diff --git a/contracts/payloads/IGP26/PayloadIGP26.sol b/contracts/payloads/IGP26/PayloadIGP26.sol index 4128054..e3b36b3 100644 --- a/contracts/payloads/IGP26/PayloadIGP26.sol +++ b/contracts/payloads/IGP26/PayloadIGP26.sol @@ -3,6 +3,7 @@ pragma experimental ABIEncoderV2; import { BigMathMinified } from "./libraries/bigMathMinified.sol"; import { LiquiditySlotsLink } from "./libraries/liquiditySlotsLink.sol"; +import { LiquidityCalcs } from "./libraries/liquidityCalcs.sol"; interface IGovernorBravo { function _acceptAdmin() external; @@ -360,6 +361,33 @@ interface IFluidOracle { function getExchangeRateLiquidate() external view returns (uint256 exchangeRate_); } +interface IFluidReserveContract { + function isRebalancer(address user) external returns (bool); + + function rebalanceFToken(address protocol_) external; + + function rebalanceVault(address protocol_) external; + + function transferFunds(address token_) external; + + function getProtocolTokens(address protocol_) external; + + function updateAuth(address auth_, bool isAuth_) external; + + function updateRebalancer(address rebalancer_, bool isRebalancer_) external; + + function approve( + address[] memory protocols_, + address[] memory tokens_, + uint256[] memory amounts_ + ) external; + + function revoke( + address[] memory protocols_, + address[] memory tokens_ + ) external; +} + contract PayloadIGP26 { uint256 public constant PROPOSAL_ID = 26; @@ -386,6 +414,8 @@ contract PayloadIGP26 { IFluidLiquidityAdmin(0x52Aa899454998Be5b000Ad077a46Bbe360F4e497); IFluidVaultT1Factory public constant VAULT_T1_FACTORY = IFluidVaultT1Factory(0x324c5Dc1fC42c7a4D43d92df1eBA58a54d13Bf2d); + IFluidReserveContract public constant FLUID_RESERVE = + IFluidReserveContract(0x264786EF916af64a1DB19F513F24a3681734ce92); uint256 internal constant X8 = 0xff; uint256 internal constant X10 = 0x3ff; @@ -471,17 +501,27 @@ contract PayloadIGP26 { | Proposal Payload Helpers | |__________________________________*/ - function getUserSupplyData( + function getUserSupplyDataAndSetLimits( address token_, - address user_ + address user_, + uint256 withdrawalLimit ) internal view returns(AdminModuleStructs.UserSupplyConfig memory config_) { - bytes32 _LIQUDITY_PROTOCOL_SUPPLY_SLOT = LiquiditySlotsLink.calculateDoubleMappingStorageSlot( - LiquiditySlotsLink.LIQUIDITY_USER_SUPPLY_DOUBLE_MAPPING_SLOT, - user_, - token_ + uint256 userSupplyData_ = LIQUIDITY.readFromStorage( + LiquiditySlotsLink.calculateDoubleMappingStorageSlot( + LiquiditySlotsLink.LIQUIDITY_USER_SUPPLY_DOUBLE_MAPPING_SLOT, + user_, + token_ + ) + ); + + (uint256 supplyExchangePrice, ) = LiquidityCalcs.calcExchangePrices( + LIQUIDITY.readFromStorage( + LiquiditySlotsLink.calculateMappingStorageSlot( + LiquiditySlotsLink.LIQUIDITY_EXCHANGE_PRICES_MAPPING_SLOT, + token_ + ) + ) ); - - uint256 userSupplyData_ = LIQUIDITY.readFromStorage(_LIQUDITY_PROTOCOL_SUPPLY_SLOT); config_ = AdminModuleStructs.UserSupplyConfig({ user: user_, @@ -489,25 +529,32 @@ contract PayloadIGP26 { mode: uint8(userSupplyData_ & 1), expandPercent: (userSupplyData_ >> LiquiditySlotsLink.BITS_USER_SUPPLY_EXPAND_PERCENT) & X14, expandDuration: (userSupplyData_ >> LiquiditySlotsLink.BITS_USER_SUPPLY_EXPAND_DURATION) & X24, - baseWithdrawalLimit: BigMathMinified.fromBigNumber( - (userSupplyData_ >> LiquiditySlotsLink.BITS_USER_SUPPLY_BASE_WITHDRAWAL_LIMIT) & X18, - DEFAULT_EXPONENT_SIZE, - DEFAULT_EXPONENT_MASK - ) + baseWithdrawalLimit: withdrawalLimit * 1e12 / supplyExchangePrice }); } - function getUserBorrowData( + function getUserBorrowDataAndSetLimits( address token_, - address user_ + address user_, + uint256 baseLimit, + uint256 maxLimit ) internal view returns(AdminModuleStructs.UserBorrowConfig memory config_) { - bytes32 _LIQUDITY_PROTOCOL_BORROW_SLOT = LiquiditySlotsLink.calculateDoubleMappingStorageSlot( - LiquiditySlotsLink.LIQUIDITY_USER_BORROW_DOUBLE_MAPPING_SLOT, - user_, - token_ + uint256 userBorrowData_ = LIQUIDITY.readFromStorage( + LiquiditySlotsLink.calculateDoubleMappingStorageSlot( + LiquiditySlotsLink.LIQUIDITY_USER_BORROW_DOUBLE_MAPPING_SLOT, + user_, + token_ + ) ); - uint256 userBorrowData_ = LIQUIDITY.readFromStorage(_LIQUDITY_PROTOCOL_BORROW_SLOT); + (, uint256 borrowExchangePrice) = LiquidityCalcs.calcExchangePrices( + LIQUIDITY.readFromStorage( + LiquiditySlotsLink.calculateMappingStorageSlot( + LiquiditySlotsLink.LIQUIDITY_EXCHANGE_PRICES_MAPPING_SLOT, + token_ + ) + ) + ); config_ = AdminModuleStructs.UserBorrowConfig({ user: user_, @@ -515,20 +562,12 @@ contract PayloadIGP26 { mode: uint8(userBorrowData_ & 1), expandPercent: (userBorrowData_ >> LiquiditySlotsLink.BITS_USER_BORROW_EXPAND_PERCENT) & X14, expandDuration: (userBorrowData_ >> LiquiditySlotsLink.BITS_USER_BORROW_EXPAND_DURATION) & X24, - baseDebtCeiling: BigMathMinified.fromBigNumber( - (userBorrowData_ >> LiquiditySlotsLink.BITS_USER_BORROW_BASE_BORROW_LIMIT) & X18, - DEFAULT_EXPONENT_SIZE, - DEFAULT_EXPONENT_MASK - ), - maxDebtCeiling: BigMathMinified.fromBigNumber( - (userBorrowData_ >> LiquiditySlotsLink.BITS_USER_BORROW_MAX_BORROW_LIMIT) & X18, - DEFAULT_EXPONENT_SIZE, - DEFAULT_EXPONENT_MASK - ) + baseDebtCeiling: baseLimit * 1e12 / borrowExchangePrice, + maxDebtCeiling: maxLimit * 1e12 / borrowExchangePrice }); } - function getAllowance(address token) internal pure returns (uint256, uint256, ) { + function getAllowance(address token) internal pure returns (uint256, uint256, uint256) { if (token == ETH_ADDRESS) { return (3 * 1e18, 4 * 1e18, 0.03 * 1e18); } else if (token == wstETH_ADDRESS) { @@ -604,13 +643,15 @@ contract PayloadIGP26 { AdminModuleStructs.UserSupplyConfig[] memory configs_ = new AdminModuleStructs.UserSupplyConfig[](1); - configs_[0] = getUserSupplyData(newConstants.supplyToken, oldVaultAddress); - - (uint256 baseAllowance, , supplyAllowance) = getAllowance(newConstants.supplyToken); + (uint256 baseAllowance, , uint256 supplyAllowance) = getAllowance(newConstants.supplyToken); amounts[0] = supplyAllowance; - configs_[0].baseWithdrawalLimit = baseAllowance; + configs_[0] = getUserSupplyDataAndSetLimits( + newConstants.supplyToken, + oldVaultAddress, + baseAllowance + ); LIQUIDITY.updateUserSupplyConfigs(configs_); } @@ -620,23 +661,17 @@ contract PayloadIGP26 { AdminModuleStructs.UserBorrowConfig[] memory configs_ = new AdminModuleStructs.UserBorrowConfig[](1); - configs_[0] = getUserBorrowData(newConstants.borrowToken, oldVaultAddress); (uint256 baseAllowance, uint256 maxAllowance, uint256 borrowAllowance) = getAllowance(newConstants.borrowToken); amounts[1] = borrowAllowance; - uint256 exchangePriceAndConfig_ = LIQUIDITY.readFromStorage( - LiquiditySlotsLink.calculateMappingStorageSlot( - LiquiditySlotsLink.LIQUIDITY_EXCHANGE_PRICES_MAPPING_SLOT, - newConstants.borrowToken - ) + configs_[0] = getUserBorrowDataAndSetLimits( + newConstants.borrowToken, + oldVaultAddress, + baseAllowance, + maxAllowance ); - (uint256 supplyExchangePrice, uint256 borrowExchangePrice) = LiquidityCalcs.calcExchangePrices(exchangePriceAndConfig_); - - configs_[0].baseDebtCeiling = baseAllowance; - configs_[0].maxDebtCeiling = maxAllowance; - LIQUIDITY.updateUserBorrowConfigs(configs_); } diff --git a/contracts/payloads/IGP26/libraries/errorTypes.sol b/contracts/payloads/IGP26/libraries/errorTypes.sol new file mode 100644 index 0000000..00cd2ec --- /dev/null +++ b/contracts/payloads/IGP26/libraries/errorTypes.sol @@ -0,0 +1,27 @@ +// SPDX-License-Identifier: BUSL-1.1 +pragma solidity 0.8.21; + +library LibsErrorTypes { + /***********************************| + | LiquidityCalcs | + |__________________________________*/ + + /// @notice thrown when supply or borrow exchange price is zero at calc token data (token not configured yet) + uint256 internal constant LiquidityCalcs__ExchangePriceZero = 70001; + + /// @notice thrown when rate data is set to a version that is not implemented + uint256 internal constant LiquidityCalcs__UnsupportedRateVersion = 70002; + + /// @notice thrown when the calculated borrow rate turns negative. This should never happen. + uint256 internal constant LiquidityCalcs__BorrowRateNegative = 70003; + + /***********************************| + | SafeTransfer | + |__________________________________*/ + + /// @notice thrown when safe transfer from for an ERC20 fails + uint256 internal constant SafeTransfer__TransferFromFailed = 71001; + + /// @notice thrown when safe transfer for an ERC20 fails + uint256 internal constant SafeTransfer__TransferFailed = 71002; +} \ No newline at end of file diff --git a/contracts/payloads/IGP26/libraries/liquidityCalcs.sol b/contracts/payloads/IGP26/libraries/liquidityCalcs.sol new file mode 100644 index 0000000..9cccdb5 --- /dev/null +++ b/contracts/payloads/IGP26/libraries/liquidityCalcs.sol @@ -0,0 +1,686 @@ +// SPDX-License-Identifier: BUSL-1.1 +pragma solidity 0.8.21; + +import { LibsErrorTypes as ErrorTypes } from "./errorTypes.sol"; +import { LiquiditySlotsLink } from "./liquiditySlotsLink.sol"; +import { BigMathMinified } from "./bigMathMinified.sol"; + +/// @notice implements calculation methods used for Fluid liquidity such as updated exchange prices, +/// borrow rate, withdrawal / borrow limits, revenue amount. +library LiquidityCalcs { + error FluidLiquidityCalcsError(uint256 errorId_); + + /// @notice emitted if the calculated borrow rate surpassed max borrow rate (16 bits) and was capped at maximum value 65535 + event BorrowRateMaxCap(); + + /// @dev constants as from Liquidity variables.sol + uint256 internal constant EXCHANGE_PRICES_PRECISION = 1e12; + + /// @dev Ignoring leap years + uint256 internal constant SECONDS_PER_YEAR = 365 days; + // constants used for BigMath conversion from and to storage + uint256 internal constant DEFAULT_EXPONENT_SIZE = 8; + uint256 internal constant DEFAULT_EXPONENT_MASK = 0xFF; + + uint256 internal constant FOUR_DECIMALS = 1e4; + uint256 internal constant TWELVE_DECIMALS = 1e12; + uint256 internal constant X14 = 0x3fff; + uint256 internal constant X15 = 0x7fff; + uint256 internal constant X16 = 0xffff; + uint256 internal constant X18 = 0x3ffff; + uint256 internal constant X24 = 0xffffff; + uint256 internal constant X33 = 0x1ffffffff; + uint256 internal constant X64 = 0xffffffffffffffff; + + /////////////////////////////////////////////////////////////////////////// + ////////// CALC EXCHANGE PRICES ///////// + /////////////////////////////////////////////////////////////////////////// + + /// @dev calculates interest (exchange prices) for a token given its' exchangePricesAndConfig from storage. + /// @param exchangePricesAndConfig_ exchange prices and config packed uint256 read from storage + /// @return supplyExchangePrice_ updated supplyExchangePrice + /// @return borrowExchangePrice_ updated borrowExchangePrice + function calcExchangePrices( + uint256 exchangePricesAndConfig_ + ) internal view returns (uint256 supplyExchangePrice_, uint256 borrowExchangePrice_) { + // Extracting exchange prices + supplyExchangePrice_ = + (exchangePricesAndConfig_ >> LiquiditySlotsLink.BITS_EXCHANGE_PRICES_SUPPLY_EXCHANGE_PRICE) & + X64; + borrowExchangePrice_ = + (exchangePricesAndConfig_ >> LiquiditySlotsLink.BITS_EXCHANGE_PRICES_BORROW_EXCHANGE_PRICE) & + X64; + + if (supplyExchangePrice_ == 0 || borrowExchangePrice_ == 0) { + revert FluidLiquidityCalcsError(ErrorTypes.LiquidityCalcs__ExchangePriceZero); + } + + uint256 temp_ = exchangePricesAndConfig_ & X16; // temp_ = borrowRate + + unchecked { + // last timestamp can not be > current timestamp + uint256 secondsSinceLastUpdate_ = block.timestamp - + ((exchangePricesAndConfig_ >> LiquiditySlotsLink.BITS_EXCHANGE_PRICES_LAST_TIMESTAMP) & X33); + + uint256 borrowRatio_ = (exchangePricesAndConfig_ >> LiquiditySlotsLink.BITS_EXCHANGE_PRICES_BORROW_RATIO) & + X15; + if (secondsSinceLastUpdate_ == 0 || temp_ == 0 || borrowRatio_ == 1) { + // if no time passed, borrow rate is 0, or no raw borrowings: no exchange price update needed + // (if borrowRatio_ == 1 means there is only borrowInterestFree, as first bit is 1 and rest is 0) + return (supplyExchangePrice_, borrowExchangePrice_); + } + + // calculate new borrow exchange price. + // formula borrowExchangePriceIncrease: previous price * borrow rate * secondsSinceLastUpdate_. + // nominator is max uint112 (uint64 * uint16 * uint32). Divisor can not be 0. + borrowExchangePrice_ += + (borrowExchangePrice_ * temp_ * secondsSinceLastUpdate_) / + (SECONDS_PER_YEAR * FOUR_DECIMALS); + + // FOR SUPPLY EXCHANGE PRICE: + // all yield paid by borrowers (in mode with interest) goes to suppliers in mode with interest. + // formula: previous price * supply rate * secondsSinceLastUpdate_. + // where supply rate = (borrow rate - revenueFee%) * ratioSupplyYield. And + // ratioSupplyYield = utilization * supplyRatio * borrowRatio + // + // Example: + // supplyRawInterest is 80, supplyInterestFree is 20. totalSupply is 100. BorrowedRawInterest is 50. + // BorrowInterestFree is 10. TotalBorrow is 60. borrow rate 40%, revenueFee 10%. + // yield is 10 (so half a year must have passed). + // supplyRawInterest must become worth 89. totalSupply must become 109. BorrowedRawInterest must become 60. + // borrowInterestFree must still be 10. supplyInterestFree still 20. totalBorrow 70. + // supplyExchangePrice would have to go from 1 to 1,125 (+ 0.125). borrowExchangePrice from 1 to 1,2 (+0.2). + // utilization is 60%. supplyRatio = 20 / 80 = 25% (only 80% of lenders receiving yield). + // borrowRatio = 10 / 50 = 20% (only 83,333% of borrowers paying yield): + // x of borrowers paying yield = 100% - (20 / (100 + 20)) = 100% - 16.6666666% = 83,333%. + // ratioSupplyYield = 60% * 83,33333% * (100% + 20%) = 62,5% + // supplyRate = (40% * (100% - 10%)) * = 36% * 62,5% = 22.5% + // increase in supplyExchangePrice, assuming 100 as previous price. + // 100 * 22,5% * 1/2 (half a year) = 0,1125. + // cross-check supplyRawInterest worth = 80 * 1.1125 = 89. totalSupply worth = 89 + 20. + + // -------------- 1. calculate ratioSupplyYield -------------------------------- + // step1: utilization * supplyRatio (or actually part of lenders receiving yield) + + // temp_ => supplyRatio (in 1e2: 100% = 10_000; 1% = 100 -> max value 16_383) + // if first bit 0 then ratio is supplyInterestFree / supplyWithInterest (supplyWithInterest is bigger) + // else ratio is supplyWithInterest / supplyInterestFree (supplyInterestFree is bigger) + temp_ = (exchangePricesAndConfig_ >> LiquiditySlotsLink.BITS_EXCHANGE_PRICES_SUPPLY_RATIO) & X15; + + if (temp_ == 1) { + // if no raw supply: no exchange price update needed + // (if supplyRatio_ == 1 means there is only supplyInterestFree, as first bit is 1 and rest is 0) + return (supplyExchangePrice_, borrowExchangePrice_); + } + + // ratioSupplyYield precision is 1e27 as 100% for increased precision when supplyInterestFree > supplyWithInterest + if (temp_ & 1 == 1) { + // ratio is supplyWithInterest / supplyInterestFree (supplyInterestFree is bigger) + temp_ = temp_ >> 1; + + // Note: case where temp_ == 0 (only supplyInterestFree, no yield) already covered by early return + // in the if statement a little above. + + // based on above example but supplyRawInterest is 20, supplyInterestFree is 80. no fee. + // supplyRawInterest must become worth 30. totalSupply must become 110. + // supplyExchangePrice would have to go from 1 to 1,5. borrowExchangePrice from 1 to 1,2. + // so ratioSupplyYield must come out as 2.5 (250%). + // supplyRatio would be (20 * 10_000 / 80) = 2500. but must be inverted. + temp_ = (1e27 * FOUR_DECIMALS) / temp_; // e.g. 1e31 / 2500 = 4e27. (* 1e27 for precision) + // e.g. 5_000 * (1e27 + 4e27) / 1e27 = 25_000 (=250%). + temp_ = + // utilization * (100% + 100% / supplyRatio) + (((exchangePricesAndConfig_ >> LiquiditySlotsLink.BITS_EXCHANGE_PRICES_UTILIZATION) & X14) * + (1e27 + temp_)) / // extract utilization (max 16_383 so there is no way this can overflow). + (FOUR_DECIMALS); + // max possible value of temp_ here is 16383 * (1e27 + 1e31) / 1e4 = ~1.64e31 + } else { + // ratio is supplyInterestFree / supplyWithInterest (supplyWithInterest is bigger) + temp_ = temp_ >> 1; + // if temp_ == 0 then only supplyWithInterest => full yield. temp_ is already 0 + + // e.g. 5_000 * 10_000 + (20 * 10_000 / 80) / 10_000 = 5000 * 12500 / 10000 = 6250 (=62.5%). + temp_ = + // 1e27 * utilization * (100% + supplyRatio) / 100% + (1e27 * + ((exchangePricesAndConfig_ >> LiquiditySlotsLink.BITS_EXCHANGE_PRICES_UTILIZATION) & X14) * // extract utilization (max 16_383 so there is no way this can overflow). + (FOUR_DECIMALS + temp_)) / + (FOUR_DECIMALS * FOUR_DECIMALS); + // max possible temp_ value: 1e27 * 16383 * 2e4 / 1e8 = 3.2766e27 + } + // from here temp_ => ratioSupplyYield (utilization * supplyRatio part) scaled by 1e27. max possible value ~1.64e31 + + // step2 of ratioSupplyYield: add borrowRatio (only x% of borrowers paying yield) + if (borrowRatio_ & 1 == 1) { + // ratio is borrowWithInterest / borrowInterestFree (borrowInterestFree is bigger) + borrowRatio_ = borrowRatio_ >> 1; + // borrowRatio_ => x of total bororwers paying yield. scale to 1e27. + + // Note: case where borrowRatio_ == 0 (only borrowInterestFree, no yield) already covered + // at the beginning of the method by early return if `borrowRatio_ == 1`. + + // based on above example but borrowRawInterest is 10, borrowInterestFree is 50. no fee. borrowRatio = 20%. + // so only 16.66% of borrowers are paying yield. so the 100% - part of the formula is not needed. + // x of borrowers paying yield = (borrowRatio / (100 + borrowRatio)) = 16.6666666% + // borrowRatio_ => x of total bororwers paying yield. scale to 1e27. + borrowRatio_ = (borrowRatio_ * 1e27) / (FOUR_DECIMALS + borrowRatio_); + // max value here for borrowRatio_ is (1e31 / (1e4 + 1e4))= 5e26 (= 50% of borrowers paying yield). + } else { + // ratio is borrowInterestFree / borrowWithInterest (borrowWithInterest is bigger) + borrowRatio_ = borrowRatio_ >> 1; + + // borrowRatio_ => x of total bororwers paying yield. scale to 1e27. + // x of borrowers paying yield = 100% - (borrowRatio / (100 + borrowRatio)) = 100% - 16.6666666% = 83,333%. + borrowRatio_ = (1e27 - ((borrowRatio_ * 1e27) / (FOUR_DECIMALS + borrowRatio_))); + // borrowRatio can never be > 100%. so max subtraction can be 100% - 100% / 200%. + // or if borrowRatio_ is 0 -> 100% - 0. or if borrowRatio_ is 1 -> 100% - 1 / 101. + // max value here for borrowRatio_ is 1e27 - 0 = 1e27 (= 100% of borrowers paying yield). + } + + // temp_ => ratioSupplyYield. scaled down from 1e25 = 1% each to normal percent precision 1e2 = 1%. + // max nominator value is ~1.64e31 * 1e27 = 1.64e58. max result = 1.64e8 + temp_ = (FOUR_DECIMALS * temp_ * borrowRatio_) / 1e54; + + // 2. calculate supply rate + // temp_ => supply rate (borrow rate - revenueFee%) * ratioSupplyYield. + // division part is done in next step to increase precision. (divided by 2x FOUR_DECIMALS, fee + borrowRate) + // Note that all calculation divisions for supplyExchangePrice are rounded down. + // Note supply rate can be bigger than the borrowRate, e.g. if there are only few lenders with interest + // but more suppliers not earning interest. + temp_ = ((exchangePricesAndConfig_ & X16) * // borrow rate + temp_ * // ratioSupplyYield + (FOUR_DECIMALS - ((exchangePricesAndConfig_ >> LiquiditySlotsLink.BITS_EXCHANGE_PRICES_FEE) & X14))); // revenueFee + // fee can not be > 100%. max possible = 65535 * ~1.64e8 * 1e4 =~1.074774e17. + + // 3. calculate increase in supply exchange price + supplyExchangePrice_ += ((supplyExchangePrice_ * temp_ * secondsSinceLastUpdate_) / + (SECONDS_PER_YEAR * FOUR_DECIMALS * FOUR_DECIMALS * FOUR_DECIMALS)); + // max possible nominator = max uint 64 * 1.074774e17 * max uint32 = ~8.52e45. Denominator can not be 0. + } + } + + /////////////////////////////////////////////////////////////////////////// + ////////// CALC REVENUE ///////// + /////////////////////////////////////////////////////////////////////////// + + /// @dev gets the `revenueAmount_` for a token given its' totalAmounts and exchangePricesAndConfig from storage + /// and the current balance of the Fluid liquidity contract for the token. + /// @param totalAmounts_ total amounts packed uint256 read from storage + /// @param exchangePricesAndConfig_ exchange prices and config packed uint256 read from storage + /// @param liquidityTokenBalance_ current balance of Liquidity contract (IERC20(token_).balanceOf(address(this))) + /// @return revenueAmount_ collectable revenue amount + function calcRevenue( + uint256 totalAmounts_, + uint256 exchangePricesAndConfig_, + uint256 liquidityTokenBalance_ + ) internal view returns (uint256 revenueAmount_) { + // @dev no need to super-optimize this method as it is only used by admin + + // calculate the new exchange prices based on earned interest + (uint256 supplyExchangePrice_, uint256 borrowExchangePrice_) = calcExchangePrices(exchangePricesAndConfig_); + + // total supply = interest free + with interest converted from raw + uint256 totalSupply_ = getTotalSupply(totalAmounts_, supplyExchangePrice_); + + if (totalSupply_ > 0) { + // available revenue: balanceOf(token) + totalBorrowings - totalLendings. + revenueAmount_ = liquidityTokenBalance_ + getTotalBorrow(totalAmounts_, borrowExchangePrice_); + // ensure there is no possible case because of rounding etc. where this would revert, + // explicitly check if > + revenueAmount_ = revenueAmount_ > totalSupply_ ? revenueAmount_ - totalSupply_ : 0; + // Note: if utilization > 100% (totalSupply < totalBorrow), then all the amount above 100% utilization + // can only be revenue. + } else { + // if supply is 0, then rest of balance can be withdrawn as revenue so that no amounts get stuck + revenueAmount_ = liquidityTokenBalance_; + } + } + + /////////////////////////////////////////////////////////////////////////// + ////////// CALC LIMITS ///////// + /////////////////////////////////////////////////////////////////////////// + + /// @dev calculates withdrawal limit before an operate execution: + /// amount of user supply that must stay supplied (not amount that can be withdrawn). + /// i.e. if user has supplied 100m and can withdraw 5M, this method returns the 95M, not the withdrawable amount 5M + /// @param userSupplyData_ user supply data packed uint256 from storage + /// @param userSupply_ current user supply amount already extracted from `userSupplyData_` and converted from BigMath + /// @return currentWithdrawalLimit_ current withdrawal limit updated for expansion since last interaction. + /// returned value is in raw for with interest mode, normal amount for interest free mode! + function calcWithdrawalLimitBeforeOperate( + uint256 userSupplyData_, + uint256 userSupply_ + ) internal view returns (uint256 currentWithdrawalLimit_) { + // @dev must support handling the case where timestamp is 0 (config is set but no interactions yet). + // first tx where timestamp is 0 will enter `if (lastWithdrawalLimit_ == 0)` because lastWithdrawalLimit_ is not set yet. + // returning max withdrawal allowed, which is not exactly right but doesn't matter because the first interaction must be + // a deposit anyway. Important is that it would not revert. + + // Note the first time a deposit brings the user supply amount to above the base withdrawal limit, the active limit + // is the fully expanded limit immediately. + + // extract last set withdrawal limit + uint256 lastWithdrawalLimit_ = (userSupplyData_ >> + LiquiditySlotsLink.BITS_USER_SUPPLY_PREVIOUS_WITHDRAWAL_LIMIT) & X64; + lastWithdrawalLimit_ = + (lastWithdrawalLimit_ >> DEFAULT_EXPONENT_SIZE) << + (lastWithdrawalLimit_ & DEFAULT_EXPONENT_MASK); + if (lastWithdrawalLimit_ == 0) { + // withdrawal limit is not activated. Max withdrawal allowed + return 0; + } + + uint256 maxWithdrawableLimit_; + uint256 temp_; + unchecked { + // extract max withdrawable percent of user supply and + // calculate maximum withdrawable amount expandPercentage of user supply at full expansion duration elapsed + // e.g.: if 10% expandPercentage, meaning 10% is withdrawable after full expandDuration has elapsed. + + // userSupply_ needs to be atleast 1e73 to overflow max limit of ~1e77 in uint256 (no token in existence where this is possible). + maxWithdrawableLimit_ = + (((userSupplyData_ >> LiquiditySlotsLink.BITS_USER_SUPPLY_EXPAND_PERCENT) & X14) * userSupply_) / + FOUR_DECIMALS; + + // time elapsed since last withdrawal limit was set (in seconds) + // @dev last process timestamp is guaranteed to exist for withdrawal, as a supply must have happened before. + // last timestamp can not be > current timestamp + temp_ = + block.timestamp - + ((userSupplyData_ >> LiquiditySlotsLink.BITS_USER_SUPPLY_LAST_UPDATE_TIMESTAMP) & X33); + } + // calculate withdrawable amount of expandPercent that is elapsed of expandDuration. + // e.g. if 60% of expandDuration has elapsed, then user should be able to withdraw 6% of user supply, down to 94%. + // Note: no explicit check for this needed, it is covered by setting minWithdrawalLimit_ if needed. + temp_ = + (maxWithdrawableLimit_ * temp_) / + // extract expand duration: After this, decrement won't happen (user can withdraw 100% of withdraw limit) + ((userSupplyData_ >> LiquiditySlotsLink.BITS_USER_SUPPLY_EXPAND_DURATION) & X24); // expand duration can never be 0 + // calculate expanded withdrawal limit: last withdrawal limit - withdrawable amount. + // Note: withdrawable amount here can grow bigger than userSupply if timeElapsed is a lot bigger than expandDuration, + // which would cause the subtraction `lastWithdrawalLimit_ - withdrawableAmount_` to revert. In that case, set 0 + // which will cause minimum (fully expanded) withdrawal limit to be set in lines below. + unchecked { + // underflow explicitly checked & handled + currentWithdrawalLimit_ = lastWithdrawalLimit_ > temp_ ? lastWithdrawalLimit_ - temp_ : 0; + // calculate minimum withdrawal limit: minimum amount of user supply that must stay supplied at full expansion. + // subtraction can not underflow as maxWithdrawableLimit_ is a percentage amount (<=100%) of userSupply_ + temp_ = userSupply_ - maxWithdrawableLimit_; + } + // if withdrawal limit is decreased below minimum then set minimum + // (e.g. when more than expandDuration time has elapsed) + if (temp_ > currentWithdrawalLimit_) { + currentWithdrawalLimit_ = temp_; + } + } + + /// @dev calculates withdrawal limit after an operate execution: + /// amount of user supply that must stay supplied (not amount that can be withdrawn). + /// i.e. if user has supplied 100m and can withdraw 5M, this method returns the 95M, not the withdrawable amount 5M + /// @param userSupplyData_ user supply data packed uint256 from storage + /// @param userSupply_ current user supply amount already extracted from `userSupplyData_` and added / subtracted with the executed operate amount + /// @param newWithdrawalLimit_ current withdrawal limit updated for expansion since last interaction, result from `calcWithdrawalLimitBeforeOperate` + /// @return withdrawalLimit_ updated withdrawal limit that should be written to storage. returned value is in + /// raw for with interest mode, normal amount for interest free mode! + function calcWithdrawalLimitAfterOperate( + uint256 userSupplyData_, + uint256 userSupply_, + uint256 newWithdrawalLimit_ + ) internal pure returns (uint256) { + // temp_ => base withdrawal limit. below this, maximum withdrawals are allowed + uint256 temp_ = (userSupplyData_ >> LiquiditySlotsLink.BITS_USER_SUPPLY_BASE_WITHDRAWAL_LIMIT) & X18; + temp_ = (temp_ >> DEFAULT_EXPONENT_SIZE) << (temp_ & DEFAULT_EXPONENT_MASK); + + // if user supply is below base limit then max withdrawals are allowed + if (userSupply_ < temp_) { + return 0; + } + // temp_ => withdrawal limit expandPercent (is in 1e2 decimals) + temp_ = (userSupplyData_ >> LiquiditySlotsLink.BITS_USER_SUPPLY_EXPAND_PERCENT) & X14; + unchecked { + // temp_ => minimum withdrawal limit: userSupply - max withdrawable limit (userSupply * expandPercent)) + // userSupply_ needs to be atleast 1e73 to overflow max limit of ~1e77 in uint256 (no token in existence where this is possible). + // subtraction can not underflow as maxWithdrawableLimit_ is a percentage amount (<=100%) of userSupply_ + temp_ = userSupply_ - ((userSupply_ * temp_) / FOUR_DECIMALS); + } + // if new (before operation) withdrawal limit is less than minimum limit then set minimum limit. + // e.g. can happen on new deposits. withdrawal limit is instantly fully expanded in a scenario where + // increased deposit amount outpaces withrawals. + if (temp_ > newWithdrawalLimit_) { + return temp_; + } + return newWithdrawalLimit_; + } + + /// @dev calculates borrow limit before an operate execution: + /// total amount user borrow can reach (not borrowable amount in current operation). + /// i.e. if user has borrowed 50M and can still borrow 5M, this method returns the total 55M, not the borrowable amount 5M + /// @param userBorrowData_ user borrow data packed uint256 from storage + /// @param userBorrow_ current user borrow amount already extracted from `userBorrowData_` + /// @return currentBorrowLimit_ current borrow limit updated for expansion since last interaction. returned value is in + /// raw for with interest mode, normal amount for interest free mode! + function calcBorrowLimitBeforeOperate( + uint256 userBorrowData_, + uint256 userBorrow_ + ) internal view returns (uint256 currentBorrowLimit_) { + // @dev must support handling the case where timestamp is 0 (config is set but no interactions yet) -> base limit. + // first tx where timestamp is 0 will enter `if (maxExpandedBorrowLimit_ < baseBorrowLimit_)` because `userBorrow_` and thus + // `maxExpansionLimit_` and thus `maxExpandedBorrowLimit_` is 0 and `baseBorrowLimit_` can not be 0. + + // temp_ = extract borrow expand percent (is in 1e2 decimals) + uint256 temp_ = (userBorrowData_ >> LiquiditySlotsLink.BITS_USER_BORROW_EXPAND_PERCENT) & X14; + + uint256 maxExpansionLimit_; + uint256 maxExpandedBorrowLimit_; + unchecked { + // calculate max expansion limit: Max amount limit can expand to since last interaction + // userBorrow_ needs to be atleast 1e73 to overflow max limit of ~1e77 in uint256 (no token in existence where this is possible). + maxExpansionLimit_ = ((userBorrow_ * temp_) / FOUR_DECIMALS); + + // calculate max borrow limit: Max point limit can increase to since last interaction + maxExpandedBorrowLimit_ = userBorrow_ + maxExpansionLimit_; + } + + // currentBorrowLimit_ = extract base borrow limit + currentBorrowLimit_ = (userBorrowData_ >> LiquiditySlotsLink.BITS_USER_BORROW_BASE_BORROW_LIMIT) & X18; + currentBorrowLimit_ = + (currentBorrowLimit_ >> DEFAULT_EXPONENT_SIZE) << + (currentBorrowLimit_ & DEFAULT_EXPONENT_MASK); + + if (maxExpandedBorrowLimit_ < currentBorrowLimit_) { + return currentBorrowLimit_; + } + // time elapsed since last borrow limit was set (in seconds) + unchecked { + // temp_ = timeElapsed_ (last timestamp can not be > current timestamp) + temp_ = + block.timestamp - + ((userBorrowData_ >> LiquiditySlotsLink.BITS_USER_BORROW_LAST_UPDATE_TIMESTAMP) & X33); // extract last update timestamp + } + + // currentBorrowLimit_ = expandedBorrowableAmount + extract last set borrow limit + currentBorrowLimit_ = + // calculate borrow limit expansion since last interaction for `expandPercent` that is elapsed of `expandDuration`. + // divisor is extract expand duration (after this, full expansion to expandPercentage happened). + ((maxExpansionLimit_ * temp_) / + ((userBorrowData_ >> LiquiditySlotsLink.BITS_USER_BORROW_EXPAND_DURATION) & X24)) + // expand duration can never be 0 + // extract last set borrow limit + BigMathMinified.fromBigNumber( + (userBorrowData_ >> LiquiditySlotsLink.BITS_USER_BORROW_PREVIOUS_BORROW_LIMIT) & X64, + DEFAULT_EXPONENT_SIZE, + DEFAULT_EXPONENT_MASK + ); + + // if timeElapsed is bigger than expandDuration, new borrow limit would be > max expansion, + // so set to `maxExpandedBorrowLimit_` in that case. + // also covers the case where last process timestamp = 0 (timeElapsed would simply be very big) + if (currentBorrowLimit_ > maxExpandedBorrowLimit_) { + currentBorrowLimit_ = maxExpandedBorrowLimit_; + } + // temp_ = extract hard max borrow limit. Above this user can never borrow (not expandable above) + temp_ = (userBorrowData_ >> LiquiditySlotsLink.BITS_USER_BORROW_MAX_BORROW_LIMIT) & X18; + temp_ = (temp_ >> DEFAULT_EXPONENT_SIZE) << (temp_ & DEFAULT_EXPONENT_MASK); + + if (currentBorrowLimit_ > temp_) { + currentBorrowLimit_ = temp_; + } + } + + /// @dev calculates borrow limit after an operate execution: + /// total amount user borrow can reach (not borrowable amount in current operation). + /// i.e. if user has borrowed 50M and can still borrow 5M, this method returns the total 55M, not the borrowable amount 5M + /// @param userBorrowData_ user borrow data packed uint256 from storage + /// @param userBorrow_ current user borrow amount already extracted from `userBorrowData_` and added / subtracted with the executed operate amount + /// @param newBorrowLimit_ current borrow limit updated for expansion since last interaction, result from `calcBorrowLimitBeforeOperate` + /// @return borrowLimit_ updated borrow limit that should be written to storage. + /// returned value is in raw for with interest mode, normal amount for interest free mode! + function calcBorrowLimitAfterOperate( + uint256 userBorrowData_, + uint256 userBorrow_, + uint256 newBorrowLimit_ + ) internal pure returns (uint256 borrowLimit_) { + // temp_ = extract borrow expand percent + uint256 temp_ = (userBorrowData_ >> LiquiditySlotsLink.BITS_USER_BORROW_EXPAND_PERCENT) & X14; // (is in 1e2 decimals) + + unchecked { + // borrowLimit_ = calculate maximum borrow limit at full expansion. + // userBorrow_ needs to be at least 1e73 to overflow max limit of ~1e77 in uint256 (no token in existence where this is possible). + borrowLimit_ = userBorrow_ + ((userBorrow_ * temp_) / FOUR_DECIMALS); + } + + // temp_ = extract base borrow limit + temp_ = (userBorrowData_ >> LiquiditySlotsLink.BITS_USER_BORROW_BASE_BORROW_LIMIT) & X18; + temp_ = (temp_ >> DEFAULT_EXPONENT_SIZE) << (temp_ & DEFAULT_EXPONENT_MASK); + + if (borrowLimit_ < temp_) { + // below base limit, borrow limit is always base limit + return temp_; + } + // temp_ = extract hard max borrow limit. Above this user can never borrow (not expandable above) + temp_ = (userBorrowData_ >> LiquiditySlotsLink.BITS_USER_BORROW_MAX_BORROW_LIMIT) & X18; + temp_ = (temp_ >> DEFAULT_EXPONENT_SIZE) << (temp_ & DEFAULT_EXPONENT_MASK); + + // make sure fully expanded borrow limit is not above hard max borrow limit + if (borrowLimit_ > temp_) { + borrowLimit_ = temp_; + } + // if new borrow limit (from before operate) is > max borrow limit, set max borrow limit. + // (e.g. on a repay shrinking instantly to fully expanded borrow limit from new borrow amount. shrinking is instant) + if (newBorrowLimit_ > borrowLimit_) { + return borrowLimit_; + } + return newBorrowLimit_; + } + + /////////////////////////////////////////////////////////////////////////// + ////////// CALC RATES ///////// + /////////////////////////////////////////////////////////////////////////// + + /// @dev Calculates new borrow rate from utilization for a token + /// @param rateData_ rate data packed uint256 from storage for the token + /// @param utilization_ totalBorrow / totalSupply. 1e4 = 100% utilization + /// @return rate_ rate for that particular token in 1e2 precision (e.g. 5% rate = 500) + function calcBorrowRateFromUtilization(uint256 rateData_, uint256 utilization_) internal returns (uint256 rate_) { + // extract rate version: 4 bits (0xF) starting from bit 0 + uint256 rateVersion_ = (rateData_ & 0xF); + + if (rateVersion_ == 1) { + rate_ = calcRateV1(rateData_, utilization_); + } else if (rateVersion_ == 2) { + rate_ = calcRateV2(rateData_, utilization_); + } else { + revert FluidLiquidityCalcsError(ErrorTypes.LiquidityCalcs__UnsupportedRateVersion); + } + + if (rate_ > X16) { + // hard cap for borrow rate at maximum value 16 bits (65535) to make sure it does not overflow storage space. + // this is unlikely to ever happen if configs stay within expected levels. + rate_ = X16; + // emit event to more easily become aware + emit BorrowRateMaxCap(); + } + } + + /// @dev calculates the borrow rate based on utilization for rate data version 1 (with one kink) in 1e2 precision + /// @param rateData_ rate data packed uint256 from storage for the token + /// @param utilization_ in 1e2 (100% = 1e4) + /// @return rate_ rate in 1e2 precision + function calcRateV1(uint256 rateData_, uint256 utilization_) internal pure returns (uint256 rate_) { + /// For rate v1 (one kink) ------------------------------------------------------ + /// Next 16 bits => 4 - 19 => Rate at utilization 0% (in 1e2: 100% = 10_000; 1% = 100 -> max value 65535) + /// Next 16 bits => 20- 35 => Utilization at kink1 (in 1e2: 100% = 10_000; 1% = 100 -> max value 65535) + /// Next 16 bits => 36- 51 => Rate at utilization kink1 (in 1e2: 100% = 10_000; 1% = 100 -> max value 65535) + /// Next 16 bits => 52- 67 => Rate at utilization 100% (in 1e2: 100% = 10_000; 1% = 100 -> max value 65535) + /// Last 188 bits => 68-255 => blank, might come in use in future + + // y = mx + c. + // y is borrow rate + // x is utilization + // m = slope (m can also be negative for declining rates) + // c is constant (c can be negative) + + uint256 y1_; + uint256 y2_; + uint256 x1_; + uint256 x2_; + + // extract kink1: 16 bits (0xFFFF) starting from bit 20 + // kink is in 1e2, same as utilization, so no conversion needed for direct comparison of the two + uint256 kink1_ = (rateData_ >> LiquiditySlotsLink.BITS_RATE_DATA_V1_UTILIZATION_AT_KINK) & X16; + if (utilization_ < kink1_) { + // if utilization is less than kink + y1_ = (rateData_ >> LiquiditySlotsLink.BITS_RATE_DATA_V1_RATE_AT_UTILIZATION_ZERO) & X16; + y2_ = (rateData_ >> LiquiditySlotsLink.BITS_RATE_DATA_V1_RATE_AT_UTILIZATION_KINK) & X16; + x1_ = 0; // 0% + x2_ = kink1_; + } else { + // else utilization is greater than kink + y1_ = (rateData_ >> LiquiditySlotsLink.BITS_RATE_DATA_V1_RATE_AT_UTILIZATION_KINK) & X16; + y2_ = (rateData_ >> LiquiditySlotsLink.BITS_RATE_DATA_V1_RATE_AT_UTILIZATION_MAX) & X16; + x1_ = kink1_; + x2_ = FOUR_DECIMALS; // 100% + } + + int256 constant_; + int256 slope_; + unchecked { + // calculating slope with twelve decimal precision. m = (y2 - y1) / (x2 - x1). + // utilization of x2 can not be <= utilization of x1 (so no underflow or 0 divisor) + // y is in 1e2 so can not overflow when multiplied with TWELVE_DECIMALS + slope_ = (int256(y2_ - y1_) * int256(TWELVE_DECIMALS)) / int256((x2_ - x1_)); + + // calculating constant at 12 decimal precision. slope is already in 12 decimal hence only multiple with y1. c = y - mx. + // maximum y1_ value is 65535. 65535 * 1e12 can not overflow int256 + // maximum slope is 65535 - 0 * TWELVE_DECIMALS / 1 = 65535 * 1e12; + // maximum x1_ is 100% (9_999 actually) => slope_ * x1_ can not overflow int256 + // subtraction most extreme case would be 0 - max value slope_ * x1_ => can not underflow int256 + constant_ = int256(y1_ * TWELVE_DECIMALS) - (slope_ * int256(x1_)); + + // calculating new borrow rate + // - slope_ max value is 65535 * 1e12, + // - utilization max value is let's say 500% (extreme case where borrow rate increases borrow amount without new supply) + // - constant max value is 65535 * 1e12 + // so max values are 65535 * 1e12 * 50_000 + 65535 * 1e12 -> 3.2768*10^21, which easily fits int256 + // divisor TWELVE_DECIMALS can not be 0 + slope_ = (slope_ * int256(utilization_)) + constant_; // reusing `slope_` as variable for gas savings + if (slope_ < 0) { + revert FluidLiquidityCalcsError(ErrorTypes.LiquidityCalcs__BorrowRateNegative); + } + rate_ = uint256(slope_) / TWELVE_DECIMALS; + } + } + + /// @dev calculates the borrow rate based on utilization for rate data version 2 (with two kinks) in 1e4 precision + /// @param rateData_ rate data packed uint256 from storage for the token + /// @param utilization_ in 1e2 (100% = 1e4) + /// @return rate_ rate in 1e4 precision + function calcRateV2(uint256 rateData_, uint256 utilization_) internal pure returns (uint256 rate_) { + /// For rate v2 (two kinks) ----------------------------------------------------- + /// Next 16 bits => 4 - 19 => Rate at utilization 0% (in 1e2: 100% = 10_000; 1% = 100 -> max value 65535) + /// Next 16 bits => 20- 35 => Utilization at kink1 (in 1e2: 100% = 10_000; 1% = 100 -> max value 65535) + /// Next 16 bits => 36- 51 => Rate at utilization kink1 (in 1e2: 100% = 10_000; 1% = 100 -> max value 65535) + /// Next 16 bits => 52- 67 => Utilization at kink2 (in 1e2: 100% = 10_000; 1% = 100 -> max value 65535) + /// Next 16 bits => 68- 83 => Rate at utilization kink2 (in 1e2: 100% = 10_000; 1% = 100 -> max value 65535) + /// Next 16 bits => 84- 99 => Rate at utilization 100% (in 1e2: 100% = 10_000; 1% = 100 -> max value 65535) + /// Last 156 bits => 100-255 => blank, might come in use in future + + // y = mx + c. + // y is borrow rate + // x is utilization + // m = slope (m can also be negative for declining rates) + // c is constant (c can be negative) + + uint256 y1_; + uint256 y2_; + uint256 x1_; + uint256 x2_; + + // extract kink1: 16 bits (0xFFFF) starting from bit 20 + // kink is in 1e2, same as utilization, so no conversion needed for direct comparison of the two + uint256 kink1_ = (rateData_ >> LiquiditySlotsLink.BITS_RATE_DATA_V2_UTILIZATION_AT_KINK1) & X16; + if (utilization_ < kink1_) { + // if utilization is less than kink1 + y1_ = (rateData_ >> LiquiditySlotsLink.BITS_RATE_DATA_V2_RATE_AT_UTILIZATION_ZERO) & X16; + y2_ = (rateData_ >> LiquiditySlotsLink.BITS_RATE_DATA_V2_RATE_AT_UTILIZATION_KINK1) & X16; + x1_ = 0; // 0% + x2_ = kink1_; + } else { + // extract kink2: 16 bits (0xFFFF) starting from bit 52 + uint256 kink2_ = (rateData_ >> LiquiditySlotsLink.BITS_RATE_DATA_V2_UTILIZATION_AT_KINK2) & X16; + if (utilization_ < kink2_) { + // if utilization is less than kink2 + y1_ = (rateData_ >> LiquiditySlotsLink.BITS_RATE_DATA_V2_RATE_AT_UTILIZATION_KINK1) & X16; + y2_ = (rateData_ >> LiquiditySlotsLink.BITS_RATE_DATA_V2_RATE_AT_UTILIZATION_KINK2) & X16; + x1_ = kink1_; + x2_ = kink2_; + } else { + // else utilization is greater than kink2 + y1_ = (rateData_ >> LiquiditySlotsLink.BITS_RATE_DATA_V2_RATE_AT_UTILIZATION_KINK2) & X16; + y2_ = (rateData_ >> LiquiditySlotsLink.BITS_RATE_DATA_V2_RATE_AT_UTILIZATION_MAX) & X16; + x1_ = kink2_; + x2_ = FOUR_DECIMALS; + } + } + + int256 constant_; + int256 slope_; + unchecked { + // calculating slope with twelve decimal precision. m = (y2 - y1) / (x2 - x1). + // utilization of x2 can not be <= utilization of x1 (so no underflow or 0 divisor) + // y is in 1e2 so can not overflow when multiplied with TWELVE_DECIMALS + slope_ = (int256(y2_ - y1_) * int256(TWELVE_DECIMALS)) / int256((x2_ - x1_)); + + // calculating constant at 12 decimal precision. slope is already in 12 decimal hence only multiple with y1. c = y - mx. + // maximum y1_ value is 65535. 65535 * 1e12 can not overflow int256 + // maximum slope is 65535 - 0 * TWELVE_DECIMALS / 1 = 65535 * 1e12; + // maximum x1_ is 100% (9_999 actually) => slope_ * x1_ can not overflow int256 + // subtraction most extreme case would be 0 - max value slope_ * x1_ => can not underflow int256 + constant_ = int256(y1_ * TWELVE_DECIMALS) - (slope_ * int256(x1_)); + + // calculating new borrow rate + // - slope_ max value is 65535 * 1e12, + // - utilization max value is let's say 500% (extreme case where borrow rate increases borrow amount without new supply) + // - constant max value is 65535 * 1e12 + // so max values are 65535 * 1e12 * 50_000 + 65535 * 1e12 -> 3.2768*10^21, which easily fits int256 + // divisor TWELVE_DECIMALS can not be 0 + slope_ = (slope_ * int256(utilization_)) + constant_; // reusing `slope_` as variable for gas savings + if (slope_ < 0) { + revert FluidLiquidityCalcsError(ErrorTypes.LiquidityCalcs__BorrowRateNegative); + } + rate_ = uint256(slope_) / TWELVE_DECIMALS; + } + } + + /// @dev reads the total supply out of Liquidity packed storage `totalAmounts_` for `supplyExchangePrice_` + function getTotalSupply( + uint256 totalAmounts_, + uint256 supplyExchangePrice_ + ) internal pure returns (uint256 totalSupply_) { + // totalSupply_ => supplyInterestFree + totalSupply_ = (totalAmounts_ >> LiquiditySlotsLink.BITS_TOTAL_AMOUNTS_SUPPLY_INTEREST_FREE) & X64; + totalSupply_ = (totalSupply_ >> DEFAULT_EXPONENT_SIZE) << (totalSupply_ & DEFAULT_EXPONENT_MASK); + + uint256 totalSupplyRaw_ = totalAmounts_ & X64; // no shifting as supplyRaw is first 64 bits + totalSupplyRaw_ = (totalSupplyRaw_ >> DEFAULT_EXPONENT_SIZE) << (totalSupplyRaw_ & DEFAULT_EXPONENT_MASK); + + // totalSupply = supplyInterestFree + supplyRawInterest normalized from raw + totalSupply_ += ((totalSupplyRaw_ * supplyExchangePrice_) / EXCHANGE_PRICES_PRECISION); + } + + /// @dev reads the total borrow out of Liquidity packed storage `totalAmounts_` for `borrowExchangePrice_` + function getTotalBorrow( + uint256 totalAmounts_, + uint256 borrowExchangePrice_ + ) internal pure returns (uint256 totalBorrow_) { + // totalBorrow_ => borrowInterestFree + // no & mask needed for borrow interest free as it occupies the last bits in the storage slot + totalBorrow_ = (totalAmounts_ >> LiquiditySlotsLink.BITS_TOTAL_AMOUNTS_BORROW_INTEREST_FREE); + totalBorrow_ = (totalBorrow_ >> DEFAULT_EXPONENT_SIZE) << (totalBorrow_ & DEFAULT_EXPONENT_MASK); + + uint256 totalBorrowRaw_ = (totalAmounts_ >> LiquiditySlotsLink.BITS_TOTAL_AMOUNTS_BORROW_WITH_INTEREST) & X64; + totalBorrowRaw_ = (totalBorrowRaw_ >> DEFAULT_EXPONENT_SIZE) << (totalBorrowRaw_ & DEFAULT_EXPONENT_MASK); + + // totalBorrow = borrowInterestFree + borrowRawInterest normalized from raw + totalBorrow_ += ((totalBorrowRaw_ * borrowExchangePrice_) / EXCHANGE_PRICES_PRECISION); + } +} \ No newline at end of file