Class: Amazon::AWS::MultipleOperation

Inherits:

Operation

• Object
• Operation
• Amazon::AWS::MultipleOperation

Defined in:

lib/amazon/aws.rb

Overview

This class can be used to merge multiple operations into a single operation for greater efficiency.

Constant Summary

Constants inherited from Operation

Operation::OPERATIONS

Instance Attribute Summary

Attributes inherited from Operation

#kind, #params, #response_group

Instance Method Summary

• #initialize(operation1, operation2) ⇒ MultipleOperation constructor

  This allows you to take two Operation objects and combine them to form a single object, which can then be used to perform a single request to AWS.

Methods inherited from Operation

#batch, #batch_parameters

Constructor Details

#initialize(operation1, operation2) ⇒ MultipleOperation

This allows you to take two Operation objects and combine them to form a single object, which can then be used to perform a single request to AWS. This allows for greater efficiency, reducing the number of requests sent to AWS.

AWS currently imposes a limit of two operations when encapsulating operations in a multiple operation.

operation1 and operation2 are both objects from a subclass of Operation, such as ItemSearch, ItemLookup, etc.

Please note the following implementation details:

• If you use the response_group parameter of Search::Request#search to pass the list of response groups, it will apply to both operations.

  If you want to use a different response group set for each operation, you should assign the relevant groups to the @response_group attribute of each Operation object. You must do this before you instantiate the MultipleOperation.

• One or both operations may have multiple results pages available, but only the first page is returned. If you need the subsequent pages, perform the operations separately, not as part of a multiple operation.

Example:

is = ItemSearch.new( 'Books', { 'Title' => 'Ruby' } )
il = ItemLookup.new( 'ASIN', { 'ItemId' => 'B0013DZAYO',

‘MerchantId’ => ‘Amazon’ } )

is.response_group = ResponseGroup.new( :Large )
il.response_group = ResponseGroup.new( :Small )
mo = MultipleOperation.new( is, il )

As you can see, the operations that are combined as a MultipleOperation do not have to belong to the same class. In the above example, we compose a multiple operation consisting of an ItemSearch and an ItemLookup.

If you want to batch operations belonging to the same class, Operation#batch provides an alternative.

# File 'lib/amazon/aws.rb', line 824

def initialize(operation1, operation2)

	op_kind = [ operation1.kind, operation2.kind ].join( ',' )

	# Duplicate Operation objects and remove their Operation parameter.
	# 
	op1 = operation1.dup
	op1.params.delete( 'Operation' )

	op2 = operation2.dup
	op2.params.delete( 'Operation' )

	if op1.class == op2.class

	  # If both operations are of the same type, we combine the parameters
	  # of both.
	  #
	  b_params = op1.batch_parameters( op1.params, op2.params )
	else

	  # We have to convert the parameters to batch format.
	  #
	  bp1 = op1.batch_parameters( op1.params, {} )
	  bp2 = op2.batch_parameters( op2.params, {} )
	  b_params = bp1.merge( bp2 )
	end

	params = { 'Operation' => op_kind }.merge( b_params )
	super( params )

	@response_group = ResponseGroup.new( [] )
	@response_group.params.delete( 'ResponseGroup' )
	@response_group.params = op1.batch_response_groups( op2 )
end