dagcoin-core/lib/databaseManager.js

Dagcoin Core

'use strict';

var instance = null;

// My module
function DatabaseManager() {
    this.db = require('byteballcore/db');
    this.conf = require('byteballcore/conf');
    this.confManager = require('./confManager').getInstance();
    this.timedPromises = require('./promiseManager');
    this.fileSystemManager = require('./fileSystemManager').getInstance();
    this.osManager = require('./operatingSystemManager').getInstance();
    this.exceptionManager = require('./exceptionManager');

    var self = this;

    this.queryQueue = this.timedPromises.PromiseEnqueuer('db-manager', function (query, parameters) {
        return new Promise(function (resolve, reject) {
            try {
                self.db.query(query, parameters, resolve);
            } catch (e) {
                console.error(e, e.stack);
                var Raven = require('raven');
                Raven.captureException(e);
                reject('QUERY ' + query + ' WITH PARAMETER ' + JSON.stringify(parameters) + ' FAILED: ' + e.message);
            }
        });
    });
}

DatabaseManager.prototype.checkOrUpdateDatabase = function () {
    var self = this;
    var environment = null;

    return self.onReady().then(function () {
        return self.confManager.get('environment');
    }).then(function (environmentConfig) {
        environment = environmentConfig;
        return self.confManager.get('DATABASE_MIGRATION_TOOL');
    }).then(function (migrationEngine) {
        var dbMigrateEngine = null;

        switch (migrationEngine) {
            case 'native-queries':
                dbMigrateEngine = require('./migrating/nativeQueries');
                console.log('DATABASE MIGRATION ENGINE SET TO native-queries');
                break;
            case 'db-migrate':
                if (self.osManager.isCordova()) {
                    return Promise.reject(new Error('NPM MODULE db-migrate IS NOT SUPPORTED IN CORDOVA'));
                }

                dbMigrateEngine = require('./migrating/dbMigrate');

                console.log('DATABASE MIGRATION ENGINE SET TO db-migrate');

                break;
            default:
                console.log('PROPERTY DATABASE_MIGRATION_TOOL NOT SET: NOT MIGRATING THE DATABASE.');
                return Promise.resolve();
        }

        if (dbMigrateEngine == null) {
            console.log('NO MIGRATING ENGINE AVAILABLE. NOT MIGRATING THE DATABASE.');
            return Promise.resolve();
        }

        return dbMigrateEngine.migrate(environment, self.getFullDatabasePath());
    });
};

DatabaseManager.prototype.getDatabaseFileName = function () {
    return this.conf.database.filename || (this.conf.bLight ? 'byteball-light.sqlite' : 'byteball.sqlite');
};

DatabaseManager.prototype.getFullDatabasePath = function () {
    return this.fileSystemManager.getDatabaseDirPath() + '/' + this.getDatabaseFileName();
};

/**
 * Makes sure the database is ready.
 * @returns {Promise} A promise that resolves as soon as the database is ready
 */
DatabaseManager.prototype.onReady = function () {
    var self = this;

    return new Promise(function (resolve) {
        try {
            self.db.query('SELECT 1', [], function () {
                resolve();
            });
        } catch (e) {
            console.log('DATABASE NOT READY YET: ' + e.message + '. RETRYING IN FEW SECONDS ...');

            setTimeout(function () {
                self.onReady().then(resolve);
            }, self.conf.DB_READY_CHECK_INTERVAL);
        }
    });
};

DatabaseManager.prototype.getIgnore = function () {
    return this.db.getIgnore();
};

/**
 * Executes query in the database sequentially.
 * @param query A SQL query with question marks (?) instead of parameters
 * @param parameters An array of parameters. [] for nothing
 * @returns {Promise} A promise that resolves when the query returns rows.
 */
DatabaseManager.prototype.query = function (query, parameters) {
    return this.queryQueue.enqueue(query, parameters);
};

module.exports = DatabaseManager;
module.exports.getInstance = function () {
    if (!instance) {
        instance = new DatabaseManager();
    }

    return instance;
};