def seekBit(self,
address,
name="padding[]",
description=None,
relative=True,
null=False):
"""
Create a field to seek to specified address,
or None if it's not needed.
May raise an (ParserError) exception if address is invalid.
"""
if relative:
nbits = address - self._current_size
else:
nbits = address - (self.absolute_address + self._current_size)
if nbits < 0:
raise ParserError("Seek error, unable to go back!")
if 0 < nbits:
if null:
return createNullField(self, nbits, name, description)
else:
return createPaddingField(self, nbits, name, description)
else:
return None
def seek(self, offset):
"""
Seek to byte address relative to parent address.
"""
padding = offset - (self.address + self.current_size)/8
if 0 < padding:
return createPaddingField(self, padding*8)
else:
return None
def seek(self, offset):
"""
Seek to byte address relative to parent address.
"""
padding = offset - (self.address + self.current_size) / 8
if 0 < padding:
return createPaddingField(self, padding * 8)
else:
return None
def writeFieldsIn(self, old_field, address, new_fields):
"""
Can only write in existing fields (address < self._current_size)
"""
# Check size
total_size = sum(field.size for field in new_fields)
if old_field.size < total_size:
raise ParserError( \
"Unable to write fields at address %s " \
"(too big)!" % (address))
# Need padding before?
replace = []
size = address - old_field.address
assert 0 <= size
if 0 < size:
padding = createPaddingField(self, size)
padding._address = old_field.address
replace.append(padding)
# Set fields address
for field in new_fields:
field._address = address
address += field.size
replace.append(field)
# Need padding after?
size = (old_field.address + old_field.size) - address
assert 0 <= size
if 0 < size:
padding = createPaddingField(self, size)
padding._address = address
replace.append(padding)
self.replaceField(old_field.name, replace)
def writeFieldsIn(self, old_field, address, new_fields):
"""
Can only write in existing fields (address < self._current_size)
"""
# Check size
total_size = sum( field.size for field in new_fields )
if old_field.size < total_size:
raise ParserError( \
"Unable to write fields at address %s " \
"(too big)!" % (address))
# Need padding before?
replace = []
size = address - old_field.address
assert 0 <= size
if 0 < size:
padding = createPaddingField(self, size)
padding._address = old_field.address
replace.append(padding)
# Set fields address
for field in new_fields:
field._address = address
address += field.size
replace.append(field)
# Need padding after?
size = (old_field.address + old_field.size) - address
assert 0 <= size
if 0 < size:
padding = createPaddingField(self, size)
padding._address = address
replace.append(padding)
self.replaceField(old_field.name, replace)
def seekBit(self, address, name="padding[]",
description=None, relative=True, null=False):
"""
Create a field to seek to specified address,
or None if it's not needed.
May raise an (ParserError) exception if address is invalid.
"""
if relative:
nbits = address - self._current_size
else:
nbits = address - (self.absolute_address + self._current_size)
if nbits < 0:
raise ParserError("Seek error, unable to go back!")
if 0 < nbits:
if null:
return createNullField(self, nbits, name, description)
else:
return createPaddingField(self, nbits, name, description)
else:
return None
def createFields(self):
for x in xrange(self._width):
yield self._pixel(self, "pixel[]")
size = self.size - self.current_size
if size:
yield createPaddingField(self, size)
def createFields(self):
for x in xrange(self._width):
yield self._pixel(self, "pixel[]")
size = self.size - self.current_size
if size:
yield createPaddingField(self, size)
def createFields(self):
yield Bytes(self, "data", self.datasize / 8)
padding = self._size - self.current_size
if padding:
yield createPaddingField(self, padding)
def createFields(self):
yield Bytes(self, "data", self.datasize/8)
padding = self._size - self.current_size
if padding:
yield createPaddingField(self, padding)