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Diffstat (limited to 'packages/contracts/src/2.0.0/extensions/Forwarder/MixinForwarderCore.sol')
-rw-r--r-- | packages/contracts/src/2.0.0/extensions/Forwarder/MixinForwarderCore.sol | 213 |
1 files changed, 213 insertions, 0 deletions
diff --git a/packages/contracts/src/2.0.0/extensions/Forwarder/MixinForwarderCore.sol b/packages/contracts/src/2.0.0/extensions/Forwarder/MixinForwarderCore.sol new file mode 100644 index 000000000..42cec4d36 --- /dev/null +++ b/packages/contracts/src/2.0.0/extensions/Forwarder/MixinForwarderCore.sol @@ -0,0 +1,213 @@ +/* + + 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; +pragma experimental ABIEncoderV2; + +import "./libs/LibConstants.sol"; +import "./mixins/MWeth.sol"; +import "./mixins/MAssets.sol"; +import "./mixins/MExchangeWrapper.sol"; +import "./interfaces/IForwarderCore.sol"; +import "../../utils/LibBytes/LibBytes.sol"; +import "../../protocol/Exchange/libs/LibOrder.sol"; +import "../../protocol/Exchange/libs/LibFillResults.sol"; +import "../../protocol/Exchange/libs/LibMath.sol"; + + +contract MixinForwarderCore is + LibFillResults, + LibMath, + LibConstants, + MWeth, + MAssets, + MExchangeWrapper, + IForwarderCore +{ + + using LibBytes for bytes; + + /// @dev Constructor approves ERC20 proxy to transfer ZRX and WETH on this contract's behalf. + constructor () + public + { + address proxyAddress = EXCHANGE.getAssetProxy(ERC20_DATA_ID); + if (proxyAddress != address(0)) { + ETHER_TOKEN.approve(proxyAddress, MAX_UINT); + ZRX_TOKEN.approve(proxyAddress, MAX_UINT); + } + } + + /// @dev Purchases as much of orders' makerAssets as possible by selling up to 95% of transaction's ETH value. + /// Any ZRX required to pay fees for primary orders will automatically be purchased by this contract. + /// 5% of ETH value is reserved for paying fees to order feeRecipients (in ZRX) and forwarding contract feeRecipient (in ETH). + /// Any ETH not spent will be refunded to sender. + /// @param orders Array of order specifications used containing desired makerAsset and WETH as takerAsset. + /// @param signatures Proofs that orders have been created by makers. + /// @param feeOrders Array of order specifications containing ZRX as makerAsset and WETH as takerAsset. Used to purchase ZRX for primary order fees. + /// @param feeSignatures Proofs that feeOrders have been created by makers. + /// @param feePercentage Percentage of WETH sold that will payed as fee to forwarding contract feeRecipient. + /// @param feeRecipient Address that will receive ETH when orders are filled. + /// @return Amounts filled and fees paid by maker and taker for both sets of orders. + function marketSellOrdersWithEth( + LibOrder.Order[] memory orders, + bytes[] memory signatures, + LibOrder.Order[] memory feeOrders, + bytes[] memory feeSignatures, + uint256 feePercentage, + address feeRecipient + ) + public + payable + returns ( + FillResults memory orderFillResults, + FillResults memory feeOrderFillResults + ) + { + // Convert ETH to WETH. + convertEthToWeth(); + + uint256 wethSellAmount; + uint256 zrxBuyAmount; + uint256 makerAssetAmountPurchased; + if (orders[0].makerAssetData.equals(ZRX_ASSET_DATA)) { + // Calculate amount of WETH that won't be spent on ETH fees. + wethSellAmount = getPartialAmount( + PERCENTAGE_DENOMINATOR, + safeAdd(PERCENTAGE_DENOMINATOR, feePercentage), + msg.value + ); + // Market sell available WETH. + // ZRX fees are paid with this contract's balance. + orderFillResults = marketSellWeth( + orders, + wethSellAmount, + signatures + ); + // The fee amount must be deducted from the amount transfered back to sender. + makerAssetAmountPurchased = safeSub(orderFillResults.makerAssetFilledAmount, orderFillResults.takerFeePaid); + } else { + // 5% of WETH is reserved for filling feeOrders and paying feeRecipient. + wethSellAmount = getPartialAmount( + MAX_WETH_FILL_PERCENTAGE, + PERCENTAGE_DENOMINATOR, + msg.value + ); + // Market sell 95% of WETH. + // ZRX fees are payed with this contract's balance. + orderFillResults = marketSellWeth( + orders, + wethSellAmount, + signatures + ); + // Buy back all ZRX spent on fees. + zrxBuyAmount = orderFillResults.takerFeePaid; + feeOrderFillResults = marketBuyExactZrxWithWeth( + feeOrders, + zrxBuyAmount, + feeSignatures + ); + makerAssetAmountPurchased = orderFillResults.makerAssetFilledAmount; + } + + // Transfer feePercentage of total ETH spent on primary orders to feeRecipient. + // Refund remaining ETH to msg.sender. + transferEthFeeAndRefund( + orderFillResults.takerAssetFilledAmount, + feeOrderFillResults.takerAssetFilledAmount, + feePercentage, + feeRecipient + ); + + // Transfer purchased assets to msg.sender. + transferAssetToSender(orders[0].makerAssetData, makerAssetAmountPurchased); + } + + /// @dev Attempt to purchase makerAssetFillAmount of makerAsset by selling ETH provided with transaction. + /// Any ZRX required to pay fees for primary orders will automatically be purchased by this contract. + /// Any ETH not spent will be refunded to sender. + /// @param orders Array of order specifications used containing desired makerAsset and WETH as takerAsset. + /// @param makerAssetFillAmount Desired amount of makerAsset to purchase. + /// @param signatures Proofs that orders have been created by makers. + /// @param feeOrders Array of order specifications containing ZRX as makerAsset and WETH as takerAsset. Used to purchase ZRX for primary order fees. + /// @param feeSignatures Proofs that feeOrders have been created by makers. + /// @param feePercentage Percentage of WETH sold that will payed as fee to forwarding contract feeRecipient. + /// @param feeRecipient Address that will receive ETH when orders are filled. + /// @return Amounts filled and fees paid by maker and taker for both sets of orders. + function marketBuyOrdersWithEth( + LibOrder.Order[] memory orders, + uint256 makerAssetFillAmount, + bytes[] memory signatures, + LibOrder.Order[] memory feeOrders, + bytes[] memory feeSignatures, + uint256 feePercentage, + address feeRecipient + ) + public + payable + returns ( + FillResults memory orderFillResults, + FillResults memory feeOrderFillResults + ) + { + // Convert ETH to WETH. + convertEthToWeth(); + + uint256 zrxBuyAmount; + uint256 makerAssetAmountPurchased; + if (orders[0].makerAssetData.equals(ZRX_ASSET_DATA)) { + // If the makerAsset is ZRX, it is not necessary to pay fees out of this + // contracts's ZRX balance because fees are factored into the price of the order. + orderFillResults = marketBuyExactZrxWithWeth( + orders, + makerAssetFillAmount, + signatures + ); + // The fee amount must be deducted from the amount transfered back to sender. + makerAssetAmountPurchased = safeSub(orderFillResults.makerAssetFilledAmount, orderFillResults.takerFeePaid); + } else { + // Attemp to purchase desired amount of makerAsset. + // ZRX fees are payed with this contract's balance. + orderFillResults = marketBuyExactAmountWithWeth( + orders, + makerAssetFillAmount, + signatures + ); + // Buy back all ZRX spent on fees. + zrxBuyAmount = orderFillResults.takerFeePaid; + feeOrderFillResults = marketBuyExactZrxWithWeth( + feeOrders, + zrxBuyAmount, + feeSignatures + ); + makerAssetAmountPurchased = orderFillResults.makerAssetFilledAmount; + } + + // Transfer feePercentage of total ETH spent on primary orders to feeRecipient. + // Refund remaining ETH to msg.sender. + transferEthFeeAndRefund( + orderFillResults.takerAssetFilledAmount, + feeOrderFillResults.takerAssetFilledAmount, + feePercentage, + feeRecipient + ); + + // Transfer purchased assets to msg.sender. + transferAssetToSender(orders[0].makerAssetData, makerAssetAmountPurchased); + } +} |