Merge pull request #936 from 0xProject/feature/contract-wrappers/forwader-optimizations

ForwarderWrapper order optimizations

2 files changed, 45 insertions, 0 deletions

diff --git a/packages/contract-wrappers/src/utils/calldata_optimization_utils.ts b/packages/contract-wrappers/src/utils/calldata_optimization_utils.ts
new file mode 100644
index 000000000..3172cf531
--- /dev/null
+++ b/packages/contract-wrappers/src/utils/calldata_optimization_utils.ts
@@ -0,0 +1,44 @@
+import { SignedOrder } from '@0xproject/types';
+import * as _ from 'lodash';
+
+import { constants } from './constants';
+
+export const calldataOptimizationUtils = {
+    /**
+     * Takes an array of orders and outputs an array of equivalent orders where all takerAssetData are '0x' and
+     * all makerAssetData are '0x' except for that of the first order, which retains its original value
+     * @param   orders         An array of SignedOrder objects
+     * @returns optimized orders
+     */
+    optimizeForwarderOrders(orders: SignedOrder[]): SignedOrder[] {
+        const optimizedOrders = _.map(orders, (order, index) =>
+            transformOrder(order, {
+                makerAssetData: index === 0 ? order.makerAssetData : constants.NULL_BYTES,
+                takerAssetData: constants.NULL_BYTES,
+            }),
+        );
+        return optimizedOrders;
+    },
+    /**
+     * Takes an array of orders and outputs an array of equivalent orders where all takerAssetData are '0x' and
+     * all makerAssetData are '0x'
+     * @param   orders         An array of SignedOrder objects
+     * @returns optimized orders
+     */
+    optimizeForwarderFeeOrders(orders: SignedOrder[]): SignedOrder[] {
+        const optimizedOrders = _.map(orders, (order, index) =>
+            transformOrder(order, {
+                makerAssetData: constants.NULL_BYTES,
+                takerAssetData: constants.NULL_BYTES,
+            }),
+        );
+        return optimizedOrders;
+    },
+};
+
+const transformOrder = (order: SignedOrder, partialOrder: Partial<SignedOrder>) => {
+    return {
+        ...order,
+        ...partialOrder,
+    };
+};
diff --git a/packages/contract-wrappers/src/utils/constants.ts b/packages/contract-wrappers/src/utils/constants.ts
index d436efefc..2df11538c 100644
--- a/packages/contract-wrappers/src/utils/constants.ts
+++ b/packages/contract-wrappers/src/utils/constants.ts
@@ -2,6 +2,7 @@ import { BigNumber } from '@0xproject/utils';
 
 export const constants = {
     NULL_ADDRESS: '0x0000000000000000000000000000000000000000',
+    NULL_BYTES: '0x',
     TESTRPC_NETWORK_ID: 50,
     INVALID_JUMP_PATTERN: 'invalid JUMP at',
     REVERT: 'revert',