snowflake/README.md

Snowflake: a 64-bit UUID generator

Original design by Twitter.

1> application:start(snowflake).
2> snowflake:new().
<<0,231,97,68,12,192,0,0>>
3> snowflake:serialize(snowflake:new()).
<<"AOdiTg5AAAA=">>
4> sets:size(sets:from_list([snowflake:new() || _I <- lists:seq(1,100000)])).
100000
5> lists:map(fun ({T, _}) -> T end,[timer:tc(snowflake, new, []) || _I <- lists:seq(1,100)]).
[93,46,42,42,42,53,55,43,42,43,73,36,34,33,39,52,48,39,35,
 54,36,34,33,34,40,35,33,33,34|...]

To do

• Fix for NTP adjustments

  Sometimes NTP will repeat milliseconds, but this violates the strict ordering of snowflake. Snowflake should keep track of the last seen time and wait until NTP catches back up so as to ensure monotonicity.