quorrajs/NodeSession

/**
 * DatabaseSessionHandler.js
 *
 * @author: Harish Anchu <harishanchu@gmail.com>
 * @copyright 2015, Harish Anchu. All rights reserved.
 * @license Licensed under MIT
 */

function DatabaseSessionHandler(model) {
    /**
     * Session table waterline model instance.
     *
     * @type {Object}
     * @private
     */
    this.__model = model;

    /**
     * The existence state of the session.
     *
     * @type {Boolean}
     */
    this.__exists;
}

/**
 * Reads the session data.
 *
 * @param {String} sessionId
 * @param {function} callback
 */
DatabaseSessionHandler.prototype.read = function (sessionId, callback) {
    var self = this;
    var response = '';

    this.__model.findOne(sessionId, function (err, session) {
        if (!err && session && session.payload) {
            self.__exists = true;

            response = JSON.parse(session.payload);
        }

        if (callback) {
            callback(response);
        }
    });
};

/**
 * Writes the session data to the storage.
 *
 * @param {String} sessionId
 * @param {String} data
 * @param {function} callback
 */
DatabaseSessionHandler.prototype.write = function (sessionId, data, callback) {
    var self = this;
    if (this.__exists) {
        this.__model.update(sessionId,
            {payload: JSON.stringify(data), lastActivity: (new Date()).getTime()},
            function (err, record) {
                if (!err) {
                    self.__exists = true;
                }

                if (callback) {
                    callback(err);
                }
            }
        );
    }
    else {
        this.__model.create(
            {
                id: sessionId,
                payload: JSON.stringify(data),
                lastActivity: (new Date()).getTime()
            },
            function (err, record) {
                if (!err) {
                    self.__exists = true;
                }

                if (callback) {
                    callback(err);
                }
            }
        );
    }

};

/**
 * Destroys a session.
 *
 * @param {String} sessionId
 * @param {function} callback
 */
DatabaseSessionHandler.prototype.destroy = function (sessionId, callback) {
    this.__model.destroy(sessionId, function (err) {
        if (callback) {
            callback(err);
        }
    })
};

/**
 * Cleans up expired sessions (garbage collection).
 *
 * @param {String|number} maxAge Sessions that have not updated for the last maxAge seconds will be removed
 */
DatabaseSessionHandler.prototype.gc = function (maxAge) {
    var age = (new Date()).getTime() - maxAge;
    this.__model.destroy({lastActivity: {'<': age}}, function (err) {
    });
};

/**
 * Set the existence state for the session.
 *
 * @param  {Boolean} value
 * @return {DatabaseSessionHandler}
 */
DatabaseSessionHandler.prototype.setExists = function (value) {
    this.__exists = value;

    return this;
};

module.exports = DatabaseSessionHandler;