- bigdata = Web Intelligence and Big Data
- clinical skills = Teaching and Assessing Clinical Skills
- comp finance = Introduction to Computational Finance and Financial Econometrics
- data sci = Introduction to Data Science
- dmathgen = 离散数学概论 Discrete Mathematics Generality
- global introuslaw = The Global Student's Introduction to U.S. Law
- global theatre = Theatre and Globalization
- global theatre = Theatre and Globalization
- inforiskman = Information Security and Risk Management in Context
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
(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.
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 |
Ok, I geeked out, and this is probably more information than you need. But it completely answers the question. Sorry. ☺
Locally, I'm at this commit:
$ git show
commit d6cd1e2bd19e03a81132a23b2025920577f84e37
Author: jnthn <[email protected]>
Date: Sun Apr 15 16:35:03 2012 +0200
When I added FIRST/NEXT/LAST, it was idiomatic but not quite so fast. This makes it faster. Another little bit of masak++'s program.
// Example 1 | |
mediator.name = 'Doug'; | |
mediator.subscribe('nameChange', function(arg){ | |
console.log(this.name); | |
this.name = arg; | |
console.log(this.name); | |
}); | |
mediator.publish('nameChange', 'Jorn'); |