Method DescriptorWrite

src/cmd/linuxkit/cache/write.go:475–502

DescriptorWrite writes a descriptor to the cache index; it validates that it has a name and replaces any existing one

(image string, desc v1.Descriptor)

// DescriptorWrite writes a descriptor to the cache index; it validates that it has a name
// and replaces any existing one
func (p *Provider) DescriptorWrite(image string, desc v1.Descriptor) error {
	if image == "" {
		return errors.New("cannot write descriptor without reference name")
	}
	if desc.Annotations == nil {
		desc.Annotations = map[string]string{}
	}
	desc.Annotations[imagespec.AnnotationRefName] = image
	log.Debugf("writing descriptor for image %s", image)

	// get our lock
	if err := p.Lock(); err != nil {
		return fmt.Errorf("unable to lock cache for writing descriptors: %v", err)
	}
	defer p.Unlock()

	// get our lock
	// do we update an existing one? Or create a new one?
	if err := p.cache.RemoveDescriptors(match.Name(image)); err != nil {
		return fmt.Errorf("unable to remove old descriptors for %s: %v", image, err)
	}

	if err := p.cache.AppendDescriptor(desc); err != nil {
		return fmt.Errorf("unable to append new descriptor for %s: %v", image, err)
	}

	return nil
}

// RemoveDescriptors removes all descriptors that match the provided matcher.
// It does so in a parallel-access-safe way