bgadrian

type Set struct {
	list map[int]struct{} //empty structs occupy 0 memory
}

func (s *Set) Has(v int) bool {
	_, ok := s.list[v]
	return ok
}

usernaamee

"""
:|
- Email provider doesn't allow me to send certain file types.
- I have python installed on all my machines.
- Inflates the file size by ~4.5X, still remains under 25M for me.
"""

from __future__ import print_function
import sys

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

rondy

FWIW: I (@rondy) am not the creator of the content shared here, which is an excerpt from Edmond Lau's book. I simply copied and pasted it from another location and saved it as a personal note, before it gained popularity on news.ycombinator.com. Unfortunately, I cannot recall the exact origin of the original source, nor was I able to find the author's name, so I am can't provide the appropriate credits.

---

Effective Engineer - Notes

• By Edmond Lau
• Highly Recommended 👍
• http://www.theeffectiveengineer.com/

What's an Effective Engineer?

nathan-osman

package main

import (
	"log"
	"syscall"
	"unsafe"
)

var (
	kernel32 = syscall.NewLazyDLL("kernel32.dll")

yefim

{
  "AWSEBDockerrunVersion": "1",
  "Image": {
    "Name": "<AWS_ACCOUNT_ID>.dkr.ecr.us-east-1.amazonaws.com/<NAME>:<TAG>",
    "Update": "true"
  },
  "Ports": [
    {
      "ContainerPort": "443"
    }

vasanthk

System Design Cheatsheet

Picking the right architecture = Picking the right battles + Managing trade-offs

Basic Steps

1. Clarify and agree on the scope of the system

• User cases (description of sequences of events that, taken together, lead to a system doing something useful)
  • Who is going to use it?
  • How are they going to use it?

m-ou-se

# Download latest archlinux bootstrap package, see https://www.archlinux.org/download/
wget 'ftp://ftp.nluug.nl/pub/os/Linux/distr/archlinux/iso/latest/archlinux-bootstrap-*-x86_64.tar.gz'

# Make sure you'll have enough entropy for pacman-key later.
apt-get install haveged

# Install the arch bootstrap image in a tmpfs.
mount -t tmpfs none /mnt
cd /mnt
tar xvf ~/archlinux-bootstrap-*-x86_64.tar.gz --strip-components=1

jakebellacera

Below are a list of best practices and techniques that you should be using while building out your HTML5 banners (and other websites).

Styles

CSS should be clear and concise. You should not have any rules that are unused. You can check for unused styles by running the "Audit" feature found in Chrome's Developer Tools. Try to combine rules if possible to retain wasted bytes.

JS

JS should be clear and concise. Try not to use external libraries at all if possible. Try to leverage recursive functions whenever possible to reduce byte-size.

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