Migrate from levelup/leveldown/subleveldown to classic-level

[axel-krapotke]

Background

ODIN currently uses the deprecated LevelDB stack:

• levelup (5.0.1)
• leveldown (6.1.1)
• subleveldown (6.0.1)
• abstract-leveldown (7.2.0)

These packages have been superseded by:

• classic-level (replaces levelup + leveldown)
• Built-in .sublevel() (replaces subleveldown)

Scope

Files to update

• src/shared/level/index.js — main DB factory, sublevel creation
• All consumers of subleveldown and levelup APIs
• package.json — swap dependencies

API changes

Old (levelup)	New (abstract-level)
createReadStream()	iterator().all() or for await...of db.iterator()
db.batch([...], callback)	await db.batch([...])
subleveldown(db, prefix, opts)	db.sublevel(prefix, opts)
Callback-based get/put/del	Promise-based get/put/del

Key consideration

The on-disk LevelDB format is identical between old and new APIs. No data migration required — users can update ODIN without losing any data.

Related

• Migrate from levelup/subleveldown to classic-level/sublevel matrix-client-api#7 — same migration for the matrix-client-api persistent command queue