1 files changed, 43 insertions, 17 deletions
diff --git a/src/contract_wrappers/exchange_wrapper.ts b/src/contract_wrappers/exchange_wrapper.ts
index 4f132656e..47c49fad6 100644
--- a/src/contract_wrappers/exchange_wrapper.ts
+++ b/src/contract_wrappers/exchange_wrapper.ts
@@ -19,6 +19,7 @@ import {
     ContractEventObj,
     EventCallback,
     ContractResponse,
+    OrderCancellationRequest,
 } from '../types';
 import {assert} from '../utils/assert';
 import {utils} from '../utils/utils';
@@ -226,32 +227,57 @@ export class ExchangeWrapper extends ContractWrapper {
     /**
      * Cancel a given fill amount of an order. Cancellations are cumulative.
      */
-    public async cancelOrderAsync(order: Order|SignedOrder, takerTokenCancelAmount: BigNumber.BigNumber):
-        Promise<void> {
-        assert.doesConformToSchema('order',
-            SchemaValidator.convertToJSONSchemaCompatibleObject(order as object),
-            orderSchema);
-        assert.isBigNumber('takerTokenCancelAmount', takerTokenCancelAmount);
-        await assert.isSenderAddressAvailableAsync(this.web3Wrapper, 'order.maker', order.maker);
-
+    public async cancelOrderAsync(
+        order: Order|SignedOrder, takerTokenCancelAmount: BigNumber.BigNumber): Promise<void> {
+        await this.batchCancelOrderAsync([{
+            order,
+            takerTokenCancelAmount,
+        }]);
+    }
+    /**
+     * Batch version of cancelOrderAsync. Atomically cancels multiple orders in a single transaction.
+     */
+    public async batchCancelOrderAsync(cancellationRequestsBatch: OrderCancellationRequest[]): Promise<void> {
+        const makers = _.map(cancellationRequestsBatch, cancellationRequest => cancellationRequest.order.maker);
+        if (_.isEmpty(cancellationRequestsBatch)) {
+            return;
+        }
+        assert.assert(_.uniq(makers).length === 1, ExchangeContractErrs.MULTIPLE_MAKERS_IN_SINGLE_CANCEL_BATCH);
+        const maker = makers[0];
+        await assert.isSenderAddressAvailableAsync(this.web3Wrapper, 'maker', maker);
+        _.forEach(cancellationRequestsBatch,
+            async (cancellationRequest: OrderCancellationRequest, i: number) => {
+            assert.doesConformToSchema(`orderCancellationRequests[${i}].order`,
+                SchemaValidator.convertToJSONSchemaCompatibleObject(cancellationRequest.order as object), orderSchema);
+            assert.isBigNumber(`orderCancellationRequests[${i}].takerTokenCancelAmount`,
+                cancellationRequest.takerTokenCancelAmount);
+            await this.validateCancelOrderAndThrowIfInvalidAsync(
+                cancellationRequest.order, cancellationRequest.takerTokenCancelAmount);
+        });
         const exchangeInstance = await this.getExchangeContractAsync();
-        await this.validateCancelOrderAndThrowIfInvalidAsync(order, takerTokenCancelAmount);
-
-        const [orderAddresses, orderValues] = ExchangeWrapper.getOrderAddressesAndValues(order);
-        const gas = await exchangeInstance.cancel.estimateGas(
+        const orderAddressesValuesAndTakerTokenCancelAmounts = _.map(cancellationRequestsBatch, cancellationRequest => {
+            return [
+                ...ExchangeWrapper.getOrderAddressesAndValues(cancellationRequest.order),
+                cancellationRequest.takerTokenCancelAmount,
+            ];
+        });
+        // _.unzip doesn't type check if values have different types :'(
+        const [orderAddresses, orderValues, takerTokenCancelAmounts] =
+            _.unzip<any>(orderAddressesValuesAndTakerTokenCancelAmounts);
+        const gas = await exchangeInstance.batchCancel.estimateGas(
             orderAddresses,
             orderValues,
-            takerTokenCancelAmount,
+            takerTokenCancelAmounts,
             {
-                from: order.maker,
+                from: maker,
             },
         );
-        const response: ContractResponse = await exchangeInstance.cancel(
+        const response: ContractResponse = await exchangeInstance.batchCancel(
             orderAddresses,
             orderValues,
-            takerTokenCancelAmount,
+            takerTokenCancelAmounts,
             {
-                from: order.maker,
+                from: maker,
                 gas,
             },
         );