use super::{OracleConfig, TokenIndex, TokenPosition}; use crate::accounts_zerocopy::KeyedAccountReader; use crate::error::*; use crate::i80f48::ClampToInt; use crate::state::{oracle, StablePriceModel}; use crate::util; use anchor_lang::prelude::*; use anchor_spl::token::TokenAccount; use derivative::Derivative; use fixed::types::I80F48; use static_assertions::const_assert_eq; use std::mem::size_of; pub const HOUR: i64 = 3600; pub const DAY: i64 = 86400; pub const DAY_I80F48: I80F48 = I80F48::from_bits(86_400 * I80F48::ONE.to_bits()); pub const YEAR_I80F48: I80F48 = I80F48::from_bits(31_536_000 * I80F48::ONE.to_bits()); pub const MINIMUM_MAX_RATE: I80F48 = I80F48::from_bits(I80F48::ONE.to_bits() / 2); #[derive(Derivative)] #[derivative(Debug)] #[account(zero_copy)] pub struct Bank { // ABI: Clients rely on this being at offset 8 pub group: Pubkey, #[derivative(Debug(format_with = "util::format_zero_terminated_utf8_bytes"))] pub name: [u8; 16], pub mint: Pubkey, pub vault: Pubkey, pub oracle: Pubkey, pub oracle_config: OracleConfig, pub stable_price_model: StablePriceModel, /// the index used to scale the value of an IndexedPosition /// TODO: should always be >= 0, add checks? pub deposit_index: I80F48, pub borrow_index: I80F48, /// deposits/borrows for this bank /// /// Note that these may become negative. It's perfectly fine for users to borrow one one bank /// (increasing indexed_borrows there) and paying back on another (possibly decreasing indexed_borrows /// below zero). /// /// The vault amount is not deducable from these values. /// /// These become meaningful when summed over all banks (like in update_index_and_rate). pub indexed_deposits: I80F48, pub indexed_borrows: I80F48, pub index_last_updated: u64, pub bank_rate_last_updated: u64, pub avg_utilization: I80F48, pub adjustment_factor: I80F48, pub util0: I80F48, pub rate0: I80F48, pub util1: I80F48, pub rate1: I80F48, pub max_rate: I80F48, // TODO: add ix/logic to regular send this to DAO pub collected_fees_native: I80F48, pub loan_origination_fee_rate: I80F48, pub loan_fee_rate: I80F48, // This is a _lot_ of bytes (64) - seems unnecessary // (could maybe store them in one byte each, as an informal U1F7? // that could store values between 0-2 and converting to I80F48 would be a cheap expand+shift) pub maint_asset_weight: I80F48, pub init_asset_weight: I80F48, pub maint_liab_weight: I80F48, pub init_liab_weight: I80F48, // a fraction of the price, like 0.05 for a 5% fee during liquidation // // Liquidation always involves two tokens, and the sum of the two configured fees is used. pub liquidation_fee: I80F48, // Collection of all fractions-of-native-tokens that got rounded away pub dust: I80F48, pub flash_loan_token_account_initial: u64, pub flash_loan_approved_amount: u64, // Index into TokenInfo on the group pub token_index: TokenIndex, pub bump: u8, pub mint_decimals: u8, pub bank_num: u32, /// Min fraction of deposits that must remain in the vault when borrowing. pub min_vault_to_deposits_ratio: f64, /// Size in seconds of a net borrows window pub net_borrow_limit_window_size_ts: u64, /// Timestamp at which the last net borrows window started pub last_net_borrows_window_start_ts: u64, /// Net borrow limit per window in quote native; set to -1 to disable. pub net_borrow_limit_per_window_quote: i64, /// Sum of all deposits and borrows in the last window, in native units. pub net_borrows_in_window: i64, /// Soft borrow limit in native quote /// /// Once the borrows on the bank exceed this quote value, init_liab_weight is scaled up. /// Set to f64::MAX to disable. /// /// See scaled_init_liab_weight(). pub borrow_weight_scale_start_quote: f64, /// Limit for collateral of deposits in native quote /// /// Once the deposits in the bank exceed this quote value, init_asset_weight is scaled /// down to keep the total collateral value constant. /// Set to f64::MAX to disable. /// /// See scaled_init_asset_weight(). pub deposit_weight_scale_start_quote: f64, // We have 3 modes // 0 - Off, // 1 - ReduceDepositsReduceBorrows - standard // 2 - ReduceBorrows - borrows can only be reduced, but deposits have no restriction, special case for // force close mode, where liqor should first acquire deposits before closing liqee's borrows pub reduce_only: u8, pub force_close: u8, #[derivative(Debug = "ignore")] pub reserved: [u8; 2118], } const_assert_eq!( size_of::(), 32 + 16 + 32 * 3 + 96 + 288 + 16 * 2 + 16 * 2 + 8 * 2 + 16 + 16 * 6 + 16 * 3 + 16 * 4 + 16 + 16 + 8 + 8 + 2 + 1 + 1 + 4 + 8 + 8 * 4 + 8 + 8 + 1 + 1 + 2118 ); const_assert_eq!(size_of::(), 3064); const_assert_eq!(size_of::() % 8, 0); impl Bank { pub fn from_existing_bank( existing_bank: &Bank, vault: Pubkey, bank_num: u32, bump: u8, ) -> Self { Self { // values that must be reset/changed vault, indexed_deposits: I80F48::ZERO, indexed_borrows: I80F48::ZERO, collected_fees_native: I80F48::ZERO, dust: I80F48::ZERO, flash_loan_approved_amount: 0, flash_loan_token_account_initial: u64::MAX, bump, bank_num, // values that can be copied // these are listed explicitly, so someone must make the decision when a // new field is added! name: existing_bank.name, group: existing_bank.group, mint: existing_bank.mint, oracle: existing_bank.oracle, deposit_index: existing_bank.deposit_index, borrow_index: existing_bank.borrow_index, index_last_updated: existing_bank.index_last_updated, bank_rate_last_updated: existing_bank.bank_rate_last_updated, avg_utilization: existing_bank.avg_utilization, adjustment_factor: existing_bank.adjustment_factor, util0: existing_bank.util0, rate0: existing_bank.rate0, util1: existing_bank.util1, rate1: existing_bank.rate1, max_rate: existing_bank.max_rate, loan_origination_fee_rate: existing_bank.loan_origination_fee_rate, loan_fee_rate: existing_bank.loan_fee_rate, maint_asset_weight: existing_bank.maint_asset_weight, init_asset_weight: existing_bank.init_asset_weight, maint_liab_weight: existing_bank.maint_liab_weight, init_liab_weight: existing_bank.init_liab_weight, liquidation_fee: existing_bank.liquidation_fee, token_index: existing_bank.token_index, mint_decimals: existing_bank.mint_decimals, oracle_config: existing_bank.oracle_config, stable_price_model: StablePriceModel::default(), min_vault_to_deposits_ratio: existing_bank.min_vault_to_deposits_ratio, net_borrow_limit_per_window_quote: existing_bank.net_borrow_limit_per_window_quote, net_borrow_limit_window_size_ts: existing_bank.net_borrow_limit_window_size_ts, last_net_borrows_window_start_ts: existing_bank.last_net_borrows_window_start_ts, net_borrows_in_window: 0, borrow_weight_scale_start_quote: f64::MAX, deposit_weight_scale_start_quote: f64::MAX, reduce_only: 0, force_close: 0, reserved: [0; 2118], } } pub fn name(&self) -> &str { std::str::from_utf8(&self.name) .unwrap() .trim_matches(char::from(0)) } pub fn are_deposits_reduce_only(&self) -> bool { self.reduce_only == 1 } pub fn are_borrows_reduce_only(&self) -> bool { self.reduce_only == 1 || self.reduce_only == 2 } pub fn is_force_close(&self) -> bool { self.force_close == 1 } #[inline(always)] pub fn native_borrows(&self) -> I80F48 { self.borrow_index * self.indexed_borrows } #[inline(always)] pub fn native_deposits(&self) -> I80F48 { self.deposit_index * self.indexed_deposits } /// Prevent borrowing away the full bank vault. /// Keep some in reserve to satisfy non-borrow withdraws. pub fn enforce_min_vault_to_deposits_ratio(&self, vault_ai: &AccountInfo) -> Result<()> { require_keys_eq!(self.vault, vault_ai.key()); let vault = Account::::try_from(vault_ai)?; let vault_amount = vault.amount as f64; let bank_native_deposits = self.native_deposits(); if bank_native_deposits != I80F48::ZERO { let bank_native_deposits: f64 = bank_native_deposits.to_num(); if vault_amount < self.min_vault_to_deposits_ratio * bank_native_deposits { return err!(MangoError::BankBorrowLimitReached).with_context(|| { format!( "vault_amount ({:?}) below min_vault_to_deposits_ratio * bank_native_deposits ({:?})", vault_amount, self.min_vault_to_deposits_ratio * bank_native_deposits, ) }); } } Ok(()) } /// Deposits `native_amount`. /// /// If the token position ends up positive but below one native token and this token /// position isn't marked as in-use, the token balance will be dusted, the position /// will be set to zero and this function returns Ok(false). /// /// native_amount must be >= 0 /// fractional deposits can be relevant during liquidation, for example pub fn deposit( &mut self, position: &mut TokenPosition, native_amount: I80F48, now_ts: u64, ) -> Result { self.deposit_internal_wrapper(position, native_amount, !position.is_in_use(), now_ts) } /// Like `deposit()`, but allows dusting of in-use accounts. /// /// Returns Ok(false) if the position was dusted and was not in-use. pub fn deposit_with_dusting( &mut self, position: &mut TokenPosition, native_amount: I80F48, now_ts: u64, ) -> Result { self.deposit_internal_wrapper(position, native_amount, true, now_ts) .map(|not_dusted| not_dusted || position.is_in_use()) } pub fn deposit_internal_wrapper( &mut self, position: &mut TokenPosition, native_amount: I80F48, allow_dusting: bool, now_ts: u64, ) -> Result { let opening_indexed_position = position.indexed_position; let result = self.deposit_internal(position, native_amount, allow_dusting, now_ts)?; self.update_cumulative_interest(position, opening_indexed_position); Ok(result) } /// Internal function to deposit funds pub fn deposit_internal( &mut self, position: &mut TokenPosition, mut native_amount: I80F48, allow_dusting: bool, now_ts: u64, ) -> Result { require_gte!(native_amount, 0); let native_position = position.native(self); // Adding DELTA to amount/index helps because (amount/index)*index <= amount, but // we want to ensure that users can withdraw the same amount they have deposited, so // (amount/index + delta)*index >= amount is a better guarantee. // Additionally, we require that we don't adjust values if // (native / index) * index == native, because we sometimes call this function with // values that are products of index. let div_rounding_up = |native: I80F48, index: I80F48| { let indexed = native / index; if (indexed * index) < native { indexed + I80F48::DELTA } else { indexed } }; if native_position.is_negative() { // Only account for the borrows we are repaying self.update_net_borrows(native_position.max(-native_amount), now_ts); let new_native_position = native_position + native_amount; let indexed_change = div_rounding_up(native_amount, self.borrow_index); // this is only correct if it's not positive, because it scales the whole amount by borrow_index let new_indexed_value = position.indexed_position + indexed_change; if new_indexed_value.is_negative() { // pay back borrows only, leaving a negative position self.indexed_borrows -= indexed_change; position.indexed_position = new_indexed_value; return Ok(true); } else if new_native_position < I80F48::ONE && allow_dusting { // if there's less than one token deposited, zero the position self.dust += new_native_position; self.indexed_borrows += position.indexed_position; position.indexed_position = I80F48::ZERO; return Ok(false); } // pay back all borrows self.indexed_borrows += position.indexed_position; // position.value is negative position.indexed_position = I80F48::ZERO; // deposit the rest // note: .max(0) because there's a scenario where new_indexed_value == 0 and new_native_position < 0 native_amount = new_native_position.max(I80F48::ZERO); } // add to deposits let indexed_change = div_rounding_up(native_amount, self.deposit_index); self.indexed_deposits += indexed_change; position.indexed_position += indexed_change; Ok(true) } /// Withdraws `native_amount` without applying the loan origination fee. /// /// If the token position ends up positive but below one native token and this token /// position isn't marked as in-use, the token balance will be dusted, the position /// will be set to zero and this function returns Ok(false). /// /// native_amount must be >= 0 /// fractional withdraws can be relevant during liquidation, for example pub fn withdraw_without_fee( &mut self, position: &mut TokenPosition, native_amount: I80F48, now_ts: u64, ) -> Result { let (position_is_active, _) = self.withdraw_internal_wrapper( position, native_amount, false, !position.is_in_use(), now_ts, )?; Ok(position_is_active) } /// Like `withdraw_without_fee()` but allows dusting of in-use token accounts. /// /// Returns Ok(false) on dusted positions that weren't in-use. pub fn withdraw_without_fee_with_dusting( &mut self, position: &mut TokenPosition, native_amount: I80F48, now_ts: u64, ) -> Result { self.withdraw_internal_wrapper(position, native_amount, false, true, now_ts) .map(|(not_dusted, _)| not_dusted || position.is_in_use()) } /// Withdraws `native_amount` while applying the loan origination fee if a borrow is created. /// /// If the token position ends up positive but below one native token and this token /// position isn't marked as in-use, the token balance will be dusted, the position /// will be set to zero and this function returns Ok(false). /// /// native_amount must be >= 0 /// fractional withdraws can be relevant during liquidation, for example pub fn withdraw_with_fee( &mut self, position: &mut TokenPosition, native_amount: I80F48, now_ts: u64, ) -> Result<(bool, I80F48)> { self.withdraw_internal_wrapper(position, native_amount, true, !position.is_in_use(), now_ts) } /// Internal function to withdraw funds fn withdraw_internal_wrapper( &mut self, position: &mut TokenPosition, native_amount: I80F48, with_loan_origination_fee: bool, allow_dusting: bool, now_ts: u64, ) -> Result<(bool, I80F48)> { let opening_indexed_position = position.indexed_position; let res = self.withdraw_internal( position, native_amount, with_loan_origination_fee, allow_dusting, now_ts, ); self.update_cumulative_interest(position, opening_indexed_position); res } /// Internal function to withdraw funds fn withdraw_internal( &mut self, position: &mut TokenPosition, mut native_amount: I80F48, with_loan_origination_fee: bool, allow_dusting: bool, now_ts: u64, ) -> Result<(bool, I80F48)> { require_gte!(native_amount, 0); let native_position = position.native(self); if native_position.is_positive() { let new_native_position = native_position - native_amount; if !new_native_position.is_negative() { // withdraw deposits only if new_native_position < I80F48::ONE && allow_dusting { // zero the account collecting the leftovers in `dust` self.dust += new_native_position; self.indexed_deposits -= position.indexed_position; position.indexed_position = I80F48::ZERO; return Ok((false, I80F48::ZERO)); } else { // withdraw some deposits leaving a positive balance let indexed_change = native_amount / self.deposit_index; self.indexed_deposits -= indexed_change; position.indexed_position -= indexed_change; return Ok((true, I80F48::ZERO)); } } // withdraw all deposits self.indexed_deposits -= position.indexed_position; position.indexed_position = I80F48::ZERO; // borrow the rest native_amount = -new_native_position; } let mut loan_origination_fee = I80F48::ZERO; if with_loan_origination_fee { loan_origination_fee = self.loan_origination_fee_rate * native_amount; self.collected_fees_native += loan_origination_fee; native_amount += loan_origination_fee; } // add to borrows let indexed_change = native_amount / self.borrow_index; self.indexed_borrows += indexed_change; position.indexed_position -= indexed_change; // net borrows requires updating in only this case, since other branches of the method deal with // withdraws and not borrows self.update_net_borrows(native_amount, now_ts); Ok((true, loan_origination_fee)) } // withdraw the loan origination fee for a borrow that happenend earlier pub fn withdraw_loan_origination_fee( &mut self, position: &mut TokenPosition, already_borrowed_native_amount: I80F48, now_ts: u64, ) -> Result<(bool, I80F48)> { let loan_origination_fee = self.loan_origination_fee_rate * already_borrowed_native_amount; self.collected_fees_native += loan_origination_fee; let (position_is_active, _) = self.withdraw_internal_wrapper( position, loan_origination_fee, false, !position.is_in_use(), now_ts, )?; Ok((position_is_active, loan_origination_fee)) } /// Change a position without applying the loan origination fee pub fn change_without_fee( &mut self, position: &mut TokenPosition, native_amount: I80F48, now_ts: u64, ) -> Result { if native_amount >= 0 { self.deposit(position, native_amount, now_ts) } else { self.withdraw_without_fee(position, -native_amount, now_ts) } } /// Change a position, while taking the loan origination fee into account pub fn change_with_fee( &mut self, position: &mut TokenPosition, native_amount: I80F48, now_ts: u64, ) -> Result<(bool, I80F48)> { if native_amount >= 0 { Ok((self.deposit(position, native_amount, now_ts)?, I80F48::ZERO)) } else { self.withdraw_with_fee(position, -native_amount, now_ts) } } /// Update the bank's net_borrows fields. /// /// If oracle_price is set, also do a net borrows check and error if the threshold is exceeded. pub fn update_net_borrows(&mut self, native_amount: I80F48, now_ts: u64) { let in_new_window = now_ts >= self.last_net_borrows_window_start_ts + self.net_borrow_limit_window_size_ts; let amount = native_amount.ceil().clamp_to_i64(); self.net_borrows_in_window = if in_new_window { // reset to latest window self.last_net_borrows_window_start_ts = now_ts / self.net_borrow_limit_window_size_ts * self.net_borrow_limit_window_size_ts; amount } else { self.net_borrows_in_window + amount }; } pub fn check_net_borrows(&self, oracle_price: I80F48) -> Result<()> { if self.net_borrows_in_window < 0 || self.net_borrow_limit_per_window_quote < 0 { return Ok(()); } let price = oracle_price.max(self.stable_price()); let net_borrows_quote = price .checked_mul_int(self.net_borrows_in_window.into()) .unwrap(); if net_borrows_quote > self.net_borrow_limit_per_window_quote { return Err(error_msg_typed!(MangoError::BankNetBorrowsLimitReached, "net_borrows_in_window ({:?}) valued at ({:?} exceed net_borrow_limit_per_window_quote ({:?}) for last_net_borrows_window_start_ts ({:?}) ", self.net_borrows_in_window, net_borrows_quote, self.net_borrow_limit_per_window_quote, self.last_net_borrows_window_start_ts )); } Ok(()) } pub fn update_cumulative_interest( &self, position: &mut TokenPosition, opening_indexed_position: I80F48, ) { if opening_indexed_position.is_positive() { let interest = ((self.deposit_index - position.previous_index) * opening_indexed_position) .to_num::(); position.cumulative_deposit_interest += interest; } else { let interest = ((self.borrow_index - position.previous_index) * opening_indexed_position) .to_num::(); position.cumulative_borrow_interest -= interest; } if position.indexed_position.is_positive() { position.previous_index = self.deposit_index } else { position.previous_index = self.borrow_index } } pub fn compute_index( &self, indexed_total_deposits: I80F48, indexed_total_borrows: I80F48, diff_ts: I80F48, ) -> Result<(I80F48, I80F48, I80F48, I80F48, I80F48)> { // compute index based on utilization let native_total_deposits = self.deposit_index * indexed_total_deposits; let native_total_borrows = self.borrow_index * indexed_total_borrows; // This will be >= 0, but can also be > 1 let instantaneous_utilization = if native_total_deposits == I80F48::ZERO { I80F48::ZERO } else { native_total_borrows / native_total_deposits }; let borrow_rate = self.compute_interest_rate(instantaneous_utilization); // We want to grant depositors a rate that exactly matches the amount that is // taken from borrowers. That means: // (new_deposit_index - old_deposit_index) * indexed_deposits // = (new_borrow_index - old_borrow_index) * indexed_borrows // with // new_deposit_index = old_deposit_index * (1 + deposit_rate) and // new_borrow_index = old_borrow_index * (1 * borrow_rate) // we have // deposit_rate = borrow_rate * (old_borrow_index * indexed_borrows) / (old_deposit_index * indexed_deposits) // and the latter factor is exactly instantaneous_utilization. let deposit_rate = borrow_rate * instantaneous_utilization; // The loan fee rate is not distributed to depositors. let borrow_rate_with_fees = borrow_rate + self.loan_fee_rate; let borrow_fees = native_total_borrows * self.loan_fee_rate * diff_ts / YEAR_I80F48; let borrow_index = (self.borrow_index * borrow_rate_with_fees * diff_ts) / YEAR_I80F48 + self.borrow_index; let deposit_index = (self.deposit_index * deposit_rate * diff_ts) / YEAR_I80F48 + self.deposit_index; Ok(( deposit_index, borrow_index, borrow_fees, borrow_rate, deposit_rate, )) } /// returns the current interest rate in APR #[inline(always)] pub fn compute_interest_rate(&self, utilization: I80F48) -> I80F48 { Bank::interest_rate_curve_calculator( utilization, self.util0, self.rate0, self.util1, self.rate1, self.max_rate, ) } /// calcualtor function that can be used to compute an interest /// rate based on the given parameters #[inline(always)] pub fn interest_rate_curve_calculator( utilization: I80F48, util0: I80F48, rate0: I80F48, util1: I80F48, rate1: I80F48, max_rate: I80F48, ) -> I80F48 { if utilization <= util0 { let slope = rate0 / util0; slope * utilization } else if utilization <= util1 { let extra_util = utilization - util0; let slope = (rate1 - rate0) / (util1 - util0); rate0 + slope * extra_util } else { let extra_util = utilization - util1; let slope = (max_rate - rate1) / (I80F48::ONE - util1); rate1 + slope * extra_util } } // compute new avg utilization pub fn compute_new_avg_utilization( &self, indexed_total_deposits: I80F48, indexed_total_borrows: I80F48, now_ts: u64, ) -> I80F48 { if now_ts == 0 { return I80F48::ZERO; } let native_total_deposits = self.deposit_index * indexed_total_deposits; let native_total_borrows = self.borrow_index * indexed_total_borrows; let instantaneous_utilization = if native_total_deposits == I80F48::ZERO { I80F48::ZERO } else { native_total_borrows / native_total_deposits }; // Compute a time-weighted average since bank_rate_last_updated. let previous_avg_time = I80F48::from_num(self.index_last_updated - self.bank_rate_last_updated); let diff_ts = I80F48::from_num(now_ts - self.index_last_updated); let new_avg_time = I80F48::from_num(now_ts - self.bank_rate_last_updated); if new_avg_time <= 0 { return instantaneous_utilization; } (self.avg_utilization * previous_avg_time + instantaneous_utilization * diff_ts) / new_avg_time } // computes new optimal rates and max rate pub fn compute_rates(&self) -> (I80F48, I80F48, I80F48) { // interest rate legs 2 and 3 are seen as punitive legs, encouraging utilization to move towards optimal utilization // lets choose util0 as optimal utilization and 0 to utli0 as the leg where we want the utlization to preferably be let optimal_util = self.util0; // use avg_utilization and not instantaneous_utilization so that rates cannot be manipulated easily let avg_util = self.avg_utilization; // move rates up when utilization is above optimal utilization, and vice versa // util factor is between -1 (avg util = 0) and +1 (avg util = 100%) let util_factor = if avg_util > optimal_util { (avg_util - optimal_util) / (I80F48::ONE - optimal_util) } else { (avg_util - optimal_util) / optimal_util }; let adjustment = I80F48::ONE + self.adjustment_factor * util_factor; // 1. irrespective of which leg current utilization is in, update all rates // 2. only update rates as long as new adjusted rates are above MINIMUM_MAX_RATE, // since we don't want to fall to such low rates that it would take a long time to // recover to high rates if utilization suddently increases to a high value if (self.max_rate * adjustment) > MINIMUM_MAX_RATE { ( (self.rate0 * adjustment), (self.rate1 * adjustment), (self.max_rate * adjustment), ) } else { (self.rate0, self.rate1, self.max_rate) } } pub fn oracle_price( &self, oracle_acc: &impl KeyedAccountReader, staleness_slot: Option, ) -> Result { require_keys_eq!(self.oracle, *oracle_acc.key()); let (price, _) = oracle::oracle_price_and_state( oracle_acc, &self.oracle_config, self.mint_decimals, staleness_slot, )?; Ok(price) } pub fn stable_price(&self) -> I80F48 { I80F48::from_num(self.stable_price_model.stable_price) } /// Returns the init asset weight, adjusted for the number of deposits on the bank. /// /// If max_collateral is 0, then the scaled init weight will be 0. /// Otherwise the weight is unadjusted until max_collateral and then scaled down /// such that scaled_init_weight * deposits remains constant. #[inline(always)] pub fn scaled_init_asset_weight(&self, price: I80F48) -> I80F48 { if self.deposit_weight_scale_start_quote == f64::MAX { return self.init_asset_weight; } // The next line is around 500 CU let deposits_quote = self.native_deposits().to_num::() * price.to_num::(); if deposits_quote <= self.deposit_weight_scale_start_quote { self.init_asset_weight } else { // The next line is around 500 CU let scale = self.deposit_weight_scale_start_quote / deposits_quote; self.init_asset_weight * I80F48::from_num(scale) } } #[inline(always)] pub fn scaled_init_liab_weight(&self, price: I80F48) -> I80F48 { if self.borrow_weight_scale_start_quote == f64::MAX { return self.init_liab_weight; } // The next line is around 500 CU let borrows_quote = self.native_borrows().to_num::() * price.to_num::(); if borrows_quote <= self.borrow_weight_scale_start_quote { self.init_liab_weight } else if self.borrow_weight_scale_start_quote == 0.0 { // TODO: will certainly cause overflow, so it's not exactly what is needed; health should be -MAX? // maybe handling this case isn't super helpful? I80F48::MAX } else { // The next line is around 500 CU let scale = borrows_quote / self.borrow_weight_scale_start_quote; self.init_liab_weight * I80F48::from_num(scale) } } } #[macro_export] macro_rules! bank_seeds { ( $bank:expr ) => { &[ b"Bank".as_ref(), $bank.group.as_ref(), $bank.token_index.to_le_bytes(), &bank.bank_num.to_le_bytes(), &[$bank.bump], ] }; } pub use bank_seeds; #[cfg(test)] mod tests { use bytemuck::Zeroable; use std::cmp::min; use super::*; #[test] pub fn change() -> Result<()> { let epsilon = I80F48::from_bits(1); let cases = [ (-10.1, 1), (-10.1, 10), (-10.1, 11), (-10.1, 50), (-10.0, 10), (-10.0, 11), (-2.0, 2), (-2.0, 3), (-0.1, 1), (0.0, 1), (0.1, 1), (10.1, -1), (10.1, -9), (10.1, -10), (10.1, -11), (10.0, -10), (10.0, -9), (1.0, -1), (0.1, -1), (0.0, -1), (-0.1, -1), (-1.1, -10), ]; for is_in_use in [false, true] { for (start, change) in cases { println!( "testing: in use: {}, start: {}, change: {}", is_in_use, start, change ); // // SETUP // let mut bank = Bank::zeroed(); bank.net_borrow_limit_window_size_ts = 1; // dummy bank.net_borrow_limit_per_window_quote = i64::MAX; // max since we don't want this to interfere bank.deposit_index = I80F48::from_num(100.0); bank.borrow_index = I80F48::from_num(10.0); bank.loan_origination_fee_rate = I80F48::from_num(0.1); let indexed = |v: I80F48, b: &Bank| { if v > 0 { v / b.deposit_index } else { v / b.borrow_index } }; let mut account = TokenPosition { indexed_position: I80F48::ZERO, token_index: 0, in_use_count: u8::from(is_in_use), cumulative_deposit_interest: 0.0, cumulative_borrow_interest: 0.0, previous_index: I80F48::ZERO, padding: Default::default(), reserved: [0; 128], }; account.indexed_position = indexed(I80F48::from_num(start), &bank); if start >= 0.0 { bank.indexed_deposits = account.indexed_position; } else { bank.indexed_borrows = -account.indexed_position; } // get the rounded start value let start_native = account.native(&bank); // // TEST // let change = I80F48::from(change); let dummy_now_ts = 1 as u64; let dummy_price = I80F48::ZERO; let (is_active, _) = bank.change_with_fee(&mut account, change, dummy_now_ts)?; let mut expected_native = start_native + change; if expected_native >= 0.0 && expected_native < 1.0 && !is_in_use { assert!(!is_active); assert_eq!(bank.dust, expected_native); expected_native = I80F48::ZERO; } else { assert!(is_active); assert_eq!(bank.dust, I80F48::ZERO); } if change < 0 && expected_native < 0 { let new_borrow = -(expected_native - min(start_native, I80F48::ZERO)); expected_native -= new_borrow * bank.loan_origination_fee_rate; } let expected_indexed = indexed(expected_native, &bank); // at most one epsilon error in the resulting indexed value assert!((account.indexed_position - expected_indexed).abs() <= epsilon); if account.indexed_position.is_positive() { assert_eq!(bank.indexed_deposits, account.indexed_position); assert_eq!(bank.indexed_borrows, I80F48::ZERO); } else { assert_eq!(bank.indexed_deposits, I80F48::ZERO); assert_eq!(bank.indexed_borrows, -account.indexed_position); } } } Ok(()) } #[test] fn test_compute_new_avg_utilization() { let mut bank = Bank::zeroed(); bank.deposit_index = I80F48::from_num(1.0); bank.borrow_index = I80F48::from_num(1.0); bank.bank_rate_last_updated = 1000; bank.index_last_updated = 1000; let compute_new_avg_utilization_runner = |bank: &mut Bank, utilization: I80F48, now_ts: u64| { bank.avg_utilization = bank.compute_new_avg_utilization(I80F48::ONE, utilization, now_ts); bank.index_last_updated = now_ts; }; compute_new_avg_utilization_runner(&mut bank, I80F48::ZERO, 1000); assert_eq!(bank.avg_utilization, I80F48::ZERO); compute_new_avg_utilization_runner(&mut bank, I80F48::from_num(0.5), 1010); assert!((bank.avg_utilization - I80F48::from_num(0.5)).abs() < 0.0001); compute_new_avg_utilization_runner(&mut bank, I80F48::from_num(0.8), 1015); assert!((bank.avg_utilization - I80F48::from_num(0.6)).abs() < 0.0001); compute_new_avg_utilization_runner(&mut bank, I80F48::ONE, 1020); assert!((bank.avg_utilization - I80F48::from_num(0.7)).abs() < 0.0001); bank.bank_rate_last_updated = 1020; compute_new_avg_utilization_runner(&mut bank, I80F48::ONE, 1040); assert_eq!(bank.avg_utilization, I80F48::ONE); } #[test] pub fn test_net_borrows() -> Result<()> { let mut bank = Bank::zeroed(); bank.net_borrow_limit_window_size_ts = 100; bank.net_borrow_limit_per_window_quote = 1000; bank.deposit_index = I80F48::from_num(100.0); bank.borrow_index = I80F48::from_num(100.0); let price = I80F48::from(2); let mut account = TokenPosition::default(); bank.change_without_fee(&mut account, I80F48::from(100), 0) .unwrap(); assert_eq!(bank.net_borrows_in_window, 0); bank.change_without_fee(&mut account, I80F48::from(-100), 0) .unwrap(); assert_eq!(bank.net_borrows_in_window, 0); account = TokenPosition::default(); bank.change_without_fee(&mut account, I80F48::from(10), 0) .unwrap(); bank.change_without_fee(&mut account, I80F48::from(-110), 0) .unwrap(); assert_eq!(bank.net_borrows_in_window, 100); bank.change_without_fee(&mut account, I80F48::from(50), 0) .unwrap(); assert_eq!(bank.net_borrows_in_window, 50); bank.change_without_fee(&mut account, I80F48::from(100), 0) .unwrap(); assert_eq!(bank.net_borrows_in_window, 1); // rounding account = TokenPosition::default(); bank.net_borrows_in_window = 0; bank.change_without_fee(&mut account, I80F48::from(-450), 0) .unwrap(); bank.change_without_fee(&mut account, I80F48::from(-51), 0) .unwrap(); bank.check_net_borrows(price).unwrap_err(); account = TokenPosition::default(); bank.net_borrows_in_window = 0; bank.change_without_fee(&mut account, I80F48::from(-450), 0) .unwrap(); bank.change_without_fee(&mut account, I80F48::from(-50), 0) .unwrap(); bank.change_without_fee(&mut account, I80F48::from(-50), 101) .unwrap(); Ok(()) } }