| Latency Comparison Numbers | |
| -------------------------- | |
| 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 | |
| Send 1K bytes over 1 Gbps network 10,000 ns 0.01 ms | |
| Read 4K randomly from SSD* 150,000 ns 0.15 ms |
In August 2007 a hacker found a way to expose the PHP source code on facebook.com. He retrieved two files and then emailed them to me, and I wrote about the issue:
http://techcrunch.com/2007/08/11/facebook-source-code-leaked/
It became a big deal:
http://www.techmeme.com/070812/p1#a070812p1
The two files are index.php (the homepage) and search.php (the search page)
| # 30 minutes Lisp in Ruby | |
| # Hong Minhee <http://dahlia.kr/> | |
| # | |
| # This Lisp implementation does not provide a s-expression reader. | |
| # Instead, it uses Ruby syntax like following code: | |
| # | |
| # [:def, :factorial, | |
| # [:lambda, [:n], | |
| # [:if, [:"=", :n, 1], | |
| # 1, |