Python struct.calcsize函数代码示例

	def _callfunc(self, fid, argsfmt, args, retfmt):
		"""Call a function on the device by id, directly passing argument/return format parameters."""
		# Make a list out of the arguments if they are none
		#print('calling function No. {}, args({}) {}, returning {}'.format(fid, argsfmt, args, retfmt))
		if not (isinstance(args, tuple) or isinstance(args, list)):
			args = [args]
		with self._ser as s:
			# Send the encoded data
			cmd = b'\\#' + escape(struct.pack(">HHH", self.node_id, fid, struct.calcsize(argsfmt)) + struct.pack(argsfmt, *args))
			s.write(cmd)
			# payload length
			(clen,) = struct.unpack(">H", s.read(2))
			# payload data
			cbytes = s.read(clen)
			if clen != struct.calcsize(retfmt):
				# CAUTION! This error is thrown not because the user supplied a wrong value but because the device answered in an unexpected manner.
				# FIXME raise an error here or let the whole operation just fail in the following struct.unpack?
				raise AttributeError("Device response format problem: Length mismatch: {} != {}".format(clen, struct.calcsize(retfmt)))
			rv = struct.unpack(retfmt, cbytes)
			# Try to interpret the return value in a useful manner
			if len(rv) == 0:
				return None
			elif len(rv) == 1:
				return rv[0]
			else:
				return list(rv)

    def _parse_directional_spectrum(self, offset, rules):
        """
        Convert the binary data into particle data for the Directional Spectrum Data Type
        """
        # Unpack the unpacking rules
        (num_freq_name, num_dir_name, good_name, dat_name),\
        (num_freq_fmt, num_dir_fmt, good_fmt, dat_fmt) = zip(*rules)

        # First unpack the array lengths and single length values
        (num_freq_data, num_dir_data, dspec_good_data) = struct.unpack_from(
            '<%s%s%s' % (num_freq_fmt, num_dir_fmt, good_fmt), self.raw_data, offset)

        # Then unpack the array using the retrieved lengths values
        next_offset = offset + struct.calcsize(num_freq_fmt) + struct.calcsize(num_dir_fmt) + \
                      struct.calcsize(good_fmt)
        dspec_dat_list_data = struct.unpack_from(
            '<%s%s' % (num_freq_data * num_dir_data, dat_fmt), self.raw_data, next_offset)

        # convert to numpy array and reshape the data per IDD spec
        transformed_dat_data = numpy.array(dspec_dat_list_data).reshape(
            (num_freq_data, num_dir_data)).tolist()

        # Add to the collected parameter data
        self.final_result.extend(
            ({DataParticleKey.VALUE_ID: num_freq_name, DataParticleKey.VALUE: num_freq_data},
             {DataParticleKey.VALUE_ID: num_dir_name, DataParticleKey.VALUE: num_dir_data},
             {DataParticleKey.VALUE_ID: good_name, DataParticleKey.VALUE: dspec_good_data},
             {DataParticleKey.VALUE_ID: dat_name, DataParticleKey.VALUE: transformed_dat_data}))

    def _parse_values(self, offset, rules):
        """
        Convert the binary data into particle data for the given rules
        """
        position = offset

        # Iterate through the unpacking rules and append the retrieved values with its corresponding
        # particle name
        for key, formatter in rules:
            # Skip over spare values
            if AdcptMWVSParticleKey.SPARE in key:
                position += struct.calcsize(formatter)
                continue
            value = list(struct.unpack_from('<%s' % formatter, self.raw_data, position))
            # Support unpacking single values and lists
            if len(value) == 1:
                value = value[0]
            if AdcptMWVSParticleKey.START_TIME in key:
                timestamp = ((value[0]*100 + value[1]), value[2], value[3], value[4],
                             value[5], value[6], value[7], 0, 0)
                log.trace("TIMESTAMP: %s", timestamp)
                elapsed_seconds = calendar.timegm(timestamp)
                self.set_internal_timestamp(unix_time=elapsed_seconds)
            log.trace("DATA: %s:%s @ %s", key, value, position)
            position += struct.calcsize(formatter)
            self.final_result.append({DataParticleKey.VALUE_ID: key,
                                      DataParticleKey.VALUE: value})

  def old_obs_callback(self, data, sender=None):
    print "Received deprecated observation messages. Please update your Piksi."
    if (sender is not None and
        (self.relay ^ (sender == 0))):
      return

    hdr_fmt = "<dH"
    hdr_size = struct.calcsize(hdr_fmt)
    tow, wn = struct.unpack("<dH", data[:hdr_size])
    self.gps_tow = tow
    self.gps_week = wn
    self.t = datetime.datetime(1980, 1, 6) + \
             datetime.timedelta(weeks=self.gps_week) + \
             datetime.timedelta(seconds=self.gps_tow)

    # Observation message format
    # double P;      /**< Pseudorange (m) */
    # double L;      /**< Carrier-phase (cycles) */
    # float snr;     /**< Signal-to-Noise ratio */
    # u8 prn;        /**< Satellite number. */
    obs_fmt = '<ddfB'

    obs_size = struct.calcsize(obs_fmt)
    n_obs = (len(data) - hdr_size) / obs_size
    obs_data = data[hdr_size:]

    self.obs = {}
    for i in range(n_obs):
      P, L, snr, prn = struct.unpack(obs_fmt, obs_data[:obs_size])
      obs_data = obs_data[obs_size:]
      self.obs[prn] = (P, L, snr)

    self.update_obs()
    self.rinex_save()

    def _parse_sync_response(self, data):
        keyspecs = []
        nkeys = struct.unpack(">H", data[0: struct.calcsize("H")])[0]
        offset = struct.calcsize("H")
        for i in xrange(nkeys):
            spec = {}
            width = struct.calcsize("QHHB")
            spec['cas'], spec['vbucket'], keylen, eventid = struct.unpack(">QHHB", data[offset: offset + width])

            offset += width
            spec['key'] = data[offset: offset + keylen]
            offset += keylen

            if eventid == MemcachedConstants.CMD_SYNC_EVENT_PERSISTED:
                spec['event'] = 'persisted'
            elif eventid == MemcachedConstants.CMD_SYNC_EVENT_MODIFED:
                spec['event'] = 'modified'
            elif eventid == MemcachedConstants.CMD_SYNC_EVENT_DELETED:
                spec['event'] = 'deleted'
            elif eventid == MemcachedConstants.CMD_SYNC_EVENT_REPLICATED:
                spec['event'] = 'replicated'
            elif eventid == MemcachedConstants.CMD_SYNC_INVALID_KEY:
                spec['event'] = 'invalid key'
            elif spec['event'] == MemcachedConstants.CMD_SYNC_INVALID_CAS:
                spec['event'] = 'invalid cas'
            else:
                spec['event'] = eventid

            keyspecs.append(spec)
        return keyspecs

 def deserialize_numpy(self, str, numpy):
   """
   unpack serialized message in str into this message instance using numpy for array types
   :param str: byte array of serialized message, ``str``
   :param numpy: numpy python module
   """
   try:
     if self.timestamp is None:
       self.timestamp = genpy.Time()
     end = 0
     _x = self
     start = end
     end += 8
     (_x.timestamp.secs, _x.timestamp.nsecs,) = _struct_2I.unpack(str[start:end])
     start = end
     end += 4
     (length,) = _struct_I.unpack(str[start:end])
     pattern = '<%sd'%length
     start = end
     end += struct.calcsize(pattern)
     self.state = numpy.frombuffer(str[start:end], dtype=numpy.float64, count=length)
     start = end
     end += 4
     (length,) = _struct_I.unpack(str[start:end])
     pattern = '<%sd'%length
     start = end
     end += struct.calcsize(pattern)
     self.covariance = numpy.frombuffer(str[start:end], dtype=numpy.float64, count=length)
     self.timestamp.canon()
     return self
   except struct.error as e:
     raise genpy.DeserializationError(e) #most likely buffer underfill

 def __init__(self, idx, buf):
     self.inode_no = idx
     sb = buffer(bytearray(buf))
     sz = 0
     fmt = "<2H5I2H3I"
     (self.i_mode,
      self.i_uid,
      self.i_size,
      self.i_atime,
      self.i_ctime,
      self.i_mtime,
      self.i_dtime,
      self.i_gid,
      self.i_links_count,
      self.i_blocks,
      self.i_flags,
      self.i_osd1) = struct.unpack_from(fmt, sb, sz)
     sz += struct.calcsize(fmt)
     fmt = "<15I"
     self.i_block = struct.unpack_from(fmt, sb, sz)
     sz += struct.calcsize(fmt)
     fmt = "<4I12s"
     (self.i_gneration,
      self.i_file_acl,
      self.i_dir_acl,
      self.i_faddr,
      self.i_osd2) = struct.unpack_from(fmt, sb, sz)

 def deserialize_numpy(self, str, numpy):
     """
 unpack serialized message in str into this message instance using numpy for array types
 :param str: byte array of serialized message, ``str``
 :param numpy: numpy python module
 """
     try:
         if self.c is None:
             self.c = lab5_msgs.msg.ColorMsg()
         end = 0
         _x = self
         start = end
         end += 28
         (_x.c.r, _x.c.g, _x.c.b, _x.numVertices) = _struct_3qi.unpack(str[start:end])
         start = end
         end += 4
         (length,) = _struct_I.unpack(str[start:end])
         pattern = "<%sf" % length
         start = end
         end += struct.calcsize(pattern)
         self.x = numpy.frombuffer(str[start:end], dtype=numpy.float32, count=length)
         start = end
         end += 4
         (length,) = _struct_I.unpack(str[start:end])
         pattern = "<%sf" % length
         start = end
         end += struct.calcsize(pattern)
         self.y = numpy.frombuffer(str[start:end], dtype=numpy.float32, count=length)
         _x = self
         start = end
         end += 8
         (_x.closed, _x.filled) = _struct_2i.unpack(str[start:end])
         return self
     except struct.error as e:
         raise genpy.DeserializationError(e)  # most likely buffer underfill

 def deserialize(self, str):
     """
 unpack serialized message in str into this message instance
 :param str: byte array of serialized message, ``str``
 """
     try:
         if self.c is None:
             self.c = lab5_msgs.msg.ColorMsg()
         end = 0
         _x = self
         start = end
         end += 28
         (_x.c.r, _x.c.g, _x.c.b, _x.numVertices) = _struct_3qi.unpack(str[start:end])
         start = end
         end += 4
         (length,) = _struct_I.unpack(str[start:end])
         pattern = "<%sf" % length
         start = end
         end += struct.calcsize(pattern)
         self.x = struct.unpack(pattern, str[start:end])
         start = end
         end += 4
         (length,) = _struct_I.unpack(str[start:end])
         pattern = "<%sf" % length
         start = end
         end += struct.calcsize(pattern)
         self.y = struct.unpack(pattern, str[start:end])
         _x = self
         start = end
         end += 8
         (_x.closed, _x.filled) = _struct_2i.unpack(str[start:end])
         return self
     except struct.error as e:
         raise genpy.DeserializationError(e)  # most likely buffer underfill

 def deserialize(self, str):
   """
   unpack serialized message in str into this message instance
   :param str: byte array of serialized message, ``str``
   """
   try:
     if self.header is None:
       self.header = std_msgs.msg.Header()
     end = 0
     _x = self
     start = end
     end += 12
     (_x.header.seq, _x.header.stamp.secs, _x.header.stamp.nsecs,) = _struct_3I.unpack(str[start:end])
     start = end
     end += 4
     (length,) = _struct_I.unpack(str[start:end])
     start = end
     end += length
     if python3:
       self.header.frame_id = str[start:end].decode('utf-8')
     else:
       self.header.frame_id = str[start:end]
     start = end
     end += 4
     (length,) = _struct_I.unpack(str[start:end])
     pattern = '<%sd'%length
     start = end
     end += struct.calcsize(pattern)
     self.acceleration = struct.unpack(pattern, str[start:end])
     start = end
     end += 4
     (length,) = _struct_I.unpack(str[start:end])
     pattern = '<%sd'%length
     start = end
     end += struct.calcsize(pattern)
     self.orientation = struct.unpack(pattern, str[start:end])
     start = end
     end += 4
     (length,) = _struct_I.unpack(str[start:end])
     pattern = '<%sd'%length
     start = end
     end += struct.calcsize(pattern)
     self.angular = struct.unpack(pattern, str[start:end])
     start = end
     end += 4
     (length,) = _struct_I.unpack(str[start:end])
     pattern = '<%sd'%length
     start = end
     end += struct.calcsize(pattern)
     self.magnetic = struct.unpack(pattern, str[start:end])
     start = end
     end += 4
     (length,) = _struct_I.unpack(str[start:end])
     pattern = '<%sd'%length
     start = end
     end += struct.calcsize(pattern)
     self.timestamp = struct.unpack(pattern, str[start:end])
     return self
   except struct.error as e:
     raise genpy.DeserializationError(e) #most likely buffer underfill

def UnpackDEV_BROADCAST(lparam):
    # guard for 0 here, otherwise PyMakeBuffer will create a new buffer.
    if lparam == 0:
        return None
    hdr_size = struct.calcsize("iii")
    hdr_buf = win32gui.PyMakeBuffer(hdr_size, lparam)
    size, devtype, reserved = struct.unpack("iii", hdr_buf)
    rest = win32gui.PyMakeBuffer(size-hdr_size, lparam+hdr_size)

    extra = x = {}
    if devtype == win32con.DBT_DEVTYP_HANDLE:
        # 2 handles, a GUID, a LONG and possibly an array following...
        fmt = "PP16sl"
        x['handle'], x['hdevnotify'], guid_bytes, x['nameoffset'] = \
            struct.unpack(fmt, rest[:struct.calcsize(fmt)])
        x['eventguid'] = pywintypes.IID(guid_bytes, True)
    elif devtype == win32con.DBT_DEVTYP_DEVICEINTERFACE:
        # guid, null-terminated name
        x['classguid'] = pywintypes.IID(rest[:16], 1)
        name = rest[16:]
        if '\0' in name:
            name = name.split('\0', 1)[0]
        x['name'] = name
    elif devtype == win32con.DBT_DEVTYP_VOLUME:
        # int mask and flags
        x['unitmask'], x['flags'] = struct.unpack("II", rest[:struct.calcsize("II")])
    else:
        raise NotImplementedError("unknown device type %d" % (devtype,))
    return DEV_BROADCAST_INFO(devtype, **extra)

 def shake_hand(self, size=0, action="receive"):
     hi_msg_len = struct.calcsize(self.hi_format)
     ack_msg_len = struct.calcsize(self.ack_format)
     if action == "send":
         self.send(self.hi_msg)
         txt = self.receive(hi_msg_len)
         out = struct.unpack(self.hi_format, txt)[0]
         if out != "HI":
             raise ShakeHandError("Fail to get HI from guest.")
         size_s = struct.pack("q", size)
         self.send(size_s)
         txt = self.receive(ack_msg_len)
         ack_str = struct.unpack(self.ack_format, txt)[0]
         if ack_str != self.ack_msg:
             raise "Guest did not ACK the file size message."
         return size
     elif action == "receive":
         txt = self.receive(hi_msg_len)
         hi_str = struct.unpack(self.hi_format, txt)[0]
         if hi_str != self.hi_msg:
             raise ShakeHandError("Fail to get HI from guest.")
         self.send(txt)
         size = self.receive(8)
         print("xxxx size = %s" % size)
         if size:
             size = struct.unpack("q", size)[0]
             txt = struct.pack(self.ack_format, self.ack_msg)
             self.send(txt)
         return size

def ReadRecord(d, offset=0x0):
    id = d[0]
    d=d[1:] # Eat id
    if id == 0xff or id == 0x4: # Normal end of Data
        return id, None, None
    sztotal = 1 
    assert RecPack.has_key(id), "Unknown record ID %i at offset %i" % (id, offset)
    if RecRepeat.has_key(id):
        sz = struct.calcsize(RecPack[id])
        init=struct.unpack_from(RecRepeat[id][1], d)
        szinit=struct.calcsize(RecRepeat[id][1])
        d=d[szinit:]
        sztotal += szinit
        res=[]
        for i in range(0, RecRepeat[id][0]):
            res.append(struct.unpack_from(RecPack[id], d))
            d=d[sz:]
            sztotal += sz
    elif type(RecPack[id]) == str:
        sz = struct.calcsize(RecPack[id])
        res = struct.unpack_from(RecPack[id], d)
        sztotal += sz
    elif type(RecPack[id]) == int: # 12-bit field array
        # A padding byte 0xFF may be present
        sz = RecPack[id] - 1
        res = ReadPacked12Bit(d[:sz])
        sztotal += sz
    return id, sztotal, res

def PrintRecords(labels, s4, fmtHead, fmtTail="", printHex=True, printNorm=True):
    fmt = fmtHead
    szHead = struct.calcsize(fmtHead)
    szTail = struct.calcsize(fmtTail)
    printableHead = string.join([x for x in fmtHead if fmtmap.has_key(x)],"")
    printableTail = string.join([x for x in fmtTail if fmtmap.has_key(x)],"")
    if fmtTail != "":
        gap = len(s4[0]) - (struct.calcsize(fmtHead) + struct.calcsize(fmtTail))
        fmt = fmtHead + ("x"*gap) + fmtTail
    labels = ["LINE"] + labels[:len(printableHead)] + labels[len(labels)-len(printableTail):]
    PrintMultiLineLabels(labels,6)
    sys.stdout.write(6*" ")
    PrintByteLabels(fmt, len(s4))
    for i in range(0, len(s4)):
        if printNorm:
            sys.stdout.write("%5i:%s\n" % (i, StructToString(s4[i], fmt, 6)))
        if printHex:
            sys.stdout.write("\33[0m")
            sys.stdout.write("            %s\n" % (StructToString(s4[i], fmt, 6, color=False, hexonly=True)))
        if not ((i+1) % 40) or (i == len(s4) - 1):
            PrintMultiLineLabels(labels,6)
            sys.stdout.write(6*" ")
            PrintByteLabels(fmt, len(s4))
        #HexPrintMod(s4[i][:szHead].tostring() + s4[i][len(s4[i]) - szTail:].tostring(), szHead + szTail)
    PrintByteStats(s4, fmt)

 def deserialize(self, str):
   """
   unpack serialized message in str into this message instance
   :param str: byte array of serialized message, ``str``
   """
   try:
     end = 0
     start = end
     end += 4
     (length,) = _struct_I.unpack(str[start:end])
     pattern = '<%si'%length
     start = end
     end += struct.calcsize(pattern)
     self.handles = struct.unpack(pattern, str[start:end])
     start = end
     end += 4
     (length,) = _struct_I.unpack(str[start:end])
     start = end
     end += length
     if python3:
       self.setModes = str[start:end].decode('utf-8')
     else:
       self.setModes = str[start:end]
     start = end
     end += 4
     (length,) = _struct_I.unpack(str[start:end])
     pattern = '<%sf'%length
     start = end
     end += struct.calcsize(pattern)
     self.values = struct.unpack(pattern, str[start:end])
     return self
   except struct.error as e:
     raise genpy.DeserializationError(e) #most likely buffer underfill