pezkuwichain/pezkuwi-subxt
1
0
Fork 0
mirror of https://github.com/pezkuwichain/pezkuwi-subxt.git synced 2026-06-13 07:01:05 +00:00
Code Issues Packages Projects Releases Wiki Activity

Introduce ReservableCurrency Trait in Balances Module (#2124)

Browse Source 
* Introduce `ReservableCurrency`

* Update Docs for `ReservableCurrency`

* Update Tests

* Bump spec and rebuild wasm

* Extra: Add a note to `slash()`

Discussion in Riot clarified the behavior of `slash()` and `can_slash()`. Trying to sneak clarifying comments about it into this PR

* Update lib.rs

* Don't drop the periods!

CC @shawntabrizi
This commit is contained in:
Shawn Tabrizi
2019-03-27 16:48:38 +01:00
committed by Gav Wood
parent b32653d0a8
commit 1c1609342c
10 changed files with 66 additions and 50 deletions
Download Patch File Download Diff File Expand all files Collapse all files
substrate/srml/support/src/traits.rs
+30 -26
View File
@@ -249,10 +249,6 @@ pub trait Currency<AccountId> {
/// balance changes in the meantime and only the reserved balance is not taken into account.
fn can_slash(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.
fn can_reserve(who: &AccountId, value: Self::Balance) -> bool;
/// The total amount of issuance in the system.
fn total_issuance() -> Self::Balance;
@@ -273,19 +269,6 @@ pub trait Currency<AccountId> {
/// collapsed to zero if it ever becomes less than `ExistentialDeposit`.
fn free_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.
///
/// When this balance falls below the value of `ExistentialDeposit`, then this 'reserve account'
/// is deleted: specifically, `ReservedBalance`.
///
/// `system::AccountNonce` is also deleted if `FreeBalance` is also zero (it also gets
/// collapsed to zero if it ever becomes less than `ExistentialDeposit`.
fn reserved_balance(who: &AccountId) -> Self::Balance;
/// Returns `Ok` iff the account is able to make a withdrawal of the given amount
/// for the given reason. Basically, it's just a dry-run of `withdraw`.
///
@@ -361,6 +344,36 @@ pub trait Currency<AccountId> {
SignedImbalance<Self::Balance, Self::PositiveImbalance>,
UpdateBalanceOutcome,
);
}
/// A currency where funds can be reserved from the user.
pub trait ReservableCurrency<AccountId>: Currency<AccountId> {
/// Same result as `reserve(who, value)` (but without the side-effects) assuming there
/// are no balance changes in the meantime.
fn can_reserve(who: &AccountId, value: Self::Balance) -> bool;
/// 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 a non-zero second item will be returned.
fn slash_reserved(
who: &AccountId,
value: Self::Balance
) -> (Self::NegativeImbalance, 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.
///
/// When this balance falls below the value of `ExistentialDeposit`, then this 'reserve account'
/// is deleted: specifically, `ReservedBalance`.
///
/// `system::AccountNonce` is also deleted if `FreeBalance` is also zero (it also gets
/// collapsed to zero if it ever becomes less than `ExistentialDeposit`.
fn reserved_balance(who: &AccountId) -> Self::Balance;
/// Moves `value` from balance to reserved balance.
///
@@ -380,15 +393,6 @@ pub trait Currency<AccountId> {
/// invoke `on_reserved_too_low` and could reap the account.
fn unreserve(who: &AccountId, value: Self::Balance) -> 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 a non-zero second item will be returned.
fn slash_reserved(
who: &AccountId,
value: Self::Balance
) -> (Self::NegativeImbalance, Self::Balance);
/// Moves up to `value` from reserved balance of account `slashed` to free balance of account
/// `beneficiary`. `beneficiary` must exist for this to succeed. If it does not, `Err` will be
/// returned.