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Class: FFI::AutoPointer

Relationships & Source Files
Namespace Children
Classes:
Releaser
Super Chains via Extension / Inclusion / Inheritance
Class Chain:
self, DataConverter, Pointer, AbstractMemory
Instance Chain:
self, Pointer, AbstractMemory
Inherits: FFI::Pointer
Defined in: lib/ffi/autopointer.rb

Constant Summary

AbstractMemory - Inherited

LONG_MAX

Pointer - Inherited

NULL, SIZE

Class Method Summary

DataConverter - Extended

from_native

Convert from a native type.
native_type

Get native type.
to_native

Convert to a native type.

Pointer - Inherited

.new

A new instance of Pointer.
.size

Return the size of a pointer on the current platform, in bytes.

Instance Attribute Summary

Pointer - Inherited

#autorelease=, #autorelease?, #null?

AbstractMemory - Inherited

#size_limit?

Return true if self has a size limit.

Instance Method Summary

Pointer - Inherited

#+, #==,
#address

Alias for Pointer#to_i.
#free,
#initialize_copy

This method is internally used by #dup and #clone.
#inspect

Alias for Pointer#to_s.
#order

Get or set self‘s endianness.
#read

Read pointer’s contents as type
#read_array_of_type

Read an array of type of length length.
#read_string

Read pointer’s contents as a string, or the first len bytes of the equivalent string if len is not nil.
#read_string_length

Read the first len bytes of pointer’s contents as a string.
#read_string_to_null

Read pointer’s contents as a string.
#slice, #to_i, #to_ptr, #to_s, #type_size,
#write

Write value of type type to pointer’s content.
#write_array_of_type

Write ary in pointer’s contents as type.
#write_string

Write str in pointer’s contents, or first len bytes if len is not nil.
#write_string_length

Write len first bytes of str in pointer’s contents.

AbstractMemory - Inherited

#[], #__copy_from__, #clear,
#freeze

Freeze the AbstractMemory object and unset the writable flag.
#get, #get_array_of_double, #get_array_of_float,
#get_array_of_float32

Alias for AbstractMemory#get_array_of_float.
#get_array_of_float64

Alias for AbstractMemory#get_array_of_double.
#get_array_of_pointer, #get_array_of_string, #get_bytes, #get_double, #get_float,
#get_float32

Alias for AbstractMemory#get_float.
#get_float64

Alias for AbstractMemory#get_double.
#get_pointer, #get_string, #put, #put_array_of_double, #put_array_of_float,
#put_array_of_float32

Alias for AbstractMemory#put_array_of_float.
#put_array_of_float64

Alias for AbstractMemory#put_array_of_double.
#put_array_of_pointer, #put_bytes, #put_double, #put_float,
#put_float32

Alias for AbstractMemory#put_float.
#put_float64

Alias for AbstractMemory#put_double.
#put_pointer, #put_string, #read_array_of_double, #read_array_of_float, #read_array_of_pointer, #read_array_of_string, #read_bytes, #read_double, #read_float, #read_pointer, #size,
#total

Alias for AbstractMemory#size.
#type_size, #write_array_of_double, #write_array_of_float, #write_array_of_pointer, #write_bytes, #write_double, #write_float, #write_pointer

Constructor Details

.new(pointer, method) ⇒ self .new(pointer, proc) ⇒ self .new(pointer) ⇒ self

Note:

The safest, and therefore preferred, calling idiom is to pass a Method as the second parameter. Example usage:

class PointerHelper
  def self.release(pointer)
    #...
  end
end

p = AutoPointer.new(other_pointer, PointerHelper.method(:release))

The above code will cause PointerHelper#release to be invoked at GC time.

Note:

The last calling idiom (only one parameter) is generally only going to be useful if you subclass AutoPointer, and override #release, which by default does nothing.

Raises:

  • (TypeError)
[ GitHub ] 

  


# File 'lib/ffi/autopointer.rb', line 70



def initialize(ptr, proc=nil)
  raise TypeError, "Invalid pointer" if ptr.nil? || !ptr.kind_of?(Pointer) ||
      ptr.kind_of?(MemoryPointer) || ptr.kind_of?(AutoPointer)
  super(ptr.type_size, ptr)

  @releaser = if proc
                if not proc.respond_to?(:call)
                  raise RuntimeError.new("proc must be callable")
                end
                Releaser.new(ptr, proc)

              else
                if not self.class.respond_to?(:release, true)
                  raise RuntimeError.new("no release method defined")
                end
                Releaser.new(ptr, self.class.method(:release))
              end

  ObjectSpace.define_finalizer(self, @releaser)
  self
end


  







Class Method Details



  

    .self.from_native(ptr, ctx)  ⇒ AutoPointer   



  

    

Create a new AutoPointer.



Override DataConverter#from_native.


  





  


  [ GitHub ]


  

  


# File 'lib/ffi/autopointer.rb', line 175



def self.from_native(val, ctx)
  self.new(val)
end


  








  

    .native_type  ⇒ Type::POINTER 
  



  

    

Return native type of AutoPointer.



Override DataConverter#native_type.


  





  
Raises:


    
  
  • 
    (RuntimeError)
—    
    

    if class does not implement a #release method
    

    
  
    • 





  [ GitHub ]


  

  


# File 'lib/ffi/autopointer.rb', line 161



def self.native_type
  if not self.respond_to?(:release, true)
    raise RuntimeError.new("no release method defined for #{self.inspect}")
  end
  Type::POINTER
end


  







Instance Attribute Details



  

    #autorelease=(autorelease)  ⇒ Boolean  (rw)
  



  

    

Set autorelease property. See Autorelease section at Pointer.


  





  
Parameters:


    
  
  • 
    autorelease
    (Boolean)
  
    • 



Returns:


    
  
  • 
    (Boolean)
—    
    

    autorelease
    

    
  
    • 



Raises:


    
  
  • 
    (FrozenError)
  
    • 





  [ GitHub ]


  

  


# File 'lib/ffi/autopointer.rb', line 101



def autorelease=(autorelease)
  raise FrozenError.new("can't modify frozen #{self.class}") if frozen?
  @releaser.autorelease=(autorelease)
end


  








  

    #autorelease?  ⇒ Boolean  (rw)
  



  

    

Get autorelease property. See Autorelease section at Pointer.


  





  
Returns:


    
  
  • 
    (Boolean)
—    
    

    autorelease
    

    
  
    • 





  [ GitHub ]


  

  


# File 'lib/ffi/autopointer.rb', line 108



def autorelease?
  @releaser.autorelease
end


  







Instance Method Details



  

    #free  ⇒ nil 
  



  

    

Free the pointer.


  





  


  [ GitHub ]


  

  


# File 'lib/ffi/autopointer.rb', line 94



def free
  @releaser.free
end