Merge pull request #299 from bancorprotocol/reorg-reset

better work on resetting self on reorg

Author: zavelevsky

package.json

@@ -2,7 +2,7 @@
   "name": "@bancor/carbon-sdk",
   "type": "module",
   "source": "src/index.ts",
-  "version": "0.0.120-DEV",
+  "version": "0.0.121-DEV",
   "description": "The SDK is a READ-ONLY tool, intended to facilitate working with Carbon contracts. It's a convenient wrapper around our matching algorithm, allowing programs and users get a ready to use transaction data that will allow them to manage strategies and fulfill trades",
   "main": "dist/index.cjs",
   "module": "dist/index.js",

src/chain-cache/ChainCache.ts

@@ -196,18 +196,18 @@ export class ChainCache extends (EventEmitter as new () => TypedEventEmitter<Cac
     logger.debug('Cache miss for pair', token0, token1, 'resolved');
   }
 
-  public clear(silent: boolean = false): void {
-    const pairs = Object.keys(this._strategiesByPair).map(fromPairKey);
+  public clear(): void {
     this._strategiesByPair = {};
     this._strategiesById = {};
     this._ordersByDirectedPair = {};
     this._latestBlockNumber = 0;
     this._latestTradesByPair = {};
     this._latestTradesByDirectedPair = {};
     this._blocksMetadata = [];
-    if (!silent) {
-      this.emit('onPairDataChanged', pairs);
-    }
+    this._blocksMetadata = [];
+    this._tradingFeePPMByPair = {};
+    this._isCacheInitialized = false;
+    this.emit('onCacheCleared');
   }
 
   //#region public getters

src/chain-cache/ChainSync.ts

@@ -21,13 +21,35 @@ export class ChainSync {
   private _activeTimers: Set<number> = new Set();
   private _isStopped: boolean = false;
 
+  private _reinitializeSelf(): void {
+    this._syncCalled = false;
+    this._slowPollPairs = false;
+    this._uncachedPairs = [];
+    this._lastFetch = Date.now();
+    this._activeTimers = new Set();
+    this._isStopped = false;
+  }
+
+  private _resetSelf(): void {
+    const shouldSyncAgain = this._syncCalled;
+    this.stop();
+    this._reinitializeSelf();
+    
+    // clearing the cache will emit onCacheCleared event
+    this._chainCache.clear();
+    if (shouldSyncAgain) {
+      this.startDataSync();
+    }
+  }
+
   constructor(
     fetcher: Fetcher,
     chainCache: ChainCache,
     numOfPairsToBatch: number = 100,
     msToWaitBetweenSyncs: number = 1000,
     chunkSize: number = 1000
   ) {
+    this._reinitializeSelf();
     this._fetcher = fetcher;
     this._chainCache = chainCache;
     this._numOfPairsToBatch = numOfPairsToBatch;
@@ -258,10 +280,7 @@ export class ChainSync {
         if (currentBlock > latestBlock) {
           if (await this._detectReorg(currentBlock)) {
             logger.debug('_syncEvents detected reorg - resetting');
-            this._chainCache.clear();
-            this._chainCache.applyEvents([], currentBlock);
-            this._resetPairsFetching();
-            this._setTimeout(processEvents, 1);
+            this._resetSelf();
             return;
           }
 
@@ -329,11 +348,6 @@ export class ChainSync {
     this._setTimeout(processEvents, 1);
   }
 
-  private _resetPairsFetching() {
-    this._uncachedPairs = [];
-    this._slowPollPairs = false;
-  }
-
   /**
    * Detects blockchain reorganization by comparing stored block metadata with current blockchain state
    * @param currentBlock - The current block number to check against

src/chain-cache/types.ts

@@ -9,6 +9,7 @@ export type CacheEvents = {
   onPairDataChanged: (affectedPairs: TokenPair[]) => void;
   onPairAddedToCache: (addedPair: TokenPair) => void;
   onCacheInitialized: () => void;
+  onCacheCleared: () => void;
 };
 
 export interface TypedEventEmitter<Events extends EventMap> {