Trait frame_support::traits::tokens::currency::ReservableCurrency
source · pub trait ReservableCurrency<AccountId>: Currency<AccountId> {
// Required methods
fn can_reserve(who: &AccountId, value: Self::Balance) -> bool;
fn slash_reserved(
who: &AccountId,
value: Self::Balance
) -> (Self::NegativeImbalance, Self::Balance);
fn reserved_balance(who: &AccountId) -> Self::Balance;
fn reserve(who: &AccountId, value: Self::Balance) -> DispatchResult;
fn unreserve(who: &AccountId, value: Self::Balance) -> Self::Balance;
fn repatriate_reserved(
slashed: &AccountId,
beneficiary: &AccountId,
value: Self::Balance,
status: BalanceStatus
) -> Result<Self::Balance, DispatchError>;
}
Expand description
A currency where funds can be reserved from the user.
Required Methods§
sourcefn can_reserve(who: &AccountId, value: Self::Balance) -> bool
fn can_reserve(who: &AccountId, value: Self::Balance) -> bool
Same result as reserve(who, value)
(but without the side-effects) assuming there
are no balance changes in the meantime.
sourcefn slash_reserved(
who: &AccountId,
value: Self::Balance
) -> (Self::NegativeImbalance, Self::Balance)
fn slash_reserved( who: &AccountId, value: Self::Balance ) -> (Self::NegativeImbalance, Self::Balance)
Deducts up to value
from reserved balance of who
. This function cannot fail.
As much funds up to value
will be deducted as possible. If the reserve balance of who
is less than value
, then the second item will be equal to the value not able to be
slashed.
sourcefn reserved_balance(who: &AccountId) -> Self::Balance
fn reserved_balance(who: &AccountId) -> Self::Balance
The amount of the balance of a given account that is externally reserved; this can still get slashed, but gets slashed last of all.
This balance is a ‘reserve’ balance that other subsystems use in order to set aside tokens that are still ‘owned’ by the account holder, but which are suspendable.
system::AccountNonce
is also deleted if FreeBalance
is also zero (it also gets
collapsed to zero if it ever becomes less than ExistentialDeposit
.
sourcefn reserve(who: &AccountId, value: Self::Balance) -> DispatchResult
fn reserve(who: &AccountId, value: Self::Balance) -> DispatchResult
Moves value
from balance to reserved balance.
If the free balance is lower than value
, then no funds will be moved and an Err
will
be returned to notify of this. This is different behavior than unreserve
.
sourcefn unreserve(who: &AccountId, value: Self::Balance) -> Self::Balance
fn unreserve(who: &AccountId, value: Self::Balance) -> Self::Balance
Moves up to value
from reserved balance to free balance. This function cannot fail.
As much funds up to value
will be moved as possible. If the reserve balance of who
is less than value
, then the remaining amount will be returned. This is different
behavior than reserve
.
sourcefn repatriate_reserved(
slashed: &AccountId,
beneficiary: &AccountId,
value: Self::Balance,
status: BalanceStatus
) -> Result<Self::Balance, DispatchError>
fn repatriate_reserved( slashed: &AccountId, beneficiary: &AccountId, value: Self::Balance, status: BalanceStatus ) -> Result<Self::Balance, DispatchError>
Moves up to value
from reserved balance of account slashed
to balance of account
beneficiary
. beneficiary
must exist for this to succeed. If it does not, Err
will be
returned. Funds will be placed in either the free
balance or the reserved
balance,
depending on the status
.
As much funds up to value
will be deducted as possible. If this is less than value
,
then Ok(non_zero)
will be returned.