From the design doc:
### Dentry cache dir SWHID → directory entries The dentry (directory entry) cache map SWHIDs of type `dir` to the directory entries they contain. Each entry comes with its name as well as file attributes (i.e., all its needed to perform a detailed directory listing). Additional attributes of each directory entry should be looked up on a entry by entry basis, possibly hitting the metadata cache. The dentry cache for a given dir is populated, at the latest, when the content of the directory is listed. More aggressive prefetching might happen. For instance, when first opening a dir a recursive listing of it can be retrieved from the remote backend and used to recursively populate the dentry cache for all (transitive) sub-directories.
Might not be implemented as entries inside the sqlite disk cache but probably in-memory inside FuseEntry class.