updated bunch of file paths and changed the way posts are loaded

node_modules/mongodb-core/lib/cursor.js

@@ -0,0 +1,776 @@
+"use strict";
+
+var Long = require('bson').Long
+  , Logger = require('./connection/logger')
+  , MongoError = require('./error')
+  , f = require('util').format;
+
+/**
+ * This is a cursor results callback
+ *
+ * @callback resultCallback
+ * @param {error} error An error object. Set to null if no error present
+ * @param {object} document
+ */
+
+/**
+ * @fileOverview The **Cursor** class is an internal class that embodies a cursor on MongoDB
+ * allowing for iteration over the results returned from the underlying query.
+ *
+ * **CURSORS Cannot directly be instantiated**
+ * @example
+ * var Server = require('mongodb-core').Server
+ *   , ReadPreference = require('mongodb-core').ReadPreference
+ *   , assert = require('assert');
+ *
+ * var server = new Server({host: 'localhost', port: 27017});
+ * // Wait for the connection event
+ * server.on('connect', function(server) {
+ *   assert.equal(null, err);
+ *
+ *   // Execute the write
+ *   var cursor = _server.cursor('integration_tests.inserts_example4', {
+ *       find: 'integration_tests.example4'
+ *     , query: {a:1}
+ *   }, {
+ *     readPreference: new ReadPreference('secondary');
+ *   });
+ *
+ *   // Get the first document
+ *   cursor.next(function(err, doc) {
+ *     assert.equal(null, err);
+ *     server.destroy();
+ *   });
+ * });
+ *
+ * // Start connecting
+ * server.connect();
+ */
+
+/**
+ * Creates a new Cursor, not to be used directly
+ * @class
+ * @param {object} bson An instance of the BSON parser
+ * @param {string} ns The MongoDB fully qualified namespace (ex: db1.collection1)
+ * @param {{object}|Long} cmd The selector (can be a command or a cursorId)
+ * @param {object} [options=null] Optional settings.
+ * @param {object} [options.batchSize=1000] Batchsize for the operation
+ * @param {array} [options.documents=[]] Initial documents list for cursor
+ * @param {object} [options.transforms=null] Transform methods for the cursor results
+ * @param {function} [options.transforms.query] Transform the value returned from the initial query
+ * @param {function} [options.transforms.doc] Transform each document returned from Cursor.prototype.next
+ * @param {object} topology The server topology instance.
+ * @param {object} topologyOptions The server topology options.
+ * @return {Cursor} A cursor instance
+ * @property {number} cursorBatchSize The current cursorBatchSize for the cursor
+ * @property {number} cursorLimit The current cursorLimit for the cursor
+ * @property {number} cursorSkip The current cursorSkip for the cursor
+ */
+var Cursor = function(bson, ns, cmd, options, topology, topologyOptions) {
+  options = options || {};
+  // Cursor reference
+  var self = this;
+  // Initial query
+  var query = null;
+
+  // Cursor connection
+  this.connection = null;
+  // Cursor server
+  this.server = null;
+
+  // Do we have a not connected handler
+  this.disconnectHandler = options.disconnectHandler;
+
+  // Set local values
+  this.bson = bson;
+  this.ns = ns;
+  this.cmd = cmd;
+  this.options = options;
+  this.topology = topology;
+
+  // All internal state
+  this.cursorState = {
+      cursorId: null
+    , cmd: cmd
+    , documents: options.documents || []
+    , cursorIndex: 0
+    , dead: false
+    , killed: false
+    , init: false
+    , notified: false
+    , limit: options.limit || cmd.limit || 0
+    , skip: options.skip || cmd.skip || 0
+    , batchSize: options.batchSize || cmd.batchSize || 1000
+    , currentLimit: 0
+    // Result field name if not a cursor (contains the array of results)
+    , transforms: options.transforms
+  }
+
+  // Callback controller
+  this.callbacks = null;
+
+  // Logger
+  this.logger = Logger('Cursor', options);
+
+  //
+  // Did we pass in a cursor id
+  if(typeof cmd == 'number') {
+    this.cursorState.cursorId = Long.fromNumber(cmd);
+    this.cursorState.lastCursorId = this.cursorState.cursorId;
+  } else if(cmd instanceof Long) {
+    this.cursorState.cursorId = cmd;
+    this.cursorState.lastCursorId = cmd;
+  }
+}
+
+Cursor.prototype.setCursorBatchSize = function(value) {
+  this.cursorState.batchSize = value;
+}
+
+Cursor.prototype.cursorBatchSize = function() {
+  return this.cursorState.batchSize;
+}
+
+Cursor.prototype.setCursorLimit = function(value) {
+  this.cursorState.limit = value;
+}
+
+Cursor.prototype.cursorLimit = function() {
+  return this.cursorState.limit;
+}
+
+Cursor.prototype.setCursorSkip = function(value) {
+  this.cursorState.skip = value;
+}
+
+Cursor.prototype.cursorSkip = function() {
+  return this.cursorState.skip;
+}
+
+//
+// Execute the first query
+var execInitialQuery = function(self, query, cmd, options, cursorState, connection, logger, callbacks, callback) {
+  if(logger.isDebug()) {
+    logger.debug(f("issue initial query [%s] with flags [%s]"
+      , JSON.stringify(cmd)
+      , JSON.stringify(query)));
+  }
+
+  var queryCallback = function(err, result) {
+    if(err) return callback(err);
+
+    if(result.queryFailure) {
+      return callback(MongoError.create(result.documents[0]), null);
+    }
+
+    // Check if we have a command cursor
+    if(Array.isArray(result.documents) && result.documents.length == 1
+      && (!cmd.find || (cmd.find && cmd.virtual == false))
+      && (result.documents[0].cursor != 'string'
+        || result.documents[0]['$err']
+        || result.documents[0]['errmsg']
+        || Array.isArray(result.documents[0].result))
+      ) {
+
+      // We have a an error document return the error
+      if(result.documents[0]['$err']
+        || result.documents[0]['errmsg']) {
+        return callback(MongoError.create(result.documents[0]), null);
+      }
+
+      // We have a cursor document
+      if(result.documents[0].cursor != null
+        && typeof result.documents[0].cursor != 'string') {
+          var id = result.documents[0].cursor.id;
+          // If we have a namespace change set the new namespace for getmores
+          if(result.documents[0].cursor.ns) {
+            self.ns = result.documents[0].cursor.ns;
+          }
+          // Promote id to long if needed
+          cursorState.cursorId = typeof id == 'number' ? Long.fromNumber(id) : id;
+          cursorState.lastCursorId = cursorState.cursorId;
+
+          // If we have a firstBatch set it
+          if(Array.isArray(result.documents[0].cursor.firstBatch)) {
+            cursorState.documents = result.documents[0].cursor.firstBatch;//.reverse();
+          }
+
+          // Return after processing command cursor
+          return callback(null, null);
+      }
+
+      if(Array.isArray(result.documents[0].result)) {
+        cursorState.documents = result.documents[0].result;
+        cursorState.cursorId = Long.ZERO;
+        return callback(null, null);
+      }
+    }
+
+    // Otherwise fall back to regular find path
+    cursorState.cursorId = result.cursorId;
+    cursorState.lastCursorId = result.cursorId;
+    cursorState.documents = result.documents;
+
+    // Transform the results with passed in transformation method if provided
+    if(cursorState.transforms && typeof cursorState.transforms.query == 'function') {
+      cursorState.documents = cursorState.transforms.query(result);
+    }
+
+    // Return callback
+    callback(null, null);
+  }
+
+  // If we have a raw query decorate the function
+  if(options.raw || cmd.raw) {
+    queryCallback.raw = options.raw || cmd.raw;
+  }
+
+  // Do we have documentsReturnedIn set on the query
+  if(typeof query.documentsReturnedIn == 'string') {
+    queryCallback.documentsReturnedIn = query.documentsReturnedIn;
+  }
+
+  // Set up callback
+  callbacks.register(query.requestId, queryCallback);
+
+  // Write the initial command out
+  connection.write(query.toBin());
+}
+
+//
+// Handle callback (including any exceptions thrown)
+var handleCallback = function(callback, err, result) {
+  try {
+    callback(err, result);
+  } catch(err) {
+    process.nextTick(function() {
+      throw err;
+    });
+  }
+}
+
+// Internal methods
+Cursor.prototype._find = function(callback) {
+  var self = this;
+  // execInitialQuery(self, self.query, self.cmd, self.options, self.cursorState, self.connection, self.logger, self.callbacks, function(err, r) {
+  if(self.logger.isDebug()) {
+    self.logger.debug(f("issue initial query [%s] with flags [%s]"
+      , JSON.stringify(self.cmd)
+      , JSON.stringify(self.query)));
+  }
+
+  var queryCallback = function(err, result) {
+    if(err) return callback(err);
+
+    if(result.queryFailure) {
+      return callback(MongoError.create(result.documents[0]), null);
+    }
+
+    // Check if we have a command cursor
+    if(Array.isArray(result.documents) && result.documents.length == 1
+      && (!self.cmd.find || (self.cmd.find && self.cmd.virtual == false))
+      && (result.documents[0].cursor != 'string'
+        || result.documents[0]['$err']
+        || result.documents[0]['errmsg']
+        || Array.isArray(result.documents[0].result))
+      ) {
+
+      // We have a an error document return the error
+      if(result.documents[0]['$err']
+        || result.documents[0]['errmsg']) {
+        return callback(MongoError.create(result.documents[0]), null);
+      }
+
+      // We have a cursor document
+      if(result.documents[0].cursor != null
+        && typeof result.documents[0].cursor != 'string') {
+          var id = result.documents[0].cursor.id;
+          // If we have a namespace change set the new namespace for getmores
+          if(result.documents[0].cursor.ns) {
+            self.ns = result.documents[0].cursor.ns;
+          }
+          // Promote id to long if needed
+          self.cursorState.cursorId = typeof id == 'number' ? Long.fromNumber(id) : id;
+          self.cursorState.lastCursorId = self.cursorState.cursorId;
+          // If we have a firstBatch set it
+          if(Array.isArray(result.documents[0].cursor.firstBatch)) {
+            self.cursorState.documents = result.documents[0].cursor.firstBatch;//.reverse();
+          }
+
+          // Return after processing command cursor
+          return callback(null, null);
+      }
+
+      if(Array.isArray(result.documents[0].result)) {
+        self.cursorState.documents = result.documents[0].result;
+        self.cursorState.cursorId = Long.ZERO;
+        return callback(null, null);
+      }
+    }
+
+    // Otherwise fall back to regular find path
+    self.cursorState.cursorId = result.cursorId;
+    self.cursorState.documents = result.documents;
+    self.cursorState.lastCursorId = result.cursorId;
+
+    // Transform the results with passed in transformation method if provided
+    if(self.cursorState.transforms && typeof self.cursorState.transforms.query == 'function') {
+      self.cursorState.documents = self.cursorState.transforms.query(result);
+    }
+
+    // Return callback
+    callback(null, null);
+  }
+
+  // If we have a raw query decorate the function
+  if(self.options.raw || self.cmd.raw) {
+    queryCallback.raw = self.options.raw || self.cmd.raw;
+  }
+
+  // Do we have documentsReturnedIn set on the query
+  if(typeof self.query.documentsReturnedIn == 'string') {
+    queryCallback.documentsReturnedIn = self.query.documentsReturnedIn;
+  }
+
+  // Set up callback
+  self.callbacks.register(self.query.requestId, queryCallback);
+
+  // Write the initial command out
+  self.connection.write(self.query.toBin());
+}
+
+Cursor.prototype._getmore = function(callback) {
+  if(this.logger.isDebug()) this.logger.debug(f("schedule getMore call for query [%s]", JSON.stringify(this.query)))
+  // Determine if it's a raw query
+  var raw = this.options.raw || this.cmd.raw;
+
+  // Set the current batchSize
+  var batchSize = this.cursorState.batchSize;
+  if(this.cursorState.limit > 0
+    && ((this.cursorState.currentLimit + batchSize) > this.cursorState.limit)) {
+    batchSize = this.cursorState.limit - this.cursorState.currentLimit;
+  }
+
+  // We have a wire protocol handler
+  this.server.wireProtocolHandler.getMore(this.bson, this.ns, this.cursorState, batchSize, raw, this.connection, this.callbacks, this.options, callback);
+}
+
+Cursor.prototype._killcursor = function(callback) {
+  // Set cursor to dead
+  this.cursorState.dead = true;
+  this.cursorState.killed = true;
+  // Remove documents
+  this.cursorState.documents = [];
+
+  // If no cursor id just return
+  if(this.cursorState.cursorId == null || this.cursorState.cursorId.isZero() || this.cursorState.init == false) {
+    if(callback) callback(null, null);
+    return;
+  }
+
+  // Execute command
+  this.server.wireProtocolHandler.killCursor(this.bson, this.ns, this.cursorState.cursorId, this.connection, this.callbacks, callback);
+}
+
+/**
+ * Clone the cursor
+ * @method
+ * @return {Cursor}
+ */
+Cursor.prototype.clone = function() {
+  return this.topology.cursor(this.ns, this.cmd, this.options);
+}
+
+/**
+ * Checks if the cursor is dead
+ * @method
+ * @return {boolean} A boolean signifying if the cursor is dead or not
+ */
+Cursor.prototype.isDead = function() {
+  return this.cursorState.dead == true;
+}
+
+/**
+ * Checks if the cursor was killed by the application
+ * @method
+ * @return {boolean} A boolean signifying if the cursor was killed by the application
+ */
+Cursor.prototype.isKilled = function() {
+  return this.cursorState.killed == true;
+}
+
+/**
+ * Checks if the cursor notified it's caller about it's death
+ * @method
+ * @return {boolean} A boolean signifying if the cursor notified the callback
+ */
+Cursor.prototype.isNotified = function() {
+  return this.cursorState.notified == true;
+}
+
+/**
+ * Returns current buffered documents length
+ * @method
+ * @return {number} The number of items in the buffered documents
+ */
+Cursor.prototype.bufferedCount = function() {
+  return this.cursorState.documents.length - this.cursorState.cursorIndex;
+}
+
+/**
+ * Returns current buffered documents
+ * @method
+ * @return {Array} An array of buffered documents
+ */
+Cursor.prototype.readBufferedDocuments = function(number) {
+  var unreadDocumentsLength = this.cursorState.documents.length - this.cursorState.cursorIndex;
+  var length = number < unreadDocumentsLength ? number : unreadDocumentsLength;
+  var elements = this.cursorState.documents.slice(this.cursorState.cursorIndex, this.cursorState.cursorIndex + length);
+
+  // Transform the doc with passed in transformation method if provided
+  if(this.cursorState.transforms && typeof this.cursorState.transforms.doc == 'function') {
+    // Transform all the elements
+    for(var i = 0; i < elements.length; i++) {
+      elements[i] = this.cursorState.transforms.doc(elements[i]);
+    }
+  }
+
+  // Ensure we do not return any more documents than the limit imposed
+  // Just return the number of elements up to the limit
+  if(this.cursorState.limit > 0 && (this.cursorState.currentLimit + elements.length) > this.cursorState.limit) {
+    elements = elements.slice(0, (this.cursorState.limit - this.cursorState.currentLimit));
+    this.kill();
+  }
+
+  // Adjust current limit
+  this.cursorState.currentLimit = this.cursorState.currentLimit + elements.length;
+  this.cursorState.cursorIndex = this.cursorState.cursorIndex + elements.length;
+
+  // Return elements
+  return elements;
+}
+
+/**
+ * Kill the cursor
+ * @method
+ * @param {resultCallback} callback A callback function
+ */
+Cursor.prototype.kill = function(callback) {
+  this._killcursor(callback);
+}
+
+/**
+ * Resets the cursor
+ * @method
+ * @return {null}
+ */
+Cursor.prototype.rewind = function() {
+  if(this.cursorState.init) {
+    if(!this.cursorState.dead) {
+      this.kill();
+    }
+
+    this.cursorState.currentLimit = 0;
+    this.cursorState.init = false;
+    this.cursorState.dead = false;
+    this.cursorState.killed = false;
+    this.cursorState.notified = false;
+    this.cursorState.documents = [];
+    this.cursorState.cursorId = null;
+    this.cursorState.cursorIndex = 0;
+  }
+}
+
+/**
+ * Validate if the connection is dead and return error
+ */
+var isConnectionDead = function(self, callback) {
+  if(self.connection
+    && !self.connection.isConnected()) {
+    self.cursorState.notified = true;
+    self.cursorState.killed = true;
+    self.cursorState.documents = [];
+    self.cursorState.cursorIndex = 0;
+    callback(MongoError.create(f('connection to host %s:%s was destroyed', self.connection.host, self.connection.port)))
+    return true;
+  }
+
+  return false;
+}
+
+/**
+ * Validate if the cursor is dead but was not explicitly killed by user
+ */
+var isCursorDeadButNotkilled = function(self, callback) {
+  // Cursor is dead but not marked killed, return null
+  if(self.cursorState.dead && !self.cursorState.killed) {
+    self.cursorState.notified = true;
+    self.cursorState.killed = true;
+    self.cursorState.documents = [];
+    self.cursorState.cursorIndex = 0;
+    handleCallback(callback, null, null);
+    return true;
+  }
+
+  return false;
+}
+
+/**
+ * Validate if the cursor is dead and was killed by user
+ */
+var isCursorDeadAndKilled = function(self, callback) {
+  if(self.cursorState.dead && self.cursorState.killed) {
+    handleCallback(callback, MongoError.create("cursor is dead"));
+    return true;
+  }
+
+  return false;
+}
+
+/**
+ * Validate if the cursor was killed by the user
+ */
+var isCursorKilled = function(self, callback) {
+  if(self.cursorState.killed) {
+    self.cursorState.notified = true;
+    self.cursorState.documents = [];
+    self.cursorState.cursorIndex = 0;
+    handleCallback(callback, null, null);
+    return true;
+  }
+
+  return false;
+}
+
+/**
+ * Mark cursor as being dead and notified
+ */
+var setCursorDeadAndNotified = function(self, callback) {
+  self.cursorState.dead = true;
+  self.cursorState.notified = true;
+  self.cursorState.documents = [];
+  self.cursorState.cursorIndex = 0;
+  handleCallback(callback, null, null);
+}
+
+/**
+ * Mark cursor as being notified
+ */
+var setCursorNotified = function(self, callback) {
+  self.cursorState.notified = true;
+  self.cursorState.documents = [];
+  self.cursorState.cursorIndex = 0;
+  handleCallback(callback, null, null);
+}
+
+var nextFunction = function(self, callback) {
+  // Exhaust message and cursor already finished and notified
+  if(self.cmd.exhaust && self.cursorState.notified) return;
+  // We have notified about it
+  if(self.cursorState.notified) {
+    return callback(new Error('cursor is exhausted'));
+  }
+
+  // Cursor is killed return null
+  if(isCursorKilled(self, callback)) return;
+
+  // Cursor is dead but not marked killed, return null
+  if(isCursorDeadButNotkilled(self, callback)) return;
+
+  // We have a dead and killed cursor, attempting to call next should error
+  if(isCursorDeadAndKilled(self, callback)) return;
+
+  // We have just started the cursor
+  if(!self.cursorState.init) {
+    // Topology is not connected, save the call in the provided store to be
+    // Executed at some point when the handler deems it's reconnected
+    if(!self.topology.isConnected(self.options) && self.disconnectHandler != null) {
+      return self.disconnectHandler.addObjectAndMethod('cursor', self, 'next', [callback], callback);
+    }
+
+    try {
+      // Get a server
+      self.server = self.topology.getServer(self.options);
+      // Get a connection
+      self.connection = self.server.getConnection();
+      // Get the callbacks
+      self.callbacks = self.server.getCallbacks();
+    } catch(err) {
+      return callback(err);
+    }
+
+    // Set as init
+    self.cursorState.init = true;
+
+    try {
+      // Get the right wire protocol command
+      self.query = self.server.wireProtocolHandler.command(self.bson, self.ns, self.cmd, self.cursorState, self.topology, self.options);
+    } catch(err) {
+      return callback(err);
+    }
+  }
+
+  // Process exhaust messages
+  var processExhaustMessages = function(err, result) {
+    if(err) {
+      self.cursorState.dead = true;
+      self.callbacks.unregister(self.query.requestId);
+      return callback(err);
+    }
+
+    // Concatenate all the documents
+    self.cursorState.documents = self.cursorState.documents.concat(result.documents);
+
+    // If we have no documents left
+    if(Long.ZERO.equals(result.cursorId)) {
+      self.cursorState.cursorId = Long.ZERO;
+      self.callbacks.unregister(self.query.requestId);
+      return nextFunction(self, callback);
+    }
+
+    // Set up next listener
+    self.callbacks.register(result.requestId, processExhaustMessages)
+
+    // Initial result
+    if(self.cursorState.cursorId == null) {
+      self.cursorState.cursorId = result.cursorId;
+      self.cursorState.lastCursorId = result.cursorId;
+      nextFunction(self, callback);
+    }
+  }
+
+  // If we have exhaust
+  if(self.cmd.exhaust && self.cursorState.cursorId == null) {
+    // Handle all the exhaust responses
+    self.callbacks.register(self.query.requestId, processExhaustMessages);
+    // Write the initial command out
+    return self.connection.write(self.query.toBin());
+  } else if(self.cmd.exhaust && self.cursorState.cursorIndex < self.cursorState.documents.length) {
+    return handleCallback(callback, null, self.cursorState.documents[self.cursorState.cursorIndex++]);
+  } else if(self.cmd.exhaust && Long.ZERO.equals(self.cursorState.cursorId)) {
+    self.callbacks.unregister(self.query.requestId);
+    return setCursorNotified(self, callback);
+  } else if(self.cmd.exhaust) {
+    return setTimeout(function() {
+      if(Long.ZERO.equals(self.cursorState.cursorId)) return;
+      nextFunction(self, callback);
+    }, 1);
+  }
+
+  // If we don't have a cursorId execute the first query
+  if(self.cursorState.cursorId == null) {
+    // Check if connection is dead and return if not possible to
+    // execute the query against the db
+    if(isConnectionDead(self, callback)) return;
+
+    // Check if topology is destroyed
+    if(self.topology.isDestroyed()) return callback(new MongoError(f('connection destroyed, not possible to instantiate cursor')));
+
+    // query, cmd, options, cursorState, callback
+    self._find(function(err, r) {
+      if(err) return handleCallback(callback, err, null);
+      if(self.cursorState.documents.length == 0 && !self.cmd.tailable && !self.cmd.awaitData) {
+        return setCursorNotified(self, callback);
+      }
+
+      nextFunction(self, callback);
+    });
+  } else if(self.cursorState.limit > 0 && self.cursorState.currentLimit >= self.cursorState.limit) {
+    // Ensure we kill the cursor on the server
+    self.kill();
+    // Set cursor in dead and notified state
+    return setCursorDeadAndNotified(self, callback);
+  } else if(self.cursorState.cursorIndex == self.cursorState.documents.length
+      && !Long.ZERO.equals(self.cursorState.cursorId)) {
+      // Ensure an empty cursor state
+      self.cursorState.documents = [];
+      self.cursorState.cursorIndex = 0;
+
+      // Check if topology is destroyed
+      if(self.topology.isDestroyed()) return callback(new MongoError(f('connection destroyed, not possible to instantiate cursor')));
+
+      // Check if connection is dead and return if not possible to
+      // execute a getmore on this connection
+      if(isConnectionDead(self, callback)) return;
+
+      // Execute the next get more
+      self._getmore(function(err, doc) {
+        if(err) return handleCallback(callback, err);
+        if(self.cursorState.documents.length == 0
+          && Long.ZERO.equals(self.cursorState.cursorId) && !self.cmd.tailable) {
+            self.cursorState.dead = true;
+            // Finished iterating over the cursor
+            return setCursorDeadAndNotified(self, callback);
+          }
+
+        // Tailable cursor getMore result, notify owner about it
+        // No attempt is made here to retry, this is left to the user of the
+        // core module to handle to keep core simple
+        if(self.cursorState.documents.length == 0 && self.cmd.tailable) {
+          return handleCallback(callback, MongoError.create({
+              message: "No more documents in tailed cursor"
+            , tailable: self.cmd.tailable
+            , awaitData: self.cmd.awaitData
+          }));
+        }
+
+        if(self.cursorState.limit > 0 && self.cursorState.currentLimit >= self.cursorState.limit) {
+          return setCursorDeadAndNotified(self, callback);
+        }
+
+        nextFunction(self, callback);
+      });
+  } else if(self.cursorState.documents.length == self.cursorState.cursorIndex
+    && self.cmd.tailable) {
+      return handleCallback(callback, MongoError.create({
+          message: "No more documents in tailed cursor"
+        , tailable: self.cmd.tailable
+        , awaitData: self.cmd.awaitData
+      }));
+  } else if(self.cursorState.documents.length == self.cursorState.cursorIndex
+      && Long.ZERO.equals(self.cursorState.cursorId)) {
+      setCursorDeadAndNotified(self, callback);
+  } else {
+    if(self.cursorState.limit > 0 && self.cursorState.currentLimit >= self.cursorState.limit) {
+      // Ensure we kill the cursor on the server
+      self.kill();
+      // Set cursor in dead and notified state
+      return setCursorDeadAndNotified(self, callback);
+    }
+
+    // Increment the current cursor limit
+    self.cursorState.currentLimit += 1;
+
+    // Get the document
+    var doc = self.cursorState.documents[self.cursorState.cursorIndex++];
+
+    // Doc overflow
+    if(doc.$err) {
+      // Ensure we kill the cursor on the server
+      self.kill();
+      // Set cursor in dead and notified state
+      return setCursorDeadAndNotified(self, function() {
+        handleCallback(callback, new MongoError(doc.$err));
+      });
+    }
+
+    // Transform the doc with passed in transformation method if provided
+    if(self.cursorState.transforms && typeof self.cursorState.transforms.doc == 'function') {
+      doc = self.cursorState.transforms.doc(doc);
+    }
+
+    // Return the document
+    handleCallback(callback, null, doc);
+  }
+}
+
+/**
+ * Retrieve the next document from the cursor
+ * @method
+ * @param {resultCallback} callback A callback function
+ */
+Cursor.prototype.next = function(callback) {
+  nextFunction(this, callback);
+}
+
+module.exports = Cursor;