Source code for data_specification.memory_region

# Copyright (c) 2017-2019 The University of Manchester
# This program is free software: you can redistribute it and/or modify
# it under the terms of the GNU General Public License as published by
# the Free Software Foundation, either version 3 of the License, or
# (at your option) any later version.
# This program is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# GNU General Public License for more details.
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[docs]class MemoryRegion(object): """ Memory region storage object. """ __slots__ = [ "_unfilled", "_allocated_size", "_region_data", "_write_pointer", "_max_write_pointer" ] def __init__(self, unfilled, size): """ :param bool unfilled: if the region should not be written to by the data specification (i.e., because the vertex uses it as a working data region or an output region) :param int size: the size of the region, in bytes """ #: flag that states if the region is filled or not self._unfilled = unfilled #: the amount of memory allocated to this DSG self._allocated_size = size #: the region buffer, or None for unfilled regions self._region_data = None if unfilled else bytearray(size) #: the position in the memory where the writing is currently occurring self._write_pointer = 0 #: the max point where if written over, it will cause an error self._max_write_pointer = 0 @property def allocated_size(self): """ The size of the region. :rtype: int """ return self._allocated_size @property def remaining_space(self): """ The space between the current write pointer and the end of the\ region, which is the number of bytes remaining in the region that\ can be written. :rtype: int """ return self._allocated_size - self._write_pointer @property def unfilled(self): """ Whether the region is marked as not fillable; unfilled regions\ will not contain any data at write time. :rtype: bool """ return self._unfilled @property def region_data(self): """ The buffer which holds the data written in this region. :rtype: bytearray """ return ( bytearray(self._allocated_size) if self._unfilled else self._region_data) @property def write_pointer(self): """ The position in the buffer where data will be written to next. :rtype: int """ return self._write_pointer @write_pointer.setter def write_pointer(self, write_pointer): self._write_pointer = write_pointer self._max_write_pointer = max(( self._write_pointer, self._max_write_pointer)) @property def max_write_pointer(self): """ The max point where if written over, it will cause an error. :rtype: int """ return self._max_write_pointer
[docs] def increment_write_pointer(self, n_bytes): """ Advance the write pointer. :param int n_bytes: The number of bytes to advance the pointer by. """ self._write_pointer += n_bytes self._max_write_pointer = max(( self._write_pointer, self._max_write_pointer))