@pythnetwork/price-pusher/lib/pyth-price-listener.js

Pyth Price Pusher

"use strict";
Object.defineProperty(exports, "__esModule", { value: true });
exports.PythPriceListener = void 0;
class PythPriceListener {
    hermesClient;
    priceIds;
    priceIdToAlias;
    latestPriceInfo;
    logger;
    lastUpdated;
    healthCheckInterval;
    constructor(hermesClient, priceItems, logger) {
        this.hermesClient = hermesClient;
        this.priceIds = priceItems.map((priceItem) => priceItem.id);
        this.priceIdToAlias = new Map(priceItems.map((priceItem) => [priceItem.id, priceItem.alias]));
        this.latestPriceInfo = new Map();
        this.logger = logger;
    }
    // This method should be awaited on and once it finishes it has the latest value
    // for the given price feeds (if they exist).
    async start() {
        const eventSource = await this.hermesClient.getPriceUpdatesStream(this.priceIds, {
            parsed: true,
            ignoreInvalidPriceIds: true,
        });
        eventSource.onmessage = (event) => {
            const priceUpdates = JSON.parse(event.data);
            priceUpdates.parsed?.forEach((priceUpdate) => {
                this.logger.debug(`Received new price feed update from Pyth price service: ${this.priceIdToAlias.get(priceUpdate.id)} ${priceUpdate.id}`);
                // Consider price to be currently available if it is not older than 60s
                const currentPrice = Date.now() / 1000 - priceUpdate.price.publish_time > 60
                    ? undefined
                    : priceUpdate.price;
                if (currentPrice === undefined) {
                    this.logger.debug("Price is older than 60s, skipping");
                    return;
                }
                const priceInfo = {
                    conf: currentPrice.conf,
                    price: currentPrice.price,
                    publishTime: currentPrice.publish_time,
                };
                this.latestPriceInfo.set(priceUpdate.id, priceInfo);
                this.lastUpdated = Date.now();
            });
        };
        eventSource.onerror = (error) => {
            console.error("Error receiving updates from Hermes:", error);
            eventSource.close();
        };
        // Store health check interval reference
        this.healthCheckInterval = setInterval(() => {
            if (this.lastUpdated === undefined ||
                this.lastUpdated < Date.now() - 30 * 1000) {
                throw new Error("Hermes Price feeds are not updating.");
            }
        }, 5000);
    }
    getLatestPriceInfo(priceId) {
        return this.latestPriceInfo.get(priceId);
    }
    cleanup() {
        if (this.healthCheckInterval) {
            clearInterval(this.healthCheckInterval);
        }
    }
}
exports.PythPriceListener = PythPriceListener;