(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.
=Navigating= | |
visit('/projects') | |
visit(post_comments_path(post)) | |
=Clicking links and buttons= | |
click_link('id-of-link') | |
click_link('Link Text') | |
click_button('Save') | |
click('Link Text') # Click either a link or a button | |
click('Button Value') |
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 |
# Run this in the project repo from the command-line | |
# http://stackoverflow.com/a/4593065/99923 | |
git log --shortstat --author "Xeoncross" --since "2 weeks ago" --until "1 week ago" | grep "files changed" | awk '{files+=$1; inserted+=$4; deleted+=$6} END {print "files changed", files, "lines inserted:", inserted, "lines deleted:", deleted}' |
(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.
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