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

tykurtz

GROKKING NOTES

I liked the way Grokking the coding interview organized problems into learnable patterns. However, the course is expensive and the majority of the time the problems are copy-pasted from leetcode. As the explanations on leetcode are usually just as good, the course really boils down to being a glorified curated list of leetcode problems.

So below I made a list of leetcode problems that are as close to grokking problems as possible.

Pattern: Sliding Window

• https://leetcode.com/problems/maximum-subarray/ # Close enough
• https://leetcode.com/problems/minimum-size-subarray-sum/

kevin-smets

Default

Powerlevel10k

domenic

Auto-deploying built products to gh-pages with GitHub Actions

This is a set up for projects which want to check in only their source files, but have their gh-pages branch automatically updated with some compiled output every time they push.

A file below this one contains the steps for doing this with Travis CI. However, these days I recommend GitHub Actions, for the following reasons:

• It is much easier and requires less steps, because you are already authenticated with GitHub, so you don't need to share secret keys across services like you do when coordinate Travis CI and GitHub.
• It is free, with no quotas.
• Anecdotally, builds are much faster with GitHub Actions than with Travis CI, especially in terms of time spent waiting for a builder.

yossorion

What I Wish I'd Known About Equity Before Joining A Unicorn

Disclaimer: This piece is written anonymously. The names of a few particular companies are mentioned, but as common examples only.

This is a short write-up on things that I wish I'd known and considered before joining a private company (aka startup, aka unicorn in some cases). I'm not trying to make the case that you should never join a private company, but the power imbalance between founder and employee is extreme, and that potential candidates would

bowsersenior

require 'rubygems'
require 'yaml'

# A demonstration of YAML anchors, references and handling of nested values
# For more info, see: 
#   http://atechie.net/2009/07/merging-hashes-in-yaml-conf-files/

stooges = YAML::load( File.read('stooges.yml') )
# =>  {
#             "default" => {

viktorklang

/*
Copyright 2012-2021 Viktor Klang
 
   Licensed under the Apache License, Version 2.0 (the "License");
   you may not use this file except in compliance with the License.
   You may obtain a copy of the License at
 
       http://www.apache.org/licenses/LICENSE-2.0
 
   Unless required by applicable law or agreed to in writing, software

brandt

# Optimal bloom filter size and number of hashes

# Tips:
# 1. One byte per item in the input set gives about a 2% false positive rate.
# 2. The optimal number of hash functions is ~0.7x the number of bits per item.
# 3. The number of hashes dominates performance.

# Expected number of items in the collection
# n = (m * ln(2))/k;
n = 300_000

danielrw7

#!/bin/sh

command="${*}"
printf "Initialized REPL for `%s`\n" "$command"
printf "%s> " "$command"
read -r input
while [ "$input" != "" ];
do
    eval "$command $input"
    printf "%s> " "$command"

aslakknutsen

JDK 8 Released

Most of us won’t be able to use/deploy JDK 8 in production for a looong time. But that shouldn’t stop us from using it, right?

It should be possible to sneak in JDK 8 in the back way, the same way we snuck in Groovy and other libraries we wanted to use.

The Test Suite to the rescue

The Maven compiler plugin run in two separate lifecycles, compile and testCompile. Those can be configured separately.