closes#1324
#### Problem
Currently, it is possible to accidentally use inner unversioned
migration instead of `VersionedMigration` since both implement
`OnRuntimeUpgrade`.
#### Solution
With this change, we make it clear that value of `Inner` is not intended
to be used directly. It is achieved by bounding `Inner` to new trait
`UncheckedOnRuntimeUpgrade`, which has the same interface (except
`unchecked_` prefix) as `OnRuntimeUpgrade`.
#### `try-runtime` functions
Since developers can implement `try-runtime` for `Inner` value in
`VersionedMigration` and have custom logic for it, I added the same
`try-runtime` functions to `UncheckedOnRuntimeUpgrade`. I looked for a
ways to not duplicate functions, but couldn't find anything that doesn't
significantly change the codebase. So I would appreciate If you have any
suggestions to improve this
cc @liamaharon @xlc
polkadot address: 16FqwPZ8GRC5U5D4Fu7W33nA55ZXzXGWHwmbnE1eT6pxuqcT
---------
Co-authored-by: Liam Aharon <liam.aharon@hotmail.com>
This PR allows _username authorities_ to issue unique usernames that
correspond with an account. It also provides two-way lookup, that is
from `AccountId` to a single, "primary" `Username` (alongside
`Registration`) and multiple unique `Username`s to an `AccountId`.
Key features:
- Username Authorities added (and removed) via privileged origin.
- Authorities have a `suffix` and an `allocation`. They can grant up to
`allocation` usernames. Their `suffix` will be appended to the usernames
that they issue. A suffix may be up to 7 characters long.
- Users can ask an authority to grant them a username. This will take
the form `myusername.suffix`. The entire name (including suffix) must be
less than or equal to 32 alphanumeric characters.
- Users can approve a username for themselves in one of two ways (that
is, authorities cannot grant them arbitrarily):
- Pre-sign the entire username (including suffix) with a secret key that
corresponds to their `AccountId` (for keyed accounts, obviously); or
- Accept the username after it has been granted by an authority (it will
be queued until accepted) (for non-keyed accounts like pure proxies or
multisigs).
- The system does not require any funds or deposits. Users without an
identity will be given a default one (presumably all fields set to
`None`). If they update this info, they will need to place the normal
storage deposit.
- If a user does not have any username, their first one will be set as
`Primary`, and their `AccountId` will map to that one. If they get
subsequent usernames, they can choose which one to be their primary via
`set_primary_username`.
- There are some state cleanup functions to remove expired usernames
that have not been accepted and dangling usernames whose owners have
called `clear_identity`.
TODO:
- [x] Add migration to runtimes
- [x] Probably do off-chain migration into People Chain genesis
- [x] Address a few TODO questions in code (please review)
---------
Co-authored-by: Liam Aharon <liam.aharon@hotmail.com>
Co-authored-by: Gonçalo Pestana <g6pestana@gmail.com>
Co-authored-by: Oliver Tale-Yazdi <oliver.tale-yazdi@parity.io>
Co-authored-by: Dónal Murray <donal.murray@parity.io>
Dastan