connectors/ConnectorBase.py
author Edouard Tisserant
Wed, 01 Mar 2023 10:54:54 +0100
changeset 3740 ac0e6de439b5
parent 2621 af09744a468e
child 3750 f62625418bff
child 3861 7e17f7e02a2b
permissions -rw-r--r--
Linux runtime: overrun detection for real-time timers and for plc execution.

If real-time timer wakes-up PLC thread too late (10% over period), then
warning is logged.

If PLC code (IO retreive, execution, IO publish) takes longer than requested
PLC execution cycle, then warning is logged, and CPU hoogging is mitigated
by delaying next PLC execution a few cylces more until having at least
1ms minimal idle time.
#!/usr/bin/env python
# -*- coding: utf-8 -*-

# See COPYING file for copyrights details.

from __future__ import absolute_import
import hashlib


class ConnectorBase(object):

    chuncksize = 1024*1024

    def BlobFromFile(self, filepath, seed):
        s = hashlib.new('md5')
        s.update(seed)
        blobID = self.SeedBlob(seed)
        with open(filepath, "rb") as f:
            while blobID == s.digest():
                chunk = f.read(self.chuncksize)
                if len(chunk) == 0:
                    return blobID
                blobID = self.AppendChunkToBlob(chunk, blobID)
                s.update(chunk)
        raise IOError("Data corrupted during transfer or connection lost")