This content moved here: https://exploringjs.com/impatient-js/ch_arrays.html#quickref-arrays
Seven different types of CSS attribute selectors | |
// This attribute exists on the element | |
[value] | |
// This attribute has a specific value of cool | |
[value='cool'] | |
// This attribute value contains the word cool somewhere in it | |
[value*='cool'] |
I recently had several days of extremely frustrating experiences with service workers. Here are a few things I've since learned which would have made my life much easier but which isn't particularly obvious from most of the blog posts and videos I've seen.
I'll add to this list over time – suggested additions welcome in the comments or via twitter.com/rich_harris.
Chrome 51 has some pretty wild behaviour related to console.log
in service workers. Canary doesn't, and it has a load of really good service worker related stuff in devtools.
#!/bin/bash | |
# Script for placing sudoers.d files with syntax-checking | |
# Making a temporary file to contain the sudoers-changes to be pre-checked | |
TMP=$(mktemp -t vagrant_sudoers) | |
cat /etc/sudoers > $TMP | |
cat >> $TMP <<EOF | |
# Allow passwordless startup of Vagrant when using NFS. | |
# see http://docs.vagrantup.com/v2/synced-folders/nfs.html |
I've had the opertunity to try a variety of different server configurations but never really got around to trying HHVM with Magento until recently. I thought I would share a detailed walkthrough of configuring a single instance Magento server running Nginx + Fast CGI + HHVM / PHP-FPM + Redis + Percona. For the purpose of this blog post I'm assuming you are using Fedora, CentOS, or in my case RHEL 6.5.
Please note: I'm 100% open to suggestions. If you see something I did that needs to be done a different way, please let me know. I haven't included my Perconca my.conf file yet. I will shortly. Also I plan on trying this same test with HHVM 3.3 and PHP 7.
rpm -Uvh http://download.fedoraproject.org/pub/epel/6/i386/epel-release-6-8.noarch.rpm
rpm -Uvh http://rpms.famillecollet.com/enterprise/remi-release-6.rpm
rpm -Uvh http://mirror.webtatic.com/yum/el6/latest.rpm
<?php | |
ignore_user_abort(true); | |
function syscall ($cmd, $cwd) { | |
$descriptorspec = array( | |
1 => array('pipe', 'w'), // stdout is a pipe that the child will write to | |
2 => array('pipe', 'w') // stderr |
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
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 |
These set of scripts are for Magento 1. For Magento 2, see this Gist.