hellerbarde

Latency numbers every programmer should know

L1 cache reference ......................... 0.5 ns
Branch mispredict ............................ 5 ns
L2 cache reference ........................... 7 ns
Mutex lock/unlock ........................... 25 ns
Main memory reference ...................... 100 ns             
Compress 1K bytes with Zippy ............. 3,000 ns  =   3 µs
Send 2K bytes over 1 Gbps network ....... 20,000 ns  =  20 µs
SSD random read ........................ 150,000 ns  = 150 µs

Read 1 MB sequentially from memory ..... 250,000 ns = 250 µs

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

stephenhardy

-- Remove the history from 
rm -rf .git

-- recreate the repos from the current content only
git init
git add .
git commit -m "Initial commit"

-- push to the github remote repos ensuring you overwrite history
git remote add origin git@github.com:<YOUR ACCOUNT>/<YOUR REPOS>.git

asukakenji

Go (Golang) GOOS and GOARCH

All of the following information is based on go version go1.17.1 darwin/amd64.

GOOS Values

GOOS	Out of the Box
aix	✅
android	✅

Arinerron

android.permission.ACCESS_ALL_DOWNLOADS
android.permission.ACCESS_BLUETOOTH_SHARE
android.permission.ACCESS_CACHE_FILESYSTEM
android.permission.ACCESS_CHECKIN_PROPERTIES
android.permission.ACCESS_CONTENT_PROVIDERS_EXTERNALLY
android.permission.ACCESS_DOWNLOAD_MANAGER
android.permission.ACCESS_DOWNLOAD_MANAGER_ADVANCED
android.permission.ACCESS_DRM_CERTIFICATES
android.permission.ACCESS_EPHEMERAL_APPS
android.permission.ACCESS_FM_RADIO

tejainece

import "bytes"

func StreamToByte(stream io.Reader) []byte {
  buf := new(bytes.Buffer)
	buf.ReadFrom(stream)
	return buf.Bytes()
}

func StreamToString(stream io.Reader) string {
	buf := new(bytes.Buffer)

cookrn

Couldn't find the text of this for a while...

• Original (404'ed) -- https://plus.google.com/115094562986465477143/posts/Di6RwCNKCrf
• Fakeout -- http://www.dzone.com/links/rss/ryan_dahl_i_hate_almost_all_software.html
• Repost -- https://plus.google.com/116904230181415286707/posts/DnAMAN5sUR8

jtriley

#!/usr/bin/env python
import os
import shlex
import struct
import platform
import subprocess
 
 
def get_terminal_size():
    """ getTerminalSize()

simonw

How to recover lost Python source code if it's still resident in-memory

I screwed up using git ("git checkout --" on the wrong file) and managed to delete the code I had just written... but it was still running in a process in a docker container. Here's how I got it back, using https://pypi.python.org/pypi/pyrasite/ and https://pypi.python.org/pypi/uncompyle6

Attach a shell to the docker container

Install GDB (needed by pyrasite)

apt-get update && apt-get install gdb

nileshtrivedi

Raspberry Pi on Internet via reverse SSH tunnel

HackerNews discussed this with many alternative solutions: https://news.ycombinator.com/item?id=24893615

I already have my own domain name: mydomain.com. I wanted to be able to run some webapps on my Raspberry Pi 4B running perpetually at home in headless mode (just needs 5W power and wireless internet). I wanted to be able to access these apps from public Internet. Dynamic DNS wasn't an option because my ISP blocks all incoming traffic. ngrok would work but the free plan is too restrictive.

I bought a cheap 2GB RAM, 20GB disk VM + a 25GB volume on Hetzner for about 4 EUR/month. Hetzner gave me a static IP for it. I haven't purchased a floating IP yet.