db.js

• Classes
  • DBStore
    • constructor
    • configure
    • close
    • get

store/db.js
  
/**
 * Database-Connections Store
 *
 * @module greppy/store/db
 * @author Hermann Mayer <hermann.mayer92@gmail.com>
 */
var util       = require('util');
var async      = require('async');
var Connection = require('../db/connection');
/**
 * @constructor
 */
var DBStore = function(config)
{
    this.store  = {};
    this.config = config;
};
/**
 * Configure all selected backends and/or connections.
 *
 * @param {Object} select - Selection of backends and connections
 * @param {Function} callback - Function to call on finish
 */
DBStore.prototype.configure = function(select, callback)
{
    if (null === select) {
        return callback && callback();
    }
    var self             = this;
    var backendsSelected = Object.keys(select);
    var map              = {};
    // If we got no selection - use all backends with all connections
    if (0 === backendsSelected.length) {
        Object.keys(this.config).forEach(function(backend) {
            // Setup backends map
            if (!map.hasOwnProperty(backend)) {
                map[backend] = [];
            }
            // Map all connections for the current backend
            Object.keys(self.config[backend]).forEach(function(connection) {
                map[backend].push({
                    name       : connection,
                    backend    : backend,
                    connection : new Connection(
                        connection,
                        backend,
                        self.config[backend][connection]
                    )
                });
            });
        });
    } else {
        // Walk throuh all selected backends
        backendsSelected.forEach(function(backend) {
            // We got backends selected, proof their config existence
            if (!self.config.hasOwnProperty(backend)) {
                throw new Error('Requested backend "' + backend + '" is not configured.');
            }
            // Setup backends map
            if (!map.hasOwnProperty(backend)) {
                map[backend] = [];
            }
            var backendConnections = Object.keys(select[backend]).length;
            var connections        = [];
            // Map all connections for the current backend
            Object.keys(self.config[backend]).forEach(function(connection) {
                connections.push({
                    name       : connection,
                    backend    : backend,
                    connection : new Connection(
                        connection,
                        backend,
                        self.config[backend][connection]
                    )
                });
            });
            // We got no specific connections selection - use all
            if (0 === backendConnections) {
                map[backend] = connections;
                return;
            }
            // Iterate over all selected connections of the current backend
            select[backend].forEach(function(connection) {
                if (!self.config[backend].hasOwnProperty(connection)) {
                    throw new Error(
                        'Requested backend "' + backend +
                        '" has no configured "' + connection + '" connection'
                    );
                }
                map[backend].push({
                    name       : connection,
                    backend    : backend,
                    connection : new Connection(
                        connection,
                        backend,
                        self.config[backend][connection]
                    )
                });
            });
        });
    }
    // Prepare connections for async configure
    var connections = [];
    Object.keys(map).forEach(function(backend) {
        connections = connections.concat(map[backend]);
    });
    if (0 === connections.length) {
        callback && callback();
        return;
    }
    // Configure all connections for all backends parallel
    async.each(connections, function(connection, callback) {
        // Write the connection to the DB Store
        if (!self.store[connection.backend]) {
            self.store[connection.backend] = {};
        }
        self.store[connection.backend][connection.name] = connection.connection;
        // Configure connection
        connection.connection.configure(callback);
    }, function(err) {
        if (err) {
            callback && callback(err);
            return;
        }
        logger.info('All ' + 'backend connections'.yellow + ' established');
        callback && callback();
    });
};
/**
 * Close all connections for this store.
 *
 * @param {Function} callback - Function to call on finish
 */
DBStore.prototype.close = function(callback)
{
    var self = this;
    var connections = [];
    Object.keys(this.store).forEach(function(backend) {
        Object.keys(self.store[backend]).forEach(function(connection) {
            connections.push(self.store[backend][connection]);
        });
    });
    async.each(connections, function(connection, callback) {
        connection.close(callback);
    }, function(err) {
        if (err) {
            callback && callback(err);
            return;
        }
        callback && callback();
    });
};
/**
 * Get a connection by namepath from the store.
 *
 * @param {String} namepath - The namepath to search the backend/connection for
 * @return {Object}
 */
DBStore.prototype.get = function(namepath)
{
    if (!namepath) {
        throw new Error('Namepath was not given');
    }
    namepath       = namepath.split('.');
    var backend    = namepath.shift();
    var connection = namepath.join('.');
    if (!backend || !connection) {
        throw new Error('Namepath "' + namepath + '" is faulty');
    }
    if (!this.store.hasOwnProperty(backend)) {
        throw new Error('Backend "' + backend + '" is not registered');
    }
    if (!this.store[backend].hasOwnProperty(connection)) {
        throw new Error(
            'Backend "' + backend + '" got no connection "' +
            connection + '" registered'
        );
    }
    return this.store[backend][connection];
};
module.exports = DBStore;