@bazilio-san/af-stream/dist/esm/StartTimeRedis.js

Data stream from database table

import { createClient } from 'redis';
import { DateTime } from 'luxon';
import { getStreamKey, getTimeParamMillis, millis2iso, timeParamRE } from './utils/utils';
export class StartTimeRedis {
    constructor(options) {
        this.options = options;
        const url = `redis://${options.host}:${options.port}`;
        console.log(`[AF-STREAM]: Redis are expected at ${url}`);
        this.client = createClient({ url });
        this.client.on('error', (err) => {
            console.error('Redis Client Error');
            options.exitOnError(err);
        });
        const streamKey = getStreamKey(options.streamId);
        this.streamKey = streamKey;
        options.eventEmitter.on('save-last-ts', async ({ lastTs }) => {
            const redisClient = await this.getRedisClient();
            redisClient === null || redisClient === void 0 ? void 0 : redisClient.set(streamKey, lastTs).catch((err) => {
                options.logger.error(err);
            });
        });
    }
    async getRedisClient() {
        if (this.client.isOpen) {
            return this.client;
        }
        try {
            await this.client.connect();
        }
        catch (err) {
            this.options.logger.error('Failed to initialize Redis client');
            this.options.exitOnError(err);
        }
        if (!this.client.isOpen) {
            this.options.exitOnError('Failed to initialize Redis client');
        }
        return this.client;
    }
    async getStartTimeFromRedis() {
        const redisClient = await this.getRedisClient();
        let startTime;
        try {
            startTime = await redisClient.get(this.streamKey);
        }
        catch (err) {
            this.options.logger.error(err);
            return 0;
        }
        startTime = Number(startTime);
        if (!startTime) {
            return 0;
        }
        if (!DateTime.fromMillis(startTime).isValid) {
            this.options.logger.error(`Cache stored data is not a unix timestamp: ${startTime}`);
            return 0;
        }
        this.options.logger.info(`Get time of last sent entry: ${millis2iso(startTime, { includeOffset: true })} from the Redis cache using key ${this.streamKey}`);
        return startTime;
    }
    // !!!Attention!!! STREAM_START_TIME - time in GMT
    getStartTimeFromENV() {
        const { logger } = this.options;
        const { STREAM_START_TIME = '', STREAM_START_BEFORE = '' } = process.env;
        const dt = DateTime.fromISO(STREAM_START_TIME, { zone: 'GMT' });
        if (STREAM_START_TIME) {
            if (dt.isValid) {
                return dt.toMillis();
            }
            logger.error(`Start time is incorrect. STREAM_START_TIME: ${STREAM_START_TIME}`);
        }
        if (STREAM_START_BEFORE) {
            if (timeParamRE.test(STREAM_START_BEFORE)) {
                return Date.now() - getTimeParamMillis(STREAM_START_BEFORE);
            }
            logger.error(`Start time is incorrect. STREAM_START_BEFORE: ${STREAM_START_BEFORE}`);
        }
        return 0;
    }
    async getStartTime() {
        // initialize connection with Redis to save state later
        await this.getRedisClient();
        let startTime = 0;
        let isUsedSavedStartTime = false;
        if (this.options.useStartTimeFromRedisCache) {
            startTime = await this.getStartTimeFromRedis();
            isUsedSavedStartTime = !!startTime;
        }
        startTime = startTime || this.getStartTimeFromENV() || Date.now();
        return { isUsedSavedStartTime, startTime };
    }
}
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