rf-web/vendor/bundle/gems/ffi-1.11.1/lib/ffi/struct.rb
2019-10-21 10:18:17 +02:00

312 lines
8.4 KiB
Ruby

#
# Copyright (C) 2008-2010 Wayne Meissner
# Copyright (C) 2008, 2009 Andrea Fazzi
# Copyright (C) 2008, 2009 Luc Heinrich
#
# This file is part of ruby-ffi.
#
# All rights reserved.
#
# Redistribution and use in source and binary forms, with or without
# modification, are permitted provided that the following conditions are met:
#
# * Redistributions of source code must retain the above copyright notice, this
# list of conditions and the following disclaimer.
# * Redistributions in binary form must reproduce the above copyright notice
# this list of conditions and the following disclaimer in the documentation
# and/or other materials provided with the distribution.
# * Neither the name of the Ruby FFI project nor the names of its contributors
# may be used to endorse or promote products derived from this software
# without specific prior written permission.
#
# THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
# AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
# IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
# DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE
# FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
# DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
# SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
# CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
# OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
# OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
#
require 'ffi/platform'
require 'ffi/struct_layout'
require 'ffi/struct_layout_builder'
require 'ffi/struct_by_reference'
module FFI
class Struct
# Get struct size
# @return [Numeric]
def size
self.class.size
end
# @return [Fixnum] Struct alignment
def alignment
self.class.alignment
end
alias_method :align, :alignment
# (see FFI::StructLayout#offset_of)
def offset_of(name)
self.class.offset_of(name)
end
# (see FFI::StructLayout#members)
def members
self.class.members
end
# @return [Array]
# Get array of values from Struct fields.
def values
members.map { |m| self[m] }
end
# (see FFI::StructLayout#offsets)
def offsets
self.class.offsets
end
# Clear the struct content.
# @return [self]
def clear
pointer.clear
self
end
# Get {Pointer} to struct content.
# @return [AbstractMemory]
def to_ptr
pointer
end
# Get struct size
# @return [Numeric]
def self.size
defined?(@layout) ? @layout.size : defined?(@size) ? @size : 0
end
# set struct size
# @param [Numeric] size
# @return [size]
def self.size=(size)
raise ArgumentError, "Size already set" if defined?(@size) || defined?(@layout)
@size = size
end
# @return (see Struct#alignment)
def self.alignment
@layout.alignment
end
# (see FFI::Type#members)
def self.members
@layout.members
end
# (see FFI::StructLayout#offsets)
def self.offsets
@layout.offsets
end
# (see FFI::StructLayout#offset_of)
def self.offset_of(name)
@layout.offset_of(name)
end
def self.in
ptr(:in)
end
def self.out
ptr(:out)
end
def self.ptr(flags = :inout)
@ref_data_type ||= Type::Mapped.new(StructByReference.new(self))
end
def self.val
@val_data_type ||= StructByValue.new(self)
end
def self.by_value
self.val
end
def self.by_ref(flags = :inout)
self.ptr(flags)
end
class ManagedStructConverter < StructByReference
# @param [Struct] struct_class
def initialize(struct_class)
super(struct_class)
raise NoMethodError, "release() not implemented for class #{struct_class}" unless struct_class.respond_to? :release
@method = struct_class.method(:release)
end
# @param [Pointer] ptr
# @param [nil] ctx
# @return [Struct]
def from_native(ptr, ctx)
struct_class.new(AutoPointer.new(ptr, @method))
end
end
def self.auto_ptr
@managed_type ||= Type::Mapped.new(ManagedStructConverter.new(self))
end
class << self
public
# @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+ (Ruby 1.9 only)
# 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
# @note Creating a layout from a hash +spec+ is supported only for Ruby 1.9.
def layout(*spec)
#raise RuntimeError, "struct layout already defined for #{self.inspect}" if defined?(@layout)
return @layout if spec.size == 0
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
protected
def callback(params, ret)
mod = enclosing_module
FFI::CallbackInfo.new(find_type(ret, mod), params.map { |e| find_type(e, mod) })
end
def packed(packed = 1)
@packed = packed
end
alias :pack :packed
def aligned(alignment = 1)
@min_alignment = alignment
end
alias :align :aligned
def enclosing_module
begin
mod = self.name.split("::")[0..-2].inject(Object) { |obj, c| obj.const_get(c) }
(mod < FFI::Library || mod < FFI::Struct || mod.respond_to?(:find_type)) ? mod : nil
rescue Exception
nil
end
end
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
def find_type(type, mod = enclosing_module)
if mod
mod.find_type(type)
end || FFI.find_type(type)
end
private
# @param [StructLayoutBuilder] builder
# @param [Hash] spec
# @return [builder]
# Add hash +spec+ to +builder+.
def hash_layout(builder, spec)
spec[0].each do |name, type|
builder.add name, find_field_type(type), nil
end
end
# @param [StructLayoutBuilder] builder
# @param [Array<Symbol, Integer>] spec
# @return [builder]
# Add array +spec+ to +builder+.
def array_layout(builder, spec)
i = 0
while i < spec.size
name, type = spec[i, 2]
i += 2
# If the next param is a Integer, it specifies the offset
if spec[i].kind_of?(Integer)
offset = spec[i]
i += 1
else
offset = nil
end
builder.add name, find_field_type(type), offset
end
end
end
end
end