runtime/typemapping.py
author Edouard Tisserant
Tue, 25 Aug 2020 14:32:39 +0200
branchsvghmi
changeset 3036 4930455428df
parent 1973 cc7a46953471
child 2741 3cc5663af196
permissions -rw-r--r--
SVGHMI: JsonTable now use intermediate variables again to address JSON data without duplicating code or referencing. Using intermediate variables also alows to check for availability of data and stop evaluating early if data is missing. Finally added complete roundtrip example to illustrate use of JSonTable to display "alarms" collected in python from changes on PLC boolean variables.
#!/usr/bin/env python
# -*- coding: utf-8 -*-
#
# See COPYING.Runtime file for copyrights details.
#

from __future__ import absolute_import
import ctypes
from ctypes import *
from datetime import timedelta as td

ctypes.pythonapi.PyString_AsString.argtypes = (ctypes.c_void_p,)
ctypes.pythonapi.PyString_AsString.restype = ctypes.POINTER(ctypes.c_char)


class IEC_STRING(Structure):
    """
    Must be changed according to changes in iec_types.h
    """
    _fields_ = [("len", c_uint8),
                ("body", c_char * 126)]


class IEC_TIME(Structure):
    """
    Must be changed according to changes in iec_types.h
    """
    _fields_ = [("s", c_long),   # tv_sec
                ("ns", c_long)]  # tv_nsec


def _t(t, u=lambda x: x.value, p=lambda t, x: t(x)):
    return (t, u, p)


def _ttime():
    return (IEC_TIME,
            lambda x: td(0, x.s, x.ns/1000.0),
            lambda t, x: t(x.days * 24 * 3600 + x.seconds, x.microseconds*1000))


SameEndianessTypeTranslator = {
    "BOOL":       _t(c_uint8, lambda x: x.value != 0),
    "STEP":       _t(c_uint8),
    "TRANSITION": _t(c_uint8),
    "ACTION":     _t(c_uint8),
    "SINT":       _t(c_int8),
    "USINT":      _t(c_uint8),
    "BYTE":       _t(c_uint8),
    "STRING":     (IEC_STRING,
                   lambda x: x.body[:x.len],
                   lambda t, x: t(len(x), x)),
    "INT":        _t(c_int16),
    "UINT":       _t(c_uint16),
    "WORD":       _t(c_uint16),
    "DINT":       _t(c_int32),
    "UDINT":      _t(c_uint32),
    "DWORD":      _t(c_uint32),
    "LINT":       _t(c_int64),
    "ULINT":      _t(c_uint64),
    "LWORD":      _t(c_uint64),
    "REAL":       _t(c_float),
    "LREAL":      _t(c_double),
    "TIME":       _ttime(),
    "TOD":        _ttime(),
    "DATE":       _ttime(),
    "DT":         _ttime(),
    }

SwapedEndianessTypeTranslator = {
    # TODO
    }

TypeTranslator = SameEndianessTypeTranslator

# Construct debugger natively supported types
DebugTypesSize = dict([(key, sizeof(t)) for key, (t, p, u) in SameEndianessTypeTranslator.iteritems() if t is not None])


def UnpackDebugBuffer(buff, indexes):
    res = []
    buffoffset = 0
    buffsize = len(buff)
    buffptr = cast(ctypes.pythonapi.PyString_AsString(id(buff)), c_void_p).value
    for iectype in indexes:
        c_type, unpack_func, _pack_func = \
            TypeTranslator.get(iectype, (None, None, None))
        if c_type is not None and buffoffset < buffsize:
            cursor = c_void_p(buffptr + buffoffset)
            value = unpack_func(cast(cursor,
                                     POINTER(c_type)).contents)
            buffoffset += sizeof(c_type) if iectype != "STRING" else len(value)+1
            res.append(value)
        else:
            break
    if buffoffset and buffoffset == buffsize:
        return res
    return None