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@0x/contracts-staking: Remove IStructs.CumulativeRewardInfo, etc.

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`@0x/contracts-staking`: Convert all rewards to WETH.
`@0x/contracts-staking`: Style changes.
`@0x/contracts-staking`: Address misc. review comments.
`@0x/contracts-staking`: Make `LibFractions` scaling a separate step.
This commit is contained in:
Lawrence Forman
2019-09-21 03:42:38 -04:00
parent 14c4491b8c
commit 3ad7728a0e
31 changed files with 504 additions and 623 deletions
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73
contracts/utils/contracts/src/LibFractions.sol
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@@ -7,17 +7,14 @@ library LibFractions {
using LibSafeMath for uint256;
/// @dev Maximum value for addition result components.
uint256 constant internal RESCALE_THRESHOLD = 10 ** 27;
/// @dev Safely adds two fractions `n1/d1 + n2/d2`
/// @param n1 numerator of `1`
/// @param d1 denominator of `1`
/// @param n2 numerator of `2`
/// @param d2 denominator of `2`
/// @return numerator of sum
/// @return denominator of sum
function addFractions(
/// @return numerator Numerator of sum
/// @return denominator Denominator of sum
function add(
uint256 n1,
uint256 d1,
uint256 n2,
@@ -40,15 +37,61 @@ library LibFractions {
.safeMul(d2)
.safeAdd(n2.safeMul(d1));
denominator = d1.safeMul(d2);
return (numerator, denominator);
}
// If either the numerator or the denominator are > RESCALE_THRESHOLD,
// re-scale them to prevent overflows in future operations.
if (numerator > RESCALE_THRESHOLD || denominator > RESCALE_THRESHOLD) {
/// @dev Rescales a fraction to prevent overflows during addition if either
/// the numerator or the denominator are > `maxValue`.
/// @param numerator The numerator.
/// @param denominator The denominator.
/// @param maxValue The maximum value allowed for both the numerator and
/// denominator.
/// @return scaledNumerator The rescaled numerator.
/// @return scaledDenominator The rescaled denominator.
function normalize(
uint256 numerator,
uint256 denominator,
uint256 maxValue
)
internal
pure
returns (
uint256 scaledNumerator,
uint256 scaledDenominator
)
{
// If either the numerator or the denominator are > `maxValue`,
// re-scale them by `maxValue` to prevent overflows in future operations.
if (numerator > maxValue || denominator > maxValue) {
uint256 rescaleBase = numerator >= denominator ? numerator : denominator;
rescaleBase /= RESCALE_THRESHOLD;
numerator = numerator.safeDiv(rescaleBase);
denominator = denominator.safeDiv(rescaleBase);
rescaleBase /= maxValue;
scaledNumerator = numerator.safeDiv(rescaleBase);
scaledDenominator = denominator.safeDiv(rescaleBase);
} else {
scaledNumerator = numerator;
scaledDenominator = denominator;
}
return (scaledNumerator, scaledDenominator);
}
/// @dev Rescales a fraction to prevent overflows during addition if either
/// the numerator or the denominator are > 2 ** 127.
/// @param numerator The numerator.
/// @param denominator The denominator.
/// @return scaledNumerator The rescaled numerator.
/// @return scaledDenominator The rescaled denominator.
function normalize(
uint256 numerator,
uint256 denominator
)
internal
pure
returns (
uint256 scaledNumerator,
uint256 scaledDenominator
)
{
return normalize(numerator, denominator, 2 ** 127);
}
/// @dev Safely scales the difference between two fractions.
@@ -57,8 +100,8 @@ library LibFractions {
/// @param n2 numerator of `2`
/// @param d2 denominator of `2`
/// @param s scalar to multiply by difference.
/// @return result = `s * (n1/d1 - n2/d2)`.
function scaleFractionalDifference(
/// @return result `s * (n1/d1 - n2/d2)`.
function scaleDifference(
uint256 n1,
uint256 d1,
uint256 n2,
@@ -81,7 +124,7 @@ library LibFractions {
.safeMul(d2)
.safeSub(n2.safeMul(d1));
uint256 tmp = numerator.safeDiv(d2);
result = s
return s
.safeMul(tmp)
.safeDiv(d1);
}