src/bindings/python/bt2/bt2/field.py

   1 # The MIT License (MIT)
   2 #
   3 # Copyright (c) 2017 Philippe Proulx <pproulx@efficios.com>
   4 #
   5 # Permission is hereby granted, free of charge, to any person obtaining a copy
   6 # of this software and associated documentation files (the "Software"), to deal
   7 # in the Software without restriction, including without limitation the rights
   8 # to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
   9 # copies of the Software, and to permit persons to whom the Software is
  10 # furnished to do so, subject to the following conditions:
  11 #
  12 # The above copyright notice and this permission notice shall be included in
  13 # all copies or substantial portions of the Software.
  14 #
  15 # THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
  16 # IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
  17 # FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
  18 # AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
  19 # LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
  20 # OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
  21 # THE SOFTWARE.
  22
  23 from bt2 import native_bt, object, utils
  24 from bt2 import field_class as bt2_field_class
  25 import collections.abc
  26 import functools
  27 import numbers
  28 import math
  29
  30
  31 def _create_field_from_ptr(ptr, owner_ptr, owner_get_ref, owner_put_ref):
  32     field_class_ptr = native_bt.field_borrow_class_const(ptr)
  33     typeid = native_bt.field_class_get_type(field_class_ptr)
  34     field = _TYPE_ID_TO_OBJ[typeid]._create_from_ptr_and_get_ref(
  35         ptr, owner_ptr, owner_get_ref, owner_put_ref
  36     )
  37     return field
  38
  39
  40 # Get the "effective" field of `field`.  If `field` is a variant, return the
  41 # currently selected field.  If `field` is of any other type, return `field`
  42 # directly.
  43
  44
  45 def _get_leaf_field(field):
  46     if not isinstance(field, _VariantField):
  47         return field
  48
  49     return _get_leaf_field(field.selected_option)
  50
  51
  52 class _Field(object._UniqueObject):
  53     def __eq__(self, other):
  54         other = _get_leaf_field(other)
  55         return self._spec_eq(other)
  56
  57     @property
  58     def field_class(self):
  59         field_class_ptr = native_bt.field_borrow_class_const(self._ptr)
  60         assert field_class_ptr is not None
  61         return bt2_field_class._create_field_class_from_ptr_and_get_ref(field_class_ptr)
  62
  63     def _repr(self):
  64         raise NotImplementedError
  65
  66     def __repr__(self):
  67         return self._repr()
  68
  69
  70 @functools.total_ordering
  71 class _NumericField(_Field):
  72     @staticmethod
  73     def _extract_value(other):
  74         if isinstance(other, bool):
  75             return other
  76
  77         if isinstance(other, numbers.Integral):
  78             return int(other)
  79
  80         if isinstance(other, numbers.Real):
  81             return float(other)
  82
  83         if isinstance(other, numbers.Complex):
  84             return complex(other)
  85
  86         raise TypeError(
  87             "'{}' object is not a number object".format(other.__class__.__name__)
  88         )
  89
  90     def __int__(self):
  91         return int(self._value)
  92
  93     def __float__(self):
  94         return float(self._value)
  95
  96     def _repr(self):
  97         return repr(self._value)
  98
  99     def __lt__(self, other):
 100         if not isinstance(other, numbers.Number):
 101             raise TypeError(
 102                 'unorderable types: {}() < {}()'.format(
 103                     self.__class__.__name__, other.__class__.__name__
 104                 )
 105             )
 106
 107         return self._value < self._extract_value(other)
 108
 109     def _spec_eq(self, other):
 110         try:
 111             return self._value == self._extract_value(other)
 112         except:
 113             return False
 114
 115     def __rmod__(self, other):
 116         return self._extract_value(other) % self._value
 117
 118     def __mod__(self, other):
 119         return self._value % self._extract_value(other)
 120
 121     def __rfloordiv__(self, other):
 122         return self._extract_value(other) // self._value
 123
 124     def __floordiv__(self, other):
 125         return self._value // self._extract_value(other)
 126
 127     def __round__(self, ndigits=None):
 128         if ndigits is None:
 129             return round(self._value)
 130         else:
 131             return round(self._value, ndigits)
 132
 133     def __ceil__(self):
 134         return math.ceil(self._value)
 135
 136     def __floor__(self):
 137         return math.floor(self._value)
 138
 139     def __trunc__(self):
 140         return int(self._value)
 141
 142     def __abs__(self):
 143         return abs(self._value)
 144
 145     def __add__(self, other):
 146         return self._value + self._extract_value(other)
 147
 148     def __radd__(self, other):
 149         return self.__add__(other)
 150
 151     def __neg__(self):
 152         return -self._value
 153
 154     def __pos__(self):
 155         return +self._value
 156
 157     def __mul__(self, other):
 158         return self._value * self._extract_value(other)
 159
 160     def __rmul__(self, other):
 161         return self.__mul__(other)
 162
 163     def __truediv__(self, other):
 164         return self._value / self._extract_value(other)
 165
 166     def __rtruediv__(self, other):
 167         return self._extract_value(other) / self._value
 168
 169     def __pow__(self, exponent):
 170         return self._value ** self._extract_value(exponent)
 171
 172     def __rpow__(self, base):
 173         return self._extract_value(base) ** self._value
 174
 175
 176 class _IntegralField(_NumericField, numbers.Integral):
 177     def __lshift__(self, other):
 178         return self._value << self._extract_value(other)
 179
 180     def __rlshift__(self, other):
 181         return self._extract_value(other) << self._value
 182
 183     def __rshift__(self, other):
 184         return self._value >> self._extract_value(other)
 185
 186     def __rrshift__(self, other):
 187         return self._extract_value(other) >> self._value
 188
 189     def __and__(self, other):
 190         return self._value & self._extract_value(other)
 191
 192     def __rand__(self, other):
 193         return self._extract_value(other) & self._value
 194
 195     def __xor__(self, other):
 196         return self._value ^ self._extract_value(other)
 197
 198     def __rxor__(self, other):
 199         return self._extract_value(other) ^ self._value
 200
 201     def __or__(self, other):
 202         return self._value | self._extract_value(other)
 203
 204     def __ror__(self, other):
 205         return self._extract_value(other) | self._value
 206
 207     def __invert__(self):
 208         return ~self._value
 209
 210
 211 class _IntegerField(_IntegralField, _Field):
 212     pass
 213
 214
 215 class _UnsignedIntegerField(_IntegerField, _Field):
 216     _NAME = 'Unsigned integer'
 217
 218     def _value_to_int(self, value):
 219         if not isinstance(value, numbers.Integral):
 220             raise TypeError('expecting an integral number object')
 221
 222         value = int(value)
 223         utils._check_uint64(value)
 224
 225         return value
 226
 227     @property
 228     def _value(self):
 229         return native_bt.field_integer_unsigned_get_value(self._ptr)
 230
 231     def _set_value(self, value):
 232         value = self._value_to_int(value)
 233         native_bt.field_integer_unsigned_set_value(self._ptr, value)
 234
 235     value = property(fset=_set_value)
 236
 237
 238 class _SignedIntegerField(_IntegerField, _Field):
 239     _NAME = 'Signed integer'
 240
 241     def _value_to_int(self, value):
 242         if not isinstance(value, numbers.Integral):
 243             raise TypeError('expecting an integral number object')
 244
 245         value = int(value)
 246         utils._check_int64(value)
 247
 248         return value
 249
 250     @property
 251     def _value(self):
 252         return native_bt.field_integer_signed_get_value(self._ptr)
 253
 254     def _set_value(self, value):
 255         value = self._value_to_int(value)
 256         native_bt.field_integer_signed_set_value(self._ptr, value)
 257
 258     value = property(fset=_set_value)
 259
 260
 261 class _RealField(_NumericField, numbers.Real):
 262     _NAME = 'Real'
 263
 264     def _value_to_float(self, value):
 265         if not isinstance(value, numbers.Real):
 266             raise TypeError("expecting a real number object")
 267
 268         return float(value)
 269
 270     @property
 271     def _value(self):
 272         return native_bt.field_real_get_value(self._ptr)
 273
 274     def _set_value(self, value):
 275         value = self._value_to_float(value)
 276         native_bt.field_real_set_value(self._ptr, value)
 277
 278     value = property(fset=_set_value)
 279
 280
 281 class _EnumerationField(_IntegerField):
 282     def _repr(self):
 283         return '{} ({})'.format(self._value, ', '.join(self.labels))
 284
 285     @property
 286     def labels(self):
 287         status, labels = self._get_mapping_labels(self._ptr)
 288         utils._handle_func_status(status, "cannot get label for enumeration field")
 289
 290         assert labels is not None
 291         return labels
 292
 293
 294 class _UnsignedEnumerationField(_EnumerationField, _UnsignedIntegerField):
 295     _NAME = 'Unsigned Enumeration'
 296     _get_mapping_labels = staticmethod(
 297         native_bt.field_enumeration_unsigned_get_mapping_labels
 298     )
 299
 300
 301 class _SignedEnumerationField(_EnumerationField, _SignedIntegerField):
 302     _NAME = 'Signed Enumeration'
 303     _get_mapping_labels = staticmethod(
 304         native_bt.field_enumeration_signed_get_mapping_labels
 305     )
 306
 307
 308 @functools.total_ordering
 309 class _StringField(_Field):
 310     _NAME = 'String'
 311
 312     def _value_to_str(self, value):
 313         if isinstance(value, self.__class__):
 314             value = value._value
 315
 316         if not isinstance(value, str):
 317             raise TypeError("expecting a 'str' object")
 318
 319         return value
 320
 321     @property
 322     def _value(self):
 323         return native_bt.field_string_get_value(self._ptr)
 324
 325     def _set_value(self, value):
 326         value = self._value_to_str(value)
 327         native_bt.field_string_set_value(self._ptr, value)
 328
 329     value = property(fset=_set_value)
 330
 331     def _spec_eq(self, other):
 332         try:
 333             return self._value == self._value_to_str(other)
 334         except:
 335             return False
 336
 337     def __lt__(self, other):
 338         return self._value < self._value_to_str(other)
 339
 340     def __bool__(self):
 341         return bool(self._value)
 342
 343     def _repr(self):
 344         return repr(self._value)
 345
 346     def __str__(self):
 347         return str(self._value)
 348
 349     def __getitem__(self, index):
 350         return self._value[index]
 351
 352     def __len__(self):
 353         return native_bt.field_string_get_length(self._ptr)
 354
 355     def __iadd__(self, value):
 356         value = self._value_to_str(value)
 357         status = native_bt.field_string_append(self._ptr, value)
 358         utils._handle_func_status(
 359             status, "cannot append to string field object's value"
 360         )
 361         return self
 362
 363
 364 class _ContainerField(_Field):
 365     def __bool__(self):
 366         return len(self) != 0
 367
 368     def __len__(self):
 369         count = self._count()
 370         assert count >= 0
 371         return count
 372
 373     def __delitem__(self, index):
 374         raise NotImplementedError
 375
 376
 377 class _StructureField(_ContainerField, collections.abc.MutableMapping):
 378     _NAME = 'Structure'
 379
 380     def _count(self):
 381         return len(self.field_class)
 382
 383     def __setitem__(self, key, value):
 384         # raises if key is somehow invalid
 385         field = self[key]
 386
 387         # the field's property does the appropriate conversion or raises
 388         # the appropriate exception
 389         field.value = value
 390
 391     def __iter__(self):
 392         # same name iterator
 393         return iter(self.field_class)
 394
 395     def _spec_eq(self, other):
 396         if not isinstance(other, collections.abc.Mapping):
 397             return False
 398
 399         if len(self) != len(other):
 400             # early mismatch
 401             return False
 402
 403         for self_key in self:
 404             if self_key not in other:
 405                 return False
 406
 407             if self[self_key] != other[self_key]:
 408                 return False
 409
 410         return True
 411
 412     def _set_value(self, values):
 413         try:
 414             for key, value in values.items():
 415                 self[key].value = value
 416         except Exception:
 417             raise
 418
 419     value = property(fset=_set_value)
 420
 421     def _repr(self):
 422         items = ['{}: {}'.format(repr(k), repr(v)) for k, v in self.items()]
 423         return '{{{}}}'.format(', '.join(items))
 424
 425     def __getitem__(self, key):
 426         utils._check_str(key)
 427         field_ptr = native_bt.field_structure_borrow_member_field_by_name(
 428             self._ptr, key
 429         )
 430
 431         if field_ptr is None:
 432             raise KeyError(key)
 433
 434         return _create_field_from_ptr(
 435             field_ptr, self._owner_ptr, self._owner_get_ref, self._owner_put_ref
 436         )
 437
 438     def member_at_index(self, index):
 439         utils._check_uint64(index)
 440
 441         if index >= len(self):
 442             raise IndexError
 443
 444         field_ptr = native_bt.field_structure_borrow_member_field_by_index(
 445             self._ptr, index
 446         )
 447         assert field_ptr is not None
 448         return _create_field_from_ptr(
 449             field_ptr, self._owner_ptr, self._owner_get_ref, self._owner_put_ref
 450         )
 451
 452
 453 class _VariantField(_ContainerField, _Field):
 454     _NAME = 'Variant'
 455
 456     @property
 457     def selected_option_index(self):
 458         return native_bt.field_variant_get_selected_option_field_index(self._ptr)
 459
 460     @selected_option_index.setter
 461     def selected_option_index(self, index):
 462         native_bt.field_variant_select_option_field_by_index(self._ptr, index)
 463
 464     @property
 465     def selected_option(self):
 466         # TODO: Is there a way to check if the variant field has a selected_option,
 467         # so we can raise an exception instead of hitting a pre-condition check?
 468         # If there is something, that check should be added to selected_option_index too.
 469         field_ptr = native_bt.field_variant_borrow_selected_option_field(self._ptr)
 470
 471         return _create_field_from_ptr(
 472             field_ptr, self._owner_ptr, self._owner_get_ref, self._owner_put_ref
 473         )
 474
 475     def _spec_eq(self, other):
 476         return _get_leaf_field(self) == other
 477
 478     def __bool__(self):
 479         raise NotImplementedError
 480
 481     def __str__(self):
 482         return str(self.selected_option)
 483
 484     def _repr(self):
 485         return repr(self.selected_option)
 486
 487     def _set_value(self, value):
 488         self.selected_option.value = value
 489
 490     value = property(fset=_set_value)
 491
 492
 493 class _ArrayField(_ContainerField, _Field, collections.abc.MutableSequence):
 494     def _get_length(self):
 495         return native_bt.field_array_get_length(self._ptr)
 496
 497     length = property(fget=_get_length)
 498
 499     def __getitem__(self, index):
 500         if not isinstance(index, numbers.Integral):
 501             raise TypeError(
 502                 "'{}' is not an integral number object: invalid index".format(
 503                     index.__class__.__name__
 504                 )
 505             )
 506
 507         index = int(index)
 508
 509         if index < 0 or index >= len(self):
 510             raise IndexError('{} field object index is out of range'.format(self._NAME))
 511
 512         field_ptr = native_bt.field_array_borrow_element_field_by_index(
 513             self._ptr, index
 514         )
 515         assert field_ptr
 516         return _create_field_from_ptr(
 517             field_ptr, self._owner_ptr, self._owner_get_ref, self._owner_put_ref
 518         )
 519
 520     def __setitem__(self, index, value):
 521         # raises if index is somehow invalid
 522         field = self[index]
 523
 524         if not isinstance(field, (_NumericField, _StringField)):
 525             raise TypeError('can only set the value of a number or string field')
 526
 527         # the field's property does the appropriate conversion or raises
 528         # the appropriate exception
 529         field.value = value
 530
 531     def insert(self, index, value):
 532         raise NotImplementedError
 533
 534     def _spec_eq(self, other):
 535         if not isinstance(other, collections.abc.Sequence):
 536             return False
 537
 538         if len(self) != len(other):
 539             # early mismatch
 540             return False
 541
 542         for self_elem, other_elem in zip(self, other):
 543             if self_elem != other_elem:
 544                 return False
 545
 546         return True
 547
 548     def _repr(self):
 549         return '[{}]'.format(', '.join([repr(v) for v in self]))
 550
 551
 552 class _StaticArrayField(_ArrayField, _Field):
 553     _NAME = 'Static array'
 554
 555     def _count(self):
 556         return native_bt.field_array_get_length(self._ptr)
 557
 558     def _set_value(self, values):
 559         if len(self) != len(values):
 560             raise ValueError('expected length of value and array field to match')
 561
 562         for index, value in enumerate(values):
 563             if value is not None:
 564                 self[index].value = value
 565
 566     value = property(fset=_set_value)
 567
 568
 569 class _DynamicArrayField(_ArrayField, _Field):
 570     _NAME = 'Dynamic array'
 571
 572     def _count(self):
 573         return self.length
 574
 575     def _set_length(self, length):
 576         utils._check_uint64(length)
 577         status = native_bt.field_array_dynamic_set_length(self._ptr, length)
 578         utils._handle_func_status(status, "cannot set dynamic array length")
 579
 580     length = property(fget=_ArrayField._get_length, fset=_set_length)
 581
 582     def _set_value(self, values):
 583         if len(values) != self.length:
 584             self.length = len(values)
 585
 586         for index, value in enumerate(values):
 587             if value is not None:
 588                 self[index].value = value
 589
 590     value = property(fset=_set_value)
 591
 592
 593 _TYPE_ID_TO_OBJ = {
 594     native_bt.FIELD_CLASS_TYPE_UNSIGNED_INTEGER: _UnsignedIntegerField,
 595     native_bt.FIELD_CLASS_TYPE_SIGNED_INTEGER: _SignedIntegerField,
 596     native_bt.FIELD_CLASS_TYPE_REAL: _RealField,
 597     native_bt.FIELD_CLASS_TYPE_UNSIGNED_ENUMERATION: _UnsignedEnumerationField,
 598     native_bt.FIELD_CLASS_TYPE_SIGNED_ENUMERATION: _SignedEnumerationField,
 599     native_bt.FIELD_CLASS_TYPE_STRING: _StringField,
 600     native_bt.FIELD_CLASS_TYPE_STRUCTURE: _StructureField,
 601     native_bt.FIELD_CLASS_TYPE_STATIC_ARRAY: _StaticArrayField,
 602     native_bt.FIELD_CLASS_TYPE_DYNAMIC_ARRAY: _DynamicArrayField,
 603     native_bt.FIELD_CLASS_TYPE_VARIANT_WITHOUT_SELECTOR: _VariantField,
 604     native_bt.FIELD_CLASS_TYPE_VARIANT_WITH_UNSIGNED_SELECTOR: _VariantField,
 605     native_bt.FIELD_CLASS_TYPE_VARIANT_WITH_SIGNED_SELECTOR: _VariantField,
 606 }