timvisee

Falsehoods programmers believe about time

This is a compiled list of falsehoods programmers tend to believe about working with time.

Don't re-invent a date time library yourself. If you think you understand everything about time, you're probably doing it wrong.

Falsehoods

• There are always 24 hours in a day.
• February is always 28 days long.
• Any 24-hour period will always begin and end in the same day (or week, or month).

klauspost

"  </div>"
"  })();\r\n"
" && "
" &amp; "
" &nbsp;"
" ''The "
" (&quot;"
" (199"
" (200"
" (e.g."

dupuy

Markdown and reStructuredText

GitHub supports several lightweight markup languages for documentation; the most popular ones (generally, not just at GitHub) are Markdown and reStructuredText. Markdown is sometimes considered easier to use, and is often preferred when the purpose is simply to generate HTML. On the other hand, reStructuredText is more extensible and powerful, with native support (not just embedded HTML) for tables, as well as things like automatic generation of tables of contents.

jboner

Latency Comparison Numbers (~2012)
----------------------------------
L1 cache reference                           0.5 ns
Branch mispredict                            5   ns
L2 cache reference                           7   ns                      14x L1 cache
Mutex lock/unlock                           25   ns
Main memory reference                      100   ns                      20x L2 cache, 200x L1 cache
Compress 1K bytes with Zippy             3,000   ns        3 us
Send 1K bytes over 1 Gbps network       10,000   ns       10 us
Read 4K randomly from SSD*             150,000   ns      150 us          ~1GB/sec SSD

ageis

security and hardening options for systemd service units

A common and reliable pattern in service unit files is thus:

NoNewPrivileges=yes
PrivateTmp=yes
PrivateDevices=yes
DevicePolicy=closed
ProtectSystem=strict

HenningTimm

Memory profiling Rust code with heaptrack in 2019

I recently ran into a classic case of "our code is using way more memory than it should". So I took my first dive into memory profiling Rust code. I read several posts about this, including the following

• KodrAus' gist on profiling rust
• This reddit thread
• Brendan D. Gregg's post about memory flamegraphs
• Bradlee Speice's A Case Study in Heaptrack

staltz

The introduction to Reactive Programming you've been missing

(by @andrestaltz)

---

This tutorial as a series of videos

If you prefer to watch video tutorials with live-coding, then check out this series I recorded with the same contents as in this article: Egghead.io - Introduction to Reactive Programming.

---

bskinn

# The entries in this file are checked regularly for validity via the Github Action
# sited at github.com/bskinn/intersphinx-gist.
# Please feel free to post an issue at that repo if any of these mappings don't work for you,
# or if you're having trouble constructing a mapping for a project not listed here.

Python 3 [latest]: ('https://docs.python.org/3/', None)
Python 3 [3.x]: ('https://docs.python.org/3.9/', None)
attrs [stable]: ('https://www.attrs.org/en/stable/', None)
Django [dev]: ('https://docs.djangoproject.com/en/dev/', 'https://docs.djangoproject.com/en/dev/_objects/')
Flask [2.2.x]: ('https://flask.palletsprojects.com/en/2.2.x/', None)

HaleTom

#!/bin/bash

# Tom Hale, 2016. MIT Licence.
# Print out 256 colours, with each number printed in its corresponding colour
# See http://askubuntu.com/questions/821157/print-a-256-color-test-pattern-in-the-terminal/821163#821163

set -eu # Fail on errors or undeclared variables

printable_colours=256

jFransham

Achieving warp speed with Rust

Contents:

• Number one optimization tip: don't
• Never optimize blindly
• Don't bother optimizing one-time costs
• Improve your algorithms
• CPU architecture primer
• Keep as much as possible in cache
• Keep as much as possible in registers