Each of these commands will run an ad hoc http static server in your current (or specified) directory, available at http://localhost:8000. Use this power wisely.
$ python -m SimpleHTTPServer 8000
Each of these commands will run an ad hoc http static server in your current (or specified) directory, available at http://localhost:8000. Use this power wisely.
$ python -m SimpleHTTPServer 8000
All of the below properties or methods, when requested/called in JavaScript, will trigger the browser to synchronously calculate the style and layout*. This is also called reflow or layout thrashing, and is common performance bottleneck.
Generally, all APIs that synchronously provide layout metrics will trigger forced reflow / layout. Read on for additional cases and details.
elem.offsetLeft
, elem.offsetTop
, elem.offsetWidth
, elem.offsetHeight
, elem.offsetParent
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 |
(by @andrestaltz)
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.
This guide enables you to install (ruby-build) and use (rbenv) multiple versions of ruby, isolate project gems (gemsets and/or bundler), and automatically use appropriate combinations of rubies and gems.
# Ensure system is in ship-shape.
aptitude install git zsh libssl-dev zlib1g-dev libreadline-dev libyaml-dev
<? | |
///////////////////// | |
// slack2html | |
// by @levelsio | |
///////////////////// | |
// | |
///////////////////// | |
// WHAT DOES THIS DO? | |
///////////////////// | |
// |
// === Arrays | |
var [a, b] = [1, 2]; | |
console.log(a, b); | |
//=> 1 2 | |
// Use from functions, only select from pattern | |
var foo = () => [1, 2, 3]; |
UNLOGGED
table. This reduces the amount of data written to persistent storage by up to 2x.WITH (autovacuum_enabled=false)
on the table. This saves CPU time and IO bandwidth
on useless vacuuming of the table (since we never DELETE
or UPDATE
the table).COPY FROM STDIN
. This is the fastest possible approach to insert rows into table.time timestamp with time zone
is enough.synchronous_commit = off
to postgresql.conf
.https://github.com/djvirgen/virgen-acl Simple and elegant, create your own checks. No middleware?
https://github.com/OptimalBits/node_acl Use as middleware, create your own roles and access. Great choice.
https://github.com/tschaub/authorized Similar to connect roles... but a bit more robust? you can create roles and action, and associate many roles with that action