introduce command handlers
A command handler can be used to deal with parameters which have a common command for querying and writing to the hardware. Support for parsing and formatting commands is included. Change-Id: I79a1b6c9daf3af3be2e1875875ced41ec1a1829d Reviewed-on: https://forge.frm2.tum.de/review/c/sine2020/secop/playground/+/21946 Tested-by: JenkinsCodeReview <bjoern_pedersen@frm2.tum.de> Reviewed-by: Markus Zolliker <markus.zolliker@psi.ch>
This commit is contained in:
264
secop/commandhandler.py
Executable file
264
secop/commandhandler.py
Executable file
@ -0,0 +1,264 @@
|
||||
#!/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 <markus.zolliker@psi.ch>
|
||||
# *****************************************************************************
|
||||
"""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_<group> and change_<group> 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_<group> and change_<group>)
|
||||
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)
|
||||
Reference in New Issue
Block a user