Revert "sdk: fast tx sender blockhash queue (#755)"

This reverts commit 1bf38e9.

sdk/src/tx/fastSingleTxSender.ts

@@ -15,8 +15,7 @@ import { IWallet } from '../types';
 import { BaseTxSender } from './baseTxSender';
 
 const DEFAULT_TIMEOUT = 35000;
-const DEFAULT_BLOCKHASH_REFRESH = 500;
-const MAX_BLOCKHASH_QUEUE_LENGTH = 100;
+const DEFAULT_BLOCKHASH_REFRESH = 10000;
 
 export class FastSingleTxSender extends BaseTxSender {
 	connection: Connection;
@@ -26,7 +25,7 @@ export class FastSingleTxSender extends BaseTxSender {
 	blockhashRefreshInterval: number;
 	additionalConnections: Connection[];
 	timoutCount = 0;
-	blockhashQueue: string[] = [];
+	recentBlockhash: string;
 	skipConfirmation: boolean;
 
 	public constructor({
@@ -60,25 +59,15 @@ export class FastSingleTxSender extends BaseTxSender {
 	startBlockhashRefreshLoop(): void {
 		setInterval(async () => {
 			try {
-				const blockhash = (await this.connection.getLatestBlockhash(this.opts))
-					.blockhash;
-				this.addBlockhashToQueue(blockhash);
+				this.recentBlockhash = (
+					await this.connection.getLatestBlockhash(this.opts)
+				).blockhash;
 			} catch (e) {
 				console.error('Error in startBlockhashRefreshLoop: ', e);
 			}
 		}, this.blockhashRefreshInterval);
 	}
 
-	addBlockhashToQueue(blockhash: string): void {
-		if (blockhash !== this.blockhashQueue[0]) {
-			this.blockhashQueue.push(blockhash);
-			return;
-		}
-		if (this.blockhashQueue.length > MAX_BLOCKHASH_QUEUE_LENGTH) {
-			this.blockhashQueue.shift();
-		}
-	}
-
 	async prepareTx(
 		tx: Transaction,
 		additionalSigners: Array<Signer>,
@@ -87,7 +76,7 @@ export class FastSingleTxSender extends BaseTxSender {
 		tx.feePayer = this.wallet.publicKey;
 
 		tx.recentBlockhash =
-			this.blockhashQueue.shift() ??
+			this.recentBlockhash ??
 			(await this.connection.getLatestBlockhash(opts.preflightCommitment))
 				.blockhash;
 
@@ -118,7 +107,7 @@ export class FastSingleTxSender extends BaseTxSender {
 		const message = new TransactionMessage({
 			payerKey: this.wallet.publicKey,
 			recentBlockhash:
-				this.blockhashQueue.shift() ??
+				this.recentBlockhash ??
 				(await this.connection.getLatestBlockhash(opts.preflightCommitment))
 					.blockhash,
 			instructions: ixs,