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Direktori : /usr/lib64/python3.6/site-packages/cffi/ |
Current File : //usr/lib64/python3.6/site-packages/cffi/backend_ctypes.py |
import ctypes, ctypes.util, operator, sys from . import model if sys.version_info < (3,): bytechr = chr else: unicode = str long = int xrange = range bytechr = lambda num: bytes([num]) class CTypesType(type): pass class CTypesData(object): __metaclass__ = CTypesType __slots__ = ['__weakref__'] __name__ = '<cdata>' def __init__(self, *args): raise TypeError("cannot instantiate %r" % (self.__class__,)) @classmethod def _newp(cls, init): raise TypeError("expected a pointer or array ctype, got '%s'" % (cls._get_c_name(),)) @staticmethod def _to_ctypes(value): raise TypeError @classmethod def _arg_to_ctypes(cls, *value): try: ctype = cls._ctype except AttributeError: raise TypeError("cannot create an instance of %r" % (cls,)) if value: res = cls._to_ctypes(*value) if not isinstance(res, ctype): res = cls._ctype(res) else: res = cls._ctype() return res @classmethod def _create_ctype_obj(cls, init): if init is None: return cls._arg_to_ctypes() else: return cls._arg_to_ctypes(init) @staticmethod def _from_ctypes(ctypes_value): raise TypeError @classmethod def _get_c_name(cls, replace_with=''): return cls._reftypename.replace(' &', replace_with) @classmethod def _fix_class(cls): cls.__name__ = 'CData<%s>' % (cls._get_c_name(),) cls.__qualname__ = 'CData<%s>' % (cls._get_c_name(),) cls.__module__ = 'ffi' def _get_own_repr(self): raise NotImplementedError def _addr_repr(self, address): if address == 0: return 'NULL' else: if address < 0: address += 1 << (8*ctypes.sizeof(ctypes.c_void_p)) return '0x%x' % address def __repr__(self, c_name=None): own = self._get_own_repr() return '<cdata %r %s>' % (c_name or self._get_c_name(), own) def _convert_to_address(self, BClass): if BClass is None: raise TypeError("cannot convert %r to an address" % ( self._get_c_name(),)) else: raise TypeError("cannot convert %r to %r" % ( self._get_c_name(), BClass._get_c_name())) @classmethod def _get_size(cls): return ctypes.sizeof(cls._ctype) def _get_size_of_instance(self): return ctypes.sizeof(self._ctype) @classmethod def _cast_from(cls, source): raise TypeError("cannot cast to %r" % (cls._get_c_name(),)) def _cast_to_integer(self): return self._convert_to_address(None) @classmethod def _alignment(cls): return ctypes.alignment(cls._ctype) def __iter__(self): raise TypeError("cdata %r does not support iteration" % ( self._get_c_name()),) def _make_cmp(name): cmpfunc = getattr(operator, name) def cmp(self, other): v_is_ptr = not isinstance(self, CTypesGenericPrimitive) w_is_ptr = (isinstance(other, CTypesData) and not isinstance(other, CTypesGenericPrimitive)) if v_is_ptr and w_is_ptr: return cmpfunc(self._convert_to_address(None), other._convert_to_address(None)) elif v_is_ptr or w_is_ptr: return NotImplemented else: if isinstance(self, CTypesGenericPrimitive): self = self._value if isinstance(other, CTypesGenericPrimitive): other = other._value return cmpfunc(self, other) cmp.func_name = name return cmp __eq__ = _make_cmp('__eq__') __ne__ = _make_cmp('__ne__') __lt__ = _make_cmp('__lt__') __le__ = _make_cmp('__le__') __gt__ = _make_cmp('__gt__') __ge__ = _make_cmp('__ge__') def __hash__(self): return hash(self._convert_to_address(None)) def _to_string(self, maxlen): raise TypeError("string(): %r" % (self,)) class CTypesGenericPrimitive(CTypesData): __slots__ = [] def __hash__(self): return hash(self._value) def _get_own_repr(self): return repr(self._from_ctypes(self._value)) class CTypesGenericArray(CTypesData): __slots__ = [] @classmethod def _newp(cls, init): return cls(init) def __iter__(self): for i in xrange(len(self)): yield self[i] def _get_own_repr(self): return self._addr_repr(ctypes.addressof(self._blob)) class CTypesGenericPtr(CTypesData): __slots__ = ['_address', '_as_ctype_ptr'] _automatic_casts = False kind = "pointer" @classmethod def _newp(cls, init): return cls(init) @classmethod def _cast_from(cls, source): if source is None: address = 0 elif isinstance(source, CTypesData): address = source._cast_to_integer() elif isinstance(source, (int, long)): address = source else: raise TypeError("bad type for cast to %r: %r" % (cls, type(source).__name__)) return cls._new_pointer_at(address) @classmethod def _new_pointer_at(cls, address): self = cls.__new__(cls) self._address = address self._as_ctype_ptr = ctypes.cast(address, cls._ctype) return self def _get_own_repr(self): try: return self._addr_repr(self._address) except AttributeError: return '???' def _cast_to_integer(self): return self._address def __nonzero__(self): return bool(self._address) __bool__ = __nonzero__ @classmethod def _to_ctypes(cls, value): if not isinstance(value, CTypesData): raise TypeError("unexpected %s object" % type(value).__name__) address = value._convert_to_address(cls) return ctypes.cast(address, cls._ctype) @classmethod def _from_ctypes(cls, ctypes_ptr): address = ctypes.cast(ctypes_ptr, ctypes.c_void_p).value or 0 return cls._new_pointer_at(address) @classmethod def _initialize(cls, ctypes_ptr, value): if value: ctypes_ptr.contents = cls._to_ctypes(value).contents def _convert_to_address(self, BClass): if (BClass in (self.__class__, None) or BClass._automatic_casts or self._automatic_casts): return self._address else: return CTypesData._convert_to_address(self, BClass) class CTypesBaseStructOrUnion(CTypesData): __slots__ = ['_blob'] @classmethod def _create_ctype_obj(cls, init): # may be overridden raise TypeError("cannot instantiate opaque type %s" % (cls,)) def _get_own_repr(self): return self._addr_repr(ctypes.addressof(self._blob)) @classmethod def _offsetof(cls, fieldname): return getattr(cls._ctype, fieldname).offset def _convert_to_address(self, BClass): if getattr(BClass, '_BItem', None) is self.__class__: return ctypes.addressof(self._blob) else: return CTypesData._convert_to_address(self, BClass) @classmethod def _from_ctypes(cls, ctypes_struct_or_union): self = cls.__new__(cls) self._blob = ctypes_struct_or_union return self @classmethod def _to_ctypes(cls, value): return value._blob def __repr__(self, c_name=None): return CTypesData.__repr__(self, c_name or self._get_c_name(' &')) class CTypesBackend(object): PRIMITIVE_TYPES = { 'char': ctypes.c_char, 'short': ctypes.c_short, 'int': ctypes.c_int, 'long': ctypes.c_long, 'long long': ctypes.c_longlong, 'signed char': ctypes.c_byte, 'unsigned char': ctypes.c_ubyte, 'unsigned short': ctypes.c_ushort, 'unsigned int': ctypes.c_uint, 'unsigned long': ctypes.c_ulong, 'unsigned long long': ctypes.c_ulonglong, 'float': ctypes.c_float, 'double': ctypes.c_double, '_Bool': ctypes.c_bool, } for _name in ['unsigned long long', 'unsigned long', 'unsigned int', 'unsigned short', 'unsigned char']: _size = ctypes.sizeof(PRIMITIVE_TYPES[_name]) PRIMITIVE_TYPES['uint%d_t' % (8*_size)] = PRIMITIVE_TYPES[_name] if _size == ctypes.sizeof(ctypes.c_void_p): PRIMITIVE_TYPES['uintptr_t'] = PRIMITIVE_TYPES[_name] if _size == ctypes.sizeof(ctypes.c_size_t): PRIMITIVE_TYPES['size_t'] = PRIMITIVE_TYPES[_name] for _name in ['long long', 'long', 'int', 'short', 'signed char']: _size = ctypes.sizeof(PRIMITIVE_TYPES[_name]) PRIMITIVE_TYPES['int%d_t' % (8*_size)] = PRIMITIVE_TYPES[_name] if _size == ctypes.sizeof(ctypes.c_void_p): PRIMITIVE_TYPES['intptr_t'] = PRIMITIVE_TYPES[_name] PRIMITIVE_TYPES['ptrdiff_t'] = PRIMITIVE_TYPES[_name] if _size == ctypes.sizeof(ctypes.c_size_t): PRIMITIVE_TYPES['ssize_t'] = PRIMITIVE_TYPES[_name] def __init__(self): self.RTLD_LAZY = 0 # not supported anyway by ctypes self.RTLD_NOW = 0 self.RTLD_GLOBAL = ctypes.RTLD_GLOBAL self.RTLD_LOCAL = ctypes.RTLD_LOCAL def set_ffi(self, ffi): self.ffi = ffi def _get_types(self): return CTypesData, CTypesType def load_library(self, path, flags=0): cdll = ctypes.CDLL(path, flags) return CTypesLibrary(self, cdll) def new_void_type(self): class CTypesVoid(CTypesData): __slots__ = [] _reftypename = 'void &' @staticmethod def _from_ctypes(novalue): return None @staticmethod def _to_ctypes(novalue): if novalue is not None: raise TypeError("None expected, got %s object" % (type(novalue).__name__,)) return None CTypesVoid._fix_class() return CTypesVoid def new_primitive_type(self, name): if name == 'wchar_t': raise NotImplementedError(name) ctype = self.PRIMITIVE_TYPES[name] if name == 'char': kind = 'char' elif name in ('float', 'double'): kind = 'float' else: if name in ('signed char', 'unsigned char'): kind = 'byte' elif name == '_Bool': kind = 'bool' else: kind = 'int' is_signed = (ctype(-1).value == -1) # def _cast_source_to_int(source): if isinstance(source, (int, long, float)): source = int(source) elif isinstance(source, CTypesData): source = source._cast_to_integer() elif isinstance(source, bytes): source = ord(source) elif source is None: source = 0 else: raise TypeError("bad type for cast to %r: %r" % (CTypesPrimitive, type(source).__name__)) return source # kind1 = kind class CTypesPrimitive(CTypesGenericPrimitive): __slots__ = ['_value'] _ctype = ctype _reftypename = '%s &' % name kind = kind1 def __init__(self, value): self._value = value @staticmethod def _create_ctype_obj(init): if init is None: return ctype() return ctype(CTypesPrimitive._to_ctypes(init)) if kind == 'int' or kind == 'byte': @classmethod def _cast_from(cls, source): source = _cast_source_to_int(source) source = ctype(source).value # cast within range return cls(source) def __int__(self): return self._value if kind == 'bool': @classmethod def _cast_from(cls, source): if not isinstance(source, (int, long, float)): source = _cast_source_to_int(source) return cls(bool(source)) def __int__(self): return self._value if kind == 'char': @classmethod def _cast_from(cls, source): source = _cast_source_to_int(source) source = bytechr(source & 0xFF) return cls(source) def __int__(self): return ord(self._value) if kind == 'float': @classmethod def _cast_from(cls, source): if isinstance(source, float): pass elif isinstance(source, CTypesGenericPrimitive): if hasattr(source, '__float__'): source = float(source) else: source = int(source) else: source = _cast_source_to_int(source) source = ctype(source).value # fix precision return cls(source) def __int__(self): return int(self._value) def __float__(self): return self._value _cast_to_integer = __int__ if kind == 'int' or kind == 'byte' or kind == 'bool': @staticmethod def _to_ctypes(x): if not isinstance(x, (int, long)): if isinstance(x, CTypesData): x = int(x) else: raise TypeError("integer expected, got %s" % type(x).__name__) if ctype(x).value != x: if not is_signed and x < 0: raise OverflowError("%s: negative integer" % name) else: raise OverflowError("%s: integer out of bounds" % name) return x if kind == 'char': @staticmethod def _to_ctypes(x): if isinstance(x, bytes) and len(x) == 1: return x if isinstance(x, CTypesPrimitive): # <CData <char>> return x._value raise TypeError("character expected, got %s" % type(x).__name__) def __nonzero__(self): return ord(self._value) != 0 else: def __nonzero__(self): return self._value != 0 __bool__ = __nonzero__ if kind == 'float': @staticmethod def _to_ctypes(x): if not isinstance(x, (int, long, float, CTypesData)): raise TypeError("float expected, got %s" % type(x).__name__) return ctype(x).value @staticmethod def _from_ctypes(value): return getattr(value, 'value', value) @staticmethod def _initialize(blob, init): blob.value = CTypesPrimitive._to_ctypes(init) if kind == 'char': def _to_string(self, maxlen): return self._value if kind == 'byte': def _to_string(self, maxlen): return chr(self._value & 0xff) # CTypesPrimitive._fix_class() return CTypesPrimitive def new_pointer_type(self, BItem): getbtype = self.ffi._get_cached_btype if BItem is getbtype(model.PrimitiveType('char')): kind = 'charp' elif BItem in (getbtype(model.PrimitiveType('signed char')), getbtype(model.PrimitiveType('unsigned char'))): kind = 'bytep' elif BItem is getbtype(model.void_type): kind = 'voidp' else: kind = 'generic' # class CTypesPtr(CTypesGenericPtr): __slots__ = ['_own'] if kind == 'charp': __slots__ += ['__as_strbuf'] _BItem = BItem if hasattr(BItem, '_ctype'): _ctype = ctypes.POINTER(BItem._ctype) _bitem_size = ctypes.sizeof(BItem._ctype) else: _ctype = ctypes.c_void_p if issubclass(BItem, CTypesGenericArray): _reftypename = BItem._get_c_name('(* &)') else: _reftypename = BItem._get_c_name(' * &') def __init__(self, init): ctypeobj = BItem._create_ctype_obj(init) if kind == 'charp': self.__as_strbuf = ctypes.create_string_buffer( ctypeobj.value + b'\x00') self._as_ctype_ptr = ctypes.cast( self.__as_strbuf, self._ctype) else: self._as_ctype_ptr = ctypes.pointer(ctypeobj) self._address = ctypes.cast(self._as_ctype_ptr, ctypes.c_void_p).value self._own = True def __add__(self, other): if isinstance(other, (int, long)): return self._new_pointer_at(self._address + other * self._bitem_size) else: return NotImplemented def __sub__(self, other): if isinstance(other, (int, long)): return self._new_pointer_at(self._address - other * self._bitem_size) elif type(self) is type(other): return (self._address - other._address) // self._bitem_size else: return NotImplemented def __getitem__(self, index): if getattr(self, '_own', False) and index != 0: raise IndexError return BItem._from_ctypes(self._as_ctype_ptr[index]) def __setitem__(self, index, value): self._as_ctype_ptr[index] = BItem._to_ctypes(value) if kind == 'charp' or kind == 'voidp': @classmethod def _arg_to_ctypes(cls, *value): if value and isinstance(value[0], bytes): return ctypes.c_char_p(value[0]) else: return super(CTypesPtr, cls)._arg_to_ctypes(*value) if kind == 'charp' or kind == 'bytep': def _to_string(self, maxlen): if maxlen < 0: maxlen = sys.maxsize p = ctypes.cast(self._as_ctype_ptr, ctypes.POINTER(ctypes.c_char)) n = 0 while n < maxlen and p[n] != b'\x00': n += 1 return b''.join([p[i] for i in range(n)]) def _get_own_repr(self): if getattr(self, '_own', False): return 'owning %d bytes' % ( ctypes.sizeof(self._as_ctype_ptr.contents),) return super(CTypesPtr, self)._get_own_repr() # if (BItem is self.ffi._get_cached_btype(model.void_type) or BItem is self.ffi._get_cached_btype(model.PrimitiveType('char'))): CTypesPtr._automatic_casts = True # CTypesPtr._fix_class() return CTypesPtr def new_array_type(self, CTypesPtr, length): if length is None: brackets = ' &[]' else: brackets = ' &[%d]' % length BItem = CTypesPtr._BItem getbtype = self.ffi._get_cached_btype if BItem is getbtype(model.PrimitiveType('char')): kind = 'char' elif BItem in (getbtype(model.PrimitiveType('signed char')), getbtype(model.PrimitiveType('unsigned char'))): kind = 'byte' else: kind = 'generic' # class CTypesArray(CTypesGenericArray): __slots__ = ['_blob', '_own'] if length is not None: _ctype = BItem._ctype * length else: __slots__.append('_ctype') _reftypename = BItem._get_c_name(brackets) _declared_length = length _CTPtr = CTypesPtr def __init__(self, init): if length is None: if isinstance(init, (int, long)): len1 = init init = None elif kind == 'char' and isinstance(init, bytes): len1 = len(init) + 1 # extra null else: init = tuple(init) len1 = len(init) self._ctype = BItem._ctype * len1 self._blob = self._ctype() self._own = True if init is not None: self._initialize(self._blob, init) @staticmethod def _initialize(blob, init): if isinstance(init, bytes): init = [init[i:i+1] for i in range(len(init))] else: init = tuple(init) if len(init) > len(blob): raise IndexError("too many initializers") addr = ctypes.cast(blob, ctypes.c_void_p).value PTR = ctypes.POINTER(BItem._ctype) itemsize = ctypes.sizeof(BItem._ctype) for i, value in enumerate(init): p = ctypes.cast(addr + i * itemsize, PTR) BItem._initialize(p.contents, value) def __len__(self): return len(self._blob) def __getitem__(self, index): if not (0 <= index < len(self._blob)): raise IndexError return BItem._from_ctypes(self._blob[index]) def __setitem__(self, index, value): if not (0 <= index < len(self._blob)): raise IndexError self._blob[index] = BItem._to_ctypes(value) if kind == 'char' or kind == 'byte': def _to_string(self, maxlen): if maxlen < 0: maxlen = len(self._blob) p = ctypes.cast(self._blob, ctypes.POINTER(ctypes.c_char)) n = 0 while n < maxlen and p[n] != b'\x00': n += 1 return b''.join([p[i] for i in range(n)]) def _get_own_repr(self): if getattr(self, '_own', False): return 'owning %d bytes' % (ctypes.sizeof(self._blob),) return super(CTypesArray, self)._get_own_repr() def _convert_to_address(self, BClass): if BClass in (CTypesPtr, None) or BClass._automatic_casts: return ctypes.addressof(self._blob) else: return CTypesData._convert_to_address(self, BClass) @staticmethod def _from_ctypes(ctypes_array): self = CTypesArray.__new__(CTypesArray) self._blob = ctypes_array return self @staticmethod def _arg_to_ctypes(value): return CTypesPtr._arg_to_ctypes(value) def __add__(self, other): if isinstance(other, (int, long)): return CTypesPtr._new_pointer_at( ctypes.addressof(self._blob) + other * ctypes.sizeof(BItem._ctype)) else: return NotImplemented @classmethod def _cast_from(cls, source): raise NotImplementedError("casting to %r" % ( cls._get_c_name(),)) # CTypesArray._fix_class() return CTypesArray def _new_struct_or_union(self, kind, name, base_ctypes_class): # class struct_or_union(base_ctypes_class): pass struct_or_union.__name__ = '%s_%s' % (kind, name) kind1 = kind # class CTypesStructOrUnion(CTypesBaseStructOrUnion): __slots__ = ['_blob'] _ctype = struct_or_union _reftypename = '%s &' % (name,) _kind = kind = kind1 # CTypesStructOrUnion._fix_class() return CTypesStructOrUnion def new_struct_type(self, name): return self._new_struct_or_union('struct', name, ctypes.Structure) def new_union_type(self, name): return self._new_struct_or_union('union', name, ctypes.Union) def complete_struct_or_union(self, CTypesStructOrUnion, fields, tp, totalsize=-1, totalalignment=-1, sflags=0): if totalsize >= 0 or totalalignment >= 0: raise NotImplementedError("the ctypes backend of CFFI does not support " "structures completed by verify(); please " "compile and install the _cffi_backend module.") struct_or_union = CTypesStructOrUnion._ctype fnames = [fname for (fname, BField, bitsize) in fields] btypes = [BField for (fname, BField, bitsize) in fields] bitfields = [bitsize for (fname, BField, bitsize) in fields] # bfield_types = {} cfields = [] for (fname, BField, bitsize) in fields: if bitsize < 0: cfields.append((fname, BField._ctype)) bfield_types[fname] = BField else: cfields.append((fname, BField._ctype, bitsize)) bfield_types[fname] = Ellipsis if sflags & 8: struct_or_union._pack_ = 1 struct_or_union._fields_ = cfields CTypesStructOrUnion._bfield_types = bfield_types # @staticmethod def _create_ctype_obj(init): result = struct_or_union() if init is not None: initialize(result, init) return result CTypesStructOrUnion._create_ctype_obj = _create_ctype_obj # def initialize(blob, init): if is_union: if len(init) > 1: raise ValueError("union initializer: %d items given, but " "only one supported (use a dict if needed)" % (len(init),)) if not isinstance(init, dict): if isinstance(init, (bytes, unicode)): raise TypeError("union initializer: got a str") init = tuple(init) if len(init) > len(fnames): raise ValueError("too many values for %s initializer" % CTypesStructOrUnion._get_c_name()) init = dict(zip(fnames, init)) addr = ctypes.addressof(blob) for fname, value in init.items(): BField, bitsize = name2fieldtype[fname] assert bitsize < 0, \ "not implemented: initializer with bit fields" offset = CTypesStructOrUnion._offsetof(fname) PTR = ctypes.POINTER(BField._ctype) p = ctypes.cast(addr + offset, PTR) BField._initialize(p.contents, value) is_union = CTypesStructOrUnion._kind == 'union' name2fieldtype = dict(zip(fnames, zip(btypes, bitfields))) # for fname, BField, bitsize in fields: if fname == '': raise NotImplementedError("nested anonymous structs/unions") if hasattr(CTypesStructOrUnion, fname): raise ValueError("the field name %r conflicts in " "the ctypes backend" % fname) if bitsize < 0: def getter(self, fname=fname, BField=BField, offset=CTypesStructOrUnion._offsetof(fname), PTR=ctypes.POINTER(BField._ctype)): addr = ctypes.addressof(self._blob) p = ctypes.cast(addr + offset, PTR) return BField._from_ctypes(p.contents) def setter(self, value, fname=fname, BField=BField): setattr(self._blob, fname, BField._to_ctypes(value)) # if issubclass(BField, CTypesGenericArray): setter = None if BField._declared_length == 0: def getter(self, fname=fname, BFieldPtr=BField._CTPtr, offset=CTypesStructOrUnion._offsetof(fname), PTR=ctypes.POINTER(BField._ctype)): addr = ctypes.addressof(self._blob) p = ctypes.cast(addr + offset, PTR) return BFieldPtr._from_ctypes(p) # else: def getter(self, fname=fname, BField=BField): return BField._from_ctypes(getattr(self._blob, fname)) def setter(self, value, fname=fname, BField=BField): # xxx obscure workaround value = BField._to_ctypes(value) oldvalue = getattr(self._blob, fname) setattr(self._blob, fname, value) if value != getattr(self._blob, fname): setattr(self._blob, fname, oldvalue) raise OverflowError("value too large for bitfield") setattr(CTypesStructOrUnion, fname, property(getter, setter)) # CTypesPtr = self.ffi._get_cached_btype(model.PointerType(tp)) for fname in fnames: if hasattr(CTypesPtr, fname): raise ValueError("the field name %r conflicts in " "the ctypes backend" % fname) def getter(self, fname=fname): return getattr(self[0], fname) def setter(self, value, fname=fname): setattr(self[0], fname, value) setattr(CTypesPtr, fname, property(getter, setter)) def new_function_type(self, BArgs, BResult, has_varargs): nameargs = [BArg._get_c_name() for BArg in BArgs] if has_varargs: nameargs.append('...') nameargs = ', '.join(nameargs) # class CTypesFunctionPtr(CTypesGenericPtr): __slots__ = ['_own_callback', '_name'] _ctype = ctypes.CFUNCTYPE(getattr(BResult, '_ctype', None), *[BArg._ctype for BArg in BArgs], use_errno=True) _reftypename = BResult._get_c_name('(* &)(%s)' % (nameargs,)) def __init__(self, init, error=None): # create a callback to the Python callable init() import traceback assert not has_varargs, "varargs not supported for callbacks" if getattr(BResult, '_ctype', None) is not None: error = BResult._from_ctypes( BResult._create_ctype_obj(error)) else: error = None def callback(*args): args2 = [] for arg, BArg in zip(args, BArgs): args2.append(BArg._from_ctypes(arg)) try: res2 = init(*args2) res2 = BResult._to_ctypes(res2) except: traceback.print_exc() res2 = error if issubclass(BResult, CTypesGenericPtr): if res2: res2 = ctypes.cast(res2, ctypes.c_void_p).value # .value: http://bugs.python.org/issue1574593 else: res2 = None #print repr(res2) return res2 if issubclass(BResult, CTypesGenericPtr): # The only pointers callbacks can return are void*s: # http://bugs.python.org/issue5710 callback_ctype = ctypes.CFUNCTYPE( ctypes.c_void_p, *[BArg._ctype for BArg in BArgs], use_errno=True) else: callback_ctype = CTypesFunctionPtr._ctype self._as_ctype_ptr = callback_ctype(callback) self._address = ctypes.cast(self._as_ctype_ptr, ctypes.c_void_p).value self._own_callback = init @staticmethod def _initialize(ctypes_ptr, value): if value: raise NotImplementedError("ctypes backend: not supported: " "initializers for function pointers") def __repr__(self): c_name = getattr(self, '_name', None) if c_name: i = self._reftypename.index('(* &)') if self._reftypename[i-1] not in ' )*': c_name = ' ' + c_name c_name = self._reftypename.replace('(* &)', c_name) return CTypesData.__repr__(self, c_name) def _get_own_repr(self): if getattr(self, '_own_callback', None) is not None: return 'calling %r' % (self._own_callback,) return super(CTypesFunctionPtr, self)._get_own_repr() def __call__(self, *args): if has_varargs: assert len(args) >= len(BArgs) extraargs = args[len(BArgs):] args = args[:len(BArgs)] else: assert len(args) == len(BArgs) ctypes_args = [] for arg, BArg in zip(args, BArgs): ctypes_args.append(BArg._arg_to_ctypes(arg)) if has_varargs: for i, arg in enumerate(extraargs): if arg is None: ctypes_args.append(ctypes.c_void_p(0)) # NULL continue if not isinstance(arg, CTypesData): raise TypeError( "argument %d passed in the variadic part " "needs to be a cdata object (got %s)" % (1 + len(BArgs) + i, type(arg).__name__)) ctypes_args.append(arg._arg_to_ctypes(arg)) result = self._as_ctype_ptr(*ctypes_args) return BResult._from_ctypes(result) # CTypesFunctionPtr._fix_class() return CTypesFunctionPtr def new_enum_type(self, name, enumerators, enumvalues, CTypesInt): assert isinstance(name, str) reverse_mapping = dict(zip(reversed(enumvalues), reversed(enumerators))) # class CTypesEnum(CTypesInt): __slots__ = [] _reftypename = '%s &' % name def _get_own_repr(self): value = self._value try: return '%d: %s' % (value, reverse_mapping[value]) except KeyError: return str(value) def _to_string(self, maxlen): value = self._value try: return reverse_mapping[value] except KeyError: return str(value) # CTypesEnum._fix_class() return CTypesEnum def get_errno(self): return ctypes.get_errno() def set_errno(self, value): ctypes.set_errno(value) def string(self, b, maxlen=-1): return b._to_string(maxlen) def buffer(self, bptr, size=-1): raise NotImplementedError("buffer() with ctypes backend") def sizeof(self, cdata_or_BType): if isinstance(cdata_or_BType, CTypesData): return cdata_or_BType._get_size_of_instance() else: assert issubclass(cdata_or_BType, CTypesData) return cdata_or_BType._get_size() def alignof(self, BType): assert issubclass(BType, CTypesData) return BType._alignment() def newp(self, BType, source): if not issubclass(BType, CTypesData): raise TypeError return BType._newp(source) def cast(self, BType, source): return BType._cast_from(source) def callback(self, BType, source, error, onerror): assert onerror is None # XXX not implemented return BType(source, error) _weakref_cache_ref = None def gcp(self, cdata, destructor, size=0): if self._weakref_cache_ref is None: import weakref class MyRef(weakref.ref): def __eq__(self, other): myref = self() return self is other or ( myref is not None and myref is other()) def __ne__(self, other): return not (self == other) def __hash__(self): try: return self._hash except AttributeError: self._hash = hash(self()) return self._hash self._weakref_cache_ref = {}, MyRef weak_cache, MyRef = self._weakref_cache_ref if destructor is None: try: del weak_cache[MyRef(cdata)] except KeyError: raise TypeError("Can remove destructor only on a object " "previously returned by ffi.gc()") return None def remove(k): cdata, destructor = weak_cache.pop(k, (None, None)) if destructor is not None: destructor(cdata) new_cdata = self.cast(self.typeof(cdata), cdata) assert new_cdata is not cdata weak_cache[MyRef(new_cdata, remove)] = (cdata, destructor) return new_cdata typeof = type def getcname(self, BType, replace_with): return BType._get_c_name(replace_with) def typeoffsetof(self, BType, fieldname, num=0): if isinstance(fieldname, str): if num == 0 and issubclass(BType, CTypesGenericPtr): BType = BType._BItem if not issubclass(BType, CTypesBaseStructOrUnion): raise TypeError("expected a struct or union ctype") BField = BType._bfield_types[fieldname] if BField is Ellipsis: raise TypeError("not supported for bitfields") return (BField, BType._offsetof(fieldname)) elif isinstance(fieldname, (int, long)): if issubclass(BType, CTypesGenericArray): BType = BType._CTPtr if not issubclass(BType, CTypesGenericPtr): raise TypeError("expected an array or ptr ctype") BItem = BType._BItem offset = BItem._get_size() * fieldname if offset > sys.maxsize: raise OverflowError return (BItem, offset) else: raise TypeError(type(fieldname)) def rawaddressof(self, BTypePtr, cdata, offset=None): if isinstance(cdata, CTypesBaseStructOrUnion): ptr = ctypes.pointer(type(cdata)._to_ctypes(cdata)) elif isinstance(cdata, CTypesGenericPtr): if offset is None or not issubclass(type(cdata)._BItem, CTypesBaseStructOrUnion): raise TypeError("unexpected cdata type") ptr = type(cdata)._to_ctypes(cdata) elif isinstance(cdata, CTypesGenericArray): ptr = type(cdata)._to_ctypes(cdata) else: raise TypeError("expected a <cdata 'struct-or-union'>") if offset: ptr = ctypes.cast( ctypes.c_void_p( ctypes.cast(ptr, ctypes.c_void_p).value + offset), type(ptr)) return BTypePtr._from_ctypes(ptr) class CTypesLibrary(object): def __init__(self, backend, cdll): self.backend = backend self.cdll = cdll def load_function(self, BType, name): c_func = getattr(self.cdll, name) funcobj = BType._from_ctypes(c_func) funcobj._name = name return funcobj def read_variable(self, BType, name): try: ctypes_obj = BType._ctype.in_dll(self.cdll, name) except AttributeError as e: raise NotImplementedError(e) return BType._from_ctypes(ctypes_obj) def write_variable(self, BType, name, value): new_ctypes_obj = BType._to_ctypes(value) ctypes_obj = BType._ctype.in_dll(self.cdll, name) ctypes.memmove(ctypes.addressof(ctypes_obj), ctypes.addressof(new_ctypes_obj), ctypes.sizeof(BType._ctype))