Added forwardOnly tx sender (#1001)

* Added forwardOnly tx sender

* Bump

sdk/src/index.ts

@@ -76,6 +76,7 @@ export * from './tx/fastSingleTxSender';
 export * from './tx/retryTxSender';
 export * from './tx/whileValidTxSender';
 export * from './tx/priorityFeeCalculator';
+export * from './tx/forwardOnlyTxSender';
 export * from './tx/types';
 export * from './util/computeUnits';
 export * from './util/tps';

sdk/src/tx/forwardOnlyTxSender.ts

@@ -0,0 +1,121 @@
+import { AnchorProvider } from '@coral-xyz/anchor';
+import { ConfirmOptions, Connection, VersionedTransaction } from '@solana/web3.js';
+import bs58 from 'bs58';
+import { IWallet } from '../types';
+import { BaseTxSender } from './baseTxSender';
+import { ConfirmationStrategy, TxSigAndSlot } from './types';
+
+const DEFAULT_TIMEOUT = 35000;
+const DEFAULT_RETRY = 5000;
+
+type ResolveReference = {
+	resolve?: () => void;
+};
+
+export class ForwardOnlyTxSender extends BaseTxSender {
+	connection: Connection;
+	wallet: IWallet;
+	opts: ConfirmOptions;
+	timeout: number;
+	retrySleep: number;
+	additionalConnections: Connection[];
+	timoutCount = 0;
+
+	public constructor({
+		connection,
+		wallet,
+		opts = { ...AnchorProvider.defaultOptions(), maxRetries: 0 },
+		timeout = DEFAULT_TIMEOUT,
+		retrySleep = DEFAULT_RETRY,
+		confirmationStrategy = ConfirmationStrategy.Combo,
+		additionalTxSenderCallbacks = [],
+	}: {
+		connection: Connection;
+		wallet: IWallet;
+		opts?: ConfirmOptions;
+		timeout?: number;
+		retrySleep?: number;
+		confirmationStrategy?: ConfirmationStrategy;
+		additionalTxSenderCallbacks?: ((base58EncodedTx: string) => void)[];
+	}) {
+		super({
+			connection,
+			wallet,
+			opts,
+			timeout,
+			additionalConnections: [],
+			confirmationStrategy,
+			additionalTxSenderCallbacks,
+		});
+		this.connection = connection;
+		this.wallet = wallet;
+		this.opts = opts;
+		this.timeout = timeout;
+		this.retrySleep = retrySleep;
+		this.additionalConnections = [];
+	}
+
+	async sleep(reference: ResolveReference): Promise<void> {
+		return new Promise((resolve) => {
+			reference.resolve = resolve;
+			setTimeout(resolve, this.retrySleep);
+		});
+	}
+
+	sendToAdditionalConnections(
+		rawTx: Buffer | Uint8Array,
+		_opts: ConfirmOptions
+	): void {
+		this.additionalTxSenderCallbacks?.map((callback) => {
+			callback(bs58.encode(rawTx));
+		});
+	}
+
+	async sendRawTransaction(
+		rawTransaction: Buffer | Uint8Array,
+		opts: ConfirmOptions
+	): Promise<TxSigAndSlot> {
+
+		const deserializedTx = VersionedTransaction.deserialize(rawTransaction);
+
+		const txSig = deserializedTx.signatures[0];
+		const encodedTxSig = bs58.encode(txSig);
+
+		const startTime = this.getTimestamp();
+
+		this.sendToAdditionalConnections(rawTransaction, opts);
+
+		let done = false;
+		const resolveReference: ResolveReference = {
+			resolve: undefined,
+		};
+		const stopWaiting = () => {
+			done = true;
+			if (resolveReference.resolve) {
+				resolveReference.resolve();
+			}
+		};
+
+		(async () => {
+			while (!done && this.getTimestamp() - startTime < this.timeout) {
+				await this.sleep(resolveReference);
+				if (!done) {
+					this.sendToAdditionalConnections(rawTransaction, opts);
+				}
+			}
+		})();
+
+		let slot: number;
+		try {
+			const result = await this.confirmTransaction(encodedTxSig, opts.commitment);
+			slot = result.context.slot;
+			// eslint-disable-next-line no-useless-catch
+		} catch (e) {
+			throw e;
+		} finally {
+			stopWaiting();
+		}
+
+		return { txSig: encodedTxSig, slot };
+	}
+}