Class: Fiddle::CStructEntity
Relationships & Source Files | |
Extension / Inclusion / Inheritance Descendants | |
Subclasses:
|
|
Super Chains via Extension / Inclusion / Inheritance | |
Class Chain:
self,
Pointer
|
|
Instance Chain:
self,
Pointer
|
|
Inherits: |
Fiddle::Pointer
|
Defined in: | ext/fiddle/lib/fiddle/struct.rb |
Overview
A C struct wrapper
Class Method Summary
-
.malloc(types, func = nil)
Allocates a C struct with the
types
provided. -
.new(addr, types, func = nil) ⇒ CStructEntity
constructor
Wraps the C pointer
addr
as a C struct with the giventypes
. -
.size(types)
Returns the offset for the packed sizes for the given
types
.
Pointer - Inherited
Instance Attribute Summary
Pointer - Inherited
Instance Method Summary
-
#[](name)
Fetch struct member
name
-
#[]=(name, val)
Set struct member
name
, to valueval
-
#assign_names(members)
Set the names of the
members
in this C struct. -
#set_ctypes(types)
Calculates the offsets and sizes for the given
types
in the struct.
Pointer - Inherited
#+ | Returns a new pointer instance that has been advanced |
#+@ | Returns a new Pointer instance that is a dereferenced pointer for this pointer. |
#- | Returns a new pointer instance that has been moved back |
#-@ | Returns a new Pointer instance that is a reference pointer for this pointer. |
#<=> | Returns -1 if less than, 0 if equal to, 1 if greater than |
#== | Returns true if |
#[] | Returns integer stored at index. |
#[]= | Set the value at |
#eql? | Alias for Pointer#==. |
#inspect | Returns a string formatted with an easily readable representation of the internal state of the pointer. |
#ptr | Alias for Pointer#+@. |
#ref | Alias for Pointer#-@. |
#to_i | Returns the integer memory location of this pointer. |
#to_int | Alias for Pointer#to_i. |
#to_s | Returns the pointer contents as a string. |
#to_str | Returns the pointer contents as a string. |
#to_value | Cast this pointer to a ruby object. |
Constructor Details
.new(addr, types, func = nil) ⇒ CStructEntity
Wraps the C pointer addr
as a C struct with the given types
.
When the instance is garbage collected, the C function func
is called.
See also Pointer.new
# File 'ext/fiddle/lib/fiddle/struct.rb', line 120
def initialize(addr, types, func = nil) set_ctypes(types) super(addr, @size, func) end
Class Method Details
.malloc(types, func = nil)
Allocates a C struct with the types
provided.
When the instance is garbage collected, the C function func
is called.
.size(types)
Returns the offset for the packed sizes for the given types
.
Fiddle::CStructEntity.size(
[ Fiddle::TYPE_DOUBLE,
Fiddle::TYPE_INT,
Fiddle::TYPE_CHAR,
Fiddle::TYPE_VOIDP ]) #=> 24
# File 'ext/fiddle/lib/fiddle/struct.rb', line 99
def CStructEntity.size(types) offset = 0 max_align = types.map { |type, count = 1| last_offset = offset align = PackInfo::ALIGN_MAP[type] offset = PackInfo.align(last_offset, align) + (PackInfo::SIZE_MAP[type] * count) align }.max PackInfo.align(offset, max_align) end
Instance Method Details
#[](name)
Fetch struct member name
# File 'ext/fiddle/lib/fiddle/struct.rb', line 152
def [](name) idx = @members.index(name) if( idx.nil? ) raise(ArgumentError, "no such member: #{name}") end ty = @ctypes[idx] if( ty.is_a?(Array) ) r = super(@offset[idx], SIZE_MAP[ty[0]] * ty[1]) else r = super(@offset[idx], SIZE_MAP[ty.abs]) end packer = Packer.new([ty]) val = packer.unpack([r]) case ty when Array case ty[0] when TYPE_VOIDP val = val.collect{|v| Pointer.new(v)} end when TYPE_VOIDP val = Pointer.new(val[0]) else val = val[0] end if( ty.is_a?(Integer) && (ty < 0) ) return unsigned_value(val, ty) elsif( ty.is_a?(Array) && (ty[0] < 0) ) return val.collect{|v| unsigned_value(v,ty[0])} else return val end end
#[]=(name, val)
Set struct member name
, to value val
# File 'ext/fiddle/lib/fiddle/struct.rb', line 186
def []=(name, val) idx = @members.index(name) if( idx.nil? ) raise(ArgumentError, "no such member: #{name}") end ty = @ctypes[idx] packer = Packer.new([ty]) val = wrap_arg(val, ty, []) buff = packer.pack([val].flatten()) super(@offset[idx], buff.size, buff) if( ty.is_a?(Integer) && (ty < 0) ) return unsigned_value(val, ty) elsif( ty.is_a?(Array) && (ty[0] < 0) ) return val.collect{|v| unsigned_value(v,ty[0])} else return val end end
#assign_names(members)
Set the names of the members
in this C struct
# File 'ext/fiddle/lib/fiddle/struct.rb', line 126
def assign_names(members) @members = members end
#set_ctypes(types)
Calculates the offsets and sizes for the given types
in the struct.
# File 'ext/fiddle/lib/fiddle/struct.rb', line 131
def set_ctypes(types) @ctypes = types @offset = [] offset = 0 max_align = types.map { |type, count = 1| orig_offset = offset align = ALIGN_MAP[type] offset = PackInfo.align(orig_offset, align) @offset << offset offset += (SIZE_MAP[type] * count) align }.max @size = PackInfo.align(offset, max_align) end