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Class: Mongo::Protocol::GetMore

Relationships & Source Files
Namespace Children
Classes:
Upconverter
Super Chains via Extension / Inclusion / Inheritance
Class Chain:
self, Message
Instance Chain:
self, Message, Serializers, ::Mongo::Id
Inherits: Mongo::Protocol::Message
Defined in: lib/mongo/protocol/get_more.rb

Overview

MongoDB Wire protocol getMore message.

This is a client request message that is sent to the server in order to retrieve additional documents from a cursor that has already been instantiated.

The operation requires that you specify the database and collection name as well as the cursor id because cursors are scoped to a namespace.

Constant Summary

Serializers - Included

HEADER_PACK, INT32_PACK, INT64_PACK, NULL, ZERO

Message - Inherited

BATCH_SIZE, COLLECTION, LIMIT, MAX_MESSAGE_SIZE, ORDERED, Q

Class Method Summary

Message - Inherited

.deserialize

Deserializes messages from an IO stream.
.new

:nodoc:
.deserialize_array

Deserializes an array of fields in a message.
.deserialize_field

Deserializes a single field in a message.
.deserialize_header

Deserializes the header of the message.
.field

A method for declaring a message field.
.fields

A class method for getting the fields for a message class.

Instance Attribute Summary

Message - Inherited

#replyable?

The default for messages is not to require a reply after sending a message to the server.
#request_id

Returns the request id for the message.

Instance Method Summary

Message - Inherited

#==

Tests for equality between two wire protocol messages by comparing class and field values.
#eql?

Alias for Message#==.
#hash

Creates a hash from the values of the fields of a message.
#maybe_add_server_api,
#maybe_compress

Compress the message, if supported by the wire protocol used and if the command being sent permits compression.
#maybe_decrypt

Possibly decrypt this message with libmongocrypt.
#maybe_encrypt

Possibly encrypt this message with libmongocrypt.
#maybe_inflate

Inflate a message if it is compressed.
#number_returned

Default number returned value for protocol messages.
#serialize

Serializes message into bytes that can be sent on the wire.
#set_request_id

Generates a request id for a message.
#to_s

Alias for Message#serialize.
#compress_if_possible

Compress the message, if the command being sent permits compression.
#fields

A method for getting the fields for a message class.
#merge_sections,
#serialize_fields

Serializes message fields into a buffer.
#serialize_header

Serializes the header of the message consisting of 4 32bit integers.

Constructor Details

.new(database, collection, number_to_return, cursor_id) ⇒ GetMore

Creates a new getMore message

Examples:

Get 15 additional documents from cursor 123 in ‘xgen.users’.

GetMore.new('xgen', 'users', 15, 123)

Parameters:

  • database (String, Symbol) —

    The database to query.

  • collection (String, Symbol) —

    The collection to query.

  • number_to_return (Integer) —

    The number of documents to return.

  • cursor_id (Integer) —

    The cursor id returned in a reply.

[ GitHub ] 

  


# File 'lib/mongo/protocol/get_more.rb', line 42



def initialize(database, collection, number_to_return, cursor_id)
  @database = database
  @namespace = "#{database}.#{collection}"
  @number_to_return = number_to_return
  @cursor_id = cursor_id
  @upconverter = Upconverter.new(collection, cursor_id, number_to_return)
  super
end


  







Instance Attribute Details



  

    #cursor_id  ⇒ Fixnum  (rw, private)
  



  

    
  





  
Returns:


    
  
  • 
    (Fixnum)
—    
    

    The cursor id to get more documents from.
    

    
  
    • 





  [ GitHub ]


  

  


# File 'lib/mongo/protocol/get_more.rb', line 105



field :cursor_id, Int64


  








  

    #namespace  ⇒ String  (rw, private)
  



  

    
  





  
Returns:


    
  
  • 
    (String)
—    
    

    The namespace for this getMore message.
    

    
  
    • 





  [ GitHub ]


  

  


# File 'lib/mongo/protocol/get_more.rb', line 97



field :namespace, CString


  








  

    #number_to_return  ⇒ Fixnum  (rw, private)
  



  

    
  





  
Returns:


    
  
  • 
    (Fixnum)
—    
    

    The number to return for this getMore message.
    

    
  
    • 





  [ GitHub ]


  

  


# File 'lib/mongo/protocol/get_more.rb', line 101



field :number_to_return, Int32


  








  

    #replyable?  ⇒ true  (readonly)
  



  

    

Get more messages require replies from the database.


  





    

    
Examples:

        


Does the message require a reply?



      
message.replyable?

  


Returns:


    
  
  • 
    (true)
—    
    

    Always true for get more.
    

    
  
    • 



Since:


    
  
  • 
    
    

    2.0.0
    

    
  
    • 





  [ GitHub ]


  

  


# File 'lib/mongo/protocol/get_more.rb', line 76



def replyable?
  true
end


  







Instance Method Details



  

    #payload  ⇒ BSON::Document 
  



  

    

Return the event payload for monitoring.


  





    

    
Examples:

        


Return the event payload.



      
message.payload

  


Returns:


    
  
  • 
    (BSON::Document)
—    
    

    The event payload.
    

    
  
    • 



Since:


    
  
  • 
    
    

    2.1.0
    

    
  
    • 





  [ GitHub ]


  

  


# File 'lib/mongo/protocol/get_more.rb', line 59



def payload
  BSON::Document.new(
    command_name: 'getMore',
    database_name: @database,
    command: upconverter.command,
    request_id: request_id
  )
end