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', 'ConfigKey']
  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 gvariant_to_python(value):
  39     type_string = g_variant_get_type_string(value)
  40     if type_string == 't':
  41         return g_variant_get_uint64(value)
  42     if type_string == 'b':
  43         return g_variant_get_bool(value)
  44     if type_string == 'd':
  45         return g_variant_get_double(value)
  46     if type_string == 's':
  47         return g_variant_get_string(value, None)
  48     if type_string == '(tt)':
  49         return Fraction(
  50             g_variant_get_uint64(g_variant_get_child_value(value, 0)),
  51             g_variant_get_uint64(g_variant_get_child_value(value, 1)))
  52     raise NotImplementedError(
  53         "Can't convert GVariant type '%s' to a Python type." % type_string)
  54
  55 def python_to_gvariant(value):
  56     if isinstance(value, int):
  57         return g_variant_new_uint64(value)
  58     if isinstance(value, bool):
  59         return g_variant_new_boolean(value)
  60     if isinstance(value, float):
  61         return g_variant_new_double(value)
  62     if isinstance(value, str):
  63         return g_variant_new_string(value)
  64     if isinstance(value, Fraction):
  65         array = new_gvariant_ptr_array(2)
  66         gvariant_ptr_array_setitem(array, 0,
  67             g_variant_new_uint64(value.numerator))
  68         gvariant_ptr_array_setitem(array, 1,
  69             g_variant_new_uint64(value.denominator))
  70         result = g_variant_new_tuple(array, 2)
  71         delete_gvariant_ptr_array(array)
  72         return result
  73     raise NotImplementedError(
  74         "Can't convert Python '%s' to a GVariant." % type(value))
  75
  76 def callback_wrapper(session, callback, device_ptr, packet_ptr):
  77     device = session.context._devices[int(device_ptr.this)]
  78     packet = Packet(session, packet_ptr)
  79     callback(device, packet)
  80
  81 class Context(object):
  82
  83     def __init__(self):
  84         context_ptr_ptr = new_sr_context_ptr_ptr()
  85         check(sr_init(context_ptr_ptr))
  86         self.struct = sr_context_ptr_ptr_value(context_ptr_ptr)
  87         self._drivers = None
  88         self._devices = {}
  89         self.session = None
  90
  91     def __del__(self):
  92         sr_exit(self.struct)
  93
  94     @property
  95     def drivers(self):
  96         if not self._drivers:
  97             self._drivers = {}
  98             driver_list = sr_driver_list()
  99             for i in itertools.count():
 100                 driver_ptr = sr_dev_driver_ptr_array_getitem(driver_list, i)
 101                 if driver_ptr:
 102                     self._drivers[driver_ptr.name] = Driver(self, driver_ptr)
 103                 else:
 104                     break
 105         return self._drivers
 106
 107 class Driver(object):
 108
 109     def __init__(self, context, struct):
 110         self.context = context
 111         self.struct = struct
 112         self._initialized = False
 113
 114     @property
 115     def name(self):
 116         return self.struct.name
 117
 118     def scan(self, **kwargs):
 119         if not self._initialized:
 120             check(sr_driver_init(self.context.struct, self.struct))
 121             self._initialized = True
 122         options = []
 123         for name, value in kwargs.items():
 124             key = getattr(ConfigKey, name.upper())
 125             src = sr_config()
 126             src.key = key.id
 127             src.data = python_to_gvariant(value)
 128             options.append(src.this)
 129         option_list = python_to_gslist(options)
 130         device_list = sr_driver_scan(self.struct, option_list)
 131         g_slist_free(option_list)
 132         devices = [Device(self, gpointer_to_sr_dev_inst_ptr(ptr))
 133             for ptr in gslist_to_python(device_list)]
 134         g_slist_free(device_list)
 135         return devices
 136
 137 class Device(object):
 138
 139     def __new__(cls, driver, struct):
 140         address = int(struct.this)
 141         if address not in driver.context._devices:
 142             device = super(Device, cls).__new__(cls, driver, struct)
 143             driver.context._devices[address] = device
 144         return driver.context._devices[address]
 145
 146     def __init__(self, driver, struct):
 147         self.driver = driver
 148         self.struct = struct
 149
 150     def __getattr__(self, name):
 151         key = getattr(ConfigKey, name.upper())
 152         data = new_gvariant_ptr_ptr()
 153         try:
 154             check(sr_config_get(self.driver.struct, self.struct, None,
 155                 key, data))
 156         except Error as error:
 157             if error.errno == SR_ERR_NA:
 158                 raise NotImplementedError(
 159                     "Device does not implement %s" % name)
 160             else:
 161                 raise AttributeError
 162         value = gvariant_ptr_ptr_value(data)
 163         return gvariant_to_python(value)
 164
 165     def __setattr__(self, name, value):
 166         try:
 167             key = getattr(ConfigKey, name.upper())
 168         except AttributeError:
 169             super(Device, self).__setattr__(name, value)
 170             return
 171         check(sr_config_set(self.struct, None, key, python_to_gvariant(value)))
 172
 173     @property
 174     def vendor(self):
 175         return self.struct.vendor
 176
 177     @property
 178     def model(self):
 179         return self.struct.model
 180
 181     @property
 182     def version(self):
 183         return self.struct.version
 184
 185 class Session(object):
 186
 187     def __init__(self, context):
 188         assert context.session is None
 189         self.context = context
 190         self.struct = sr_session_new()
 191         context.session = self
 192
 193     def __del__(self):
 194         check(sr_session_destroy())
 195
 196     def add_device(self, device):
 197         check(sr_session_dev_add(device.struct))
 198
 199     def open_device(self, device):
 200         check(sr_dev_open(device.struct))
 201
 202     def add_callback(self, callback):
 203         wrapper = partial(callback_wrapper, self, callback)
 204         check(sr_session_datafeed_python_callback_add(wrapper))
 205
 206     def start(self):
 207         check(sr_session_start())
 208
 209     def run(self):
 210         check(sr_session_run())
 211
 212     def stop(self):
 213         check(sr_session_stop())
 214
 215 class Packet(object):
 216
 217     def __init__(self, session, struct):
 218         self.session = session
 219         self.struct = struct
 220         self._payload = None
 221
 222     @property
 223     def type(self):
 224         return PacketType(self.struct.type)
 225
 226     @property
 227     def payload(self):
 228         if self._payload is None:
 229             pointer = self.struct.payload
 230             if self.type == PacketType.LOGIC:
 231                 self._payload = Logic(self,
 232                     void_ptr_to_sr_datafeed_logic_ptr(pointer))
 233             elif self.type == PacketType.ANALOG:
 234                 self._payload = Analog(self,
 235                     void_ptr_to_sr_datafeed_analog_ptr(pointer))
 236             else:
 237                 raise NotImplementedError(
 238                     "No Python mapping for packet type %ѕ" % self.struct.type)
 239         return self._payload
 240
 241 class Logic(object):
 242
 243     def __init__(self, packet, struct):
 244         self.packet = packet
 245         self.struct = struct
 246         self._data = None
 247
 248     @property
 249     def data(self):
 250         if self._data is None:
 251             self._data = cdata(self.struct.data, self.struct.length)
 252         return self._data
 253
 254 class Analog(object):
 255
 256     def __init__(self, packet, struct):
 257         self.packet = packet
 258         self.struct = struct
 259         self._data = None
 260
 261     @property
 262     def num_samples(self):
 263         return self.struct.num_samples
 264
 265     @property
 266     def mq(self):
 267         return Quantity(self.struct.mq)
 268
 269     @property
 270     def unit(self):
 271         return Unit(self.struct.unit)
 272
 273     @property
 274     def mqflags(self):
 275         return QuantityFlag.set_from_mask(self.struct.mqflags)
 276
 277     @property
 278     def data(self):
 279         if self._data is None:
 280             self._data = float_array.frompointer(self.struct.data)
 281         return self._data
 282
 283 class Log(object):
 284
 285     @property
 286     def level(self):
 287         return LogLevel(sr_log_loglevel_get())
 288
 289     @level.setter
 290     def level(self, l):
 291         check(sr_log_loglevel_set(l.id))
 292
 293     @property
 294     def domain(self):
 295         return sr_log_logdomain_get()
 296
 297     @domain.setter
 298     def domain(self, d):
 299         check(sr_log_logdomain_set(d))
 300
 301 class EnumValue(object):
 302
 303     _enum_values = {}
 304
 305     def __new__(cls, id):
 306         if cls not in cls._enum_values:
 307             cls._enum_values[cls] = {}
 308         if id not in cls._enum_values[cls]:
 309             value = super(EnumValue, cls).__new__(cls)
 310             value.id = id
 311             cls._enum_values[cls][id] = value
 312         return cls._enum_values[cls][id]
 313
 314 class LogLevel(EnumValue):
 315     pass
 316
 317 class PacketType(EnumValue):
 318     pass
 319
 320 class Quantity(EnumValue):
 321     pass
 322
 323 class Unit(EnumValue):
 324     pass
 325
 326 class QuantityFlag(EnumValue):
 327
 328     @classmethod
 329     def set_from_mask(cls, mask):
 330         result = set()
 331         while mask:
 332             new_mask = mask & (mask - 1)
 333             result.add(cls(mask ^ new_mask))
 334             mask = new_mask
 335         return result
 336
 337 class ConfigKey(EnumValue):
 338     pass
 339
 340 for symbol_name in dir(lowlevel):
 341     for prefix, cls in [
 342         ('SR_LOG_', LogLevel),
 343         ('SR_DF_', PacketType),
 344         ('SR_MQ_', Quantity),
 345         ('SR_UNIT_', Unit),
 346         ('SR_MQFLAG_', QuantityFlag),
 347         ('SR_CONF_', ConfigKey)]:
 348         if symbol_name.startswith(prefix):
 349             name = symbol_name[len(prefix):]
 350             value = getattr(lowlevel, symbol_name)
 351             setattr(cls, name, cls(value))