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var BaseCommand = require('./base_command').BaseCommand,
inherits = require('util').inherits,
binaryutils = require('../utils');
/**
Get More Document Command
**/
var GetMoreCommand = exports.GetMoreCommand = function(db, collectionName, numberToReturn, cursorId) {
BaseCommand.call(this);
this.collectionName = collectionName;
this.numberToReturn = numberToReturn;
this.cursorId = cursorId;
this.db = db;
};
inherits(GetMoreCommand, BaseCommand);
GetMoreCommand.OP_GET_MORE = 2005;
GetMoreCommand.prototype.toBinary = function() {
// Calculate total length of the document
var totalLengthOfCommand = 4 + Buffer.byteLength(this.collectionName) + 1 + 4 + 8 + (4 * 4);
// Let's build the single pass buffer command
var _index = 0;
var _command = new Buffer(totalLengthOfCommand);
// Write the header information to the buffer
_command[_index++] = totalLengthOfCommand & 0xff;
_command[_index++] = (totalLengthOfCommand >> 8) & 0xff;
_command[_index++] = (totalLengthOfCommand >> 16) & 0xff;
_command[_index++] = (totalLengthOfCommand >> 24) & 0xff;
// Write the request ID
_command[_index++] = this.requestId & 0xff;
_command[_index++] = (this.requestId >> 8) & 0xff;
_command[_index++] = (this.requestId >> 16) & 0xff;
_command[_index++] = (this.requestId >> 24) & 0xff;
// Write zero
_command[_index++] = 0;
_command[_index++] = 0;
_command[_index++] = 0;
_command[_index++] = 0;
// Write the op_code for the command
_command[_index++] = GetMoreCommand.OP_GET_MORE & 0xff;
_command[_index++] = (GetMoreCommand.OP_GET_MORE >> 8) & 0xff;
_command[_index++] = (GetMoreCommand.OP_GET_MORE >> 16) & 0xff;
_command[_index++] = (GetMoreCommand.OP_GET_MORE >> 24) & 0xff;
// Write zero
_command[_index++] = 0;
_command[_index++] = 0;
_command[_index++] = 0;
_command[_index++] = 0;
// Write the collection name to the command
_index = _index + _command.write(this.collectionName, _index, 'utf8') + 1;
_command[_index - 1] = 0;
// Number of documents to return
_command[_index++] = this.numberToReturn & 0xff;
_command[_index++] = (this.numberToReturn >> 8) & 0xff;
_command[_index++] = (this.numberToReturn >> 16) & 0xff;
_command[_index++] = (this.numberToReturn >> 24) & 0xff;
// Encode the cursor id
var low_bits = this.cursorId.getLowBits();
// Encode low bits
_command[_index++] = low_bits & 0xff;
_command[_index++] = (low_bits >> 8) & 0xff;
_command[_index++] = (low_bits >> 16) & 0xff;
_command[_index++] = (low_bits >> 24) & 0xff;
var high_bits = this.cursorId.getHighBits();
// Encode high bits
_command[_index++] = high_bits & 0xff;
_command[_index++] = (high_bits >> 8) & 0xff;
_command[_index++] = (high_bits >> 16) & 0xff;
_command[_index++] = (high_bits >> 24) & 0xff;
// Return command
return _command;
};
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I currently hold the following qualifications (amongst others, I also studied Music Technology and Electronics, for my sins)
- MSc (Passed with distinctions), in Information Technology for E-Commerce
- BSc Hons (1st class) in Computer Science & Artificial Intelligence
Both of these at Sussex University UK.
Award(s)
I am lucky enough to have won a few awards for Zany Crazy code articles over the years
- Microsoft C# MVP 2016
- Codeproject MVP 2016
- Microsoft C# MVP 2015
- Codeproject MVP 2015
- Microsoft C# MVP 2014
- Codeproject MVP 2014
- Microsoft C# MVP 2013
- Codeproject MVP 2013
- Microsoft C# MVP 2012
- Codeproject MVP 2012
- Microsoft C# MVP 2011
- Codeproject MVP 2011
- Microsoft C# MVP 2010
- Codeproject MVP 2010
- Microsoft C# MVP 2009
- Codeproject MVP 2009
- Microsoft C# MVP 2008
- Codeproject MVP 2008
- And numerous codeproject awards which you can see over at my blog