Upgrade Notes

Notes for downstream developers who are upgrading their modules to new, breaking versions of Hypercore.

11.0.0

sparse is no longer an option when creating a Hypercore instance. All hypercores are sparse.
encryptionKey will deprecated in favor of the encryption option when creating a Hypercore instance.
Storage is now auto migrated to hypercore-storage if a path storage argument was used.
If you are getting a TypeError: db.columnFamily is not a function error, you are likely trying to use a legacy random-access-storage instance such as random-access-memory or random-access-file.
core.indexedLength is now core.signedLength

All number encodings are now LE
Introduces an "oplog" to atomically track changes locally
Updated merkle format that only requires a single signature (stored in the oplog)

The format of signatures has been changed. This is backwards-compatible (v9 can read v8 signatures), but forward-incompatible (v8 cannot read v9 signatures). If a v8 peer replicates with a v9 peer, it will emit a "REMOTE SIGNATURE INVALID" error on the replication stream.
The encryption (NOISE) handshake has been changed in an backwards- and forwards-incompatible way. v8 peers can not handshake with v9 peers, and vice-versa. A NOISE-related error is emitted on the replication stream.
There is no way (yet) to detect whether a peer is running an incompatible version of hypercore at the replication level. One workaround for downstream developers is to include their own application-level handshake before piping to the replication stream, to communicate a "app protocol version" (maybe "v8" and "v9") and abort the connection if the peer is running an incompatible version.