lokijs/benchmark/nedb.js

Fast document oriented javascript in-memory database

(function(e){if("function"==typeof bootstrap)bootstrap("nedb",e);else if("object"==typeof exports)module.exports=e();else if("function"==typeof define&&define.amd)define(e);else if("undefined"!=typeof ses){if(!ses.ok())return;ses.makeNedb=e}else"undefined"!=typeof window?window.Nedb=e():global.Nedb=e()})(function(){var define,ses,bootstrap,module,exports;
return (function(e,t,n){function i(n,s){if(!t[n]){if(!e[n]){var o=typeof require=="function"&&require;if(!s&&o)return o(n,!0);if(r)return r(n,!0);throw new Error("Cannot find module '"+n+"'")}var u=t[n]={exports:{}};e[n][0].call(u.exports,function(t){var r=e[n][1][t];return i(r?r:t)},u,u.exports)}return t[n].exports}var r=typeof require=="function"&&require;for(var s=0;s<n.length;s++)i(n[s]);return i})({1:[function(require,module,exports){
(function(process){if (!process.EventEmitter) process.EventEmitter = function () {};

var EventEmitter = exports.EventEmitter = process.EventEmitter;
var isArray = typeof Array.isArray === 'function'
    ? Array.isArray
    : function (xs) {
        return Object.prototype.toString.call(xs) === '[object Array]'
    }
;
function indexOf (xs, x) {
    if (xs.indexOf) return xs.indexOf(x);
    for (var i = 0; i < xs.length; i++) {
        if (x === xs[i]) return i;
    }
    return -1;
}

// By default EventEmitters will print a warning if more than
// 10 listeners are added to it. This is a useful default which
// helps finding memory leaks.
//
// Obviously not all Emitters should be limited to 10. This function allows
// that to be increased. Set to zero for unlimited.
var defaultMaxListeners = 10;
EventEmitter.prototype.setMaxListeners = function(n) {
  if (!this._events) this._events = {};
  this._events.maxListeners = n;
};


EventEmitter.prototype.emit = function(type) {
  // If there is no 'error' event listener then throw.
  if (type === 'error') {
    if (!this._events || !this._events.error ||
        (isArray(this._events.error) && !this._events.error.length))
    {
      if (arguments[1] instanceof Error) {
        throw arguments[1]; // Unhandled 'error' event
      } else {
        throw new Error("Uncaught, unspecified 'error' event.");
      }
      return false;
    }
  }

  if (!this._events) return false;
  var handler = this._events[type];
  if (!handler) return false;

  if (typeof handler == 'function') {
    switch (arguments.length) {
      // fast cases
      case 1:
        handler.call(this);
        break;
      case 2:
        handler.call(this, arguments[1]);
        break;
      case 3:
        handler.call(this, arguments[1], arguments[2]);
        break;
      // slower
      default:
        var args = Array.prototype.slice.call(arguments, 1);
        handler.apply(this, args);
    }
    return true;

  } else if (isArray(handler)) {
    var args = Array.prototype.slice.call(arguments, 1);

    var listeners = handler.slice();
    for (var i = 0, l = listeners.length; i < l; i++) {
      listeners[i].apply(this, args);
    }
    return true;

  } else {
    return false;
  }
};

// EventEmitter is defined in src/node_events.cc
// EventEmitter.prototype.emit() is also defined there.
EventEmitter.prototype.addListener = function(type, listener) {
  if ('function' !== typeof listener) {
    throw new Error('addListener only takes instances of Function');
  }

  if (!this._events) this._events = {};

  // To avoid recursion in the case that type == "newListeners"! Before
  // adding it to the listeners, first emit "newListeners".
  this.emit('newListener', type, listener);

  if (!this._events[type]) {
    // Optimize the case of one listener. Don't need the extra array object.
    this._events[type] = listener;
  } else if (isArray(this._events[type])) {

    // Check for listener leak
    if (!this._events[type].warned) {
      var m;
      if (this._events.maxListeners !== undefined) {
        m = this._events.maxListeners;
      } else {
        m = defaultMaxListeners;
      }

      if (m && m > 0 && this._events[type].length > m) {
        this._events[type].warned = true;
        console.error('(node) warning: possible EventEmitter memory ' +
                      'leak detected. %d listeners added. ' +
                      'Use emitter.setMaxListeners() to increase limit.',
                      this._events[type].length);
        console.trace();
      }
    }

    // If we've already got an array, just append.
    this._events[type].push(listener);
  } else {
    // Adding the second element, need to change to array.
    this._events[type] = [this._events[type], listener];
  }

  return this;
};

EventEmitter.prototype.on = EventEmitter.prototype.addListener;

EventEmitter.prototype.once = function(type, listener) {
  var self = this;
  self.on(type, function g() {
    self.removeListener(type, g);
    listener.apply(this, arguments);
  });

  return this;
};

EventEmitter.prototype.removeListener = function(type, listener) {
  if ('function' !== typeof listener) {
    throw new Error('removeListener only takes instances of Function');
  }

  // does not use listeners(), so no side effect of creating _events[type]
  if (!this._events || !this._events[type]) return this;

  var list = this._events[type];

  if (isArray(list)) {
    var i = indexOf(list, listener);
    if (i < 0) return this;
    list.splice(i, 1);
    if (list.length == 0)
      delete this._events[type];
  } else if (this._events[type] === listener) {
    delete this._events[type];
  }

  return this;
};

EventEmitter.prototype.removeAllListeners = function(type) {
  if (arguments.length === 0) {
    this._events = {};
    return this;
  }

  // does not use listeners(), so no side effect of creating _events[type]
  if (type && this._events && this._events[type]) this._events[type] = null;
  return this;
};

EventEmitter.prototype.listeners = function(type) {
  if (!this._events) this._events = {};
  if (!this._events[type]) this._events[type] = [];
  if (!isArray(this._events[type])) {
    this._events[type] = [this._events[type]];
  }
  return this._events[type];
};

})(require("__browserify_process"))
},{"__browserify_process":3}],2:[function(require,module,exports){
var events = require('events');

exports.isArray = isArray;
exports.isDate = function(obj){return Object.prototype.toString.call(obj) === '[object Date]'};
exports.isRegExp = function(obj){return Object.prototype.toString.call(obj) === '[object RegExp]'};


exports.print = function () {};
exports.puts = function () {};
exports.debug = function() {};

exports.inspect = function(obj, showHidden, depth, colors) {
  var seen = [];

  var stylize = function(str, styleType) {
    // http://en.wikipedia.org/wiki/ANSI_escape_code#graphics
    var styles =
        { 'bold' : [1, 22],
          'italic' : [3, 23],
          'underline' : [4, 24],
          'inverse' : [7, 27],
          'white' : [37, 39],
          'grey' : [90, 39],
          'black' : [30, 39],
          'blue' : [34, 39],
          'cyan' : [36, 39],
          'green' : [32, 39],
          'magenta' : [35, 39],
          'red' : [31, 39],
          'yellow' : [33, 39] };

    var style =
        { 'special': 'cyan',
          'number': 'blue',
          'boolean': 'yellow',
          'undefined': 'grey',
          'null': 'bold',
          'string': 'green',
          'date': 'magenta',
          // "name": intentionally not styling
          'regexp': 'red' }[styleType];

    if (style) {
      return '\033[' + styles[style][0] + 'm' + str +
             '\033[' + styles[style][1] + 'm';
    } else {
      return str;
    }
  };
  if (! colors) {
    stylize = function(str, styleType) { return str; };
  }

  function format(value, recurseTimes) {
    // Provide a hook for user-specified inspect functions.
    // Check that value is an object with an inspect function on it
    if (value && typeof value.inspect === 'function' &&
        // Filter out the util module, it's inspect function is special
        value !== exports &&
        // Also filter out any prototype objects using the circular check.
        !(value.constructor && value.constructor.prototype === value)) {
      return value.inspect(recurseTimes);
    }

    // Primitive types cannot have properties
    switch (typeof value) {
      case 'undefined':
        return stylize('undefined', 'undefined');

      case 'string':
        var simple = '\'' + JSON.stringify(value).replace(/^"|"$/g, '')
                                                 .replace(/'/g, "\\'")
                                                 .replace(/\\"/g, '"') + '\'';
        return stylize(simple, 'string');

      case 'number':
        return stylize('' + value, 'number');

      case 'boolean':
        return stylize('' + value, 'boolean');
    }
    // For some reason typeof null is "object", so special case here.
    if (value === null) {
      return stylize('null', 'null');
    }

    // Look up the keys of the object.
    var visible_keys = Object_keys(value);
    var keys = showHidden ? Object_getOwnPropertyNames(value) : visible_keys;

    // Functions without properties can be shortcutted.
    if (typeof value === 'function' && keys.length === 0) {
      if (isRegExp(value)) {
        return stylize('' + value, 'regexp');
      } else {
        var name = value.name ? ': ' + value.name : '';
        return stylize('[Function' + name + ']', 'special');
      }
    }

    // Dates without properties can be shortcutted
    if (isDate(value) && keys.length === 0) {
      return stylize(value.toUTCString(), 'date');
    }

    var base, type, braces;
    // Determine the object type
    if (isArray(value)) {
      type = 'Array';
      braces = ['[', ']'];
    } else {
      type = 'Object';
      braces = ['{', '}'];
    }

    // Make functions say that they are functions
    if (typeof value === 'function') {
      var n = value.name ? ': ' + value.name : '';
      base = (isRegExp(value)) ? ' ' + value : ' [Function' + n + ']';
    } else {
      base = '';
    }

    // Make dates with properties first say the date
    if (isDate(value)) {
      base = ' ' + value.toUTCString();
    }

    if (keys.length === 0) {
      return braces[0] + base + braces[1];
    }

    if (recurseTimes < 0) {
      if (isRegExp(value)) {
        return stylize('' + value, 'regexp');
      } else {
        return stylize('[Object]', 'special');
      }
    }

    seen.push(value);

    var output = keys.map(function(key) {
      var name, str;
      if (value.__lookupGetter__) {
        if (value.__lookupGetter__(key)) {
          if (value.__lookupSetter__(key)) {
            str = stylize('[Getter/Setter]', 'special');
          } else {
            str = stylize('[Getter]', 'special');
          }
        } else {
          if (value.__lookupSetter__(key)) {
            str = stylize('[Setter]', 'special');
          }
        }
      }
      if (visible_keys.indexOf(key) < 0) {
        name = '[' + key + ']';
      }
      if (!str) {
        if (seen.indexOf(value[key]) < 0) {
          if (recurseTimes === null) {
            str = format(value[key]);
          } else {
            str = format(value[key], recurseTimes - 1);
          }
          if (str.indexOf('\n') > -1) {
            if (isArray(value)) {
              str = str.split('\n').map(function(line) {
                return '  ' + line;
              }).join('\n').substr(2);
            } else {
              str = '\n' + str.split('\n').map(function(line) {
                return '   ' + line;
              }).join('\n');
            }
          }
        } else {
          str = stylize('[Circular]', 'special');
        }
      }
      if (typeof name === 'undefined') {
        if (type === 'Array' && key.match(/^\d+$/)) {
          return str;
        }
        name = JSON.stringify('' + key);
        if (name.match(/^"([a-zA-Z_][a-zA-Z_0-9]*)"$/)) {
          name = name.substr(1, name.length - 2);
          name = stylize(name, 'name');
        } else {
          name = name.replace(/'/g, "\\'")
                     .replace(/\\"/g, '"')
                     .replace(/(^"|"$)/g, "'");
          name = stylize(name, 'string');
        }
      }

      return name + ': ' + str;
    });

    seen.pop();

    var numLinesEst = 0;
    var length = output.reduce(function(prev, cur) {
      numLinesEst++;
      if (cur.indexOf('\n') >= 0) numLinesEst++;
      return prev + cur.length + 1;
    }, 0);

    if (length > 50) {
      output = braces[0] +
               (base === '' ? '' : base + '\n ') +
               ' ' +
               output.join(',\n  ') +
               ' ' +
               braces[1];

    } else {
      output = braces[0] + base + ' ' + output.join(', ') + ' ' + braces[1];
    }

    return output;
  }
  return format(obj, (typeof depth === 'undefined' ? 2 : depth));
};


function isArray(ar) {
  return ar instanceof Array ||
         Array.isArray(ar) ||
         (ar && ar !== Object.prototype && isArray(ar.__proto__));
}


function isRegExp(re) {
  return re instanceof RegExp ||
    (typeof re === 'object' && Object.prototype.toString.call(re) === '[object RegExp]');
}


function isDate(d) {
  if (d instanceof Date) return true;
  if (typeof d !== 'object') return false;
  var properties = Date.prototype && Object_getOwnPropertyNames(Date.prototype);
  var proto = d.__proto__ && Object_getOwnPropertyNames(d.__proto__);
  return JSON.stringify(proto) === JSON.stringify(properties);
}

function pad(n) {
  return n < 10 ? '0' + n.toString(10) : n.toString(10);
}

var months = ['Jan', 'Feb', 'Mar', 'Apr', 'May', 'Jun', 'Jul', 'Aug', 'Sep',
              'Oct', 'Nov', 'Dec'];

// 26 Feb 16:19:34
function timestamp() {
  var d = new Date();
  var time = [pad(d.getHours()),
              pad(d.getMinutes()),
              pad(d.getSeconds())].join(':');
  return [d.getDate(), months[d.getMonth()], time].join(' ');
}

exports.log = function (msg) {};

exports.pump = null;

var Object_keys = Object.keys || function (obj) {
    var res = [];
    for (var key in obj) res.push(key);
    return res;
};

var Object_getOwnPropertyNames = Object.getOwnPropertyNames || function (obj) {
    var res = [];
    for (var key in obj) {
        if (Object.hasOwnProperty.call(obj, key)) res.push(key);
    }
    return res;
};

var Object_create = Object.create || function (prototype, properties) {
    // from es5-shim
    var object;
    if (prototype === null) {
        object = { '__proto__' : null };
    }
    else {
        if (typeof prototype !== 'object') {
            throw new TypeError(
                'typeof prototype[' + (typeof prototype) + '] != \'object\''
            );
        }
        var Type = function () {};
        Type.prototype = prototype;
        object = new Type();
        object.__proto__ = prototype;
    }
    if (typeof properties !== 'undefined' && Object.defineProperties) {
        Object.defineProperties(object, properties);
    }
    return object;
};

exports.inherits = function(ctor, superCtor) {
  ctor.super_ = superCtor;
  ctor.prototype = Object_create(superCtor.prototype, {
    constructor: {
      value: ctor,
      enumerable: false,
      writable: true,
      configurable: true
    }
  });
};

var formatRegExp = /%[sdj%]/g;
exports.format = function(f) {
  if (typeof f !== 'string') {
    var objects = [];
    for (var i = 0; i < arguments.length; i++) {
      objects.push(exports.inspect(arguments[i]));
    }
    return objects.join(' ');
  }

  var i = 1;
  var args = arguments;
  var len = args.length;
  var str = String(f).replace(formatRegExp, function(x) {
    if (x === '%%') return '%';
    if (i >= len) return x;
    switch (x) {
      case '%s': return String(args[i++]);
      case '%d': return Number(args[i++]);
      case '%j': return JSON.stringify(args[i++]);
      default:
        return x;
    }
  });
  for(var x = args[i]; i < len; x = args[++i]){
    if (x === null || typeof x !== 'object') {
      str += ' ' + x;
    } else {
      str += ' ' + exports.inspect(x);
    }
  }
  return str;
};

},{"events":1}],3:[function(require,module,exports){
// shim for using process in browser

var process = module.exports = {};

process.nextTick = (function () {
    var canSetImmediate = typeof window !== 'undefined'
    && window.setImmediate;
    var canPost = typeof window !== 'undefined'
    && window.postMessage && window.addEventListener
    ;

    if (canSetImmediate) {
        return function (f) { return window.setImmediate(f) };
    }

    if (canPost) {
        var queue = [];
        window.addEventListener('message', function (ev) {
            if (ev.source === window && ev.data === 'process-tick') {
                ev.stopPropagation();
                if (queue.length > 0) {
                    var fn = queue.shift();
                    fn();
                }
            }
        }, true);

        return function nextTick(fn) {
            queue.push(fn);
            window.postMessage('process-tick', '*');
        };
    }

    return function nextTick(fn) {
        setTimeout(fn, 0);
    };
})();

process.title = 'browser';
process.browser = true;
process.env = {};
process.argv = [];

process.binding = function (name) {
    throw new Error('process.binding is not supported');
}

// TODO(shtylman)
process.cwd = function () { return '/' };
process.chdir = function (dir) {
    throw new Error('process.chdir is not supported');
};

},{}],4:[function(require,module,exports){
(function(){/**
 * Specific customUtils for the browser, where we don't have access to the Crypto and Buffer modules
 */

/**
 * Taken from the crypto-browserify module
 * https://github.com/dominictarr/crypto-browserify
 * NOTE: Math.random() does not guarantee "cryptographic quality" but we actually don't need it
 */
function randomBytes (size) {
  var bytes = new Array(size);
  var r;

  for (var i = 0, r; i < size; i++) {
    if ((i & 0x03) == 0) r = Math.random() * 0x100000000;
    bytes[i] = r >>> ((i & 0x03) << 3) & 0xff;
  }

  return bytes;
}


/**
 * Taken from the base64-js module
 * https://github.com/beatgammit/base64-js/
 */
function byteArrayToBase64 (uint8) {
  var lookup = 'ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/'
    , extraBytes = uint8.length % 3   // if we have 1 byte left, pad 2 bytes
    , output = ""
    , temp, length, i;

  function tripletToBase64 (num) {
    return lookup[num >> 18 & 0x3F] + lookup[num >> 12 & 0x3F] + lookup[num >> 6 & 0x3F] + lookup[num & 0x3F];
  };

  // go through the array every three bytes, we'll deal with trailing stuff later
  for (i = 0, length = uint8.length - extraBytes; i < length; i += 3) {
    temp = (uint8[i] << 16) + (uint8[i + 1] << 8) + (uint8[i + 2]);
    output += tripletToBase64(temp);
  }

  // pad the end with zeros, but make sure to not forget the extra bytes
  switch (extraBytes) {
    case 1:
      temp = uint8[uint8.length - 1];
      output += lookup[temp >> 2];
      output += lookup[(temp << 4) & 0x3F];
      output += '==';
      break;
    case 2:
      temp = (uint8[uint8.length - 2] << 8) + (uint8[uint8.length - 1]);
      output += lookup[temp >> 10];
      output += lookup[(temp >> 4) & 0x3F];
      output += lookup[(temp << 2) & 0x3F];
      output += '=';
      break;
  }

  return output;
}


/**
 * Return a random alphanumerical string of length len
 * There is a very small probability (less than 1/1,000,000) for the length to be less than len
 * (il the base64 conversion yields too many pluses and slashes) but
 * that's not an issue here
 * The probability of a collision is extremely small (need 3*10^12 documents to have one chance in a million of a collision)
 * See http://en.wikipedia.org/wiki/Birthday_problem
 */
function uid (len) {
  return byteArrayToBase64(randomBytes(Math.ceil(Math.max(8, len * 2)))).replace(/[+\/]/g, '').slice(0, len);
}



module.exports.uid = uid;

})()
},{}],5:[function(require,module,exports){
var customUtils = require('./customUtils')
  , model = require('./model')
  , async = require('async')
  , Executor = require('./executor')
  , Index = require('./indexes')
  , util = require('util')
  , _ = require('underscore')
  , Persistence = require('./persistence')
  ;


/**
 * Create a new collection
 * @param {String} options.filename Optional, datastore will be in-memory only if not provided
 * @param {Boolean} options.inMemoryOnly Optional, default to false
 * @param {Boolean} options.nodeWebkitAppName Optional, specify the name of your NW app if you want options.filename to be relative to the directory where
 *                                            Node Webkit stores application data such as cookies and local storage (the best place to store data in my opinion)
 * @param {Boolean} options.autoload Optional, defaults to false
 */
function Datastore (options) {
  var filename;

  // Retrocompatibility with v0.6 and before
  if (typeof options === 'string') {
    filename = options;
    this.inMemoryOnly = false;   // Default
  } else {
    options = options || {};
    filename = options.filename;
    this.inMemoryOnly = options.inMemoryOnly || false;
    this.autoload = options.autoload || false;
  }

  // Determine whether in memory or persistent
  if (!filename || typeof filename !== 'string' || filename.length === 0) {
    this.filename = null;
    this.inMemoryOnly = true;
  } else {
    this.filename = filename;
  }

  // Persistence handling
  this.persistence = new Persistence({ db: this, nodeWebkitAppName: options.nodeWebkitAppName });

  // This new executor is ready if we don't use persistence
  // If we do, it will only be ready once loadDatabase is called
  this.executor = new Executor();
  if (this.inMemoryOnly) { this.executor.ready = true; }

  // Indexed by field name, dot notation can be used
  // _id is always indexed and since _ids are generated randomly the underlying
  // binary is always well-balanced
  this.indexes = {};
  this.indexes._id = new Index({ fieldName: '_id', unique: true });

  if (this.autoload) { this.loadDatabase(); }
}


/**
 * Load the database from the datafile, and trigger the execution of buffered commands if any
 */
Datastore.prototype.loadDatabase = function () {
  this.executor.push({ this: this.persistence, fn: this.persistence.loadDatabase, arguments: arguments }, true);
};


/**
 * Get an array of all the data in the database
 */
Datastore.prototype.getAllData = function () {
  return this.indexes._id.getAll();
};


/**
 * Reset all currently defined indexes
 */
Datastore.prototype.resetIndexes = function (newData) {
  var self = this;

  Object.keys(this.indexes).forEach(function (i) {
    self.indexes[i].reset(newData);
  });
};


/**
 * Ensure an index is kept for this field. Same parameters as lib/indexes
 * For now this function is synchronous, we need to test how much time it takes
 * We use an async API for consistency with the rest of the code
 * @param {String} options.fieldName
 * @param {Boolean} options.unique
 * @param {Boolean} options.sparse
 * @param {Function} cb Optional callback, signature: err
 */
Datastore.prototype.ensureIndex = function (options, cb) {
  var callback = cb || function () {};

  options = options || {};

  if (!options.fieldName) { return callback({ missingFieldName: true }); }
  if (this.indexes[options.fieldName]) { return callback(null); }

  this.indexes[options.fieldName] = new Index(options);

  try {
    this.indexes[options.fieldName].insert(this.getAllData());
  } catch (e) {
    delete this.indexes[options.fieldName];
    return callback(e);
  }

  return callback(null);
};


/**
 * Add one or several document(s) to all indexes
 */
Datastore.prototype.addToIndexes = function (doc) {
  var i, failingIndex, error
    , keys = Object.keys(this.indexes)
    ;

  for (i = 0; i < keys.length; i += 1) {
    try {
      this.indexes[keys[i]].insert(doc);
    } catch (e) {
      failingIndex = i;
      error = e;
      break;
    }
  }

  // If an error happened, we need to rollback the insert on all other indexes
  if (error) {
    for (i = 0; i < failingIndex; i += 1) {
      this.indexes[keys[i]].remove(doc);
    }

    throw error;
  }
};


/**
 * Remove one or several document(s) from all indexes
 */
Datastore.prototype.removeFromIndexes = function (doc) {
  var self = this;

  Object.keys(this.indexes).forEach(function (i) {
    self.indexes[i].remove(doc);
  });
};


/**
 * Update one or several documents in all indexes
 * If one update violates a constraint, all changes are rolled back
 */
Datastore.prototype.updateIndexes = function (oldDoc, newDoc) {
  var i, failingIndex, error
    , keys = Object.keys(this.indexes)
    ;

  for (i = 0; i < keys.length; i += 1) {
    try {
      this.indexes[keys[i]].update(oldDoc, newDoc);
    } catch (e) {
      failingIndex = i;
      error = e;
      break;
    }
  }

  // If an error happened, we need to rollback the insert on all other indexes
  if (error) {
    for (i = 0; i < failingIndex; i += 1) {
      this.indexes[keys[i]].revertUpdate(oldDoc, newDoc);
    }

    throw error;
  }
};


/**
 * Return the list of candidates for a given query
 * Crude implementation for now, we return the candidates given by the first usable index if any
 * We try the following query types, in this order: basic match, $in match, comparison match
 * One way to make it better would be to enable the use of multiple indexes if the first usable index
 * returns too much data. I may do it in the future.
 */
Datastore.prototype.getCandidates = function (query) {
  var indexNames = Object.keys(this.indexes)
    , usableQueryKeys;

  // For a basic match
  usableQueryKeys = [];
  Object.keys(query).forEach(function (k) {
    if (typeof query[k] === 'string' || typeof query[k] === 'number' || typeof query[k] === 'boolean' || util.isDate(query[k]) || query[k] === null) {
      usableQueryKeys.push(k);
    }
  });
  usableQueryKeys = _.intersection(usableQueryKeys, indexNames);
  if (usableQueryKeys.length > 0) {
    return this.indexes[usableQueryKeys[0]].getMatching(query[usableQueryKeys[0]]);
  }

  // For a $in match
  usableQueryKeys = [];
  Object.keys(query).forEach(function (k) {
    if (query[k] && query[k].hasOwnProperty('$in')) {
      usableQueryKeys.push(k);
    }
  });
  usableQueryKeys = _.intersection(usableQueryKeys, indexNames);
  if (usableQueryKeys.length > 0) {
    return this.indexes[usableQueryKeys[0]].getMatching(query[usableQueryKeys[0]].$in);
  }

  // For a comparison match
  usableQueryKeys = [];
  Object.keys(query).forEach(function (k) {
    if (query[k] && (query[k].hasOwnProperty('$lt') || query[k].hasOwnProperty('$lte') || query[k].hasOwnProperty('$gt') || query[k].hasOwnProperty('$gte'))) {
      usableQueryKeys.push(k);
    }
  });
  usableQueryKeys = _.intersection(usableQueryKeys, indexNames);
  if (usableQueryKeys.length > 0) {
    return this.indexes[usableQueryKeys[0]].getBetweenBounds(query[usableQueryKeys[0]]);
  }

  // By default, return all the DB data
  return this.getAllData();
};


/**
 * Insert a new document
 * @param {Function} cb Optional callback, signature: err, insertedDoc
 *
 * @api private Use Datastore.insert which has the same signature
 */
Datastore.prototype._insert = function (newDoc, cb) {
  var callback = cb || function () {}
    , self = this
    , insertedDoc
    ;

  // Ensure the document has the right format
  try {
    newDoc._id = customUtils.uid(16);
    model.checkObject(newDoc);
    insertedDoc = model.deepCopy(newDoc);
  } catch (e) {
    return callback(e);
  }

  // Insert in all indexes (also serves to ensure uniqueness)
  try { self.addToIndexes(insertedDoc); } catch (e) { return callback(e); }

  this.persistence.persistNewState([newDoc], function (err) {
    if (err) { return callback(err); }
    return callback(null, newDoc);
  });
};

Datastore.prototype.insert = function () {
  this.executor.push({ this: this, fn: this._insert, arguments: arguments });
};


/**
 * Find all documents matching the query
 * @param {Object} query MongoDB-style query
 *
 * @api private Use find
 */
Datastore.prototype._find = function (query, callback) {
  var res = []
    , self = this
    , candidates = this.getCandidates(query)
    , i
    ;

  try {
    for (i = 0; i < candidates.length; i += 1) {
      if (model.match(candidates[i], query)) {
        res.push(model.deepCopy(candidates[i]));
      }
    }
  } catch (err) {
    return callback(err);
  }

  return callback(null, res);
};

Datastore.prototype.find = function () {
  this.executor.push({ this: this, fn: this._find, arguments: arguments });
};


/**
 * Find one document matching the query
 * @param {Object} query MongoDB-style query
 *
 * @api private Use findOne
 */
Datastore.prototype._findOne = function (query, callback) {
  var self = this
    , candidates = this.getCandidates(query)
    , i
    ;

  try {
    for (i = 0; i < candidates.length; i += 1) {
      if (model.match(candidates[i], query)) {
        return callback(null, model.deepCopy(candidates[i]));
      }
    }
  } catch (err) {
    return callback(err);
  }

  return callback(null, null);
};

Datastore.prototype.findOne = function () {
  this.executor.push({ this: this, fn: this._findOne, arguments: arguments });
};


/**
 * Update all docs matching query
 * For now, very naive implementation (recalculating the whole database)
 * @param {Object} query
 * @param {Object} updateQuery
 * @param {Object} options Optional options
 *                 options.multi If true, can update multiple documents (defaults to false)
 *                 options.upsert If true, document is inserted if the query doesn't match anything
 * @param {Function} cb Optional callback, signature: err, numReplaced, upsert (set to true if the update was in fact an upsert)
 *
 * @api private Use Datastore.update which has the same signature
 */
Datastore.prototype._update = function (query, updateQuery, options, cb) {
  var callback
    , self = this
    , numReplaced = 0
    , multi, upsert
    , updatedDocs = []
    , candidates
    , i
    ;

  if (typeof options === 'function') { cb = options; options = {}; }
  callback = cb || function () {};
  multi = options.multi !== undefined ? options.multi : false;
  upsert = options.upsert !== undefined ? options.upsert : false;

  async.waterfall([
  function (cb) {   // If upsert option is set, check whether we need to insert the doc
    if (!upsert) { return cb(); }

    self._findOne(query, function (err, doc) {
      if (err) { return callback(err); }
      if (doc) {
        return cb();
      } else {
        // The upserted document is the query (since for now queries have the same structure as
        // documents), modified by the updateQuery
        return self._insert(model.modify(query, updateQuery), function (err) {
          if (err) { return callback(err); }
          return callback(null, 1, true);
        });
      }
    });
  }
  , function () {   // Perform the update
    var modifiedDoc;

    candidates = self.getCandidates(query);

    try {
      for (i = 0; i < candidates.length; i += 1) {
        if (model.match(candidates[i], query) && (multi || numReplaced === 0)) {
          numReplaced += 1;
          modifiedDoc = model.modify(candidates[i], updateQuery);
          self.updateIndexes(candidates[i], modifiedDoc);
          updatedDocs.push(modifiedDoc);
        }
      }
    } catch (err) {
      return callback(err);
    }

    self.persistence.persistNewState(updatedDocs, function (err) {
      if (err) { return callback(err); }
      return callback(null, numReplaced);
    });
  }
  ]);
};
Datastore.prototype.update = function () {
  this.executor.push({ this: this, fn: this._update, arguments: arguments });
};


/**
 * Remove all docs matching the query
 * For now very naive implementation (similar to update)
 * @param {Object} query
 * @param {Object} options Optional options
 *                 options.multi If true, can update multiple documents (defaults to false)
 * @param {Function} cb Optional callback, signature: err, numRemoved
 *
 * @api private Use Datastore.remove which has the same signature
 */
Datastore.prototype._remove = function (query, options, cb) {
  var callback
    , self = this
    , numRemoved = 0
    , multi
    , removedDocs = []
    , candidates = this.getCandidates(query)
    ;

  if (typeof options === 'function') { cb = options; options = {}; }
  callback = cb || function () {};
  multi = options.multi !== undefined ? options.multi : false;

  try {
    candidates.forEach(function (d) {
      if (model.match(d, query) && (multi || numRemoved === 0)) {
        numRemoved += 1;
        removedDocs.push({ $$deleted: true, _id: d._id });
        self.removeFromIndexes(d);
      }
    });
  } catch (err) { return callback(err); }

  self.persistence.persistNewState(removedDocs, function (err) {
    if (err) { return callback(err); }
    return callback(null, numRemoved);
  });
};
Datastore.prototype.remove = function () {
  this.executor.push({ this: this, fn: this._remove, arguments: arguments });
};



module.exports = Datastore;

},{"./customUtils":4,"./executor":6,"./indexes":7,"./model":8,"./persistence":9,"async":10,"underscore":15,"util":2}],6:[function(require,module,exports){
(function(){/**
 * Responsible for sequentially executing actions on the database
 */

var async = require('async')
  ;

function Executor () {
  this.buffer = [];
  this.ready = false;

  // This queue will execute all commands, one-by-one in order
  this.queue = async.queue(function (task, cb) {
    var callback
      , lastArg = task.arguments[task.arguments.length - 1]
      , i, newArguments = []
      ;

    // task.arguments is an array-like object on which adding a new field doesn't work, so we transform it into a real array
    for (i = 0; i < task.arguments.length; i += 1) { newArguments.push(task.arguments[i]); }

    // Always tell the queue task is complete. Execute callback if any was given.
    if (typeof lastArg === 'function') {
      callback = function () {
        lastArg.apply(null, arguments);
        cb();
      };

      newArguments[newArguments.length - 1] = callback;
    } else {
      callback = function () { cb(); };
      newArguments.push(callback);
    }


    task.fn.apply(task.this, newArguments);
  }, 1);
}


/**
 * If executor is ready, queue task (and process it immediately if executor was idle)
 * If not, buffer task for later processing
 * @param {Object} task
 *                 task.this - Object to use as this
 *                 task.fn - Function to execute
 *                 task.arguments - Array of arguments
 * @param {Boolean} forceQueuing Optional (defaults to false) force executor to queue task even if it is not ready
 */
Executor.prototype.push = function (task, forceQueuing) {
  if (this.ready || forceQueuing) {
    this.queue.push(task);
  } else {
    this.buffer.push(task);
  }
};


/**
 * Queue all tasks in buffer (in the same order they came in)
 * Automatically sets executor as ready
 */
Executor.prototype.processBuffer = function () {
  var i;
  this.ready = true;
  for (i = 0; i < this.buffer.length; i += 1) { this.queue.push(this.buffer[i]); }
  this.buffer = [];
};



// Interface
module.exports = Executor;

})()
},{"async":10}],7:[function(require,module,exports){
var BinarySearchTree = require('binary-search-tree').AVLTree
  , model = require('./model')
  , _ = require('underscore')
  , util = require('util')
  ;

/**
 * Two indexed pointers are equal iif they point to the same place
 */
function checkValueEquality (a, b) {
  return a === b;
}


/**
 * Create a new index
 * @param {String} options.fieldName On which field should the index apply (can use dot notation to index on sub fields)
 * @param {Boolean} options.unique Optional, enforce a unique constraint (default: false)
 * @param {Boolean} options.sparse Optional, allow a sparse index (we can have documents for which fieldName is undefined) (default: false)
 */
function Index (options) {
  this.fieldName = options.fieldName;
  this.unique = options.unique || false;
  this.sparse = options.sparse || false;

  this.treeOptions = { unique: this.unique, compareKeys: model.compareThings, checkValueEquality: checkValueEquality };

  this.reset();   // No data in the beginning
}


/**
 * Reset an index
 * @param {Document or Array of documents} newData Optional, data to initialize the index with
 *                                                 If an error is thrown during insertion, the index is not modified
 */
Index.prototype.reset = function (newData) {
  this.tree = new BinarySearchTree(this.treeOptions);

  if (newData) { this.insert(newData); }
};


/**
 * Insert a new document in the index
 * If an array is passed, we insert all its elements (if one insertion fails the index is not modified)
 * O(log(n))
 */
Index.prototype.insert = function (doc) {
  var key, self = this;

  if (util.isArray(doc)) { this.insertMultipleDocs(doc); return; }

  key = model.getDotValue(doc, this.fieldName);

  // We don't index documents that don't contain the field if the index is sparse
  if (key === undefined && this.sparse) { return; }

  this.tree.insert(key, doc);
};


/**
 * Insert an array of documents in the index
 * If a constraint is violated, an error should be thrown and the changes rolled back
 */
Index.prototype.insertMultipleDocs = function (docs) {
  var i, error, failingI;

  for (i = 0; i < docs.length; i += 1) {
    try {
      this.insert(docs[i]);
    } catch (e) {
      error = e;
      failingI = i;
      break;
    }
  }

  if (error) {
    for (i = 0; i < failingI; i += 1) {
      this.remove(docs[i]);
    }

    throw error;
  }
};


/**
 * Remove a document from the index
 * If an array is passed, we remove all its elements
 * The remove operation is safe with regards to the 'unique' constraint
 * O(log(n))
 */
Index.prototype.remove = function (doc) {
  var key, self = this;

  if (util.isArray(doc)) { doc.forEach(function (d) { self.remove(d); }); return; }

  key = model.getDotValue(doc, this.fieldName);

  if (key === undefined && this.sparse) { return; }

  this.tree.delete(key, doc);
};


/**
 * Update a document in the index
 * If a constraint is violated, changes are rolled back and an error thrown
 * Naive implementation, still in O(log(n))
 */
Index.prototype.update = function (oldDoc, newDoc) {
  if (util.isArray(oldDoc)) { this.updateMultipleDocs(oldDoc); return; }

  this.remove(oldDoc);

  try {
    this.insert(newDoc);
  } catch (e) {
    this.insert(oldDoc);
    throw e;
  }
};


/**
 * Update multiple documents in the index
 * If a constraint is violated, the changes need to be rolled back
 * and an error thrown
 * @param {Array of oldDoc, newDoc pairs} pairs
 */
Index.prototype.updateMultipleDocs = function (pairs) {
  var i, failingI, error;

  for (i = 0; i < pairs.length; i += 1) {
    this.remove(pairs[i].oldDoc);
  }

  for (i = 0; i < pairs.length; i += 1) {
    try {
      this.insert(pairs[i].newDoc);
    } catch (e) {
      error = e;
      failingI = i;
      break;
    }
  }

  // If an error was raised, roll back changes in the inverse order
  if (error) {
    for (i = 0; i < failingI; i += 1) {
      this.remove(pairs[i].newDoc);
    }

    for (i = 0; i < pairs.length; i += 1) {
      this.insert(pairs[i].oldDoc);
    }

    throw error;
  }
};


/**
 * Revert an update
 */
Index.prototype.revertUpdate = function (oldDoc, newDoc) {
  var revert = [];

  if (!util.isArray(oldDoc)) {
    this.update(newDoc, oldDoc);
  } else {
    oldDoc.forEach(function (pair) {
      revert.push({ oldDoc: pair.newDoc, newDoc: pair.oldDoc });
    });
    this.update(revert);
  }
};


// Append all elements in toAppend to array
function append (array, toAppend) {
  var i;

  for (i = 0; i < toAppend.length; i += 1) {
    array.push(toAppend[i]);
  }
}


/**
 * Get all documents in index whose key match value (if it is a Thing) or one of the elements of value (if it is an array of Things)
 * @param {Thing} value Value to match the key against
 * @return {Array of documents}
 */
Index.prototype.getMatching = function (value) {
  var res, self = this;

  if (!util.isArray(value)) {
    return this.tree.search(value);
  } else {
    res = [];
    value.forEach(function (v) { append(res, self.getMatching(v)); });
    return res;
  }
};


/**
 * Get all documents in index whose key is between bounds are they are defined by query
 * Documents are sorted by key
 * @param {Query} query
 * @return {Array of documents}
 */
Index.prototype.getBetweenBounds = function (query) {
  return this.tree.betweenBounds(query);
};


/**
 * Get all elements in the index
 * @return {Array of documents}
 */
Index.prototype.getAll = function () {
  var res = [];

  this.tree.executeOnEveryNode(function (node) {
    var i;

    for (i = 0; i < node.data.length; i += 1) {
      res.push(node.data[i]);
    }
  });

  return res;
};




// Interface
module.exports = Index;

},{"./model":8,"binary-search-tree":11,"underscore":15,"util":2}],8:[function(require,module,exports){
/**
 * Handle models (i.e. docs)
 * Serialization/deserialization
 * Copying
 */

var dateToJSON = function () { return { $$date: this.getTime() }; }
  , originalDateToJSON = Date.prototype.toJSON
  , util = require('util')
  , _ = require('underscore')
  , modifierFunctions = {}
  , lastStepModifierFunctions = {}
  , comparisonFunctions = {}
  , logicalOperators = {}
  ;


/**
 * Check a key, throw an error if the key is non valid
 * @param {String} k key
 * @param {Model} v value, needed to treat the Date edge case
 * Non-treatable edge cases here: if part of the object if of the form { $$date: number } or { $$deleted: true }
 * Its serialized-then-deserialized version it will transformed into a Date object
 * But you really need to want it to trigger such behaviour, even when warned not to use '$' at the beginning of the field names...
 */
function checkKey (k, v) {
  if (k[0] === '$' && !(k === '$$date' && typeof v === 'number') && !(k === '$$deleted' && v === true)) {
    throw 'Field names cannot begin with the $ character';
  }

  if (k.indexOf('.') !== -1) {
    throw 'Field names cannot contain a .';
  }
}


/**
 * Check a DB object and throw an error if it's not valid
 * Works by applying the above checkKey function to all fields recursively
 */
function checkObject (obj) {
  if (util.isArray(obj)) {
    obj.forEach(function (o) {
      checkObject(o);
    });
  }

  if (typeof obj === 'object' && obj !== null) {
    Object.keys(obj).forEach(function (k) {
      checkKey(k, obj[k]);
      checkObject(obj[k]);
    });
  }
}


/**
 * Serialize an object to be persisted to a one-line string
 * For serialization/deserialization, we use the native JSON parser and not eval or Function
 * That gives us less freedom but data entered in the database may come from users
 * so eval and the like are not safe
 * Accepted primitive types: Number, String, Boolean, Date, null
 * Accepted secondary types: Objects, Arrays
 */
function serialize (obj) {
  var res;

  // Keep track of the fact that this is a Date object
  Date.prototype.toJSON = dateToJSON;

  res = JSON.stringify(obj, function (k, v) {
    checkKey(k, v);

    if (typeof v === undefined) { return null; }
    if (typeof v === 'string' || typeof v === 'number' || typeof v === 'boolean' || v === null) { return v; }

    return v;
  });

  // Return Date to its original state
  Date.prototype.toJSON = originalDateToJSON;

  return res;
}


/**
 * From a one-line representation of an object generate by the serialize function
 * Return the object itself
 */
function deserialize (rawData) {
  return JSON.parse(rawData, function (k, v) {
    if (k === '$$date') { return new Date(v); }
    if (typeof v === 'string' || typeof v === 'number' || typeof v === 'boolean' || v === null) { return v; }
    if (v && v.$$date) { return v.$$date; }

    return v;
  });
}


/**
 * Deep copy a DB object
 */
function deepCopy (obj) {
  var res;

  if ( typeof obj === 'boolean' ||
       typeof obj === 'number' ||
       typeof obj === 'string' ||
       obj === null ||
       (util.isDate(obj)) ) {
    return obj;
  }

  if (util.isArray(obj)) {
    res = [];
    obj.forEach(function (o) { res.push(o); });
    return res;
  }

  if (typeof obj === 'object') {
    res = {};
    Object.keys(obj).forEach(function (k) {
      res[k] = deepCopy(obj[k]);
    });
    return res;
  }

  return undefined;   // For now everything else is undefined. We should probably throw an error instead
}


/**
 * Utility functions for comparing things
 * Assumes type checking was already done (a and b already have the same type)
 * compareNSB works for numbers, strings and booleans
 */
function compareNSB (a, b) {
  if (a < b) { return -1; }
  if (a > b) { return 1; }
  return 0;
}

function compareArrays (a, b) {
  var i, comp;

  for (i = 0; i < Math.min(a.length, b.length); i += 1) {
    comp = compareThings(a[i], b[i]);

    if (comp !== 0) { return comp; }
  }

  // Common section was identical, longest one wins
  return compareNSB(a.length, b.length);
}


/**
 * Compare { things U undefined }
 * Things are defined as any native types (string, number, boolean, null, date) and objects
 * We need to compare with undefined as it will be used in indexes
 * In the case of objects and arrays, we compare the serialized versions
 * If two objects dont have the same type, the (arbitrary) type hierarchy is: undefined, null, number, strings, boolean, dates, arrays, objects
 * Return -1 if a < b, 1 if a > b and 0 if a = b (note that equality here is NOT the same as defined in areThingsEqual!)
 */
function compareThings (a, b) {
  var aKeys, bKeys, comp, i;

  // undefined
  if (a === undefined) { return b === undefined ? 0 : -1; }
  if (b === undefined) { return a === undefined ? 0 : 1; }

  // null
  if (a === null) { return b === null ? 0 : -1; }
  if (b === null) { return a === null ? 0 : 1; }

  // Numbers
  if (typeof a === 'number') { return typeof b === 'number' ? compareNSB(a, b) : -1; }
  if (typeof b === 'number') { return typeof a === 'number' ? compareNSB(a, b) : 1; }

  // Strings
  if (typeof a === 'string') { return typeof b === 'string' ? compareNSB(a, b) : -1; }
  if (typeof b === 'string') { return typeof a === 'string' ? compareNSB(a, b) : 1; }

  // Booleans
  if (typeof a === 'boolean') { return typeof b === 'boolean' ? compareNSB(a, b) : -1; }
  if (typeof b === 'boolean') { return typeof a === 'boolean' ? compareNSB(a, b) : 1; }

  // Dates
  if (util.isDate(a)) { return util.isDate(b) ? compareNSB(a.getTime(), b.getTime()) : -1; }
  if (util.isDate(b)) { return util.isDate(a) ? compareNSB(a.getTime(), b.getTime()) : 1; }

  // Arrays (first element is most significant and so on)
  if (util.isArray(a)) { return util.isArray(b) ? compareArrays(a, b) : -1; }
  if (util.isArray(b)) { return util.isArray(a) ? compareArrays(a, b) : 1; }

  // Objects
  aKeys = Object.keys(a).sort();
  bKeys = Object.keys(b).sort();

  for (i = 0; i < Math.min(aKeys.length, bKeys.length); i += 1) {
    comp = compareThings(a[aKeys[i]], b[bKeys[i]]);

    if (comp !== 0) { return comp; }
  }

  return compareNSB(aKeys.length, bKeys.length);
}



// ==============================================================
// Updating documents
// ==============================================================

/**
 * The signature of modifier functions is as follows
 * Their structure is always the same: recursively follow the dot notation while creating
 * the nested documents if needed, then apply the "last step modifier"
 * @param {Object} obj The model to modify
 * @param {String} field Can contain dots, in that case that means we will set a subfield recursively
 * @param {Model} value
 */

/**
 * Set a field to a new value
 */
lastStepModifierFunctions.$set = function (obj, field, value) {
  obj[field] = value;
};


/**
 * Push an element to the end of an array field
 */
lastStepModifierFunctions.$push = function (obj, field, value) {
  // Create the array if it doesn't exist
  if (!obj.hasOwnProperty(field)) { obj[field] = []; }

  if (!util.isArray(obj[field])) { throw "Can't $push an element on non-array values"; }

  if (value !== null && typeof value === 'object' && value.$each) {
    if (Object.keys(value).length > 1) { throw "Can't use another field in conjunction with $each"; }
    if (!util.isArray(value.$each)) { throw "$each requires an array value"; }

    value.$each.forEach(function (v) {
      obj[field].push(v);
    });
  } else {
    obj[field].push(value);
  }
};


/**
 * Add an element to an array field only if it is not already in it
 * No modification if the element is already in the array
 * Note that it doesn't check whether the original array contains duplicates
 */
lastStepModifierFunctions.$addToSet = function (obj, field, value) {
  var addToSet = true;

  // Create the array if it doesn't exist
  if (!obj.hasOwnProperty(field)) { obj[field] = []; }

  if (!util.isArray(obj[field])) { throw "Can't $addToSet an element on non-array values"; }

  if (value !== null && typeof value === 'object' && value.$each) {
    if (Object.keys(value).length > 1) { throw "Can't use another field in conjunction with $each"; }
    if (!util.isArray(value.$each)) { throw "$each requires an array value"; }

    value.$each.forEach(function (v) {
      lastStepModifierFunctions.$addToSet(obj, field, v);
    });
  } else {
    obj[field].forEach(function (v) {
      if (compareThings(v, value) === 0) { addToSet = false; }
    });
    if (addToSet) { obj[field].push(value); }
  }
};


/**
 * Remove the first or last element of an array
 */
lastStepModifierFunctions.$pop = function (obj, field, value) {
  if (!util.isArray(obj[field])) { throw "Can't $pop an element from non-array values"; }
  if (typeof value !== 'number') { throw value + " isn't an integer, can't use it with $pop"; }
  if (value =