github.com/moby/docker@v26.1.3+incompatible/daemon/containerd/handlers.go (about)

     1  package containerd
     2  
     3  import (
     4  	"context"
     5  
     6  	"github.com/containerd/containerd/content"
     7  	cerrdefs "github.com/containerd/containerd/errdefs"
     8  	containerdimages "github.com/containerd/containerd/images"
     9  	ocispec "github.com/opencontainers/image-spec/specs-go/v1"
    10  )
    11  
    12  // walkPresentChildren is a simple wrapper for containerdimages.Walk with presentChildrenHandler.
    13  // This is only a convenient helper to reduce boilerplate.
    14  func (i *ImageService) walkPresentChildren(ctx context.Context, target ocispec.Descriptor, f func(context.Context, ocispec.Descriptor) error) error {
    15  	return containerdimages.Walk(ctx, presentChildrenHandler(i.content, containerdimages.HandlerFunc(
    16  		func(ctx context.Context, desc ocispec.Descriptor) ([]ocispec.Descriptor, error) {
    17  			return nil, f(ctx, desc)
    18  		})), target)
    19  }
    20  
    21  // presentChildrenHandler is a handler wrapper which traverses all children
    22  // descriptors that are present in the store and calls specified handler.
    23  func presentChildrenHandler(store content.Store, h containerdimages.HandlerFunc) containerdimages.HandlerFunc {
    24  	return func(ctx context.Context, desc ocispec.Descriptor) ([]ocispec.Descriptor, error) {
    25  		_, err := store.Info(ctx, desc.Digest)
    26  		if err != nil {
    27  			if cerrdefs.IsNotFound(err) {
    28  				return nil, nil
    29  			}
    30  			return nil, err
    31  		}
    32  
    33  		children, err := h(ctx, desc)
    34  		if err != nil {
    35  			return nil, err
    36  		}
    37  
    38  		c, err := containerdimages.Children(ctx, store, desc)
    39  		if err != nil {
    40  			return nil, err
    41  		}
    42  		children = append(children, c...)
    43  
    44  		return children, nil
    45  	}
    46  }