josiahcarlson

"""
Copyright 2025 Dr. Josiah Carlson, Phd <[email protected]>
Released under the "don't be a jerk" license - which requires that you
include this entire header, and that you not be a jerk. Can't do that?
You don't have a license. Want to be super cool? Buy me a pizza:
https://josiahcarlson.github.io/

Why was this created? There are a lot of complainers about Python's
syntax for magic methods. This module allows you to not need to use __add__
to override the + operation, you can instead use::

josiahcarlson

"""
one_bit_difference.py

Written September / October 2023 by Josiah Carlson - josiah.carlson@gmail.com
Released into the public domain. Please include this authorship note / reference
to this GIST if you use / derive this software. Thank you.

Been thinking about this algorithm for about 17 years, haven't seen it around.
I might not know the proper literature search to find relevant references, or if
this was already done.

josiahcarlson

$ time docker-compose run redis-server numactl -N 1 -l /usr/src/redis/src/redis-benchmark --crc 512000000 --csv --combine
algorithm,buffer,performance,crc64_matches
crc_1byte,512000000,400,1
crcspeed,512000000,1354,1
crcdual,512000000,2129,1
crctri,512000000,2243,1
crc_1byte,312000000,401,1
crcspeed,312000000,1352,1
crcdual,312000000,2090,1
crctri,312000000,2213,1

josiahcarlson

'''
This this was retyped from https://www.twitch.tv/videos/459202303 for notes and
then updated by the author of rom, me, Josiah Carlson


Notes:
* For created_at, or any default, if it is "callable", it will be called at
  entity creation/instantiation. In the demo in the video, we see:
    created_at = rom.DateTime(default=datetime.datetime.now())

josiahcarlson

This is my reply to Alex Mills: http://www.binpress.com/tutorial/introduction-to-rate-limiting-with-redis/155

Yes, with threads, processes, or an async reactor. That said...

$ redis-benchmark -n 2000000 -c 20 -q
[snip]
SET: 115141.05 requests per second
GET: 134048.27 requests per second
INCR: 180505.41 requests per second
LPUSH: 176056.33 requests per second

josiahcarlson

-- keys: key dest
-- argv: score member [score member ...]
-- e.g. keys: "data:test:1:2" "data-sum:test:1:2"
--      argv: 10 a 15 b
 
local key = KEYS[1]
local dest = KEYS[2]
local sum = tonumber(redis.call('get', dest)) or 0
 
for i=1, #ARGV, 2 do

josiahcarlson

'''
Released into the public domain.

This code will append 2 bytes to the end of a key to force the key to a specific Redis slot.
'''


from collections import defaultdict
from itertools import imap
import struct

josiahcarlson

'''
rate_limit2.py

Copyright 2014, Josiah Carlson - josiah.carlson@gmail.com
Released under the MIT license

This module intends to show how to perform standard and sliding-window rate
limits as a companion to the two articles posted on Binpress entitled
"Introduction to rate limiting with Redis", parts 1 and 2:

josiahcarlson

'''
result_multiplex.py

Copyright 2014 Josiah Carlson
Released as LGPL 2 or 3, your choice.


Problem:
You have a task processor that writes the results of tasks to a specified key

josiahcarlson

'''
rate_limit.py

Written May 7-8, 2014 by Josiah Carlson
Released under the MIT license.

Offers a simple interface for offering rate limiting on a per second, minute,
hour, and day basis. Useful for offering varying rate limits depending on user
behavior. Sliding window based limits offer per minute, hour, and day limits