connectors/ConnectorBase.py
author Edouard Tisserant
Wed, 10 Mar 2021 09:59:18 +0100
branchsvghmi
changeset 3182 a7941f053a83
parent 2621 af09744a468e
child 3750 f62625418bff
child 3861 7e17f7e02a2b
permissions -rw-r--r--
Runtime: Added PostStart methot to PLCObject, called after PLC is started, with all libraries and python object already created, and python extensions "Start" methods being called.
This is called before python thread processing py_eval blocks starts. Example purpose: attach additional ressource to web services
#!/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")