jeffbass / imagehub Goto Github PK

This following error occurs with Windows 10:

Traceback (most recent call last):
  File "imagehub\imagehub\imagehub.py", line 41, in main
    with Patience(hub.patience):
  File "C:\Stephens_Folder\Programming\Home_Monitor\imagehub\imagehub\tools\utils.py", line 63, in __enter__
    signal.signal(signal.SIGALRM, self.raise_timeout)
AttributeError: module 'signal' has no attribute 'SIGALRM'
2020-08-05 08:31:47,888 ~ Exiting imagehub.py

A work-around (not a fix) for this error can be made to utils.py. Add the following line of code to the import section of utils.py.

from sys import platform

Next, replace the __enter__ and __exit__ functions of class Patience section with the following:

    def __enter__(self):
        if platform != "win32":
            signal.signal(signal.SIGALRM, self.raise_timeout)
            signal.alarm(self.seconds)
        else:
            pass

    def __exit__(self, *args):
        if platform != "win32":
            signal.alarm(0)    # disable alarm
        else:
            pass

Note: This will allow you to run imagehub.py on a Windows platform, but it will not function as a normal, and may result in some unusual behavior of the imagehub.

For an overview of the yin-yang-ranch distributed computer vision pipeline design, see this repo. The essence of the design is that multiple imagenodes send images and event messages to each imagehub. The imagehub uses Python logging to save the imagenode event messages since it is easy to use and allows easy rotation of log files. In the current version of imagehub, the RotatingFileHandler file handler is used, which means that the log files are named like this at each rotation:

        current (today)  imagehub.log
        previous log     imagehub.log.1
        previous log     imagehub.log.2
        previous log     imagehub.log.3

As my development of the librarian code progresses, the current naming convention for the event log files presents 2 problems:

1. It is not easy to find the event text lines for a specific date; the log files have to be searched.
2. The librarian uses rsync for backups of imagehub data, since it is very good at efficiently backing up only what changes. But with the current RotatingFileHandler, all the log files are backed up every time because every existing log file is renumbered at each rotation.

To address these problems, I am changing the imagehub logging to use the TimedRotatingFileHandler. This is what the log files will look like after the change:

        current (today)  imagehub.log
        previous log     imagehub.log.2020-10-22
        previous log     imagehub.log.2020-10-21
        previous log     imagehub.log.2020-10-20

It solves both of the above problems, and, frankly, it should have been done that way from the start. For anyone currently using imagehub and using a program that reads the event log files, this change will require that those programs be modified.

The actual code change is simple and only involves changing 2 lines in the logging section of imagehub.py. Here is the existing code:

    handler = logging.handlers.RotatingFileHandler(hub.logfile,
        maxBytes=99000, backupCount=995)

which becomes:

    handler = logging.handlers.TimedRotatingFileHandler(hub.logfile,
        when='midnight', backupCount=995)

My existing librarian code has been changed and I'll be testing it for a few more weeks. The new imagehub code will be merged into the master branch when the librarian testing is done. This issue is a heads up to anyone currently using imagehub that the change is coming. Feel free to comment.