Storage abstraction for zarr v2 stores — .zarr_make

Returns a list of method closures that hide the difference between a local-filesystem store and a remote HTTP-backed store. Every .zarr_* read helper that previously took a store_path string now also accepts the list returned here.

Usage

.zarr_make_store(x, cache = NA)

Arguments

x: Either a filesystem path, an s3:///gs:///HTTP URL, or an already-constructed store list.
cache: For HTTP stores: TRUE to persist fetched objects under tools::R_user_dir("scConvert", "cache"), FALSE for a tempdir that is discarded with the session, NA for default (TRUE).

Value

A store list.

Details

Methods:

kind: "local" or "http".
root: The store root URI (filesystem path or URL).
exists(rel): Logical: does rel exist in the store?
read_bytes(rel): Raw vector with the contents of rel. Errors on missing keys; callers should store$exists(rel) first if a missing key is expected.
read_json(rel): Parsed JSON list, or empty list if missing.
list_dirs(rel): Character vector of immediate subgroup names under rel (zarr-meaningful only; filters c/, dotfiles, and __*).