deprogressapi 0.1.2

basic back-end progress api for the data analytics software framework dasf

Progress api for DASF modules based on python. Developed and tested with Python 3.8

Scope

This library is part of the Data Analytics Software Framework DASF (https://git.geomar.de/digital-earth/dasf), which was developed by the GFZ Potsdam (https://www.gfz-potsdam.de) in the Digital Earth project (https://www.digitalearth-hgf.de/).

Usage

A progress report is stored in a tree structure. So there will be one ‘root’ report instance containing multiple ‘sub-reports’.

The root report will be initialized directly. The contructor demands a send_handler argument, so we need to create one first. The dasf-messaging-python module provides a ready to use implementation for the send_handler via the ProgressSendHandler class. In order to instantiate the send handler you need to pass the PulsarMessageConsumer that is used to receive the request that is monitored, as well as the corresponding request message. You might add additional message properties via the msg_props dictionary.

from demessaging.progress_send_handler import ProgressSendHandler

send_handler=ProgressSendHandler(pulsar=self.__pulsar,
                                 request_msg=request_msg,
                                 msg_props={'additional': 'some addtional property'})

Once we have a send_handler we can use it to create the ‘root’ progress report for the request. In case we already know how many steps (sub-reports) there are going to be on the next level, we can pass it via the optional steps argument.

root_report = ProgressReport(step_message="Label/message of the root report",
                                 send_handler=send_handler,
                                 steps=2)

Once we have the root report instance we create new subreports for it via the create_subreport method. Each created report is published automatically upon creation and completion.

# create a subreport
sub_report = root_report.create_subreport(step_message="Calculating something")

# execute some logic
# ...

# mark the sub-report as compelte
sub_report.complete()

All sub-reports are again instances of ProgressReport, so you can create more sub-reports for each.

error handling

For now there is now distinct error flag in the report. But you can update the step_message prop before marking it as complete to indicate an error.

# some code that raises an exception
# ...
except Exception as e:
    error = str(e)
    progress_report.step_message = "error '{msg}': {err}".format(msg=progress_report.step_message, err=error)
    progress_report.complete()