Class: Fiddley::Struct

Inherits:
Object
  • Object
show all
Extended by:
Utils
Includes:
Utils
Defined in:
lib/fiddley/struct.rb

Constant Summary

Constants included from Utils

Utils::SIZET_FORMAT, Utils::SIZET_TYPE

Class Method Summary collapse

Instance Method Summary collapse

Methods included from Utils

str2value, type2offset_size, type2size, type2str, type2type, value2str

Constructor Details

#initialize ⇒ Struct

Returns a new instance of Struct.



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# File 'lib/fiddley/struct.rb', line 36

def initialize
  @ptr = Fiddle::Pointer.malloc(self.class.size)
end

Class Method Details

.layout(*args) ⇒ Object 



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# File 'lib/fiddley/struct.rb', line 9

def self.layout(*args)
  @members = {}
  @size = 0
  args.each_slice(2) do |name, type|
    @members[name] = [type, @size]
    @size += type2offset_size(type)
  end
end

.members ⇒ Object 



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# File 'lib/fiddley/struct.rb', line 22

def self.members
  @members
end

.offset_of(key) ⇒ Object

Raises:

  • (IndexError) 


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# File 'lib/fiddley/struct.rb', line 30

def self.offset_of(key)
  raise IndexError, "#{key} is not defined" unless members.has_key?(key)
  type, offset = members[key]
  offset
end

.ptr ⇒ Object 



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# File 'lib/fiddley/struct.rb', line 18

def self.ptr
  :pointer
end

.size ⇒ Object 



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# File 'lib/fiddley/struct.rb', line 26

def self.size
  @size
end

Instance Method Details

#[](key) ⇒ Object

Raises:

  • (IndexError) 


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# File 'lib/fiddley/struct.rb', line 40

def [](key)
  raise IndexError, "#{key} is not defined" unless self.class.members.has_key?(key)
  type, offset = self.class.members[key]
  str2value(type, @ptr[offset, type2size(type)])
end

#[]=(key, value) ⇒ Object

Raises:

  • (IndexError) 


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# File 'lib/fiddley/struct.rb', line 46

def []=(key, value)
  raise IndexError, "#{key} is not defined" unless self.class.members.has_key?(key)
  type, offset = self.class.members[key]
  @ptr[offset, type2size(type)] = value2str(type, value)
end

#to_ptr ⇒ Object 



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# File 'lib/fiddley/struct.rb', line 52

def to_ptr
  @ptr
end