bindings/python/sigrok/core/classes.py

   1 ##
   2 ## This file is part of the libsigrok project.
   3 ##
   4 ## Copyright (C) 2013 Martin Ling <martin-sigrok@earth.li>
   5 ##
   6 ## This program is free software: you can redistribute it and/or modify
   7 ## it under the terms of the GNU General Public License as published by
   8 ## the Free Software Foundation, either version 3 of the License, or
   9 ## (at your option) any later version.
  10 ##
  11 ## This program is distributed in the hope that it will be useful,
  12 ## but WITHOUT ANY WARRANTY; without even the implied warranty of
  13 ## MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  14 ## GNU General Public License for more details.
  15 ##
  16 ## You should have received a copy of the GNU General Public License
  17 ## along with this program.  If not, see <http://www.gnu.org/licenses/>.
  18 ##
  19
  20 from functools import partial
  21 from fractions import Fraction
  22 from .lowlevel import *
  23 from . import lowlevel
  24 import itertools
  25
  26 __all__ = ['Error', 'Context', 'Driver', 'Device', 'Session', 'Packet', 'Log',
  27     'LogLevel', 'PacketType', 'Quantity', 'Unit', 'QuantityFlag']
  28
  29 class Error(Exception):
  30
  31     def __str__(self):
  32         return sr_strerror(self.args[0])
  33
  34 def check(result):
  35     if result != SR_OK:
  36         raise Error(result)
  37
  38 def config_key(name):
  39     if not name.lower() == name:
  40         raise AttributeError
  41     key_name = "SR_CONF_" + name.upper()
  42     return getattr(lowlevel, key_name)
  43
  44 def gvariant_to_python(value):
  45     type_string = g_variant_get_type_string(value)
  46     if type_string == 't':
  47         return g_variant_get_uint64(value)
  48     if type_string == 'b':
  49         return g_variant_get_bool(value)
  50     if type_string == 'd':
  51         return g_variant_get_double(value)
  52     if type_string == 's':
  53         return g_variant_get_string(value, None)
  54     if type_string == '(tt)':
  55         return Fraction(
  56             g_variant_get_uint64(g_variant_get_child_value(value, 0)),
  57             g_variant_get_uint64(g_variant_get_child_value(value, 1)))
  58     raise NotImplementedError(
  59         "Can't convert GVariant type '%s' to a Python type." % type_string)
  60
  61 def python_to_gvariant(value):
  62     if isinstance(value, int):
  63         return g_variant_new_uint64(value)
  64     if isinstance(value, bool):
  65         return g_variant_new_boolean(value)
  66     if isinstance(value, float):
  67         return g_variant_new_double(value)
  68     if isinstance(value, str):
  69         return g_variant_new_string(value)
  70     if isinstance(value, Fraction):
  71         array = new_gvariant_ptr_array(2)
  72         gvariant_ptr_array_setitem(array, 0,
  73             g_variant_new_uint64(value.numerator))
  74         gvariant_ptr_array_setitem(array, 1,
  75             g_variant_new_uint64(value.denominator))
  76         result = g_variant_new_tuple(array, 2)
  77         delete_gvariant_ptr_array(array)
  78         return result
  79     raise NotImplementedError(
  80         "Can't convert Python '%s' to a GVariant." % type(value))
  81
  82 def callback_wrapper(session, callback, device_ptr, packet_ptr):
  83     device = session.context._devices[int(device_ptr.this)]
  84     packet = Packet(session, packet_ptr)
  85     callback(device, packet)
  86
  87 class Context(object):
  88
  89     def __init__(self):
  90         context_ptr_ptr = new_sr_context_ptr_ptr()
  91         check(sr_init(context_ptr_ptr))
  92         self.struct = sr_context_ptr_ptr_value(context_ptr_ptr)
  93         self._drivers = None
  94         self._devices = {}
  95         self.session = None
  96
  97     def __del__(self):
  98         sr_exit(self.struct)
  99
 100     @property
 101     def drivers(self):
 102         if not self._drivers:
 103             self._drivers = {}
 104             driver_list = sr_driver_list()
 105             for i in itertools.count():
 106                 driver_ptr = sr_dev_driver_ptr_array_getitem(driver_list, i)
 107                 if driver_ptr:
 108                     self._drivers[driver_ptr.name] = Driver(self, driver_ptr)
 109                 else:
 110                     break
 111         return self._drivers
 112
 113 class Driver(object):
 114
 115     def __init__(self, context, struct):
 116         self.context = context
 117         self.struct = struct
 118         self._initialized = False
 119
 120     @property
 121     def name(self):
 122         return self.struct.name
 123
 124     def scan(self):
 125         if not self._initialized:
 126             check(sr_driver_init(self.context.struct, self.struct))
 127             self._initialized = True
 128         device_list = sr_driver_scan(self.struct, None)
 129         devices = [Device(self, gpointer_to_sr_dev_inst_ptr(ptr))
 130             for ptr in gslist_to_python(device_list)]
 131         g_slist_free(device_list)
 132         return devices
 133
 134 class Device(object):
 135
 136     def __new__(cls, driver, struct):
 137         address = int(struct.this)
 138         if address not in driver.context._devices:
 139             device = super(Device, cls).__new__(cls, driver, struct)
 140             driver.context._devices[address] = device
 141         return driver.context._devices[address]
 142
 143     def __init__(self, driver, struct):
 144         self.driver = driver
 145         self.struct = struct
 146
 147     def __getattr__(self, name):
 148         key = config_key(name)
 149         data = new_gvariant_ptr_ptr()
 150         try:
 151             check(sr_config_get(self.driver.struct, key, data, self.struct))
 152         except Error as error:
 153             if error.errno == SR_ERR_NA:
 154                 raise NotImplementedError(
 155                     "Device does not implement %s" % name)
 156             else:
 157                 raise AttributeError
 158         value = gvariant_ptr_ptr_value(data)
 159         return gvariant_to_python(value)
 160
 161     def __setattr__(self, name, value):
 162         try:
 163             key = config_key(name)
 164         except AttributeError:
 165             super(Device, self).__setattr__(name, value)
 166             return
 167         check(sr_config_set(self.struct, key, python_to_gvariant(value)))
 168
 169     @property
 170     def vendor(self):
 171         return self.struct.vendor
 172
 173     @property
 174     def model(self):
 175         return self.struct.model
 176
 177     @property
 178     def version(self):
 179         return self.struct.version
 180
 181 class Session(object):
 182
 183     def __init__(self, context):
 184         assert context.session is None
 185         self.context = context
 186         self.struct = sr_session_new()
 187         context.session = self
 188
 189     def __del__(self):
 190         check(sr_session_destroy())
 191
 192     def add_device(self, device):
 193         check(sr_session_dev_add(device.struct))
 194
 195     def add_callback(self, callback):
 196         wrapper = partial(callback_wrapper, self, callback)
 197         check(sr_session_datafeed_python_callback_add(wrapper))
 198
 199     def start(self):
 200         check(sr_session_start())
 201
 202     def run(self):
 203         check(sr_session_run())
 204
 205     def stop(self):
 206         check(sr_session_stop())
 207
 208 class Packet(object):
 209
 210     def __init__(self, session, struct):
 211         self.session = session
 212         self.struct = struct
 213         self._payload = None
 214
 215     @property
 216     def type(self):
 217         return PacketType(self.struct.type)
 218
 219     @property
 220     def payload(self):
 221         if self._payload is None:
 222             pointer = self.struct.payload
 223             if self.type == PacketType.LOGIC:
 224                 self._payload = Logic(self,
 225                     void_ptr_to_sr_datafeed_logic_ptr(pointer))
 226             elif self.type == PacketType.ANALOG:
 227                 self._payload = Analog(self,
 228                     void_ptr_to_sr_datafeed_analog_ptr(pointer))
 229             else:
 230                 raise NotImplementedError(
 231                     "No Python mapping for packet type %ѕ" % self.struct.type)
 232         return self._payload
 233
 234 class Logic(object):
 235
 236     def __init__(self, packet, struct):
 237         self.packet = packet
 238         self.struct = struct
 239         self._data = None
 240
 241     @property
 242     def data(self):
 243         if self._data is None:
 244             self._data = cdata(self.struct.data, self.struct.length)
 245         return self._data
 246
 247 class Analog(object):
 248
 249     def __init__(self, packet, struct):
 250         self.packet = packet
 251         self.struct = struct
 252         self._data = None
 253
 254     @property
 255     def num_samples(self):
 256         return self.struct.num_samples
 257
 258     @property
 259     def mq(self):
 260         return Quantity(self.struct.mq)
 261
 262     @property
 263     def unit(self):
 264         return Unit(self.struct.unit)
 265
 266     @property
 267     def mqflags(self):
 268         return QuantityFlag.set_from_mask(self.struct.mqflags)
 269
 270     @property
 271     def data(self):
 272         if self._data is None:
 273             self._data = float_array.frompointer(self.struct.data)
 274         return self._data
 275
 276 class Log(object):
 277
 278     @property
 279     def level(self):
 280         return LogLevel(sr_log_loglevel_get())
 281
 282     @level.setter
 283     def level(self, l):
 284         check(sr_log_loglevel_set(l.id))
 285
 286     @property
 287     def domain(self):
 288         return sr_log_logdomain_get()
 289
 290     @domain.setter
 291     def domain(self, d):
 292         check(sr_log_logdomain_set(d))
 293
 294 class EnumValue(object):
 295
 296     _enum_values = {}
 297
 298     def __new__(cls, id):
 299         if cls not in cls._enum_values:
 300             cls._enum_values[cls] = {}
 301         if id not in cls._enum_values[cls]:
 302             value = super(EnumValue, cls).__new__(cls)
 303             value.id = id
 304             cls._enum_values[cls][id] = value
 305         return cls._enum_values[cls][id]
 306
 307 class LogLevel(EnumValue):
 308     pass
 309
 310 class PacketType(EnumValue):
 311     pass
 312
 313 class Quantity(EnumValue):
 314     pass
 315
 316 class Unit(EnumValue):
 317     pass
 318
 319 class QuantityFlag(EnumValue):
 320
 321     @classmethod
 322     def set_from_mask(cls, mask):
 323         result = set()
 324         while mask:
 325             new_mask = mask & (mask - 1)
 326             result.add(cls(mask ^ new_mask))
 327             mask = new_mask
 328         return result
 329
 330 for symbol_name in dir(lowlevel):
 331     for prefix, cls in [
 332         ('SR_LOG_', LogLevel),
 333         ('SR_DF_', PacketType),
 334         ('SR_MQ_', Quantity),
 335         ('SR_UNIT_', Unit),
 336         ('SR_MQFLAG_', QuantityFlag)]:
 337         if symbol_name.startswith(prefix):
 338             name = symbol_name[len(prefix):]
 339             value = getattr(lowlevel, symbol_name)
 340             setattr(cls, name, cls(value))