Module disk 

Everything the worker reads from the store directory, as blocking calls.

The worker runs each of these on Tokio’s blocking pool (tokio::task::spawn_blocking), never on a runtime thread: a segment read can be 64 MiB, and a side file grows with the store’s history.

Structs

DiskState

What one look at the store directory says.

ParentRecord

What PARENT_FILE holds.

Constants

LINEAGE_FILE

The store file naming the backup lineage it belongs to.

PARENT_FILE

The store file a restore-on-boot writes: which lineage and restore point the store was restored from. Never uploaded (it is not a side file).

Functions

crc32_of

CRC-32 of a whole file, read from its start; the file is left at its start again.

create_lineage

Give the store the backup lineage id: written to a temporary file, fsynced, renamed into place, and the directory fsynced. The one file the backup worker ever writes into a store directory.

create_parent

Write PARENT_FILE as create_lineage writes the lineage: a temporary file, fsynced, renamed into place, the directory fsynced.

floor

The store’s horizon floor (wal.floor), or 0.

ident_of

Ident of a file’s metadata, computed as the engine computes it.

local_archives

Every wal.N.archive in the directory, as (n, len), sorted by n.

observe

open_snapshot

snapshot.bin opened, with the identity of the file actually opened.

read_lineage

The store’s backup lineage, or None when it has never been backed up.

read_parent

The store’s parent record, or None when it has none (or one that does not parse: it then adopts nothing).

read_side

A side file’s identity, and its bytes when the identity differs from known. Ok(None) when the file does not exist.

Type Aliases

Ident

A file’s identity as (len, mtime_nanos) — the form the engine uses for snapshot.bin (mushroomdb::WalPosition::snapshot).