Golang storage.Preconditions類代碼示例

// Delete removes the item from storage.
func (e *Store) Delete(ctx api.Context, name string, options *api.DeleteOptions) (runtime.Object, error) {
	key, err := e.KeyFunc(ctx, name)
	if err != nil {
		return nil, err
	}

	obj := e.NewFunc()
	if err := e.Storage.Get(ctx, key, obj, false); err != nil {
		return nil, storeerr.InterpretDeleteError(err, e.QualifiedResource, name)
	}
	// support older consumers of delete by treating "nil" as delete immediately
	if options == nil {
		options = api.NewDeleteOptions(0)
	}
	var preconditions storage.Preconditions
	if options.Preconditions != nil {
		preconditions.UID = options.Preconditions.UID
	}
	graceful, pendingGraceful, err := rest.BeforeDelete(e.DeleteStrategy, ctx, obj, options)
	if err != nil {
		return nil, err
	}
	// this means finalizers cannot be updated via DeleteOptions if a deletion is already pending
	if pendingGraceful {
		return e.finalizeDelete(obj, false)
	}
	// check if obj has pending finalizers
	accessor, err := meta.Accessor(obj)
	if err != nil {
		return nil, kubeerr.NewInternalError(err)
	}
	pendingFinalizers := len(accessor.GetFinalizers()) != 0
	var ignoreNotFound bool
	var deleteImmediately bool = true
	var lastExisting, out runtime.Object
	if !EnableGarbageCollector {
		// TODO: remove the check on graceful, because we support no-op updates now.
		if graceful {
			err, ignoreNotFound, deleteImmediately, out, lastExisting = e.updateForGracefulDeletion(ctx, name, key, options, preconditions, obj)
		}
	} else {
		shouldUpdateFinalizers, _ := shouldUpdateFinalizers(accessor, options)
		// TODO: remove the check, because we support no-op updates now.
		if graceful || pendingFinalizers || shouldUpdateFinalizers {
			err, ignoreNotFound, deleteImmediately, out, lastExisting = e.updateForGracefulDeletionAndFinalizers(ctx, name, key, options, preconditions, obj)
		}
	}
	// !deleteImmediately covers all cases where err != nil. We keep both to be future-proof.
	if !deleteImmediately || err != nil {
		return out, err
	}

	// delete immediately, or no graceful deletion supported
	glog.V(6).Infof("going to delete %s from regitry: ", name)
	out = e.NewFunc()
	if err := e.Storage.Delete(ctx, key, out, &preconditions); err != nil {
		// Please refer to the place where we set ignoreNotFound for the reason
		// why we ignore the NotFound error .
		if storage.IsNotFound(err) && ignoreNotFound && lastExisting != nil {
			// The lastExisting object may not be the last state of the object
			// before its deletion, but it's the best approximation.
			return e.finalizeDelete(lastExisting, true)
		}
		return nil, storeerr.InterpretDeleteError(err, e.QualifiedResource, name)
	}
	return e.finalizeDelete(out, true)
}

// Delete removes the item from storage.
func (e *Store) Delete(ctx api.Context, name string, options *api.DeleteOptions) (runtime.Object, error) {
	key, err := e.KeyFunc(ctx, name)
	if err != nil {
		return nil, err
	}

	obj := e.NewFunc()
	if err := e.Storage.Get(ctx, key, obj, false); err != nil {
		return nil, storeerr.InterpretDeleteError(err, e.QualifiedResource, name)
	}

	// support older consumers of delete by treating "nil" as delete immediately
	if options == nil {
		options = api.NewDeleteOptions(0)
	}
	var preconditions storage.Preconditions
	if options.Preconditions != nil {
		preconditions.UID = options.Preconditions.UID
	}
	graceful, pendingGraceful, err := rest.BeforeDelete(e.DeleteStrategy, ctx, obj, options)
	if err != nil {
		return nil, err
	}
	if pendingGraceful {
		return e.finalizeDelete(obj, false)
	}
	var ignoreNotFound bool = false
	var lastExisting runtime.Object = nil
	if graceful {
		out := e.NewFunc()
		lastGraceful := int64(0)
		err := e.Storage.GuaranteedUpdate(
			ctx, key, out, false, &preconditions,
			storage.SimpleUpdate(func(existing runtime.Object) (runtime.Object, error) {
				graceful, pendingGraceful, err := rest.BeforeDelete(e.DeleteStrategy, ctx, existing, options)
				if err != nil {
					return nil, err
				}
				if pendingGraceful {
					return nil, errAlreadyDeleting
				}
				if !graceful {
					return nil, errDeleteNow
				}
				lastGraceful = *options.GracePeriodSeconds
				lastExisting = existing
				return existing, nil
			}),
		)
		switch err {
		case nil:
			if lastGraceful > 0 {
				return out, nil
			}
			// If we are here, the registry supports grace period mechanism and
			// we are intentionally delete gracelessly. In this case, we may
			// enter a race with other k8s components. If other component wins
			// the race, the object will not be found, and we should tolerate
			// the NotFound error. See
			// https://github.com/kubernetes/kubernetes/issues/19403 for
			// details.
			ignoreNotFound = true
			// exit the switch and delete immediately
		case errDeleteNow:
			// we've updated the object to have a zero grace period, or it's already at 0, so
			// we should fall through and truly delete the object.
		case errAlreadyDeleting:
			return e.finalizeDelete(obj, true)
		default:
			return nil, storeerr.InterpretUpdateError(err, e.QualifiedResource, name)
		}
	}

	// delete immediately, or no graceful deletion supported
	out := e.NewFunc()
	if err := e.Storage.Delete(ctx, key, out, &preconditions); err != nil {
		// Please refer to the place where we set ignoreNotFound for the reason
		// why we ignore the NotFound error .
		if storage.IsNotFound(err) && ignoreNotFound && lastExisting != nil {
			// The lastExisting object may not be the last state of the object
			// before its deletion, but it's the best approximation.
			return e.finalizeDelete(lastExisting, true)
		}
		return nil, storeerr.InterpretDeleteError(err, e.QualifiedResource, name)
	}
	return e.finalizeDelete(out, true)
}