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josiahcarlson / follow_file.py
Created April 13, 2014 18:03
Python function to offer "tail -F"-like functionality in Python
'''
follow_file.py
Written April 13, 2014 by Josiah Carlson
Released under the MIT license.
This could likely be made more efficient with the use of the pyinotify library,
and some of the module-level constants could be tuned for better performance,
depending on your platform.
@josiahcarlson
josiahcarlson / rate_limit.py
Last active February 25, 2022 14:33
Rate limiting with Redis primarily using Lua scripting
'''
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
@josiahcarlson
josiahcarlson / result_multiplex.py
Created October 12, 2014 21:20
Reliably multiplex receiving results via Redis lists
'''
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
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josiahcarlson / rate_limit2.py
Last active April 17, 2022 09:22
Regular and sliding window rate limiting to accompany two blog posts.
'''
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
josiahcarlson / redis_slots.py
Created November 19, 2014 22:31
Some useful crc utility functions for Redis cluster
'''
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
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josiahcarlson / redis-zadd-sum.lua
Last active May 3, 2023 09:14 — forked from Hidendra/redis-zadd-sum.lua
-- 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
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josiahcarlson / search_output.txt
Last active February 14, 2016 07:37
A new ordering on an array that offers faster searching than binary search, yet is just as simple. Allows for O(log(n)) modifications and searches. Paper and details forthcoming.
$ gcc -O4 -o shuffle_search.out shuffle_search.c
$ ./shuffle_search.out
Generate 10000000 random input values...
Select 1000000 random items from the input and duplicating 10x times...
Random reorder selected items
Sorting input... qsort O(nlogn)
Shuffle transforming input... O(n)
Binary searching
3.932018
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josiahcarlson / reply_to_blog.txt
Created February 19, 2016 04:29
Reply to a comment
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
josiahcarlson / rom_example_bruno.py
Last active August 8, 2019 04:47
Example from a livecoding stream, updated with fixes
'''
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
josiahcarlson / redis-crc64-benchmark_Intel_Xeon_2670_v0.csv
Created April 6, 2023 17:54
Running https://github.com/redis/redis/pull/11988 on Intel Xeon 2670 v0 @2.6ghz and i3 8130U @2.2ghz
We can make this file beautiful and searchable if this error is corrected: It looks like row 2 should actually have 1 column, instead of 4. in line 1.
$ 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