attractivechaos

Lessons from Hash Table Merging

Merging two hash maps seems like an O(N) operation. However, while merging millions of keys, I encountered a massive >10x performance degradation unexpectedly. This post explores why some of the most popular libraries fall into this trap and how to fix it. The source code is available here.

• The set up
• Merging hash tables may be slow

premek

# Put this function to your .bashrc file.
# Usage: mv oldfilename
# If you call mv without the second parameter it will prompt you to edit the filename on command line.
# Original mv is called when it's called with more than one argument.
# It's useful when you want to change just a few letters in a long name.
#
# Also see:
# - imv from renameutils
# - Ctrl-W Ctrl-Y Ctrl-Y (cut last word, paste, paste)

nadavrot

High-Performance Matrix Multiplication

This is a short post that explains how to write a high-performance matrix multiplication program on modern processors. In this tutorial I will use a single core of the Skylake-client CPU with AVX2, but the principles in this post also apply to other processors with different instruction sets (such as AVX512).

Intro

Matrix multiplication is a mathematical operation that defines the product of

creack

package main

import (
	"context"
	"fmt"
	"log"
	"net/http"
	"os"
	"os/signal"
	"strconv"

3n21c0

package main

import (
	"context"
	"flag"
	"fmt"
	"log"
	"net/http"
	"os"
	"os/signal"

fawkesley

#!/bin/sh

# /etc/NetworkManager/dispatcher.d/pre-up.d/randomize-mac-addresses.sh

# INSTALL
#
# > curl -L 'https://gist.github.com/paulfurley/46e0547ce5c5ea7eabeaef50dbacef3f/raw/56ee5dd5f40dec93b8f7438cbdeda5475ea3b5d2/randomize-mac-addresses.sh' |sudo tee /etc/NetworkManager/dispatcher.d/pre-up.d/randomize-mac-addresses.sh
# > sudo chmod +x /etc/NetworkManager/dispatcher.d/pre-up.d/randomize-mac-addresses.sh

# Configure every saved WiFi connection in NetworkManager with a spoofed MAC

dropmeaword

#########################################################################
#     Wifiscanner.py - A simple python script which records and logs wifi probe requests.
#     Author - D4rKP01s0n
#     Requirements - Scapy and Datetime
#     Inspiration - Tim Tomes (LaNMaSteR53)'s WUDS https://bitbucket.org/LaNMaSteR53/wuds/
#     Reminder - Change mon0 (around line 65) to your monitor-mode enabled wifi interface
#########################################################################


from datetime import datetime

Jiab77

nVidia drivers installation on ElementaryOS - Loki

ElementaryOS - Loki is an amazing ubuntu based distribution, I've just felt in love on it BUT they've removed what's required to install easily the nVidia Proprietary drivers. So here is the reason of this gist, to store the install instructions in one place inside a crystal clear documentation.

Check your device

Open your favorite terminal application then type sudo ubuntu-drivers devices, you should get something like this:

subfuzion

Common Options

-#, --progress-bar Make curl display a simple progress bar instead of the more informational standard meter.

-b, --cookie <name=data> Supply cookie with request. If no =, then specifies the cookie file to use (see -c).

-c, --cookie-jar <file name> File to save response cookies to.

anaisbetts

# VERSION:        0.1
# DESCRIPTION:    Build an Electron app in a container
# AUTHOR:         Paul Betts <paul@paulbetts.org>
# COMMENTS:
#   Use Surf to build an Electron app in a container and upload the result
#   Originally based on the Atom Dockerfile by Jessica 
#   Frazelle <jessie@docker.com>
# USAGE:
#   # Download atom Dockerfile
#   wget https://raw.githubusercontent.com/atom/atom/master/Dockerfile