x4UxSZyr

1const db = require('sqlite3');
2
3const Logger = require('../logger/logger');
4
5const dataDir = process.env.DATA_DIR;
6const dbExt = process.env.DB_EXT;
7
8const DataManager = {
9  /**
10   * Constructor for OLOO style behavior delgation.
11   * @param {string} dbFile - data base file name
12   */
13  init: function (dbFile) {
14    if (!dbFile || !dataDir || !dbExt) {
15      Logger.error('Database or exchange is undefined');
16    } else {
17      this.dbFile = dbFile;
18      this.dataDir = dataDir;
19      this.dbExt = dbExt;
20    }
21
22    Logger.info('Data manager initialized.');
23  },
24
25    /**
26   * Returns a live sqlite connection
27   */
28  getDb: function() {
29    const dbConn = new db.Database(
30      `${this.dataDir}${this.dbFile}${this.dbExt}`
31    );
32    dbConn.run("PRAGMA journal_mode = WAL");
33    return dbConn;
34  },
35
36   /**
37   * Stores a batch of trades in the sqlite db
38   * @param {array} batch - batch of trades
39   */
40  storeTrades: async function (batch) {
41    try {
42      return new Promise(resolve => {
43        if (!this.dbFile) {
44          throw('Database file unspecified');
45        }
46
47        if (!batch || !batch.length) {
48          throw('Data must be specified and an array');
49        }
50
51        const dbConn = this.getDb();
52        const table = `[${batch[0].symbol}]`;
53        const query = `CREATE TABLE IF NOT EXISTS ${table} (id INTEGER PRIMARY KEY AUTOINCREMENT, tradeId INTEGER, timestamp INTEGER, price REAL, quantity REAL)`;
54        dbConn.serialize(() => {
55          dbConn.run(query);
56          dbConn.run('BEGIN TRANSACTION');
57          const insertStmt = dbConn.prepare(`INSERT INTO ${table} (tradeId, timestamp, price, quantity) VALUES (?, ?, ?, ?)`);
58          batch.forEach(trade => insertStmt.run(trade.id, trade.timestamp, trade.info.p, trade.info.q));
59          insertStmt.finalize();
60          dbConn.run('COMMIT');
61        });
62
63        dbConn.close(resolve);
64        Logger.debug(`${batch.length} rows inserted into table`);
65      });
66    } catch (e) {
67      Logger.error(e.message);
68    }
69  }
70};