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,
 155                 key.id, data, self.struct))
 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,
 172             key.id, python_to_gvariant(value)))
 173
 174     @property
 175     def vendor(self):
 176         return self.struct.vendor
 177
 178     @property
 179     def model(self):
 180         return self.struct.model
 181
 182     @property
 183     def version(self):
 184         return self.struct.version
 185
 186 class Session(object):
 187
 188     def __init__(self, context):
 189         assert context.session is None
 190         self.context = context
 191         self.struct = sr_session_new()
 192         context.session = self
 193
 194     def __del__(self):
 195         check(sr_session_destroy())
 196
 197     def add_device(self, device):
 198         check(sr_session_dev_add(device.struct))
 199
 200     def open_device(self, device):
 201         check(sr_dev_open(device.struct))
 202
 203     def add_callback(self, callback):
 204         wrapper = partial(callback_wrapper, self, callback)
 205         check(sr_session_datafeed_python_callback_add(wrapper))
 206
 207     def start(self):
 208         check(sr_session_start())
 209
 210     def run(self):
 211         check(sr_session_run())
 212
 213     def stop(self):
 214         check(sr_session_stop())
 215
 216 class Packet(object):
 217
 218     def __init__(self, session, struct):
 219         self.session = session
 220         self.struct = struct
 221         self._payload = None
 222
 223     @property
 224     def type(self):
 225         return PacketType(self.struct.type)
 226
 227     @property
 228     def payload(self):
 229         if self._payload is None:
 230             pointer = self.struct.payload
 231             if self.type == PacketType.LOGIC:
 232                 self._payload = Logic(self,
 233                     void_ptr_to_sr_datafeed_logic_ptr(pointer))
 234             elif self.type == PacketType.ANALOG:
 235                 self._payload = Analog(self,
 236                     void_ptr_to_sr_datafeed_analog_ptr(pointer))
 237             else:
 238                 raise NotImplementedError(
 239                     "No Python mapping for packet type %ѕ" % self.struct.type)
 240         return self._payload
 241
 242 class Logic(object):
 243
 244     def __init__(self, packet, struct):
 245         self.packet = packet
 246         self.struct = struct
 247         self._data = None
 248
 249     @property
 250     def data(self):
 251         if self._data is None:
 252             self._data = cdata(self.struct.data, self.struct.length)
 253         return self._data
 254
 255 class Analog(object):
 256
 257     def __init__(self, packet, struct):
 258         self.packet = packet
 259         self.struct = struct
 260         self._data = None
 261
 262     @property
 263     def num_samples(self):
 264         return self.struct.num_samples
 265
 266     @property
 267     def mq(self):
 268         return Quantity(self.struct.mq)
 269
 270     @property
 271     def unit(self):
 272         return Unit(self.struct.unit)
 273
 274     @property
 275     def mqflags(self):
 276         return QuantityFlag.set_from_mask(self.struct.mqflags)
 277
 278     @property
 279     def data(self):
 280         if self._data is None:
 281             self._data = float_array.frompointer(self.struct.data)
 282         return self._data
 283
 284 class Log(object):
 285
 286     @property
 287     def level(self):
 288         return LogLevel(sr_log_loglevel_get())
 289
 290     @level.setter
 291     def level(self, l):
 292         check(sr_log_loglevel_set(l.id))
 293
 294     @property
 295     def domain(self):
 296         return sr_log_logdomain_get()
 297
 298     @domain.setter
 299     def domain(self, d):
 300         check(sr_log_logdomain_set(d))
 301
 302 class EnumValue(object):
 303
 304     _enum_values = {}
 305
 306     def __new__(cls, id):
 307         if cls not in cls._enum_values:
 308             cls._enum_values[cls] = {}
 309         if id not in cls._enum_values[cls]:
 310             value = super(EnumValue, cls).__new__(cls)
 311             value.id = id
 312             cls._enum_values[cls][id] = value
 313         return cls._enum_values[cls][id]
 314
 315 class LogLevel(EnumValue):
 316     pass
 317
 318 class PacketType(EnumValue):
 319     pass
 320
 321 class Quantity(EnumValue):
 322     pass
 323
 324 class Unit(EnumValue):
 325     pass
 326
 327 class QuantityFlag(EnumValue):
 328
 329     @classmethod
 330     def set_from_mask(cls, mask):
 331         result = set()
 332         while mask:
 333             new_mask = mask & (mask - 1)
 334             result.add(cls(mask ^ new_mask))
 335             mask = new_mask
 336         return result
 337
 338 class ConfigKey(EnumValue):
 339     pass
 340
 341 for symbol_name in dir(lowlevel):
 342     for prefix, cls in [
 343         ('SR_LOG_', LogLevel),
 344         ('SR_DF_', PacketType),
 345         ('SR_MQ_', Quantity),
 346         ('SR_UNIT_', Unit),
 347         ('SR_MQFLAG_', QuantityFlag),
 348         ('SR_CONF_', ConfigKey)]:
 349         if symbol_name.startswith(prefix):
 350             name = symbol_name[len(prefix):]
 351             value = getattr(lowlevel, symbol_name)
 352             setattr(cls, name, cls(value))