Avoid historical sync for block handlers and eth_getLogs without event handlers

packages/graph-node/src/watcher.ts

@@ -60,6 +60,9 @@ export class GraphWatcher {
 
   _context: Context;
 
+  _blockHandlerExists = false;
+  _eventHandlerExists = false;
+
   constructor (database: GraphDatabase, ethClient: EthClient, ethProvider: providers.BaseProvider, serverConfig: ServerConfig) {
     this._database = database;
     this._ethClient = ethClient;
@@ -110,6 +113,10 @@ export class GraphWatcher {
       };
     }, {});
 
+    // Check if handlers exist for deciding watcher behaviour
+    this._blockHandlerExists = this._dataSources.some(dataSource => Boolean(dataSource.mapping.blockHandlers));
+    this._eventHandlerExists = this._dataSources.some(dataSource => Boolean(dataSource.mapping.eventHandlers));
+
     const data = await Promise.all(dataPromises);
 
     // Create a map from dataSource contract address to instance and contract interface.
@@ -151,6 +158,14 @@ export class GraphWatcher {
     return this._dataSources;
   }
 
+  get blockHandlerExists (): boolean {
+    return this._blockHandlerExists;
+  }
+
+  get eventHandlerExists (): boolean {
+    return this._eventHandlerExists;
+  }
+
   async addContracts () {
     assert(this._indexer);
     assert(this._indexer.watchContract);

packages/util/src/events.ts

@@ -123,9 +123,15 @@ export class EventWatcher {
       startBlockNumber = syncStatus.chainHeadBlockNumber + 1;
     }
 
-    // Check if filter for logs is enabled
-    // Check if starting block for watcher is before latest canonical block
-    if (this._config.jobQueue.useBlockRanges && startBlockNumber < latestCanonicalBlockNumber) {
+    // Perform checks before starting historical block processing
+    if (
+      // Check if useBlockRanges is enabled for historical blocks processing
+      this._config.jobQueue.useBlockRanges &&
+      // Check if starting block for watcher is before latest canonical block
+      startBlockNumber < latestCanonicalBlockNumber &&
+      // Check if any block handler exists in subgraph config
+      !this._indexer.graphWatcher?.blockHandlerExists
+    ) {
       await this.startHistoricalBlockProcessing(startBlockNumber, latestCanonicalBlockNumber);
 
       return;

packages/util/src/types.ts

@@ -288,6 +288,7 @@ export interface GraphDatabaseInterface {
 }
 
 export interface GraphWatcherInterface {
+  readonly blockHandlerExists: boolean;
   init (): Promise<void>;
   setIndexer (indexer: IndexerInterface): void;
 }