Add empty implementation of order state watcher

1 files changed, 70 insertions, 0 deletions

diff --git a/src/mempool/order_state_watcher.ts b/src/mempool/order_state_watcher.ts
new file mode 100644
index 000000000..89f84647d
--- /dev/null
+++ b/src/mempool/order_state_watcher.ts
@@ -0,0 +1,70 @@
+import * as _ from 'lodash';
+import {schemas} from '0x-json-schemas';
+import {ZeroEx} from '../';
+import {EventWatcher} from './event_watcher';
+import {assert} from '../utils/assert';
+import {artifacts} from '../artifacts';
+import {AbiDecoder} from '../utils/abi_decoder';
+import {orderWatcherConfigSchema} from '../schemas/order_watcher_config_schema';
+import {
+    LogEvent,
+    SignedOrder,
+    Web3Provider,
+    LogWithDecodedArgs,
+    OrderWatcherConfig,
+    OnOrderStateChangeCallback,
+} from '../types';
+import {Web3Wrapper} from '../web3_wrapper';
+
+export class OrderStateWatcher {
+    private _orders = new Map<string, SignedOrder>();
+    private _web3Wrapper: Web3Wrapper;
+    private _config: OrderWatcherConfig;
+    private _callback?: OnOrderStateChangeCallback;
+    private _eventWatcher?: EventWatcher;
+    private _abiDecoder: AbiDecoder;
+    constructor(provider: Web3Provider, config?: OrderWatcherConfig) {
+        assert.isWeb3Provider('provider', provider);
+        if (!_.isUndefined(config)) {
+            assert.doesConformToSchema('config', config, orderWatcherConfigSchema);
+        }
+        this._web3Wrapper = new Web3Wrapper(provider);
+        this._config = config || {};
+        const artifactJSONs = _.values(artifacts);
+        const abiArrays = _.map(artifactJSONs, artifact => artifact.abi);
+        this._abiDecoder = new AbiDecoder(abiArrays);
+    }
+    public addOrder(signedOrder: SignedOrder): void {
+        assert.doesConformToSchema('signedOrder', signedOrder, schemas.signedOrderSchema);
+        const orderHash = ZeroEx.getOrderHashHex(signedOrder);
+        this._orders.set(orderHash, signedOrder);
+    }
+    public removeOrder(signedOrder: SignedOrder): void {
+        assert.doesConformToSchema('signedOrder', signedOrder, schemas.signedOrderSchema);
+        const orderHash = ZeroEx.getOrderHashHex(signedOrder);
+        this._orders.delete(orderHash);
+    }
+    public subscribe(callback: OnOrderStateChangeCallback): void {
+        assert.isFunction('callback', callback);
+        this._callback = callback;
+        this._eventWatcher = new EventWatcher(
+            this._web3Wrapper, this._config.mempoolPollingIntervalMs,
+        );
+        this._eventWatcher.subscribe(this._onMempoolEventCallbackAsync.bind(this));
+    }
+    public unsubscribe(): void {
+        delete this._callback;
+        if (!_.isUndefined(this._eventWatcher)) {
+            this._eventWatcher.unsubscribe();
+        }
+    }
+    private async _onMempoolEventCallbackAsync(log: LogEvent): Promise<void> {
+        const maybeDecodedLog = this._abiDecoder.tryToDecodeLogOrNoop(log);
+        if (!_.isUndefined((maybeDecodedLog as LogWithDecodedArgs<any>).event)) {
+            await this._revalidateOrdersAsync();
+        }
+    }
+    private async _revalidateOrdersAsync(): Promise<void> {
+        _.noop();
+    }
+}