class FFI::Struct

Public Class Methods

@return (see Struct#alignment)

# File lib/ffi/struct.rb, line 104
def self.alignment
  @layout.alignment
end

auto_ptr ()

# File lib/ffi/struct.rb, line 165
def self.auto_ptr
  @managed_type ||= Type::Mapped.new(ManagedStructConverter.new(self))
end

by_ref (flags = :inout)

# File lib/ffi/struct.rb, line 143
def self.by_ref(flags = :inout)
  self.ptr(flags)
end

by_value ()

# File lib/ffi/struct.rb, line 139
def self.by_value
  self.val
end

in ()

# File lib/ffi/struct.rb, line 123
def self.in
  ptr(:in)
end

layout (*spec)

@return [StructLayout] @overload layout

@return [StructLayout]
Get struct layout.

@overload layout(*spec)

@param [Array<Symbol, Integer>,Array(Hash)] spec
@return [StructLayout]
Create struct layout from +spec+.
@example Creating a layout from an array +spec+
  class MyStruct < Struct
    layout :field1, :int,
           :field2, :pointer,
           :field3, :string
  end
@example Creating a layout from an array +spec+ with offset
  class MyStructWithOffset < Struct
    layout :field1, :int,
           :field2, :pointer, 6,  # set offset to 6 for this field
           :field3, :string
  end
@example Creating a layout from a hash +spec+
  class MyStructFromHash < Struct
    layout :field1 => :int,
           :field2 => :pointer,
           :field3 => :string
  end
@example Creating a layout with pointers to functions
  class MyFunctionTable < Struct
    layout :function1, callback([:int, :int], :int),
           :function2, callback([:pointer], :void),
           :field3, :string
  end

# File lib/ffi/struct.rb, line 205
def layout(*spec)
  return @layout if spec.size == 0

  warn "[DEPRECATION] Struct layout is already defined for class #{self.inspect}. Redefinition as in #{caller[0]} will be disallowed in ffi-2.0." if defined?(@layout)

  builder = StructLayoutBuilder.new
  builder.union = self < Union
  builder.packed = @packed if defined?(@packed)
  builder.alignment = @min_alignment if defined?(@min_alignment)

  if spec[0].kind_of?(Hash)
    hash_layout(builder, spec)
  else
    array_layout(builder, spec)
  end
  builder.size = @size if defined?(@size) && @size > builder.size
  cspec = builder.build
  @layout = cspec unless self == Struct
  @size = cspec.size
  return cspec
end

members ()

(see FFI::Type#members)

# File lib/ffi/struct.rb, line 109
def self.members
  @layout.members
end

offset_of (name)

(see FFI::StructLayout#offset_of)

# File lib/ffi/struct.rb, line 119
def self.offset_of(name)
  @layout.offset_of(name)
end

offsets ()

(see FFI::StructLayout#offsets)

# File lib/ffi/struct.rb, line 114
def self.offsets
  @layout.offsets
end

out ()

# File lib/ffi/struct.rb, line 127
def self.out
  ptr(:out)
end

ptr (flags = :inout)

# File lib/ffi/struct.rb, line 131
def self.ptr(flags = :inout)
  @ref_data_type ||= Type::Mapped.new(StructByReference.new(self))
end

size ()

Get struct size @return [Integer]

# File lib/ffi/struct.rb, line 91
def self.size
  defined?(@layout) ? @layout.size : defined?(@size) ? @size : 0
end

size= (size)

set struct size @param [Integer] size @return [size]

# File lib/ffi/struct.rb, line 98
def self.size=(size)
  raise ArgumentError, "Size already set" if defined?(@size) || defined?(@layout)
  @size = size
end

val ()

# File lib/ffi/struct.rb, line 135
def self.val
  @val_data_type ||= StructByValue.new(self)
end

Protected Class Methods

align (alignment = 1)

Alias for: aligned

aligned (alignment = 1)

# File lib/ffi/struct.rb, line 244
def aligned(alignment = 1)
  @min_alignment = alignment
end

Also aliased as: align

callback (params, ret)

# File lib/ffi/struct.rb, line 230
def callback(params, ret)
  mod = enclosing_module
  ret_type = find_type(ret, mod)
  if ret_type == Type::STRING
    raise TypeError, ":string is not allowed as return type of callbacks"
  end
  FFI::CallbackInfo.new(ret_type, params.map { |e| find_type(e, mod) })
end

enclosing_module ()

# File lib/ffi/struct.rb, line 249
def enclosing_module
  begin
    mod = self.name.split("::")[0..-2].inject(Object) { |obj, c| obj.const_get(c) }
    if mod.respond_to?(:find_type) && (mod.is_a?(FFI::Library) || mod < FFI::Struct)
      mod
    end
  rescue Exception
    nil
  end
end

find_field_type (type, mod = enclosing_module)

# File lib/ffi/struct.rb, line 261
def find_field_type(type, mod = enclosing_module)
  if type.kind_of?(Class) && type < Struct
    FFI::Type::Struct.new(type)

  elsif type.kind_of?(Class) && type < FFI::StructLayout::Field
    type

  elsif type.kind_of?(::Array)
    FFI::Type::Array.new(find_field_type(type[0]), type[1])

  else
    find_type(type, mod)
  end
end

find_type (type, mod = enclosing_module)

# File lib/ffi/struct.rb, line 276
def find_type(type, mod = enclosing_module)
  if mod
    mod.find_type(type)
  end || FFI.find_type(type)
end

pack (packed = 1)

Alias for: packed

packed (packed = 1)

# File lib/ffi/struct.rb, line 239
def packed(packed = 1)
  @packed = packed
end

Also aliased as: pack

Public Instance Methods

align ()

Alias for: alignment

alignment ()

@return [Integer] Struct alignment

# File lib/ffi/struct.rb, line 50
def alignment
  self.class.alignment
end

Also aliased as: align

clear ()

Clear the struct content. @return [self]

# File lib/ffi/struct.rb, line 78
def clear
  pointer.clear
  self
end

members ()

(see FFI::StructLayout#members)

# File lib/ffi/struct.rb, line 61
def members
  self.class.members
end

offset_of (name)

(see FFI::StructLayout#offset_of)

# File lib/ffi/struct.rb, line 56
def offset_of(name)
  self.class.offset_of(name)
end

offsets ()

(see FFI::StructLayout#offsets)

# File lib/ffi/struct.rb, line 72
def offsets
  self.class.offsets
end

size ()

Get struct size @return [Integer]

# File lib/ffi/struct.rb, line 45
def size
  self.class.size
end

to_ptr ()

Get {Pointer} to struct content. @return [AbstractMemory]

# File lib/ffi/struct.rb, line 85
def to_ptr
  pointer
end

values ()

@return [Array] Get array of values from Struct fields.

# File lib/ffi/struct.rb, line 67
def values
  members.map { |m| self[m] }
end