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Diffstat (limited to 'packages/contracts/contracts/protocol/Exchange/libs/LibMath.sol')
| -rw-r--r-- | packages/contracts/contracts/protocol/Exchange/libs/LibMath.sol | 253 |
1 files changed, 0 insertions, 253 deletions
diff --git a/packages/contracts/contracts/protocol/Exchange/libs/LibMath.sol b/packages/contracts/contracts/protocol/Exchange/libs/LibMath.sol deleted file mode 100644 index c0b85ea10..000000000 --- a/packages/contracts/contracts/protocol/Exchange/libs/LibMath.sol +++ /dev/null @@ -1,253 +0,0 @@ -/* - - Copyright 2018 ZeroEx Intl. - - Licensed under the Apache License, Version 2.0 (the "License"); - you may not use this file except in compliance with the License. - You may obtain a copy of the License at - - http://www.apache.org/licenses/LICENSE-2.0 - - Unless required by applicable law or agreed to in writing, software - distributed under the License is distributed on an "AS IS" BASIS, - WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. - See the License for the specific language governing permissions and - limitations under the License. - -*/ - -pragma solidity 0.4.24; - -import "../../../utils/SafeMath/SafeMath.sol"; - - -contract LibMath is - SafeMath -{ - /// @dev Calculates partial value given a numerator and denominator rounded down. - /// Reverts if rounding error is >= 0.1% - /// @param numerator Numerator. - /// @param denominator Denominator. - /// @param target Value to calculate partial of. - /// @return Partial value of target rounded down. - function safeGetPartialAmountFloor( - uint256 numerator, - uint256 denominator, - uint256 target - ) - internal - pure - returns (uint256 partialAmount) - { - require( - denominator > 0, - "DIVISION_BY_ZERO" - ); - - require( - !isRoundingErrorFloor( - numerator, - denominator, - target - ), - "ROUNDING_ERROR" - ); - - partialAmount = safeDiv( - safeMul(numerator, target), - denominator - ); - return partialAmount; - } - - /// @dev Calculates partial value given a numerator and denominator rounded down. - /// Reverts if rounding error is >= 0.1% - /// @param numerator Numerator. - /// @param denominator Denominator. - /// @param target Value to calculate partial of. - /// @return Partial value of target rounded up. - function safeGetPartialAmountCeil( - uint256 numerator, - uint256 denominator, - uint256 target - ) - internal - pure - returns (uint256 partialAmount) - { - require( - denominator > 0, - "DIVISION_BY_ZERO" - ); - - require( - !isRoundingErrorCeil( - numerator, - denominator, - target - ), - "ROUNDING_ERROR" - ); - - // safeDiv computes `floor(a / b)`. We use the identity (a, b integer): - // ceil(a / b) = floor((a + b - 1) / b) - // To implement `ceil(a / b)` using safeDiv. - partialAmount = safeDiv( - safeAdd( - safeMul(numerator, target), - safeSub(denominator, 1) - ), - denominator - ); - return partialAmount; - } - - /// @dev Calculates partial value given a numerator and denominator rounded down. - /// @param numerator Numerator. - /// @param denominator Denominator. - /// @param target Value to calculate partial of. - /// @return Partial value of target rounded down. - function getPartialAmountFloor( - uint256 numerator, - uint256 denominator, - uint256 target - ) - internal - pure - returns (uint256 partialAmount) - { - require( - denominator > 0, - "DIVISION_BY_ZERO" - ); - - partialAmount = safeDiv( - safeMul(numerator, target), - denominator - ); - return partialAmount; - } - - /// @dev Calculates partial value given a numerator and denominator rounded down. - /// @param numerator Numerator. - /// @param denominator Denominator. - /// @param target Value to calculate partial of. - /// @return Partial value of target rounded up. - function getPartialAmountCeil( - uint256 numerator, - uint256 denominator, - uint256 target - ) - internal - pure - returns (uint256 partialAmount) - { - require( - denominator > 0, - "DIVISION_BY_ZERO" - ); - - // safeDiv computes `floor(a / b)`. We use the identity (a, b integer): - // ceil(a / b) = floor((a + b - 1) / b) - // To implement `ceil(a / b)` using safeDiv. - partialAmount = safeDiv( - safeAdd( - safeMul(numerator, target), - safeSub(denominator, 1) - ), - denominator - ); - return partialAmount; - } - - /// @dev Checks if rounding error >= 0.1% when rounding down. - /// @param numerator Numerator. - /// @param denominator Denominator. - /// @param target Value to multiply with numerator/denominator. - /// @return Rounding error is present. - function isRoundingErrorFloor( - uint256 numerator, - uint256 denominator, - uint256 target - ) - internal - pure - returns (bool isError) - { - require( - denominator > 0, - "DIVISION_BY_ZERO" - ); - - // The absolute rounding error is the difference between the rounded - // value and the ideal value. The relative rounding error is the - // absolute rounding error divided by the absolute value of the - // ideal value. This is undefined when the ideal value is zero. - // - // The ideal value is `numerator * target / denominator`. - // Let's call `numerator * target % denominator` the remainder. - // The absolute error is `remainder / denominator`. - // - // When the ideal value is zero, we require the absolute error to - // be zero. Fortunately, this is always the case. The ideal value is - // zero iff `numerator == 0` and/or `target == 0`. In this case the - // remainder and absolute error are also zero. - if (target == 0 || numerator == 0) { - return false; - } - - // Otherwise, we want the relative rounding error to be strictly - // less than 0.1%. - // The relative error is `remainder / (numerator * target)`. - // We want the relative error less than 1 / 1000: - // remainder / (numerator * denominator) < 1 / 1000 - // or equivalently: - // 1000 * remainder < numerator * target - // so we have a rounding error iff: - // 1000 * remainder >= numerator * target - uint256 remainder = mulmod( - target, - numerator, - denominator - ); - isError = safeMul(1000, remainder) >= safeMul(numerator, target); - return isError; - } - - /// @dev Checks if rounding error >= 0.1% when rounding up. - /// @param numerator Numerator. - /// @param denominator Denominator. - /// @param target Value to multiply with numerator/denominator. - /// @return Rounding error is present. - function isRoundingErrorCeil( - uint256 numerator, - uint256 denominator, - uint256 target - ) - internal - pure - returns (bool isError) - { - require( - denominator > 0, - "DIVISION_BY_ZERO" - ); - - // See the comments in `isRoundingError`. - if (target == 0 || numerator == 0) { - // When either is zero, the ideal value and rounded value are zero - // and there is no rounding error. (Although the relative error - // is undefined.) - return false; - } - // Compute remainder as before - uint256 remainder = mulmod( - target, - numerator, - denominator - ); - remainder = safeSub(denominator, remainder) % denominator; - isError = safeMul(1000, remainder) >= safeMul(numerator, target); - return isError; - } -} |