Skip to content

Commit

Permalink
eliminate foreign base
Browse files Browse the repository at this point in the history
  • Loading branch information
@Chralt98
Chralt98 committed Jul 17, 2023
1 parent 90027d7 commit bd48408
Show file tree
Hide file tree
Showing 2 changed files with 20 additions and 28 deletions.
2 changes: 0 additions & 2 deletions Cargo.lock
View file

Some generated files are not rendered by default. Learn more about how customized files appear on GitHub.

46 changes: 20 additions & 26 deletions runtime/common/src/fees.rs
View file
Original file line number Diff line number Diff line change
Expand Up @@ -94,31 +94,28 @@ macro_rules! impl_foreign_fees {
pub(crate) fn calculate_fee(
native_fee: Balance,
fee_factor: Balance,
base: Balance,
) -> Result<Balance, TransactionValidityError> {
let bmul = |a: Balance, b: Balance, base: Balance| -> Option<Balance> {
let bmul = |a: Balance, b: Balance| -> Option<Balance> {
let c0 = a.check_mul_rslt(&b).ok()?;
// The addition of base / 2 before the final division is a way to round to the nearest whole number
// if the fractional part of (a * b) / base is 0.5 or greater, it rounds up, otherwise, it rounds down.
let c1 = c0.check_add_rslt(&base.check_div_rslt(&2).ok()?).ok()?;
c1.check_div_rslt(&base).ok()
let c1 = c0.check_add_rslt(&BASE.check_div_rslt(&2).ok()?).ok()?;
c1.check_div_rslt(&BASE).ok()
};

// example DOT: decimals = 10, base = 10^10 = 10_000_000_000
// assume fee_factor of DOT is 143_120_520
// now assume fee is 1 ZTG (1 * 10^10),
// means DOT fee = 1 * 10^10 * 143_120_520 / dot base (10^10) = 143_120_520
// which is 143_120_520 / 10^10 = 0.0143120520 DOT
let converted_fee = bmul(native_fee, fee_factor, base)
// assume fee_factor of 143_120_520, now divide by BASE (10^10) = 0.0143120520 DOT per ZTG
// keep in mind ZTG BASE is 10_000_000_000, and because fee_factor is below that, you get less DOT per ZTG
// assume fee_factor is 20_000_000_000, then you would get (20_000_000_000 / 10_000_000_000 =) 2 units per ZTG
let converted_fee = bmul(native_fee, fee_factor)
.ok_or(TransactionValidityError::Invalid(InvalidTransaction::Custom(0u8)))?;

Ok(converted_fee)
}

#[cfg(feature = "parachain")]
pub(crate) fn get_fee_factor_and_base(
pub(crate) fn get_fee_factor(
asset_id: CurrencyId,
) -> Result<(Balance, Balance), TransactionValidityError> {
) -> Result<Balance, TransactionValidityError> {
let location = AssetConvert::convert(asset_id);
let metadata = location
.and_then(|loc| {
Expand All @@ -132,10 +129,7 @@ macro_rules! impl_foreign_fees {
.xcm
.fee_factor
.ok_or(TransactionValidityError::Invalid(InvalidTransaction::Custom(3u8)))?;
let base = 10u128
.checked_pow(metadata.decimals)
.ok_or(TransactionValidityError::Invalid(InvalidTransaction::Custom(4u8)))?;
Ok((fee_factor, base))
Ok(fee_factor)
}

pub struct TTCBalanceToAssetBalance;
Expand All @@ -156,8 +150,8 @@ macro_rules! impl_foreign_fees {
}
#[cfg(feature = "parachain")]
Asset::ForeignAsset(_) => {
let (fee_factor, base) = get_fee_factor_and_base(asset_id)?;
let converted_fee = calculate_fee(native_fee, fee_factor, base)?;
let fee_factor = get_fee_factor(asset_id)?;
let converted_fee = calculate_fee(native_fee, fee_factor)?;
Ok(converted_fee)
}
Asset::CategoricalOutcome(_, _)
Expand Down Expand Up @@ -354,20 +348,20 @@ macro_rules! fee_tests {
}

#[test]
fn get_fee_factor_and_base_metadata_not_found() {
fn get_fee_factor_metadata_not_found() {
let mut t: sp_io::TestExternalities =
frame_system::GenesisConfig::default().build_storage::<Runtime>().unwrap().into();
t.execute_with(|| {
#[cfg(feature = "parachain")]
{
// no registering of dot
assert_noop!(get_fee_factor_and_base(Asset::ForeignAsset(0)), TransactionValidityError::Invalid(InvalidTransaction::Custom(2u8)));
assert_noop!(get_fee_factor(Asset::ForeignAsset(0)), TransactionValidityError::Invalid(InvalidTransaction::Custom(2u8)));
}
});
}

#[test]
fn get_fee_factor_and_base_fee_factor_not_found() {
fn get_fee_factor_fee_factor_not_found() {
let mut t: sp_io::TestExternalities =
frame_system::GenesisConfig::default().build_storage::<Runtime>().unwrap().into();
t.execute_with(|| {
Expand All @@ -389,13 +383,13 @@ macro_rules! fee_tests {

assert_ok!(AssetRegistry::register_asset(RuntimeOrigin::root(), meta, Some(dot)));

assert_noop!(get_fee_factor_and_base(dot), TransactionValidityError::Invalid(InvalidTransaction::Custom(3u8)));
assert_noop!(get_fee_factor(dot), TransactionValidityError::Invalid(InvalidTransaction::Custom(3u8)));
}
});
}

#[test]
fn get_fee_factor_and_base_none_location() {
fn get_fee_factor_none_location() {
let mut t: sp_io::TestExternalities =
frame_system::GenesisConfig::default().build_storage::<Runtime>().unwrap().into();
t.execute_with(|| {
Expand All @@ -417,13 +411,13 @@ macro_rules! fee_tests {

assert_ok!(AssetRegistry::register_asset(RuntimeOrigin::root(), meta, Some(non_location_token)));

assert_noop!(get_fee_factor_and_base(non_location_token), TransactionValidityError::Invalid(InvalidTransaction::Custom(2u8)));
assert_noop!(get_fee_factor(non_location_token), TransactionValidityError::Invalid(InvalidTransaction::Custom(2u8)));
}
});
}

#[test]
fn get_fee_factor_and_base_decimals_overflow() {
fn get_fee_factor_decimals_overflow() {
let mut t: sp_io::TestExternalities =
frame_system::GenesisConfig::default().build_storage::<Runtime>().unwrap().into();
t.execute_with(|| {
Expand All @@ -445,7 +439,7 @@ macro_rules! fee_tests {

assert_ok!(AssetRegistry::register_asset(RuntimeOrigin::root(), meta, Some(overflow_currency)));

assert_noop!(get_fee_factor_and_base(overflow_currency), TransactionValidityError::Invalid(InvalidTransaction::Custom(4u8)));
assert_noop!(get_fee_factor(overflow_currency), TransactionValidityError::Invalid(InvalidTransaction::Custom(4u8)));
}
});
}
Expand Down

0 comments on commit bd48408

Please sign in to comment.