px-snowball 0.1.0

Snowball(or n+1) function call prevention utilities.

Snowball

Library with several utilities for merging "n+1" amount function calls into one.

This utilities might be helpful for tasks/functions that should run not very frequently, but there could be a lot of initiating calls to that functions.

Installation

pip install px-snowball

Usage

Simple usage:

from px_snowball import thread_throttle, thread_debounce
# Or shortcuts:
# from px_snowball import throttle, debounce

context = {}

# We're delaying function execution after each call:
@thread_debounce(0.2)
def debouncer(values):
  # `values` will be a list of all arguments and key arguments it was called.
  for args, kwargs in values:
    # do some stuff
    print(args)

debouncer(1)
debouncer(2)
debouncer(3)
time.sleep(0.1)
debouncer(4)
time.sleep(0.2)

# And only now `debouncer` function will be called.
# The same is for throttle function.

More practical example.

Let's assume we need to write messages to file. But system calls for every message - is too expensive:

from px_snowball import thread_throttle, thread_debounce

# At most every 1 second messages will be written to log file:
@thread_throttle(1)
def log(values: List[Tuple[Tuple[str], dict]):
  messages = (message for (message, *args), kwargs in values)
  data_to_write = '\n'.join(messages)

  with open('/tmp/log.log', 'a+') as f:
    f.write(data_to_write)


log('First')
log('Second')
# Will be empty:
# > cat /tmp/log.log
time.sleep(0.5)
log('Third')
# Still empty:
# > cat /tmp/log.log

time.sleep(0.5)
# Now, after 1 second has passed all logs are in file.
# Write operation was executed only once, instead of 3 times as would be if func
# was executed as usual.
# > cat /tmp/log.log
# > First
# > Second
# > Third

Yes, the resulting function is a bit ugly, but the main profit is that we could perform our operations once in "bulk"(with possible optimizations) even if we call functions 10k times.

Changelog

All notable changes to this project will be documented in this file.

The format is based on Keep a Changelog, and this project adheres to Semantic Versioning.

[Unreleased]

[0.1.0]

Initial version.