98 lines
3.1 KiB
JavaScript
98 lines
3.1 KiB
JavaScript
const taos = require("@tdengine/websocket");
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// ANCHOR: create_consumer
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const db = 'power';
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const stable = 'meters';
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const topics = ['power_meters_topic'];
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const url = 'ws://localhost:6041';
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async function createConsumer() {
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let groupId = "group1";
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let clientId = "1";
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let configMap = new Map([
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[taos.TMQConstants.GROUP_ID, groupId],
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[taos.TMQConstants.CLIENT_ID, clientId],
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[taos.TMQConstants.CONNECT_USER, "root"],
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[taos.TMQConstants.CONNECT_PASS, "taosdata"],
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[taos.TMQConstants.AUTO_OFFSET_RESET, "latest"],
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[taos.TMQConstants.WS_URL, url],
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[taos.TMQConstants.ENABLE_AUTO_COMMIT, 'true'],
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[taos.TMQConstants.AUTO_COMMIT_INTERVAL_MS, '1000']
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]);
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try {
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conn = await taos.tmqConnect(configMap);
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console.log(`Create consumer successfully, host: ${url}, groupId: ${groupId}, clientId: ${clientId}`)
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return conn;
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}catch (err) {
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console.log("Failed to create websocket consumer, ErrCode:" + err.code + "; ErrMessage: " + err.message);
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throw err;
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}
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}
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// ANCHOR_END: create_consumer
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async function prepare() {
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let conf = new taos.WSConfig('ws://localhost:6041');
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conf.setUser('root');
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conf.setPwd('taosdata');
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conf.setDb('power');
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const createDB = `CREATE DATABASE IF NOT EXISTS ${db}`;
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const createStable = `CREATE STABLE IF NOT EXISTS ${db}.${stable} (ts timestamp, current float, voltage int, phase float) TAGS (location binary(64), groupId int);`;
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let wsSql = await taos.sqlConnect(conf);
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await wsSql.exec(createDB);
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await wsSql.exec(createStable);
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let createTopic = `CREATE TOPIC IF NOT EXISTS ${topics[0]} AS SELECT * FROM ${db}.${stable}`;
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await wsSql.exec(createTopic);
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for (let i = 0; i < 10; i++) {
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await wsSql.exec(`INSERT INTO d1001 USING ${stable} (location, groupId) TAGS ("California.SanFrancisco", 3) VALUES (NOW, ${10 + i}, ${200 + i}, ${0.32 + i})`);
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}
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wsSql.close();
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}
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async function subscribe(consumer) {
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// ANCHOR: commit
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try {
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await consumer.subscribe(['topic_meters']);
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for (let i = 0; i < 50; i++) {
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let res = await consumer.poll(100);
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for (let [key, value] of res) {
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console.log(`data: ${key} ${value}`);
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}
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consumer.commit();
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console.log("Commit offset manually successfully.");
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}
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} catch (err) {
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console.error("Failed to poll data; ErrCode:" + err.code + "; ErrMessage: " + err.message);
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throw err;
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}
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// ANCHOR_END: commit
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}
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async function test() {
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// ANCHOR: unsubscribe
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let consumer = null;
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try {
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await prepare();
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let consumer = await createConsumer()
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await subscribe(consumer)
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await consumer.unsubscribe();
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console.log("Consumer unsubscribed successfully.");
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}
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catch (err) {
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console.error("Failed to unsubscribe consume, ErrCode:" + err.code + "; ErrMessage: " + err.message);
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}
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finally {
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if (consumer) {
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await consumer.close();
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}
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taos.destroy();
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}
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// ANCHOR_END: unsubscribe
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}
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test()
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