"use strict";
var inherits = require('util').inherits
, ReadPreference = require('./read_preference')
, MongoError = require('mongodb-core').MongoError
, Readable = require('stream').Readable || require('readable-stream').Readable
, Define = require('./metadata')
, CoreCursor = require('./cursor')
, CoreReadPreference = require('mongodb-core').ReadPreference;
/**
* @fileOverview The **CommandCursor** class is an internal class that embodies a
* generalized cursor based on a MongoDB command allowing for iteration over the
* results returned. It supports one by one document iteration, conversion to an
* array or can be iterated as a Node 0.10.X or higher stream
*
* **CommandCursor Cannot directly be instantiated**
* @example
* var MongoClient = require('mongodb').MongoClient,
* test = require('assert');
* // Connection url
* var url = 'mongodb://localhost:27017/test';
* // Connect using MongoClient
* MongoClient.connect(url, function(err, db) {
* // Create a collection we want to drop later
* var col = db.collection('listCollectionsExample1');
* // Insert a bunch of documents
* col.insert([{a:1, b:1}
* , {a:2, b:2}, {a:3, b:3}
* , {a:4, b:4}], {w:1}, function(err, result) {
* test.equal(null, err);
*
* // List the database collections available
* db.listCollections().toArray(function(err, items) {
* test.equal(null, err);
* db.close();
* });
* });
* });
*/
/**
* Namespace provided by the browser.
* @external Readable
*/
/**
* Creates a new Command Cursor instance (INTERNAL TYPE, do not instantiate directly)
* @class CommandCursor
* @extends external:Readable
* @fires CommandCursor#data
* @fires CommandCursor#end
* @fires CommandCursor#close
* @fires CommandCursor#readable
* @return {CommandCursor} an CommandCursor instance.
*/
var CommandCursor = function(bson, ns, cmd, options, topology, topologyOptions) {
CoreCursor.apply(this, Array.prototype.slice.call(arguments, 0));
var state = CommandCursor.INIT;
var streamOptions = {};
// MaxTimeMS
var maxTimeMS = null;
// Get the promiseLibrary
var promiseLibrary = options.promiseLibrary;
// No promise library selected fall back
if(!promiseLibrary) {
promiseLibrary = typeof global.Promise == 'function' ?
global.Promise : require('es6-promise').Promise;
}
// Set up
Readable.call(this, {objectMode: true});
// Internal state
this.s = {
// MaxTimeMS
maxTimeMS: maxTimeMS
// State
, state: state
// Stream options
, streamOptions: streamOptions
// BSON
, bson: bson
// Namespace
, ns: ns
// Command
, cmd: cmd
// Options
, options: options
// Topology
, topology: topology
// Topology Options
, topologyOptions: topologyOptions
// Promise library
, promiseLibrary: promiseLibrary
}
}
/**
* CommandCursor stream data event, fired for each document in the cursor.
*
* @event CommandCursor#data
* @type {object}
*/
/**
* CommandCursor stream end event
*
* @event CommandCursor#end
* @type {null}
*/
/**
* CommandCursor stream close event
*
* @event CommandCursor#close
* @type {null}
*/
/**
* CommandCursor stream readable event
*
* @event CommandCursor#readable
* @type {null}
*/
// Inherit from Readable
inherits(CommandCursor, Readable);
// Set the methods to inherit from prototype
var methodsToInherit = ['_next', 'next', 'hasNext', 'each', 'forEach', 'toArray'
, 'rewind', 'bufferedCount', 'readBufferedDocuments', 'close', 'isClosed', 'kill', 'setCursorBatchSize'
, '_find', '_getmore', '_killcursor', 'isDead', 'explain', 'isNotified', 'isKilled'];
// Only inherit the types we need
for(var i = 0; i < methodsToInherit.length; i++) {
CommandCursor.prototype[methodsToInherit[i]] = CoreCursor.prototype[methodsToInherit[i]];
}
var define = CommandCursor.define = new Define('CommandCursor', CommandCursor, true);
/**
* Set the ReadPreference for the cursor.
* @method
* @param {(string|ReadPreference)} readPreference The new read preference for the cursor.
* @throws {MongoError}
* @return {Cursor}
*/
CommandCursor.prototype.setReadPreference = function(r) {
if(this.s.state == CommandCursor.CLOSED || this.isDead()) throw MongoError.create({message: "Cursor is closed", driver:true});
if(this.s.state != CommandCursor.INIT) throw MongoError.create({message: 'cannot change cursor readPreference after cursor has been accessed', driver:true});
if(r instanceof ReadPreference) {
this.s.options.readPreference = new CoreReadPreference(r.mode, r.tags, {maxStalenessSeconds: r.maxStalenessSeconds});
} else if(typeof r == 'string') {
this.s.options.readPreference = new CoreReadPreference(r);
} else if(r instanceof CoreReadPreference) {
this.s.options.readPreference = r;
}
return this;
}
define.classMethod('setReadPreference', {callback: false, promise:false, returns: [CommandCursor]});
/**
* Set the batch size for the cursor.
* @method
* @param {number} value The batchSize for the cursor.
* @throws {MongoError}
* @return {CommandCursor}
*/
CommandCursor.prototype.batchSize = function(value) {
if(this.s.state == CommandCursor.CLOSED || this.isDead()) throw MongoError.create({message: "Cursor is closed", driver:true});
if(typeof value != 'number') throw MongoError.create({message: "batchSize requires an integer", driver:true});
if(this.s.cmd.cursor) this.s.cmd.cursor.batchSize = value;
this.setCursorBatchSize(value);
return this;
}
define.classMethod('batchSize', {callback: false, promise:false, returns: [CommandCursor]});
/**
* Add a maxTimeMS stage to the aggregation pipeline
* @method
* @param {number} value The state maxTimeMS value.
* @return {CommandCursor}
*/
CommandCursor.prototype.maxTimeMS = function(value) {
if(this.s.topology.lastIsMaster().minWireVersion > 2) {
this.s.cmd.maxTimeMS = value;
}
return this;
}
define.classMethod('maxTimeMS', {callback: false, promise:false, returns: [CommandCursor]});
CommandCursor.prototype.get = CommandCursor.prototype.toArray;
define.classMethod('get', {callback: true, promise:false});
// Inherited methods
define.classMethod('toArray', {callback: true, promise:true});
define.classMethod('each', {callback: true, promise:false});
define.classMethod('forEach', {callback: true, promise:false});
define.classMethod('next', {callback: true, promise:true});
define.classMethod('hasNext', {callback: true, promise:true});
define.classMethod('close', {callback: true, promise:true});
define.classMethod('isClosed', {callback: false, promise:false, returns: [Boolean]});
define.classMethod('rewind', {callback: false, promise:false});
define.classMethod('bufferedCount', {callback: false, promise:false, returns: [Number]});
define.classMethod('readBufferedDocuments', {callback: false, promise:false, returns: [Array]});
/**
* Get the next available document from the cursor, returns null if no more documents are available.
* @function CommandCursor.prototype.next
* @param {CommandCursor~resultCallback} [callback] The result callback.
* @throws {MongoError}
* @return {Promise} returns Promise if no callback passed
*/
/**
* Check if there is any document still available in the cursor
* @function CommandCursor.prototype.hasNext
* @param {CommandCursor~resultCallback} [callback] The result callback.
* @throws {MongoError}
* @return {Promise} returns Promise if no callback passed
*/
/**
* The callback format for results
* @callback CommandCursor~toArrayResultCallback
* @param {MongoError} error An error instance representing the error during the execution.
* @param {object[]} documents All the documents the satisfy the cursor.
*/
/**
* Returns an array of documents. The caller is responsible for making sure that there
* is enough memory to store the results. Note that the array only contain partial
* results when this cursor had been previously accessed.
* @method CommandCursor.prototype.toArray
* @param {CommandCursor~toArrayResultCallback} [callback] The result callback.
* @throws {MongoError}
* @return {Promise} returns Promise if no callback passed
*/
/**
* The callback format for results
* @callback CommandCursor~resultCallback
* @param {MongoError} error An error instance representing the error during the execution.
* @param {(object|null)} result The result object if the command was executed successfully.
*/
/**
* Iterates over all the documents for this cursor. As with **{cursor.toArray}**,
* not all of the elements will be iterated if this cursor had been previously accessed.
* In that case, **{cursor.rewind}** can be used to reset the cursor. However, unlike
* **{cursor.toArray}**, the cursor will only hold a maximum of batch size elements
* at any given time if batch size is specified. Otherwise, the caller is responsible
* for making sure that the entire result can fit the memory.
* @method CommandCursor.prototype.each
* @param {CommandCursor~resultCallback} callback The result callback.
* @throws {MongoError}
* @return {null}
*/
/**
* Close the cursor, sending a KillCursor command and emitting close.
* @method CommandCursor.prototype.close
* @param {CommandCursor~resultCallback} [callback] The result callback.
* @return {Promise} returns Promise if no callback passed
*/
/**
* Is the cursor closed
* @method CommandCursor.prototype.isClosed
* @return {boolean}
*/
/**
* Clone the cursor
* @function CommandCursor.prototype.clone
* @return {CommandCursor}
*/
/**
* Resets the cursor
* @function CommandCursor.prototype.rewind
* @return {CommandCursor}
*/
/**
* The callback format for the forEach iterator method
* @callback CommandCursor~iteratorCallback
* @param {Object} doc An emitted document for the iterator
*/
/**
* The callback error format for the forEach iterator method
* @callback CommandCursor~endCallback
* @param {MongoError} error An error instance representing the error during the execution.
*/
/*
* Iterates over all the documents for this cursor using the iterator, callback pattern.
* @method CommandCursor.prototype.forEach
* @param {CommandCursor~iteratorCallback} iterator The iteration callback.
* @param {CommandCursor~endCallback} callback The end callback.
* @throws {MongoError}
* @return {null}
*/
CommandCursor.INIT = 0;
CommandCursor.OPEN = 1;
CommandCursor.CLOSED = 2;
module.exports = CommandCursor;