Update gomod and vendor

vendor/github.com/moby/buildkit/cache/remotecache/local/local.go

@@ -0,0 +1,83 @@
+package local
+
+import (
+	"context"
+	"time"
+
+	"github.com/containerd/containerd/content"
+	"github.com/moby/buildkit/cache/remotecache"
+	"github.com/moby/buildkit/session"
+	sessioncontent "github.com/moby/buildkit/session/content"
+	digest "github.com/opencontainers/go-digest"
+	specs "github.com/opencontainers/image-spec/specs-go/v1"
+	"github.com/pkg/errors"
+)
+
+const (
+	attrDigest           = "digest"
+	attrSrc              = "src"
+	attrDest             = "dest"
+	contentStoreIDPrefix = "local:"
+)
+
+// ResolveCacheExporterFunc for "local" cache exporter.
+func ResolveCacheExporterFunc(sm *session.Manager) remotecache.ResolveCacheExporterFunc {
+	return func(ctx context.Context, attrs map[string]string) (remotecache.Exporter, error) {
+		store := attrs[attrDest]
+		if store == "" {
+			return nil, errors.New("local cache exporter requires dest")
+		}
+		csID := contentStoreIDPrefix + store
+		cs, err := getContentStore(ctx, sm, csID)
+		if err != nil {
+			return nil, err
+		}
+		return remotecache.NewExporter(cs), nil
+	}
+}
+
+// ResolveCacheImporterFunc for "local" cache importer.
+func ResolveCacheImporterFunc(sm *session.Manager) remotecache.ResolveCacheImporterFunc {
+	return func(ctx context.Context, attrs map[string]string) (remotecache.Importer, specs.Descriptor, error) {
+		dgstStr := attrs[attrDigest]
+		if dgstStr == "" {
+			return nil, specs.Descriptor{}, errors.New("local cache importer requires explicit digest")
+		}
+		dgst := digest.Digest(dgstStr)
+		store := attrs[attrSrc]
+		if store == "" {
+			return nil, specs.Descriptor{}, errors.New("local cache importer requires src")
+		}
+		csID := contentStoreIDPrefix + store
+		cs, err := getContentStore(ctx, sm, csID)
+		if err != nil {
+			return nil, specs.Descriptor{}, err
+		}
+		info, err := cs.Info(ctx, dgst)
+		if err != nil {
+			return nil, specs.Descriptor{}, err
+		}
+		desc := specs.Descriptor{
+			// MediaType is typically MediaTypeDockerSchema2ManifestList,
+			// but we leave it empty until we get correct support for local index.json
+			Digest: dgst,
+			Size:   info.Size,
+		}
+		return remotecache.NewImporter(cs), desc, nil
+	}
+}
+
+func getContentStore(ctx context.Context, sm *session.Manager, storeID string) (content.Store, error) {
+	sessionID := session.FromContext(ctx)
+	if sessionID == "" {
+		return nil, errors.New("local cache exporter/importer requires session")
+	}
+	timeoutCtx, cancel := context.WithTimeout(context.Background(), 5*time.Second)
+	defer cancel()
+
+	caller, err := sm.Get(timeoutCtx, sessionID)
+	if err != nil {
+		return nil, err
+	}
+	return sessioncontent.NewCallerStore(caller, storeID), nil
+}