@drift-labs/sdk/lib/node/slot/SlothashSubscriber.js

SDK for Drift Protocol

"use strict";
Object.defineProperty(exports, "__esModule", { value: true });
exports.SlothashSubscriber = void 0;
const web3_js_1 = require("@solana/web3.js");
const bytes_1 = require("@coral-xyz/anchor/dist/cjs/utils/bytes");
const anchor_1 = require("@coral-xyz/anchor");
class SlothashSubscriber {
    constructor(connection, config) {
        var _a;
        this.connection = connection;
        this.isUnsubscribing = false;
        this.receivingData = false;
        this.resubTimeoutMs = config === null || config === void 0 ? void 0 : config.resubTimeoutMs;
        this.commitment = (_a = config === null || config === void 0 ? void 0 : config.commitment) !== null && _a !== void 0 ? _a : 'processed';
        if (this.resubTimeoutMs < 1000) {
            console.log('resubTimeoutMs should be at least 1000ms to avoid spamming resub');
        }
    }
    async subscribe() {
        if (this.subscriptionId != null) {
            return;
        }
        const currentAccountData = await this.connection.getAccountInfo(web3_js_1.SYSVAR_SLOT_HASHES_PUBKEY, this.commitment);
        if (currentAccountData == null) {
            throw new Error('Failed to retrieve current slot hash');
        }
        this.currentSlothash = deserializeSlothash(currentAccountData.data);
        this.subscriptionId = this.connection.onAccountChange(web3_js_1.SYSVAR_SLOT_HASHES_PUBKEY, (slothashInfo, context) => {
            if (!this.currentSlothash || this.currentSlothash.slot < context.slot) {
                if (this.resubTimeoutMs && !this.isUnsubscribing) {
                    this.receivingData = true;
                    clearTimeout(this.timeoutId);
                    this.setTimeout();
                }
                this.currentSlothash = deserializeSlothash(slothashInfo.data);
            }
        }, this.commitment);
        if (this.resubTimeoutMs) {
            this.receivingData = true;
            this.setTimeout();
        }
    }
    setTimeout() {
        this.timeoutId = setTimeout(async () => {
            if (this.isUnsubscribing) {
                // If we are in the process of unsubscribing, do not attempt to resubscribe
                return;
            }
            if (this.receivingData) {
                console.log(`No new slot in ${this.resubTimeoutMs}ms, slot subscriber resubscribing`);
                await this.unsubscribe(true);
                this.receivingData = false;
                await this.subscribe();
            }
        }, this.resubTimeoutMs);
    }
    getSlothash() {
        return this.currentSlothash;
    }
    async unsubscribe(onResub = false) {
        if (!onResub) {
            this.resubTimeoutMs = undefined;
        }
        this.isUnsubscribing = true;
        clearTimeout(this.timeoutId);
        this.timeoutId = undefined;
        if (this.subscriptionId != null) {
            await this.connection.removeSlotChangeListener(this.subscriptionId);
            this.subscriptionId = undefined;
            this.isUnsubscribing = false;
        }
        else {
            this.isUnsubscribing = false;
        }
    }
}
exports.SlothashSubscriber = SlothashSubscriber;
function deserializeSlothash(data) {
    const slotNumber = new anchor_1.BN(data.subarray(8, 16), 10, 'le');
    const hash = bytes_1.bs58.encode(data.subarray(16, 48));
    return {
        slot: slotNumber.toNumber(),
        hash,
    };
}