A VoteAccount may only wrap an account if the account owner is
solana_vote_program:id or equivalently this check returns true:
solana_vote_program::check_id(account.owner())
Tracking mismatches between cached vote/stake accounts and accounts-db
in preparation of activating feature for updating rewards at
epoch-boundary using cached vote/stake accounts.
StakeAccount<Delegation> can only wrap a stake-state which is a
Delegation; whereas StakeAccount<()> wraps any account with stake state.
As a result, StakeAccount::<Delegation>::delegation() will return
Delegation instead of Option<Delegation>.
For backward compatibility, we can only serialize and deserialize
Stakes<Delegation>. However Bank caches Stakes<StakeAccount>. This type
mismatch incurs a conversion cost at epoch boundary when updating
EpochStakes.
This commit adds StakesEnum which allows EpochStakes to include either a
Stakes<StakeAccount> or Stakes<Delegation> and so bypass the conversion
cost between the two at the epoch boundary.
The commit makes values in stake_delegations map in Stakes struct
generic. Stakes<Delegation> is equivalent to the old code and is used
for backward compatibility in BankFieldsTo{Serialize,Deserialize}.
But banks cache Stakes<StakeAccount> which includes the entire stake
account and StakeState deserialized from account. Doing so, will remove
the need to load stake account from accounts-db when working with
stake-delegations.
The added type does sanity checks on the Account and stores deserialized
StakeState. Following commits will use this type instead of Delegation
in Stakes.
Brooks Prumo
behzad nouri
Jeff Washington (jwash)