#!/usr/bin/env python # -*- coding: utf-8 -*- # ***************************************************************************** # 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., # 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA # # Module authors: # Markus Zolliker # ***************************************************************************** """command handler utility class for cases, where multiple parameters are treated with a common command. The support for LakeShore and similar protocols is already included. """ import re from secop.metaclass import Done class CmdParser: """helper for parsing replies using a subset of old style python formatting the same format can be used or formatting command arguments """ # make a map of cast functions CAST_MAP = {letter: cast for letters, cast in ( ('d', int), ('s', str), # 'c' is treated separately ('o', lambda x:int(x, 8)), ('xX', lambda x:int(x, 16)), ('eEfFgG', float), ) for letter in letters } # pattern for chacaters to be escaped ESC_PAT = re.compile('([\\%s])' % '\\'.join('|^$-.+*?()[]{}<>')) # format pattern FMT_PAT = re.compile('(%%|%[^diouxXfFgGeEcrsa]*(?:.|$))') def __init__(self, argformat): # replace named patterns self.fmt = argformat spl = self.FMT_PAT.split(argformat) spl_iter = iter(spl) def escaped(text): return self.ESC_PAT.sub(lambda x: '\\' + x.group(1), text) casts = [] # the first item in spl is just plain text pat = [escaped(next(spl_iter))] todofmt = None # format set aside to be treated in next loop # loop over found formats and separators for fmt, sep in zip(spl_iter,spl_iter): if fmt == '%%': if todofmt is None: pat.append('%' + escaped(sep)) # plain text continue fmt = todofmt todofmt = None sep = '%' + sep elif todofmt: raise ValueError("a separator must follow '%s'" % todofmt) cast = self.CAST_MAP.get(fmt[-1], None) if cast is None: # special or unknown case if fmt != '%c': raise ValueError("unsupported format: '%s'" % fmt) # we do not need a separator after %c pat.append('(.)') casts.append(str) pat.append(escaped(sep)) continue if sep == '': # missing separator. postpone handling for '%%' case or end of pattern todofmt = fmt continue casts.append(cast) # accepting everything up to a separator pat.append('([^%s]*)' % escaped(sep[0]) + escaped(sep)) if todofmt: casts.append(cast) pat.append('(.*)') self.casts = casts self.pat = re.compile(''.join(pat)) try: argformat % ((0,) * len(casts)) # validate argformat except ValueError as e: raise ValueError("%s in %r" % (e, argformat)) def format(self, *values): return self.fmt % values def parse(self, reply): match = self.pat.match(reply) if not match: raise ValueError('reply "%s" does not match pattern "%s"' % (reply, self.fmt)) return [c(v) for c, v in zip(self.casts, match.groups())] class ChangeWrapper: """store parameter changes before they are applied""" def __init__(self, module, pname, value): self._module = module setattr(self, pname, value) def __getattr__(self, key): """get values from module for unknown keys""" return getattr(self._module, key) def apply(self, module): """set only changed values""" for k, v in self.__dict__.items(): if k != '_module' and v != getattr(module, k): setattr(module, k, v) def __repr__(self): return ', '.join('%s=%r' % (k, v) for k, v in self.__dict__.items() if k != '_module') class CmdHandlerBase: """generic command handler""" # def __init__(self, group, ...): # init must at least initialize self.group, which is is relevant for calling the # proper analyze_ and change_ methods def parse_reply(self, reply): """return values from a raw reply""" raise NotImplementedError def make_query(self, module): """make a query""" raise NotImplementedError def make_change(self, module, *values): """make a change command from values""" raise NotImplementedError def send_command(self, module, changecmd=''): """send a command (query or change+query) and parse the reply into a list If changecmd is given, it is prepended before the query. """ querycmd = self.make_query(module) reply = module.sendRecv((changecmd + querycmd)) return self.parse_reply(reply) def send_change(self, module, *values): """compose and send a command from values and send a query afterwards. This method might be overriden, if the change command can be combined with a query command, or if the change command already includes a reply. """ changecmd = self.make_change(module, *values) module.sendRecv(changecmd) # ignore result return self.send_command(module) def get_read_func(self, pname): """returns the read function passed to the metaclass""" return self.read def read(self, module): """the read function passed to the metaclass overwrite with None if not used """ # do a read of the current hw values reply = self.send_command(module) # convert them to parameters getattr(module, 'analyze_' + self.group)(*reply) return Done # parameters should be updated already def get_write_func(self, pname): """returns the write function passed to the metaclass return None if not used. """ def wfunc(module, value, cmd=self, pname=pname): # do a read of the current hw values values = cmd.send_command(module) # convert them to parameters analyze = getattr(module, 'analyze_' + cmd.group) analyze(*values) # create wrapper object 'new' with changed parameter 'pname' new = ChangeWrapper(module, pname, value) # call change_* for calculation new hw values values = getattr(module, 'change_' + cmd.group)(new, *values) # send the change command and a query command analyze(*cmd.send_change(module, *values)) # update only changed values new.apply(module) return Done # parameter 'pname' should be changed already return wfunc class CmdHandler(CmdHandlerBase): """more evolved command handler this command handler works for a syntax, where the change command syntax can be build from the query command syntax, with the to be changed items at the second part of the command, using the same format as for the reply. Examples: devices from LakeShore, PPMS implementing classes have to define/override the following: """ CMDARGS = [] # list of properties or parameters to be used for building # some of the the query and change commands CMDSEPARATOR = ';' # if given, it is valid to join a command a a query with # the given separator def __init__(self, group, querycmd, replyfmt): """initialize the command handler group: the handler group (used for analyze_ and change_) querycmd: the command for a query, may contain named formats for cmdargs replyfmt: the format for reading the reply with some scanf like behaviour """ self.group = group self.querycmd = querycmd self.replyfmt = CmdParser(replyfmt) def parse_reply(self, reply): """return values from a raw reply""" return self.replyfmt.parse(reply) def make_query(self, module): """make a query""" return self.querycmd % {k: getattr(module, k, None) for k in self.CMDARGS} def make_change(self, module, *values): """make a change command from a query command""" changecmd = self.querycmd.replace('?', ' ') if not self.querycmd.endswith('?'): changecmd += ',' changecmd %= {k: getattr(module, k, None) for k in self.CMDARGS} return changecmd + self.replyfmt.format(*values) def send_change(self, module, *values): """join change and query commands""" if self.CMDSEPARATOR is None: return super().send_change(module, *values) return self.send_command(module, self.make_change(module, *values) + self.CMDSEPARATOR)