Python ctypes.memmove() Examples

def consume(self, bytes, audio_format):
        '''Remove some data from beginning of packet.'''
        if bytes == self.length:
            self.data = None
            self.length = 0
            self.timestamp += self.duration
            self.duration = 0.
            return
        elif bytes == 0:
            return

        if not isinstance(self.data, str):
            # XXX Create a string buffer for the whole packet then
            #     chop it up.  Could do some pointer arith here and
            #     save a bit of data pushing, but my guess is this is
            #     faster than fudging aruond with ctypes (and easier).
            data = ctypes.create_string_buffer(self.length)
            ctypes.memmove(data, self.data, self.length)
            self.data = data
        self.data = self.data[bytes:]
        self.length -= bytes
        self.duration -= bytes / float(audio_format.bytes_per_second)
        self.timestamp += bytes / float(audio_format.bytes_per_second) 

def test_jlink_features_has_features(self):
        """Tests the J-Link ``features`` property returns a feature list.

        Args:
          self (TestJLink): the ``TestJLink`` instance

        Returns:
          ``None``
        """
        feature_string = 'RDI, JFlash, FlashDL'

        def func(b):
            ctypes.memmove(b, feature_string.encode(), len(feature_string))

        self.dll.JLINKARM_GetFeatureString = func

        result = self.jlink.features

        self.assertTrue(isinstance(result, list))
        self.assertEqual(3, len(result))
        self.assertEqual('RDI', result[0])
        self.assertEqual('JFlash', result[1])
        self.assertEqual('FlashDL', result[2]) 

def test_jlink_compatible_firmware_version(self):
        """Tests that getting a compatible firmware version from the DLL.

        Args:
          self (TestJLink): the ``TestJLink`` instance

        Returns:
          ``None``
        """
        firmware = 'J-Trace Cortex-M Rev.3 compiled Mar 30 2015 13:52:25'

        def set_firmware_string(buf, buf_size):
            ctypes.memmove(buf, firmware.encode(), len(firmware))

        self.dll.JLINKARM_GetFirmwareString = set_firmware_string

        self.dll.JLINKARM_GetEmbeddedFWString.return_value = -1
        with self.assertRaises(JLinkException):
            self.jlink.compatible_firmware_version

        self.dll.JLINKARM_GetEmbeddedFWString.return_value = 0
        self.dll.JLINKARM_GetEmbeddedFWString.assert_called()
        self.assertEqual('', self.jlink.compatible_firmware_version) 

def consume(self, bytes, audio_format):
        '''Remove some data from beginning of packet.'''
        if bytes == self.length:
            self.data = None
            self.length = 0
            self.timestamp += self.duration
            self.duration = 0.
            return
        elif bytes == 0:
            return

        if not isinstance(self.data, str):
            # XXX Create a string buffer for the whole packet then
            #     chop it up.  Could do some pointer arith here and
            #     save a bit of data pushing, but my guess is this is
            #     faster than fudging aruond with ctypes (and easier).
            data = ctypes.create_string_buffer(self.length)
            ctypes.memmove(data, self.data, self.length)
            self.data = data
        self.data = self.data[bytes:]
        self.length -= bytes
        self.duration -= bytes / float(audio_format.bytes_per_second)
        self.timestamp += bytes / float(audio_format.bytes_per_second) 

def ctypes2buffer(cptr, length):
    """Convert ctypes pointer to buffer type.

    Parameters
    ----------
    cptr : ctypes.POINTER(ctypes.c_char)
        pointer to the raw memory region
    length : int
        the length of the buffer

    Returns
    -------
    buffer : bytearray
        The raw byte memory buffer
    """
    if not isinstance(cptr, ctypes.POINTER(ctypes.c_char)):
        raise TypeError('expected char pointer')
    res = bytearray(length)
    rptr = (ctypes.c_char * length).from_buffer(res)
    if not ctypes.memmove(rptr, cptr, length):
        raise RuntimeError('memmove failed')
    return res 

def __init__(self, match_any, match_all, level, filter_in, names):
        struct_size = ((sum([len(name) for name in names]) * ct.sizeof(wt.CHAR)) + (ct.sizeof(wt.CHAR) * len(names))) +\
                      ct.sizeof(EVENT_FILTER_EVENT_NAME)
        self._buf = (ct.c_char * struct_size)()
        self._props = ct.cast(ct.pointer(self._buf), ct.POINTER(EVENT_FILTER_EVENT_NAME))
        self._props.contents.MatchAnyKeyword = match_any
        self._props.contents.MatchAllKeyword = match_all
        self._props.contents.Level = level
        self._props.contents.FilterIn = filter_in
        self._props.contents.NameCount = len(names)

        str_off = 0
        for i in range(len(names)):
            ct.memmove(ct.cast(ct.addressof(self._buf) + ct.sizeof(EVENT_FILTER_EVENT_NAME) + str_off,
                               ct.c_void_p),
                       names[i],
                       len(names[i]))
            str_off += len(names[i]) + ct.sizeof(wt.CHAR) 

def __init__(self, event_property, event_filters):
        """
        Initializes an ENABLE_TRACE_PARAMETERS structure.

        :param event_property: Property to enable.
                         See https://msdn.microsoft.com/en-us/library/windows/desktop/dd392306(v=vs.85).aspx
        :param event_filters: List of EVENT_FILTER_DESCRIPTOR structures
        """

        self._props = ct.pointer(et.ENABLE_TRACE_PARAMETERS())

        filter_buf_size = ct.sizeof(ep.EVENT_FILTER_DESCRIPTOR) * len(event_filters)
        # noinspection PyCallingNonCallable
        filter_buf = (ct.c_char * filter_buf_size)()
        # copy contents to buffer
        for i in range(len(event_filters)):
            ct.memmove(ct.cast(ct.addressof(filter_buf) + (ct.sizeof(ep.EVENT_FILTER_DESCRIPTOR) * i), ct.c_void_p),
                       ct.byref(event_filters[i]),
                       ct.sizeof(ep.EVENT_FILTER_DESCRIPTOR))

        self._props.contents.Version = et.ENABLE_TRACE_PARAMETERS_VERSION_2
        self._props.contents.EnableProperty = event_property
        self._props.contents.ControlFlags = 0
        self._props.contents.EnableFilterDesc = ct.cast(ct.pointer(filter_buf), ct.POINTER(ep.EVENT_FILTER_DESCRIPTOR))
        self._props.contents.FilterDescCount = len(event_filters) 

def ctypes2buffer(cptr, length):
    """Convert ctypes pointer to buffer type.

    Parameters
    ----------
    cptr : ctypes.POINTER(ctypes.c_char)
        Pointer to the raw memory region.
    length : int
        The length of the buffer.

    Returns
    -------
    buffer : bytearray
        The raw byte memory buffer.
    """
    if not isinstance(cptr, ctypes.POINTER(ctypes.c_char)):
        raise TypeError('expected char pointer')
    res = bytearray(length)
    rptr = (ctypes.c_char * length).from_buffer(res)
    if not ctypes.memmove(rptr, cptr, length):
        raise RuntimeError('memmove failed')
    return res 

def resize(self, size):
        array = (ctypes.c_byte * size)()
        ctypes.memmove(array, self.array, min(size, self.size))
        self.size = size
        self.array = array
        self.ptr = ctypes.cast(self.array, ctypes.c_void_p).value 

def write(self, audio_data, length=None):
        # Pass audio_data=None, length>0 to write silence
        if length is None:
            write_size = self.get_write_size()
            length = min(audio_data.length, write_size)
        if length == 0:
            return 0

        if self._data_size < self._buffer_size:
            self._data_size = min(self._data_size + length, self._buffer_size)

        p1 = ctypes.c_void_p()
        l1 = lib.DWORD()
        p2 = ctypes.c_void_p()
        l2 = lib.DWORD()
        self._buffer.Lock(self._write_cursor, length,
            ctypes.byref(p1), l1, ctypes.byref(p2), l2, 0)
        assert length == l1.value + l2.value

        if audio_data:
            if self._write_cursor >= self._play_cursor:
                wc = self._write_cursor
            else:
                wc = self._write_cursor + self._buffer_size
            self._timestamps.append((wc, audio_data.timestamp))

            ctypes.memmove(p1, audio_data.data, l1.value)
            audio_data.consume(l1.value, self.audio_format)
            if l2.value:
                ctypes.memmove(p2, audio_data.data, l2.value)
                audio_data.consume(l2.value, self.audio_format)
        else:
            ctypes.memset(p1, 0, l1.value)
            if l2.value:
                ctypes.memset(p2, 0, l2.value)
                pass
        self._buffer.Unlock(p1, l1, p2, l2)

        self._write_cursor += length
        self._write_cursor %= self._buffer_size 

def set_data(self, data):
        super(MappableVertexBufferObject, self).set_data(data)
        ctypes.memmove(self.data, data, self.size)
        self._dirty_min = 0
        self._dirty_max = self.size 

def set_data_region(self, data, start, length):
        ctypes.memmove(self.data_ptr + start, data, length)
        self._dirty_min = min(start, self._dirty_min)
        self._dirty_max = max(start + length, self._dirty_max) 

def resize(self, size):
        data = (ctypes.c_byte * size)()
        ctypes.memmove(data, self.data, min(size, self.size))
        self.data = data
        self.data_ptr = ctypes.cast(self.data, ctypes.c_void_p).value

        self.size = size
        glPushClientAttrib(GL_CLIENT_VERTEX_ARRAY_BIT)
        glBindBuffer(self.target, self.id)
        glBufferData(self.target, self.size, self.data, self.usage)
        glPopClientAttrib()

        self._dirty_min = sys.maxint
        self._dirty_max = 0 

def inet_ntop(address_family, packed_ip):
    addr = sockaddr()
    addr.sa_family = address_family
    addr_size = ctypes.c_int(ctypes.sizeof(addr))
    ip_string = ctypes.create_string_buffer(128)
    ip_string_size = ctypes.c_int(ctypes.sizeof(ip_string))

    if address_family == socket.AF_INET:
        if len(packed_ip) != ctypes.sizeof(addr.ipv4_addr):
            raise socket.error('packed IP wrong length for inet_ntoa')
        ctypes.memmove(addr.ipv4_addr, packed_ip, 4)
    elif address_family == socket.AF_INET6:
        if len(packed_ip) != ctypes.sizeof(addr.ipv6_addr):
            raise socket.error('packed IP wrong length for inet_ntoa')
        ctypes.memmove(addr.ipv6_addr, packed_ip, 16)
    else:
        raise socket.error('unknown address family')

    if WSAAddressToStringA(
            ctypes.byref(addr),
            addr_size,
            None,
            ip_string,
            ctypes.byref(ip_string_size)
    ) != 0:
        raise socket.error(ctypes.FormatError())

    return ip_string[:ip_string_size.value - 1]

# Adding our two functions to the socket library 

def get_string_data(self):
        '''Return data as a string.'''
        if type(self.data) is str:
            return self.data

        buf = ctypes.create_string_buffer(self.length)
        ctypes.memmove(buf, self.data, self.length)
        return buf.raw 

def __init__(self, packet):
        self.timestamp = packet.timestamp
        self.stream_index = packet.stream_index
        self.data = (ctypes.c_uint8 * packet.size)()
        self.size = packet.size
        ctypes.memmove(self.data, packet.data, self.size) 

def __init__(self, restype, argtypes, is_64_bit):                            
        # Load in kernel32.dll
        self.kernel32_dll = ctypes.WinDLL("C:\\Windows\\System32\\kernel32.dll")
        opc = self._OPC_64 if is_64_bit == True else self._OPC_32
        self.instructions = "".join((chr(x) for x in opc))
        self.buffer = self.kernel32_dll.VirtualAlloc(None, len(self.instructions),
            (self._MEM_COMMIT | self._MEM_RESERVE), self._PAGE_EXECUTE_READWRITE)
        ctypes.memmove(self.buffer, self.instructions, len(self.instructions))
        proto_func = ctypes.CFUNCTYPE(restype, *argtypes)
        self.cpuid = proto_func(self.buffer) 

def get_string_data(self):
        '''Return data as a string.'''
        if type(self.data) is str:
            return self.data

        buf = ctypes.create_string_buffer(self.length)
        ctypes.memmove(buf, self.data, self.length)
        return buf.raw 

def resize(self, size):
        data = (ctypes.c_byte * size)()
        ctypes.memmove(data, self.data, min(size, self.size))
        self.data = data
        self.data_ptr = ctypes.cast(self.data, ctypes.c_void_p).value

        self.size = size
        glPushClientAttrib(GL_CLIENT_VERTEX_ARRAY_BIT)
        glBindBuffer(self.target, self.id)
        glBufferData(self.target, self.size, self.data, self.usage)
        glPopClientAttrib()

        self._dirty_min = sys.maxint
        self._dirty_max = 0 

def inet_ntop(address_family, packed_ip):
    addr = sockaddr()
    addr.sa_family = address_family
    addr_size = ctypes.c_int(ctypes.sizeof(addr))
    ip_string = ctypes.create_string_buffer(128)
    ip_string_size = ctypes.c_int(ctypes.sizeof(ip_string))

    if address_family == socket.AF_INET:
        if len(packed_ip) != ctypes.sizeof(addr.ipv4_addr):
            raise socket.error('packed IP wrong length for inet_ntoa')
        ctypes.memmove(addr.ipv4_addr, packed_ip, 4)
    elif address_family == socket.AF_INET6:
        if len(packed_ip) != ctypes.sizeof(addr.ipv6_addr):
            raise socket.error('packed IP wrong length for inet_ntoa')
        ctypes.memmove(addr.ipv6_addr, packed_ip, 16)
    else:
        raise socket.error('unknown address family')

    if WSAAddressToStringA(
            ctypes.byref(addr),
            addr_size,
            None,
            ip_string,
            ctypes.byref(ip_string_size)
    ) != 0:
        raise socket.error(ctypes.FormatError())

    return ip_string[:ip_string_size.value - 1]

# Adding our two functions to the socket library 

def set_data_region(self, data, start, length):
        ctypes.memmove(self.ptr + start, data, length) 

def set_data(self, data):
        ctypes.memmove(self.ptr, data, self.size) 

def decode_32bit_rgb(bits, palette, width, height, pitch, pitch_sign):
    buffer = (ctypes.c_ubyte * (height * pitch))()
    ctypes.memmove(buffer, bits, len(buffer))
    return ImageData(width, height, 'BGRA', buffer, pitch_sign * pitch) 

def __capture(self, data, _sdr):
        timestamp = time.time()
        dst = ctypes.byref(self._capture, 0)
        ctypes.memmove(dst, data, len(data))

        iq = self.__stream_to_complex(self._capture)
        l, f = psd(iq, BINS, SAMPLE_RATE,
                   scale_by_freq=False,
                   noverlap=-SAMPLES / 64)
        f /= 1e6
        f += self._freq

        event = Event(Events.SCAN_DATA, timestamp=timestamp, l=l, f=f)
        post_event(self._eventHandler, event) 

def decode_24bit(bits, palette, width, height, pitch, pitch_sign):
    buffer = (ctypes.c_ubyte * (height * pitch))()
    ctypes.memmove(buffer, bits, len(buffer))
    return ImageData(width, height, 'BGR', buffer, pitch_sign * pitch) 

def __init__(self, packet):
        self.timestamp = packet.timestamp
        self.stream_index = packet.stream_index
        self.data = (ctypes.c_uint8 * packet.size)()
        self.size = packet.size
        ctypes.memmove(self.data, packet.data, self.size) 

def write(self, audio_data, length=None):
        # Pass audio_data=None, length>0 to write silence
        if length is None:
            write_size = self.get_write_size()
            length = min(audio_data.length, write_size)
        if length == 0:
            return 0

        if self._data_size < self._buffer_size:
            self._data_size = min(self._data_size + length, self._buffer_size)

        p1 = ctypes.c_void_p()
        l1 = lib.DWORD()
        p2 = ctypes.c_void_p()
        l2 = lib.DWORD()
        self._buffer.Lock(self._write_cursor, length,
            ctypes.byref(p1), l1, ctypes.byref(p2), l2, 0)
        assert length == l1.value + l2.value

        if audio_data:
            if self._write_cursor >= self._play_cursor:
                wc = self._write_cursor
            else:
                wc = self._write_cursor + self._buffer_size
            self._timestamps.append((wc, audio_data.timestamp))

            ctypes.memmove(p1, audio_data.data, l1.value)
            audio_data.consume(l1.value, self.audio_format)
            if l2.value:
                ctypes.memmove(p2, audio_data.data, l2.value)
                audio_data.consume(l2.value, self.audio_format)
        else:
            ctypes.memset(p1, 0, l1.value)
            if l2.value:
                ctypes.memset(p2, 0, l2.value)
                pass
        self._buffer.Unlock(p1, l1, p2, l2)

        self._write_cursor += length
        self._write_cursor %= self._buffer_size 

def get_string_data(self):
        '''Return data as a string.'''
        if type(self.data) is str:
            return self.data

        buf = ctypes.create_string_buffer(self.length)
        ctypes.memmove(buf, self.data, self.length)
        return buf.raw 

def test_cp34892(self):
        src = b''
        buf = ctypes.create_string_buffer(0)
        try:
            ctypes.memmove(ctypes.addressof(buf), src, 0)
        except Exception as ex:
            # there should be no exception of any kind
            self.fail("Unexpected exception: %s" % ex) 

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))