file_history_sink ~path (#266) is an append-only, fsync-on-append Granary_store.History.sink backed by the file at path (the <db>.aslog sidecar). A torn tail record is dropped on load.

Open a B+-tree store over a Unix file at path. Creates and pre-sizes the file if absent; otherwise reopens an existing granary database.

page_size (default 4096) and reserved_bytes_per_page (default 0) set the page geometry when CREATING a fresh file (#95); both are fixed for the life of the file. When reopening, the file's stored geometry is used. Set explicit_geometry to true to reject a reopen whose stored geometry differs from the supplied one (otherwise the stored geometry silently wins).

When supplied (key, a 32-byte AES-256 key), the database is created/opened encrypted at rest (AES-256-GCM); absent ⇒ plaintext (opt-in default). Fixed at creation.

(#266) When as_of_history is true, commits are recorded to a <path>.aslog sidecar (via file_history_sink) with a wall-clock timestamp, enabling as-of reads. Default false.

Open a WAL-mode store using path for the main DB and path ^ "-wal" for the WAL. Crash recovery on the WAL runs automatically at open. Geometry arguments behave as in open_file (#95).

When supplied (key, a 32-byte AES-256 key), the database is created/opened encrypted at rest (AES-256-GCM); absent ⇒ plaintext (opt-in default). Fixed at creation.

(#266) When as_of_history is true, commits are recorded to a <path>.aslog sidecar (via file_history_sink) with a wall-clock timestamp, enabling as-of reads. Default false.

One-shot hot copy of src to a new file at dest. Writes to a temporary file first, then atomically renames to dest (with a directory fsync), so dest is never left in a partial state. The destination is a self-contained DB with no WAL sidecar — it opens standalone via open_file.

Handles both non-WAL and WAL-mode sources (the copy resolves pages through the snapshot WAL overlay, so recently committed but un-checkpointed data is included).

rotate_key_file ~src_path ~old_key ~new_key ~dest offline-rotates the encryption key of the database at src_path (opened with old_key), writing a new self-contained file at dest encrypted under new_key (#215). Crash-safe via a temp file + atomic rename + directory fsync. WAL-aware: an existing src_path ^ "-wal" sidecar is folded in. Returns Encryption_key_mismatch for a wrong old_key, Not_encrypted if the source is not encrypted, or a Block_error for I/O / bad key length.

Note: if the post-rename directory fsync fails, this returns a Block_error even though dest is already the live, fully-written rotated file (the rename succeeded); only the directory entry's durability is in doubt.