staking todos

[4meta5]

Here is a list of features I want for stakev1:

• use FRAMEv2 macro syntax
• change name to parachain-staking, change all instances of Validator to Collator. The Validators storage item should be renamed SelectedCandidates
• add MinCollatorCandidateStk bond, as an associated type for Config trait and only use MinCollatorStk constant when selecting the SelectedCandidates
• make BlocksPerRound a storage item and add runtime method for root to update it (using > instead of % for determining round transitions)
• merge nominate_new and join_nominators into single nominate runtime method (see comment further above)
• make collator fee a pallet constant (associated type Get<Perbill> for Config), instead of configurable per collator (as per our preferred design constraints)
• remove swap_nominations logic, tis quadratic and can easily write code that calls successive runtime methods to achieve same functionality (also removes ~200 loc and puts the lib.rs under 1k loc again)

Prioritized features for future releases:

• benchmarking => weights
• nominations per collator should be top MaxNominationsPerCollator nominations instead of the first MaxNominationsPerCollator nominations
• waitlist for nominations per collator
• blocklist per collator to prevent specific accounts from nominating them if they suspect sabotage
• replace ExitQueue with usage of pallet_scheduler

Other stuff to do:

• integration tests with multiple validators and nominators
• (optimization) want to use this polkadot-js type to make balance fields compact (like in frame/pallet-staking)

[4meta5]

Right now, a nominator must call join_nominators for its first nomination and then nominate_new for every subsequent nomination. This is a bad interface -- move both into a nominate function that will choose which path to take based on whether there is an existing nomination associated with the caller.

[joelamouche]

need to use this polkadot-js type in order to make balance fields compact (like in frame/pallet-staking)

what do you mean by that? Mimic the polkadot-js types in the rust code?

[4meta5]

@joelamouche The Rust code change requires annotating the struct fields that use Balance type with #[compact]. The corresponding polkadot-js type needs to use bn.js or it isn't decoded correctly.

Let's not prioritize this until we're sure we want to optimize this implementation.

[4meta5]

Mostly addressed in #285 and will be tracked elsewhere from now on