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
Exemple #2
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 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
Exemple #7
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 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)
Exemple #8
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 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)
Exemple #9
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 def createFields(self):
     yield Bytes(self, "data", self.datasize / 8)
     padding = self._size - self.current_size
     if padding:
         yield createPaddingField(self, padding)
Exemple #10
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 def createFields(self):
     yield Bytes(self, "data", self.datasize/8)
     padding = self._size - self.current_size
     if padding:
         yield createPaddingField(self, padding)