
	// This allows Start() to be called multiple times safely.
	startedInformers map[{{.reflectType|raw}}]bool
}

// WithCustomResyncConfig sets a custom resync period for the specified informer types.
func WithCustomResyncConfig(resyncConfig map[{{.object|raw}}]{{.timeDuration|raw}}) SharedInformerOption {
	return func(factory *sharedInformerFactory) *sharedInformerFactory {
		for k, v := range resyncConfig {
			factory.customResync[reflect.TypeOf(k)] = v
		}
		return factory
	}
}

// WithTweakListOptions sets a custom filter on all listers of the configured SharedInformerFactory.
func WithTweakListOptions(tweakListOptions internalinterfaces.TweakListOptionsFunc) SharedInformerOption {
	return func(factory *sharedInformerFactory) *sharedInformerFactory {
		factory.tweakListOptions = tweakListOptions
		return factory
	}
}

// WithNamespaces limits the SharedInformerFactory to the specified namespaces.
func WithNamespaces(namespaces ...string) SharedInformerOption {
	return func(factory *sharedInformerFactory) *sharedInformerFactory {
        factory.SetNamespaces(namespaces)
		return factory
	}
}

// NewSharedInformerFactory constructs a new instance of sharedInformerFactory for all namespaces.
func NewSharedInformerFactory(client {{.clientSetInterface|raw}}, defaultResync {{.timeDuration|raw}}) SharedInformerFactory {
	return NewSharedInformerFactoryWithOptions(client, defaultResync)
}

// NewSharedInformerFactoryWithOptions constructs a new instance of a SharedInformerFactory with additional options.
func NewSharedInformerFactoryWithOptions(client {{.clientSetInterface|raw}}, defaultResync {{.timeDuration|raw}}, options ...SharedInformerOption) SharedInformerFactory {
	factory := &sharedInformerFactory{
		client:           client,
        namespaces:       {{.xnsNewNamespaceSet|raw}}(v1.NamespaceAll),
		defaultResync:    defaultResync,
		informers:        make(map[{{.reflectType|raw}}]{{.cacheSharedIndexInformer|raw}}),
		startedInformers: make(map[{{.reflectType|raw}}]bool),
		customResync:     make(map[{{.reflectType|raw}}]{{.timeDuration|raw}}),
	}

	// Apply all options
	for _, opt := range options {
		factory = opt(factory)
	}

	return factory
}

// SetNamespaces updates the set of namespaces for all current and future informers.
func (f *sharedInformerFactory) SetNamespaces(namespaces []string) {
    f.lock.Lock()
    defer f.lock.Unlock()

    f.namespaces.SetNamespaces(namespaces)
}

// Start initializes all requested informers.
func (f *sharedInformerFactory) Start(stopCh <-chan struct{}) {
  f.lock.Lock()
  defer f.lock.Unlock()

  for informerType, informer := range f.informers {
    if !f.startedInformers[informerType] {
      go informer.Run(stopCh)
      f.startedInformers[informerType] = true
    }
  }
}

// WaitForCacheSync waits for all started informers' cache were synced.
func (f *sharedInformerFactory) WaitForCacheSync(stopCh <-chan struct{}) map[reflect.Type]bool {
	informers := func()map[reflect.Type]cache.SharedIndexInformer{
               f.lock.Lock()
               defer f.lock.Unlock()

               informers := map[reflect.Type]cache.SharedIndexInformer{}
               for informerType, informer := range f.informers {
                       if f.startedInformers[informerType] {
                               informers[informerType] = informer
                       }
               }
               return informers
       }()

       res := map[reflect.Type]bool{}
       for informType, informer := range informers {
               res[informType] = cache.WaitForCacheSync(stopCh, informer.HasSynced)
       }
       return res
}

// InternalInformerFor returns the SharedIndexInformer for obj using an internal
// client.
func (f *sharedInformerFactory) InformerFor(obj {{.runtimeObject|raw}}, newFunc {{.interfacesNewInformerFunc|raw}}) {{.cacheSharedIndexInformer|raw}} {
  f.lock.Lock()
  defer f.lock.Unlock()

  informerType := reflect.TypeOf(obj)
  informer, exists := f.informers[informerType]
  if exists {
    return informer
  }

  resyncPeriod, exists := f.customResync[informerType]
  if !exists {
    resyncPeriod = f.defaultResync
  }

  informer = newFunc(f.client, resyncPeriod)
  f.informers[informerType] = informer

  return informer
}

`

var sharedInformerFactoryInterface = `
// SharedInformerFactory provides shared informers for resources in all known
// API group versions.
type SharedInformerFactory interface {
	{{.informerFactoryInterface|raw}}
    SetNamespaces(namespaces []string)
	ForResource(resource {{.schemaGroupVersionResource|raw}}) (GenericInformer, error)
	WaitForCacheSync(stopCh <-chan struct{}) map[reflect.Type]bool

	{{$gvInterfaces := .gvInterfaces}}
	{{$gvGoNames := .gvGoNames}}
	{{range $groupName, $group := .groupVersions}}{{index $gvGoNames $groupName}}() {{index $gvInterfaces $groupName|raw}}
	{{end}}
}

{{$gvNewFuncs := .gvNewFuncs}}
{{$gvGoNames := .gvGoNames}}
{{range $groupPkgName, $group := .groupVersions}}
func (f *sharedInformerFactory) {{index $gvGoNames $groupPkgName}}() {{index $gvInterfaces $groupPkgName|raw}} {
  return {{index $gvNewFuncs $groupPkgName|raw}}(f, f.namespaces, f.tweakListOptions)
}
{{end}}
`