Merge pull request #147 from BeanstalkFarms/multi-flow-pump-1.2.1

Multi flow pump 1.2.1

package.json

@@ -1,6 +1,6 @@
 {
   "name": "@beanstalk/wells",
-  "version": "1.3.0",
+  "version": "1.3.1",
   "description": "A [{Well}](/src/Well.sol) is a constant function AMM that allows the provisioning of liquidity into a single pooled on-chain liquidity position.",
   "main": "index.js",
   "directories": {

script/deploy/helpers/Logger.sol

@@ -8,7 +8,9 @@ import {console} from "forge-std/console.sol";
 import {Well} from "src/Well.sol";
 
 library logger {
-    function logWell(Well well) public view {
+    function logWell(
+        Well well
+    ) public view {
         console.log("\nWELL:", address(well));
         console.log("Name  \t", well.name());
         console.log("Symbol\t", well.symbol());

src/Well.sol

@@ -408,7 +408,9 @@ contract Well is ERC20PermitUpgradeable, IWell, IWellErrors, ReentrancyGuardUpgr
         }
     }
 
-    function getShiftOut(IERC20 tokenOut) external view readOnlyNonReentrant returns (uint256 amountOut) {
+    function getShiftOut(
+        IERC20 tokenOut
+    ) external view readOnlyNonReentrant returns (uint256 amountOut) {
         IERC20[] memory _tokens = tokens();
         uint256 tokensLength = _tokens.length;
         uint256[] memory reserves = new uint256[](tokensLength);
@@ -674,7 +676,9 @@ contract Well is ERC20PermitUpgradeable, IWell, IWellErrors, ReentrancyGuardUpgr
     /**
      * @dev Transfer excess tokens held by the Well to `recipient`.
      */
-    function skim(address recipient) external nonReentrant returns (uint256[] memory skimAmounts) {
+    function skim(
+        address recipient
+    ) external nonReentrant returns (uint256[] memory skimAmounts) {
         IERC20[] memory _tokens = tokens();
         uint256 tokensLength = _tokens.length;
         uint256[] memory reserves = _getReserves(tokensLength);
@@ -694,7 +698,9 @@ contract Well is ERC20PermitUpgradeable, IWell, IWellErrors, ReentrancyGuardUpgr
     /**
      * @dev Gets the Well's token reserves by reading from byte storage.
      */
-    function _getReserves(uint256 _numberOfTokens) internal view returns (uint256[] memory reserves) {
+    function _getReserves(
+        uint256 _numberOfTokens
+    ) internal view returns (uint256[] memory reserves) {
         reserves = LibBytes.readUint128(RESERVES_STORAGE_SLOT, _numberOfTokens);
     }
 
@@ -717,7 +723,9 @@ contract Well is ERC20PermitUpgradeable, IWell, IWellErrors, ReentrancyGuardUpgr
      * @dev Fetches the current token reserves of the Well and updates the Pumps.
      * Typically called before an operation that modifies the Well's reserves.
      */
-    function _updatePumps(uint256 _numberOfTokens) internal returns (uint256[] memory reserves) {
+    function _updatePumps(
+        uint256 _numberOfTokens
+    ) internal returns (uint256[] memory reserves) {
         reserves = _getReserves(_numberOfTokens);
 
         uint256 _numberOfPumps = numberOfPumps();
@@ -861,7 +869,9 @@ contract Well is ERC20PermitUpgradeable, IWell, IWellErrors, ReentrancyGuardUpgr
     /**
      * @dev Reverts if the deadline has passed.
      */
-    modifier expire(uint256 deadline) {
+    modifier expire(
+        uint256 deadline
+    ) {
         if (block.timestamp > deadline) {
             revert Expired();
         }

src/WellUpgradeable.sol

@@ -60,7 +60,9 @@ contract WellUpgradeable is Well, UUPSUpgradeable, OwnableUpgradeable {
      * @notice Check that the execution is being performed through a delegatecall call and that the execution context is
      * a proxy contract with an ERC1167 minimal proxy from an aquifier, pointing to a well implmentation.
      */
-    function _authorizeUpgrade(address newImplementation) internal view override onlyOwner {
+    function _authorizeUpgrade(
+        address newImplementation
+    ) internal view override onlyOwner {
         // verify the function is called through a delegatecall.
         require(address(this) != ___self, "Function must be called through delegatecall");
 
@@ -96,7 +98,9 @@ contract WellUpgradeable is Well, UUPSUpgradeable, OwnableUpgradeable {
      * @dev `upgradeTo` was modified to support ERC-1167 minimal proxies
      * cloned (Bored) by an Aquifer.
      */
-    function upgradeTo(address newImplementation) public override {
+    function upgradeTo(
+        address newImplementation
+    ) public override {
         _authorizeUpgrade(newImplementation);
         _upgradeToAndCallUUPS(newImplementation, new bytes(0), false);
     }

src/functions/ConstantProduct2.sol

@@ -82,7 +82,7 @@ contract ConstantProduct2 is ProportionalLPToken2, IBeanstalkWellFunction {
     }
 
     function version() external pure override returns (string memory) {
-        return "1.2.0";
+        return "1.2.1";
     }
 
     /// @dev `b_j = (b_0 * b_1 * r_j / r_i)^(1/2)`
@@ -107,7 +107,7 @@ contract ConstantProduct2 is ProportionalLPToken2, IBeanstalkWellFunction {
         bytes calldata
     ) external pure override returns (uint256 reserve) {
         uint256 i = j == 1 ? 0 : 1;
-        reserve = reserves[i] * ratios[j] / ratios[i];
+        reserve = reserves[i].mulDiv(ratios[j], ratios[i]);
     }
 
     function calcRate(
@@ -116,7 +116,7 @@ contract ConstantProduct2 is ProportionalLPToken2, IBeanstalkWellFunction {
         uint256 j,
         bytes calldata
     ) external pure returns (uint256 rate) {
-        return reserves[i] * CALC_RATE_PRECISION / reserves[j];
+        rate = reserves[i].mulDiv(CALC_RATE_PRECISION, reserves[j]);
     }
 
     /**

src/functions/StableLUT/Stable2LUT1.sol

@@ -24,7 +24,9 @@ contract Stable2LUT1 is ILookupTable {
      * @notice Returns the estimated range of reserve ratios for a given price,
      * assuming one token reserve remains constant.
      */
-    function getRatiosFromPriceLiquidity(uint256 price) external pure returns (PriceData memory) {
+    function getRatiosFromPriceLiquidity(
+        uint256 price
+    ) external pure returns (PriceData memory) {
         if (price < 1.006758e6) {
             if (price < 0.885627e6) {
                 if (price < 0.59332e6) {
@@ -737,7 +739,9 @@ contract Stable2LUT1 is ILookupTable {
      * @notice Returns the estimated range of reserve ratios for a given price,
      * assuming the pool liquidity remains constant.
      */
-    function getRatiosFromPriceSwap(uint256 price) external pure returns (PriceData memory) {
+    function getRatiosFromPriceSwap(
+        uint256 price
+    ) external pure returns (PriceData memory) {
         if (price < 0.993344e6) {
             if (price < 0.834426e6) {
                 if (price < 0.718073e6) {

src/interfaces/IAquifer.sol

@@ -65,5 +65,7 @@ interface IAquifer {
      * @dev Always verify that a Well was deployed by a trusted Aquifer using a trusted implementation before using.
      * If `wellImplementation == address(0)`, then the Aquifer did not deploy the Well.
      */
-    function wellImplementation(address well) external view returns (address implementation);
+    function wellImplementation(
+        address well
+    ) external view returns (address implementation);
 }

src/interfaces/ILookupTable.sol

@@ -29,7 +29,11 @@ interface ILookupTable {
         uint256 precision;
     }
 
-    function getRatiosFromPriceLiquidity(uint256) external view returns (PriceData memory);
-    function getRatiosFromPriceSwap(uint256) external view returns (PriceData memory);
+    function getRatiosFromPriceLiquidity(
+        uint256
+    ) external view returns (PriceData memory);
+    function getRatiosFromPriceSwap(
+        uint256
+    ) external view returns (PriceData memory);
     function getAParameter() external view returns (uint256);
 }

src/interfaces/IWell.sol

@@ -238,7 +238,9 @@ interface IWell {
      * @param tokenOut The token to shift into
      * @return amountOut The amount of `tokenOut` received
      */
-    function getShiftOut(IERC20 tokenOut) external returns (uint256 amountOut);
+    function getShiftOut(
+        IERC20 tokenOut
+    ) external returns (uint256 amountOut);
 
     //////////////////// ADD LIQUIDITY ////////////////////
 
@@ -279,7 +281,9 @@ interface IWell {
      * @param tokenAmountsIn The amount of each token to add; MUST match the indexing of {Well.tokens}
      * @return lpAmountOut The amount of LP tokens received
      */
-    function getAddLiquidityOut(uint256[] memory tokenAmountsIn) external view returns (uint256 lpAmountOut);
+    function getAddLiquidityOut(
+        uint256[] memory tokenAmountsIn
+    ) external view returns (uint256 lpAmountOut);
 
     //////////////////// REMOVE LIQUIDITY: BALANCED ////////////////////
 
@@ -303,7 +307,9 @@ interface IWell {
      * @param lpAmountIn The amount of LP tokens to burn
      * @return tokenAmountsOut The amount of each underlying token received
      */
-    function getRemoveLiquidityOut(uint256 lpAmountIn) external view returns (uint256[] memory tokenAmountsOut);
+    function getRemoveLiquidityOut(
+        uint256 lpAmountIn
+    ) external view returns (uint256[] memory tokenAmountsOut);
 
     //////////////////// REMOVE LIQUIDITY: ONE TOKEN ////////////////////
 
@@ -388,7 +394,9 @@ interface IWell {
      * @return skimAmounts The amount of each token skimmed
      * @dev No deadline is needed since this function does not use the user's assets.
      */
-    function skim(address recipient) external returns (uint256[] memory skimAmounts);
+    function skim(
+        address recipient
+    ) external returns (uint256[] memory skimAmounts);
 
     /**
      * @notice Gets the reserves of each token held by the Well.

src/libraries/LibContractInfo.sol

@@ -13,7 +13,9 @@ library LibContractInfo {
      * @return symbol The symbol of the contract
      * @dev if the contract does not have a symbol function, the first 4 bytes of the address are returned
      */
-    function getSymbol(address _contract) internal view returns (string memory symbol) {
+    function getSymbol(
+        address _contract
+    ) internal view returns (string memory symbol) {
         (bool success, bytes memory data) = _contract.staticcall(abi.encodeWithSignature("symbol()"));
         symbol = new string(4);
         if (success) {
@@ -31,7 +33,9 @@ library LibContractInfo {
      * @return name The name of the contract
      * @dev if the contract does not have a name function, the first 8 bytes of the address are returned
      */
-    function getName(address _contract) internal view returns (string memory name) {
+    function getName(
+        address _contract
+    ) internal view returns (string memory name) {
         (bool success, bytes memory data) = _contract.staticcall(abi.encodeWithSignature("name()"));
         name = new string(8);
         if (success) {
@@ -49,7 +53,9 @@ library LibContractInfo {
      * @return decimals The decimals of the contract
      * @dev if the contract does not have a decimals function, 18 is returned
      */
-    function getDecimals(address _contract) internal view returns (uint8 decimals) {
+    function getDecimals(
+        address _contract
+    ) internal view returns (uint8 decimals) {
         (bool success, bytes memory data) = _contract.staticcall(abi.encodeWithSignature("decimals()"));
         decimals = success ? abi.decode(data, (uint8)) : 18; // default to 18 decimals
     }

src/libraries/LibLastReserveBytes.sol

@@ -20,7 +20,9 @@ library LibLastReserveBytes {
     using ABDKMathQuad for uint256;
     using ABDKMathQuad for bytes16;
 
-    function readNumberOfReserves(bytes32 slot) internal view returns (uint8 _numberOfReserves) {
+    function readNumberOfReserves(
+        bytes32 slot
+    ) internal view returns (uint8 _numberOfReserves) {
         assembly {
             _numberOfReserves := shr(248, sload(slot))
         }
@@ -137,7 +139,17 @@ library LibLastReserveBytes {
         }
     }
 
-    function readBytes(bytes32 slot) internal view returns (bytes32 value) {
+    function resetLastReserves(bytes32 slot, uint256 n) internal {
+        for (uint256 i; i < (n + 1) / 2; ++i) {
+            assembly {
+                sstore(add(slot, i), 0)
+            }
+        }
+    }
+
+    function readBytes(
+        bytes32 slot
+    ) internal view returns (bytes32 value) {
         assembly {
             value := sload(slot)
         }

src/libraries/LibMath.sol

@@ -68,7 +68,9 @@ library LibMath {
      * Implementation from: https://github.com/Gaussian-Process/solidity-sqrt/blob/main/src/FixedPointMathLib.sol
      * based on https://github.com/transmissions11/solmate/blob/main/src/utils/FixedPointMathLib.sol
      */
-    function sqrt(uint256 a) internal pure returns (uint256 z) {
+    function sqrt(
+        uint256 a
+    ) internal pure returns (uint256 z) {
         /// @solidity memory-safe-assembly
         assembly {
             let y := a // We start y at a, which will help us make our initial estimate.

src/pumps/MultiFlowPump.sol

@@ -91,6 +91,11 @@ contract MultiFlowPump is IPump, IMultiFlowPumpErrors, IInstantaneousPump, ICumu
             return;
         }
 
+        if (reserves[0] == 0 && reserves[1] == 0) {
+            slot.resetLastReserves(numberOfReserves);
+            return;
+        }
+
         bytes16 alphaN;
         bytes16 deltaTimestampBytes;
         uint256 capExponent;
@@ -107,6 +112,12 @@ contract MultiFlowPump is IPump, IMultiFlowPumpErrors, IInstantaneousPump, ICumu
 
         pumpState.lastReserves = _capReserves(msg.sender, pumpState.lastReserves, reserves, capExponent, crp);
 
+        // If the last reserves have been manipulated to 0, reset the pump.
+        if (pumpState.lastReserves[0] == 0 && pumpState.lastReserves[1] == 0) {
+            slot.resetLastReserves(numberOfReserves);
+            return;
+        }
+
         // Read: Cumulative & EMA Reserves
         // Start at the slot after `pumpState.lastReserves`
         uint256 numSlots = _getSlotsOffset(numberOfReserves);
@@ -265,6 +276,12 @@ contract MultiFlowPump is IPump, IMultiFlowPumpErrors, IInstantaneousPump, ICumu
         crv.rLast = tryCalcRate(mfpWf, lastReserves, i, j, data);
         crv.r = tryCalcRate(mfpWf, cappedReserves, i, j, data);
 
+        // The ratio can only be infinite due to unintended behavior.
+        // Therefore, to get the reseves back to a normal state, return the current reserves.
+        if (crv.rLast == type(uint256).max) {
+            return reserves;
+        }
+
         // If the ratio increased, check that it didn't increase above the max.
         if (crv.r > crv.rLast) {
             bytes16 tempExp = ABDKMathQuad.ONE.add(crp.maxRateChanges[i][j]).powu(capExponent);
@@ -318,7 +335,7 @@ contract MultiFlowPump is IPump, IMultiFlowPumpErrors, IInstantaneousPump, ICumu
                 if (returnIfBelowMin) return new uint256[](0);
                 cappedReserves = tryCalcLPTokenUnderlying(mfpWf, maxLpTokenSupply, cappedReserves, lpTokenSupply, data);
             }
-            // If LP Token Suppply decreased, check that it didn't decrease below the min.
+            // If LP Token Supply decreased, check that it didn't decrease below the min.
         } else if (lpTokenSupply < lastLpTokenSupply) {
             uint256 minLpTokenSupply = lastLpTokenSupply
                 * (ABDKMathQuad.ONE.sub(crp.maxLpSupplyDecrease)).powu(capExponent).to128x128().toUint256() / CAP_PRECISION2;
@@ -541,7 +558,7 @@ contract MultiFlowPump is IPump, IMultiFlowPumpErrors, IInstantaneousPump, ICumu
         try wf.calcReserveAtRatioSwap(reserves, i, ratios, data) returns (uint256 _reserve) {
             reserve = _reserve;
         } catch {
-            reserve = type(uint256).max;
+            reserve = type(uint128).max;
         }
     }
 
@@ -595,15 +612,10 @@ contract MultiFlowPump is IPump, IMultiFlowPumpErrors, IInstantaneousPump, ICumu
             uint256[] memory _underlyingAmounts
         ) {
             underlyingAmounts = _underlyingAmounts;
-            for (uint256 i; i < underlyingAmounts.length; ++i) {
-                if (underlyingAmounts[i] == 0) {
-                    underlyingAmounts[i] = 1;
-                }
-            }
         } catch {
             underlyingAmounts = new uint256[](reserves.length);
             for (uint256 i; i < reserves.length; ++i) {
-                underlyingAmounts[i] = type(uint256).max;
+                underlyingAmounts[i] = 0;
             }
         }
     }

test/Stable2/Well.Stable2.RemoveLiquidity.t.sol

@@ -81,7 +81,9 @@ contract WellStable2RemoveLiquidityTest is LiquidityHelper {
 
     /// @dev Fuzz test: EQUAL token reserves, BALANCED removal
     /// The Well contains equal reserves of all underlying tokens before execution.
-    function test_removeLiquidity_fuzz(uint256 a0) public prank(user) {
+    function test_removeLiquidity_fuzz(
+        uint256 a0
+    ) public prank(user) {
         // Setup amounts of liquidity to remove
         // NOTE: amounts may or may not match the maximum removable by `user`.
         uint256[] memory amounts = new uint256[](2);

test/Stable2/Well.Stable2.RemoveLiquidityOneToken.t.sol

@@ -78,7 +78,9 @@ contract WellStable2RemoveLiquidityOneTokenTest is TestHelper {
 
     /// @dev Fuzz test: EQUAL token reserves, IMBALANCED removal
     /// The Well contains equal reserves of all underlying tokens before execution.
-    function testFuzz_removeLiquidityOneToken(uint256 a0) public prank(user) {
+    function testFuzz_removeLiquidityOneToken(
+        uint256 a0
+    ) public prank(user) {
         // Assume we're removing tokens[0]
         uint256[] memory amounts = new uint256[](2);
         amounts[0] = bound(a0, 1e18, 750e18);