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Class: DRb::DRbUnknown

Relationships & Source Files
Inherits: Object
Defined in: lib/drb/drb.rb

Overview

Class wrapping a marshalled object whose type is unknown locally.

If an object is returned by a method invoked over drb, but the class of the object is unknown in the client namespace, or the object is a constant unknown in the client namespace, then the still-marshalled object is returned wrapped in a DRbUnknown instance.

If this object is passed as an argument to a method invoked over drb, then the wrapped object is passed instead.

The class or constant name of the object can be read from the #name attribute. The marshalled object is held in the #buf attribute.

Class Method Summary

Instance Attribute Summary

  • #buf readonly

    Buffer contained the marshalled, unknown object.

  • #name readonly

    The name of the unknown thing.

Instance Method Summary

Constructor Details

.new(err, buf) ⇒ DRbUnknown

Create a new DRbUnknown object.

#buf is a string containing a marshalled object that could not be unmarshalled. err is the error message that was raised when the unmarshalling failed. It is used to determine the name of the unmarshalled object.

[ GitHub ]

  
# File 'lib/drb/drb.rb', line 465

def initialize(err, buf)
  case err.to_s
  when /uninitialized constant (\S+)/
    @name = $1
  when /undefined class\/module (\S+)/
    @name = $1
  else
    @name = nil
  end
  @buf = buf
end

Class Method Details

._load(s)

This method is for internal use only.
[ GitHub ]

  
# File 'lib/drb/drb.rb', line 486

def self._load(s) # :nodoc:
  begin
    Marshal::load(s)
  rescue NameError, ArgumentError
    DRbUnknown.new($!, s)
  end
end

Instance Attribute Details

#buf (readonly)

Buffer contained the marshalled, unknown object.

[ GitHub ]

  
# File 'lib/drb/drb.rb', line 484

attr_reader :buf

#name (readonly)

The name of the unknown thing.

Class name for unknown objects; variable name for unknown constants.

[ GitHub ]

  
# File 'lib/drb/drb.rb', line 481

attr_reader :name

Instance Method Details

#_dump(lv)

This method is for internal use only.
[ GitHub ]

  
# File 'lib/drb/drb.rb', line 494

def _dump(lv) # :nodoc:
  @buf
end

#exception

Create a DRbUnknownError exception containing this object.

[ GitHub ]

  
# File 'lib/drb/drb.rb', line 508

def exception
  DRbUnknownError.new(self)
end

#reload

Attempt to load the wrapped marshalled object again.

If the class of the object is now known locally, the object will be unmarshalled and returned. Otherwise, a new but identical DRbUnknown object will be returned.

[ GitHub ]

  
# File 'lib/drb/drb.rb', line 503

def reload
  self.class._load(@buf)
end