| 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 |
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
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
| /*** MIT LICENSE | |
| Copyright (c) 2022 torcado | |
| Permission is hereby granted, free of charge, to any person | |
| obtaining a copy of this software and associated documentation | |
| files (the "Software"), to deal in the Software without | |
| restriction, including without limitation the rights to use, | |
| copy, modify, merge, publish, distribute, sublicense, and/or sell | |
| copies of the Software, and to permit persons to whom the | |
| Software is furnished to do so, subject to the following |
Looking for support tables for HTML/CSS/JavaScript features or details on their implementation status in major browsers?
And then there’s Can I use…?.
Someone sent me an email asking me what advice I had for new developers. I get this question a bunch, so I wanted to put all my thoughts in one place, that I can update as I get more ideas!
I answered this a bunch on my AMA repo, so here's some initial general answers, before I get to some of the specific questions:
| int doubler(int x) { | |
| return 2 * x; | |
| } |
| //------------------------------------------------------------------------------ | |
| // NetClient.cc | |
| //------------------------------------------------------------------------------ | |
| #if ORYOL_WINDOWS | |
| #define _WINSOCK_DEPRECATED_NO_WARNINGS (1) | |
| #include <WinSock2.h> | |
| typedef int ssize_t; | |
| #endif | |
| #if ORYOL_POSIX |
| HTTPPort 8090 | |
| HTTPBindAddress 0.0.0.0 | |
| MaxHTTPConnections 200 | |
| MaxClients 100 | |
| MaxBandWidth 500000 | |
| CustomLog - | |
| <Feed camera.ffm> | |
| File /tmp/camera.ffm | |
| FileMaxSize 200M |