For example, you want to set 40% alpha transparence to #000000
(black color), you need to add 66
like this #66000000
.
# <type>: (If applied, this commit will...) <subject> (Max 50 char) | |
# |<---- Using a Maximum Of 50 Characters ---->| | |
# Explain why this change is being made | |
# |<---- Try To Limit Each Line to a Maximum Of 72 Characters ---->| | |
# Provide links or keys to any relevant tickets, articles or other resources | |
# Example: Github issue #23 |
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
"A beginning programmer writes her programs like an ant builds her hill, one piece at a time, without thought for the bigger structure. Her programs will be like loose sand. They may stand for a while, but growing too big they fall apart.
Realizing this problem, the programmer will start to spend a lot of time thinking about structure. Her programs will be rigidly structured, like rock sculptures. They are solid, but when they must change, violence must be done to them.
The master programmer knows when to apply structure and when to leave things in their simple form. Her programs are like clay, solid yet malleable."
-- Master Yuan-Ma, The Book of Programming
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 |