feat: externalDataDriftClientSubscriber

Author: LukasDeco

sdk/src/accounts/customizedCadenceBulkAccountLoader.ts

@@ -35,7 +35,9 @@ export class CustomizedCadenceBulkAccountLoader extends BulkAccountLoader {
 
 		for (const [key, frequency] of this.accountFrequencies.entries()) {
 			const lastPollTime = this.lastPollingTimes.get(key) || 0;
-			if (currentTime - lastPollTime >= frequency) {
+			// Add 200ms buffer to account for timing wiggle room with js execution
+			const timeDiff = currentTime - lastPollTime;
+			if (timeDiff >= frequency - 200) {
 				const account = this.accountsToLoad.get(key);
 				if (account) {
 					accountsToLoad.push(account);

sdk/src/accounts/externalDataDriftClientSubscriber.ts

@@ -0,0 +1,76 @@
+import {
+	PollingDriftClientAccountSubscriber
+} from './pollingDriftClientAccountSubscriber';
+
+import {
+	OraclePriceData,
+	OracleInfo
+} from '../oracles/types';
+
+import { getOracleId } from '../oracles/oracleId';
+
+
+// allowing app UI state to incrementally replace RPC fetched acconut data with data from our infra that is pre-indexed and decoded
+export class ExternalDataDriftClientSubscriber extends PollingDriftClientAccountSubscriber {
+	private oracleLastUpdate = new Map<string, number>();
+	private pollingOracles = new Map<string, boolean>();
+	private oraclePollIntervalId: NodeJS.Timeout;
+
+	constructor(...args: ConstructorParameters<typeof PollingDriftClientAccountSubscriber>) {
+		super(...args);
+		
+	}
+
+	/** Override to prevent oracles from being automatically polled later */
+	public override updateOraclesToPoll(): boolean {
+		return true;
+	}
+
+	/** Public method to be called externally with fresh oracle data */
+	public feedOracle(oracleInfo: OracleInfo, priceData: OraclePriceData, slot: number) {
+		const oracleId = getOracleId(oracleInfo.publicKey, oracleInfo.source);
+		this.oracles.set(oracleId, { data: priceData, slot });
+		this.oracleLastUpdate.set(oracleId, Date.now());
+		if (this.pollingOracles.has(oracleId) || this.accountLoader.accountsToLoad.has(oracleInfo.publicKey.toBase58())) {
+			const oracleToPoll = this.oraclesToPoll.get(oracleId);
+			if (oracleToPoll) {
+				this.accountLoader.removeAccount(
+					oracleToPoll.publicKey,
+					oracleToPoll.callbackId
+				);
+				this.pollingOracles.delete(oracleId);
+			}
+		}
+	}
+
+	public override async subscribe(): Promise<boolean> {
+		await super.subscribe();
+		this.startOraclePollingWatchdog();
+		return true;
+	}
+
+	private startOraclePollingWatchdog() {
+		if(this.oraclePollIntervalId) {
+			clearInterval(this.oraclePollIntervalId);
+		}
+		// how do we handle not polling bet markets every 1s from this change?
+		this.oraclePollIntervalId = setInterval(async () => {
+			for (const [oracleId, lastUpdate] of this.oracleLastUpdate.entries()) {
+				const oracleToPoll = this.oraclesToPoll.get(oracleId);
+				if(!oracleToPoll) continue;
+				const now = Date.now();
+				if (now - lastUpdate > 130_000 && !this.pollingOracles.has(oracleId)) {
+					await this.addOracleToAccountLoader(oracleToPoll);
+					this.pollingOracles.set(oracleId, true);
+				}
+			}
+		}, 60_000);
+	}
+
+	public override async unsubscribe(): Promise<void> {
+		clearInterval(this.oraclePollIntervalId);
+		await super.unsubscribe();
+		this.oracleLastUpdate.clear();
+		this.pollingOracles.clear();
+	}
+}

sdk/src/accounts/pollingDriftClientAccountSubscriber.ts

@@ -546,8 +546,13 @@ export class PollingDriftClientAccountSubscriber
 
 		for (const oracle of oracles) {
 			const oracleId = getOracleId(oracle.publicKey, oracle.source);
-			const callbackId = this.oraclesToPoll.get(oracleId).callbackId;
-			this.accountLoader.removeAccount(oracle.publicKey, callbackId);
+			const oracleToPoll = this.oraclesToPoll.get(oracleId);
+			if (oracleToPoll) {
+				this.accountLoader.removeAccount(
+					oracleToPoll.publicKey,
+					oracleToPoll.callbackId
+				);
+			}
 			if (this.delistedMarketSetting === DelistedMarketSetting.Discard) {
 				this.oracles.delete(oracleId);
 			}

sdk/src/index.ts

@@ -16,6 +16,7 @@ export * from './accounts/bulkAccountLoader';
 export * from './accounts/bulkUserSubscription';
 export * from './accounts/bulkUserStatsSubscription';
 export { CustomizedCadenceBulkAccountLoader } from './accounts/customizedCadenceBulkAccountLoader';
+export { ExternalDataDriftClientSubscriber } from './accounts/externalDataDriftClientSubscriber';
 export * from './accounts/pollingDriftClientAccountSubscriber';
 export * from './accounts/pollingOracleAccountSubscriber';
 export * from './accounts/pollingTokenAccountSubscriber';