diff options
Diffstat (limited to 'packages/asset-buyer/src/utils/order_fetcher_response_processor.ts')
-rw-r--r-- | packages/asset-buyer/src/utils/order_fetcher_response_processor.ts | 184 |
1 files changed, 184 insertions, 0 deletions
diff --git a/packages/asset-buyer/src/utils/order_fetcher_response_processor.ts b/packages/asset-buyer/src/utils/order_fetcher_response_processor.ts new file mode 100644 index 000000000..f1116a80f --- /dev/null +++ b/packages/asset-buyer/src/utils/order_fetcher_response_processor.ts @@ -0,0 +1,184 @@ +import { OrderAndTraderInfo, OrderStatus, OrderValidatorWrapper } from '@0xproject/contract-wrappers'; +import { sortingUtils } from '@0xproject/order-utils'; +import { RemainingFillableCalculator } from '@0xproject/order-utils/lib/src/remaining_fillable_calculator'; +import { SignedOrder } from '@0xproject/types'; +import { BigNumber } from '@0xproject/utils'; +import * as _ from 'lodash'; + +import { constants } from '../constants'; +import { + AssetBuyerOrdersAndFillableAmounts, + OrderFetcherResponse, + SignedOrderWithRemainingFillableMakerAssetAmount, +} from '../types'; + +import { orderUtils } from './order_utils'; + +interface OrdersAndRemainingFillableMakerAssetAmounts { + orders: SignedOrder[]; + remainingFillableMakerAssetAmounts: BigNumber[]; +} + +export const orderFetcherResponseProcessor = { + /** + * Take the responses for the target orders to buy and fee orders and process them. + * Processing includes: + * - Drop orders that are expired or not open orders (null taker address) + * - If shouldValidateOnChain, attempt to grab fillable amounts from on-chain otherwise assume completely fillable + * - Sort by rate + */ + async processAsync( + targetOrderFetcherResponse: OrderFetcherResponse, + feeOrderFetcherResponse: OrderFetcherResponse, + zrxTokenAssetData: string, + orderValidator?: OrderValidatorWrapper, + ): Promise<AssetBuyerOrdersAndFillableAmounts> { + // drop orders that are expired or not open + const filteredTargetOrders = filterOutExpiredAndNonOpenOrders(targetOrderFetcherResponse.orders); + const filteredFeeOrders = filterOutExpiredAndNonOpenOrders(feeOrderFetcherResponse.orders); + // set the orders to be sorted equal to the filtered orders + let unsortedTargetOrders = filteredTargetOrders; + let unsortedFeeOrders = filteredFeeOrders; + // if an orderValidator is provided, use on chain information to calculate remaining fillable makerAsset amounts + if (!_.isUndefined(orderValidator)) { + // TODO: critical + // try catch these requests and throw a more domain specific error + // TODO: optimization + // reduce this to once RPC call buy combining orders into one array and then splitting up the response + const [targetOrdersAndTradersInfo, feeOrdersAndTradersInfo] = await Promise.all( + _.map([filteredTargetOrders, filteredFeeOrders], ordersToBeValidated => { + const takerAddresses = _.map(ordersToBeValidated, () => constants.NULL_ADDRESS); + return orderValidator.getOrdersAndTradersInfoAsync(ordersToBeValidated, takerAddresses); + }), + ); + // take orders + on chain information and find the valid orders and remaining fillable maker asset amounts + unsortedTargetOrders = getValidOrdersWithRemainingFillableMakerAssetAmountsFromOnChain( + filteredTargetOrders, + targetOrdersAndTradersInfo, + zrxTokenAssetData, + ); + // take orders + on chain information and find the valid orders and remaining fillable maker asset amounts + unsortedFeeOrders = getValidOrdersWithRemainingFillableMakerAssetAmountsFromOnChain( + filteredFeeOrders, + feeOrdersAndTradersInfo, + zrxTokenAssetData, + ); + } + // sort orders by rate + // TODO: optimization + // provide a feeRate to the sorting function to more accurately sort based on the current market for ZRX tokens + const sortedTargetOrders = sortingUtils.sortOrdersByFeeAdjustedRate(unsortedTargetOrders); + const sortedFeeOrders = sortingUtils.sortFeeOrdersByFeeAdjustedRate(unsortedFeeOrders); + // unbundle orders and fillable amounts and compile final result + const targetOrdersAndRemainingFillableMakerAssetAmounts = unbundleOrdersWithAmounts(sortedTargetOrders); + const feeOrdersAndRemainingFillableMakerAssetAmounts = unbundleOrdersWithAmounts(sortedFeeOrders); + return { + orders: targetOrdersAndRemainingFillableMakerAssetAmounts.orders, + feeOrders: feeOrdersAndRemainingFillableMakerAssetAmounts.orders, + remainingFillableMakerAssetAmounts: + targetOrdersAndRemainingFillableMakerAssetAmounts.remainingFillableMakerAssetAmounts, + remainingFillableFeeAmounts: + feeOrdersAndRemainingFillableMakerAssetAmounts.remainingFillableMakerAssetAmounts, + }; + }, +}; + +/** + * Given an array of orders, return a new array with expired and non open orders filtered out. + */ +function filterOutExpiredAndNonOpenOrders( + orders: SignedOrderWithRemainingFillableMakerAssetAmount[], +): SignedOrderWithRemainingFillableMakerAssetAmount[] { + const result = _.filter(orders, order => { + return orderUtils.isOpenOrder(order) && orderUtils.isOrderExpired(order); + }); + return result; +} + +/** + * Given an array of orders and corresponding on-chain infos, return a subset of the orders + * that are still fillable orders with their corresponding remainingFillableMakerAssetAmounts. + */ +function getValidOrdersWithRemainingFillableMakerAssetAmountsFromOnChain( + inputOrders: SignedOrder[], + ordersAndTradersInfo: OrderAndTraderInfo[], + zrxAssetData: string, +): SignedOrderWithRemainingFillableMakerAssetAmount[] { + // iterate through the input orders and find the ones that are still fillable + // for the orders that are still fillable, calculate the remaining fillable maker asset amount + const result = _.reduce( + inputOrders, + (accOrders, order, index) => { + // get corresponding on-chain state for the order + const { orderInfo, traderInfo } = ordersAndTradersInfo[index]; + // if the order IS NOT fillable, do not add anything to the accumulations and continue iterating + if (orderInfo.orderStatus !== OrderStatus.FILLABLE) { + return accOrders; + } + // if the order IS fillable, add the order and calculate the remaining fillable amount + const transferrableAssetAmount = BigNumber.min([traderInfo.makerAllowance, traderInfo.makerBalance]); + const transferrableFeeAssetAmount = BigNumber.min([ + traderInfo.makerZrxAllowance, + traderInfo.makerZrxBalance, + ]); + const remainingTakerAssetAmount = order.takerAssetAmount.minus(orderInfo.orderTakerAssetFilledAmount); + const remainingMakerAssetAmount = orderUtils.calculateRemainingMakerAssetAmount( + order, + remainingTakerAssetAmount, + ); + const remainingFillableCalculator = new RemainingFillableCalculator( + order.makerFee, + order.makerAssetAmount, + order.makerAssetData === zrxAssetData, + transferrableAssetAmount, + transferrableFeeAssetAmount, + remainingMakerAssetAmount, + ); + const remainingFillableAmount = remainingFillableCalculator.computeRemainingFillable(); + // if the order does not have any remaining fillable makerAsset, do not add anything to the accumulations and continue iterating + if (remainingFillableAmount.lte(constants.ZERO_AMOUNT)) { + return accOrders; + } + const orderWithRemainingFillableMakerAssetAmount = { + ...order, + remainingFillableMakerAssetAmount: remainingFillableAmount, + }; + const newAccOrders = _.concat(accOrders, orderWithRemainingFillableMakerAssetAmount); + return newAccOrders; + }, + [] as SignedOrderWithRemainingFillableMakerAssetAmount[], + ); + return result; +} + +/** + * Given an array of orders with remaining fillable maker asset amounts. Unbundle into an instance of OrdersAndRemainingFillableMakerAssetAmounts. + * If an order is missing a corresponding remainingFillableMakerAssetAmount, assume it is completely fillable. + */ +function unbundleOrdersWithAmounts( + ordersWithAmounts: SignedOrderWithRemainingFillableMakerAssetAmount[], +): OrdersAndRemainingFillableMakerAssetAmounts { + const result = _.reduce( + ordersWithAmounts, + (acc, orderWithAmount) => { + const { orders, remainingFillableMakerAssetAmounts } = acc; + const { remainingFillableMakerAssetAmount, ...order } = orderWithAmount; + // if we are still missing a remainingFillableMakerAssetAmount, assume the order is completely fillable + const newRemainingAmount = remainingFillableMakerAssetAmount || order.makerAssetAmount; + // if remaining amount is less than or equal to zero, do not add it + if (newRemainingAmount.lte(constants.ZERO_AMOUNT)) { + return acc; + } + const newAcc = { + orders: _.concat(orders, order), + remainingFillableMakerAssetAmounts: _.concat(remainingFillableMakerAssetAmounts, newRemainingAmount), + }; + return newAcc; + }, + { + orders: [] as SignedOrder[], + remainingFillableMakerAssetAmounts: [] as BigNumber[], + }, + ); + return result; +} |