SickGear/lib/hachoir/field/basic_field_set.py
2023-02-09 13:41:15 +00:00

156 lines
4.7 KiB
Python

from hachoir.field import Field, FieldError
from hachoir.stream import InputStream
from hachoir.core.endian import BIG_ENDIAN, LITTLE_ENDIAN, MIDDLE_ENDIAN
from hachoir.core.event_handler import EventHandler
class ParserError(FieldError):
"""
Error raised by a field set.
@see: L{FieldError}
"""
pass
class MatchError(FieldError):
"""
Error raised by a field set when the stream content doesn't
match to file format.
@see: L{FieldError}
"""
pass
class BasicFieldSet(Field):
_event_handler = None
is_field_set = True
endian = None
def __init__(self, parent, name, stream, description, size):
# Sanity checks (preconditions)
assert not parent or issubclass(parent.__class__, BasicFieldSet)
assert issubclass(stream.__class__, InputStream)
# Set field set size
if size is None and self.static_size:
assert isinstance(self.static_size, int)
size = self.static_size
# Set Field attributes
self._parent = parent
self._name = name
self._size = size
self._description = description
self.stream = stream
self._field_array_count = {}
# Set endian
if not self.endian:
assert parent and parent.endian
self.endian = parent.endian
if parent:
# This field set is one of the root leafs
self._address = parent.nextFieldAddress()
self.root = parent.root
assert id(self.stream) == id(parent.stream)
else:
# This field set is the root
self._address = 0
self.root = self
self._global_event_handler = None
# Sanity checks (post-conditions)
assert self.endian in (BIG_ENDIAN, LITTLE_ENDIAN, MIDDLE_ENDIAN)
if (self._size is not None) and (self._size <= 0):
raise ParserError("Invalid parser '%s' size: %s" %
(self.path, self._size))
def reset(self):
self._field_array_count = {}
def createValue(self):
return None
def connectEvent(self, event_name, handler, local=True):
assert event_name in (
# Callback prototype: def f(field)
# Called when new value is already set
"field-value-changed",
# Callback prototype: def f(field)
# Called when field size is already set
"field-resized",
# A new field has been inserted in the field set
# Callback prototype: def f(index, new_field)
"field-inserted",
# Callback prototype: def f(old_field, new_field)
# Called when new field is already in field set
"field-replaced",
# Callback prototype: def f(field, new_value)
# Called to ask to set new value
"set-field-value"
), "Event name %r is invalid" % event_name
if local:
if self._event_handler is None:
self._event_handler = EventHandler()
self._event_handler.connect(event_name, handler)
else:
if self.root._global_event_handler is None:
self.root._global_event_handler = EventHandler()
self.root._global_event_handler.connect(event_name, handler)
def raiseEvent(self, event_name, *args):
# Transfer event to local listeners
if self._event_handler is not None:
self._event_handler.raiseEvent(event_name, *args)
# Transfer event to global listeners
if self.root._global_event_handler is not None:
self.root._global_event_handler.raiseEvent(event_name, *args)
def setUniqueFieldName(self, field):
key = field._name[:-2]
try:
self._field_array_count[key] += 1
except KeyError:
self._field_array_count[key] = 0
field._name = key + "[%u]" % self._field_array_count[key]
def readFirstFields(self, number):
"""
Read first number fields if they are not read yet.
Returns number of new added fields.
"""
number = number - self.current_length
if 0 < number:
return self.readMoreFields(number)
else:
return 0
def createFields(self):
raise NotImplementedError()
def __iter__(self):
raise NotImplementedError()
def __len__(self):
raise NotImplementedError()
def getField(self, key, const=True):
raise NotImplementedError()
def nextFieldAddress(self):
raise NotImplementedError()
def getFieldIndex(self, field):
raise NotImplementedError()
def readMoreFields(self, number):
raise NotImplementedError()