Class: ActiveRecord::Deferrable::Result

Inherits:
ActiveSupport::BasicObject
Defined in:
lib/active_record/connection_adapters/mysqlplus_adapter/deferrable/result.rb

Instance Method Summary collapse

Constructor Details

#initialize(&deferrable) ⇒ Result

Represents a Lazy Loaded resultset. Any method calls would block if the result hasn’t yet been processed in a background Thread.



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# File 'lib/active_record/connection_adapters/mysqlplus_adapter/deferrable/result.rb', line 9

def initialize( &deferrable )
  defer!( deferrable )
end

Dynamic Method Handling

This class handles dynamic methods through the method_missing method

#method_missing(*args, &block) ⇒ Object

Delegates to the background Thread.



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# File 'lib/active_record/connection_adapters/mysqlplus_adapter/deferrable/result.rb', line 32

def method_missing(*args, &block)
  @_result ||= @result.value
  validate!
  @_result.send(*args, &block)
end

Instance Method Details

#defer!(deferrable) ⇒ Object

Calls a given procedure in a background Thread, on another connection from the pool.Guarantees that said connection is checked back in on completion.



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# File 'lib/active_record/connection_adapters/mysqlplus_adapter/deferrable/result.rb', line 17

def defer!( deferrable )
  @result = ::Thread.new( deferrable ) do |deferrable|
    begin
      deferrable.call 
    rescue => exception
      exception 
    ensure
      ::ActiveRecord::Base.connection_pool.release_connection            
    end
  end
  self
end

#validate! ⇒ Object

Re-raise any Exceptions from the background Thread.

Raises:

  • (@_result) 


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# File 'lib/active_record/connection_adapters/mysqlplus_adapter/deferrable/result.rb', line 40

def validate!
  raise @_result if @_result.is_a?( ::Exception )
end