Module: Snow::CStruct::StructBase

Defined in:
lib/snow-data/c_struct/struct_base.rb

Overview

Struct base class. Not to be used directly, as it does not provide all the constants and methods necessary for a struct.

Defined Under Namespace

Modules: Allocators, MemberInfoSupport

Class Method Summary collapse

Instance Method Summary collapse

Class Method Details

.define_member_methods(struct_klass) ⇒ Object 



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# File 'lib/snow-data/c_struct/struct_base.rb', line 148

def self.define_member_methods(struct_klass)
  struct_klass.class_exec do
    self::MEMBERS.each do |member|

      name        = member.name
      index_range = (0...member.length)
      type_name   = member.type
      type_size   = ::Snow::CStruct::SIZES[member.type]
      offset      = member.offset
      getter      = :"get_#{type_name}"
      setter      = :"set_#{type_name}"
      get_name    = :"get_#{name}"
      set_name    = :"set_#{name}"

      define_method(get_name) do |index = 0|
        if index === index_range
          raise RangeError, "Index #{index} for #{name} is out of range: must be in #{index_range}"
        end
        off = offset + index * type_size
        __send__(getter, off)
      end # get_name


      define_method(set_name) do |value, index = 0|
        if index === index_range
          raise RangeError, "Index #{index} for #{name} is out of range: must be in #{index_range}"
        end
        off = offset + index * type_size
        __send__(setter, off, value)
        value
      end # set_name


      alias_method :"#{name}", get_name
      alias_method :"#{name}=", set_name

      extend MemberInfoSupport

    end # self::MEMBERS.each
  end # self.class_exec
end

.included(struct_klass) ⇒ Object

Upon inclusion, defines the given struct_klass’s member accessors/mutators as well as its allocator functions.



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# File 'lib/snow-data/c_struct/struct_base.rb', line 195

def self.included(struct_klass)
  struct_klass.extend(Allocators)
  struct_klass.extend(MemberInfoSupport)
  define_member_methods(struct_klass)
end

Instance Method Details

#[](name, index = 0) ⇒ Object

Gets the value of the member with the given name and index.



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# File 'lib/snow-data/c_struct/struct_base.rb', line 135

def [](name, index = 0)
  __send__(self.class::MEMBERS_GETFN[name], index)
end

#[]=(name, index = 0, value) ⇒ Object

Sets the value of the member with the given name and index.



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# File 'lib/snow-data/c_struct/struct_base.rb', line 143

def []=(name, index = 0, value)
  __send__(self.class::MEMBERS_SETFN[name], value, index)
end

#address_of(member) ⇒ Object

Returns the address of a member. This address is only valid for the receiver.



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# File 'lib/snow-data/c_struct/struct_base.rb', line 26

def address_of(member)
  self.address + self.class.offset_of(member)
end

#alignment_of(member) ⇒ Object

Returns the alignment of a member.



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# File 'lib/snow-data/c_struct/struct_base.rb', line 50

def alignment_of(member)
  self.class.alignment_of(member)
end

#bytesize_of(member) ⇒ Object

Returns the size in bytes of a member.



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# File 'lib/snow-data/c_struct/struct_base.rb', line 42

def bytesize_of(member)
  self.class.bytesize_of(member)
end

#inspect ⇒ Object

Returns a string describing the struct, including its classname, object ID, address, size, and alignment. In addition, if long_inspect is enabled, then it will also include the values of the struct’s members.



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# File 'lib/snow-data/c_struct/struct_base.rb', line 95

def inspect
  id_text     = __id__.to_s(16).rjust(14, ?0)
  addr_text   = self.address.to_s(16).rjust(14, ?0)

  member_text = if ! null? && ::Snow::CStruct.long_inspect
    # Get member text
    all_members_text = (self.class::MEMBERS.map do |member|
      name        = member.name
      type        = member.type
      align       = member.alignment
      length      = member.length
      length_decl = length > 1 ? "[#{length}]" : ''

      values_text = if length > 1
        single_member_text = (0 ... length).map { |index|
            "[#{ index }]=#{ self.__send__(member.name, index).inspect }"
          }.join(', ')

          "{ #{ single_member_text } }"
        else
          self.__send__(member.name).inspect
        end

      "#{ name }:#{ type }#{ length_decl }:#{ align }=#{ values_text }"

    end).join('; ')

    " #{all_members_text}"
  else # member_text = if ...
    # Skip members
    ''
  end # member_text = if ...

  "<#{ self.class }:0x#{ id_text } *0x#{ addr_text }:#{ self.bytesize }:#{ self.alignment }#{member_text}>"
end

#length_of(member) ⇒ Object

Returns the length of a member.



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# File 'lib/snow-data/c_struct/struct_base.rb', line 58

def length_of(member)
  self.class.length_of(member)
end

#offset_of(member) ⇒ Object

Returns the offset of a member.



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# File 'lib/snow-data/c_struct/struct_base.rb', line 34

def offset_of(member)
  self.class.offset_of(member)
end

#to_h ⇒ Object

Returns a hash of all of the struct’s member names to their values.



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# File 'lib/snow-data/c_struct/struct_base.rb', line 74

def to_h
  self.class::MEMBERS.inject({}) do |hash, member|
    length = member.length
    name   = member.name

    hash[name] = if length > 1
      (0 ... length).map { |index| __send__(name, index) }
    else
      __send__(name)
    end

    hash
  end
end

#type_of(member) ⇒ Object

Returns the type name of a member.



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# File 'lib/snow-data/c_struct/struct_base.rb', line 66

def type_of(member)
  self.class.type_of(member)
end