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# -*- coding: utf-8 -*-
#
# AWL simulator - datablocks
#
# Copyright 2012-2014 Michael Buesch <m@bues.ch>
#
# 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 2 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
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
# GNU General Public License for more details.
#
# You should have received a copy of the GNU General Public License along
# with this program; if not, write to the Free Software Foundation, Inc.,
# 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
#
from __future__ import division, absolute_import, print_function, unicode_literals
from awlsim.common.compat import *
from awlsim.common.blockinfo import *
from awlsim.core.util import *
from awlsim.core.operators import *
from awlsim.core.datatypes import *
from awlsim.core.datastructure import *
from awlsim.core.blocks import *
class DB(Block):
PERM_READ = 1 << 0
PERM_WRITE = 1 << 1
def __init__(self, index, codeBlock=None,
permissions=(PERM_READ|PERM_WRITE)):
Block.__init__(self, index)
self.setPermissions(permissions)
self.codeBlock = codeBlock # The FB, if this is an instance-DB.
if self.codeBlock:
# The data structure is declared by the interface.
self.__struct = None
else:
self.__struct = AwlStruct()
self.structInstance = None
def setPermissions(self, newPermissions):
self.permissions = newPermissions
if self.permissions & self.PERM_READ:
self.fetch = self.__fetch
else:
self.fetch = self.__fetch_noPermission
if self.permissions & self.PERM_WRITE:
self.store = self.__store
else:
self.store = self.__store_noPermission
@property
def struct(self):
if self.codeBlock:
return self.codeBlock.interface.struct
return self.__struct
def isInstanceDB(self):
return bool(self.codeBlock)
def allocate(self):
self.structInstance = AwlStructInstance(self.struct)
def __fetch(self, operator, baseOffset=AwlOffset()):
return self.structInstance.dataBytes.fetch(baseOffset + operator.value,
operator.width)
def __fetch_noPermission(self, operator, baseOffset=None):
raise AwlSimError("Fetch from read protected DB %d" % self.index)
fetch = __fetch
def __store(self, operator, value, baseOffset=AwlOffset()):
self.structInstance.dataBytes.store(baseOffset + operator.value,
operator.width,
value)
def __store_noPermission(self, operator, value, baseOffset=None):
raise AwlSimError("Store to write protected DB %d" % self.index)
store = __store
def getBlockInfo(self):
"""Get a BlockInfo instance for this block.
"""
return BlockInfo(blockType = BlockInfo.TYPE_DB,
blockIndex = self.index,
identHash = self.identHash)
def __repr__(self):
if self.index == 0:
return "DB --"
return "DB %d" % self.index
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