add Validate description

pkg/blobaccess/blobaccess/other.go

@@ -81,6 +81,9 @@ func (a *annotatedBlobAccessView[T]) Source() T {
 // It closes the wrapped access, if closed.
 // If the wrapped data access does not need a close, the BlobAccess
 // does not need a close, also.
+// It adds the additional blob access metadata (mime, digest, and size).
+// Digest and size can be set to unknown using the constants (BLOB_UNKNOWN_DIGEST
+// and BLOB_UNKNOWN_SIZE).
 func ForDataAccess[T bpi.DataAccess](digest digest.Digest, size int64, mimeType string, access T) AnnotatedBlobAccess[T] {
 	a := bpi.BaseAccessForDataAccessAndMeta(mimeType, access, digest, size)
 

pkg/blobaccess/bpi/utils.go

@@ -167,6 +167,10 @@ func BaseAccessForDataAccess(mime string, acc DataAccess) BlobAccessBase {
 	}
 }
 
+// BaseAccessForDataAccessAndMeta provides a BlobAccessBase for a DataAccess
+// adding the additional blob access metadata (mime, digest, and size).
+// Digest and size can be set to unknown using the constants (BLOB_UNKNOWN_DIGEST
+// and BLOB_UNKNOWN_SIZE).
 func BaseAccessForDataAccessAndMeta(mime string, acc DataAccess, dig digest.Digest, size int64) BlobAccessBase {
 	return &closableBlobAccess{
 		blobAccess: blobAccess{mimeType: mime, _dataAccess: acc, digest: dig, size: size},
@@ -209,6 +213,10 @@ func ForStaticDataAccess(mime string, acc DataAccess) StaticBlobAccess {
 	}
 }
 
+// ForStaticDataAccessAndMeta provides a StaticBlobAccess for a DataAccess
+// adding the additional blob access metadata (mime, digest, and size).
+// Digest and size can be set to unknown using the constants (BLOB_UNKNOWN_DIGEST
+// and BLOB_UNKNOWN_SIZE).
 func ForStaticDataAccessAndMeta(mime string, acc DataAccess, dig digest.Digest, size int64) StaticBlobAccess {
 	return &staticBlobAccess{
 		blobAccess: blobAccess{mimeType: mime, _dataAccess: acc, digest: dig, size: size},

pkg/blobaccess/file/access.go

@@ -187,6 +187,9 @@ var (
 	_ bpi.FileLocation   = (*temporaryFileBlob)(nil)
 )
 
+// Validate checks if the access is valid, meaning
+// it can provide data. Here, this means
+// that the file exists.
 func (b *temporaryFileBlob) Validate() error {
 	b.lock.Lock()
 	defer b.lock.Unlock()