Fun with snowflake

blizzard.rb

#First tweet on 21 Mar 2006 at 20:50:14.000 GMT (in ms)
TWEPOCH = 1288834974657 

#High 42 bytes are timestamp, low 22 are worker, datacenter and sequence bits
SHIFT = 22 

# Give it a snowflake id, it tells you what time it was created
# Will fail for very high ids because Ruby Time can only represent up to 
# Jan 18, 2038 at 19:14:07 UTC (max signed int in seconds since unix epoch)
def what_time?(id)
  Time.at(((id >> SHIFT)+TWEPOCH)/1000).utc
end

# Given a Ruby time object, it will give you the high part of a snowflake id
# Only goes up to 2038 thanks to Ruby Time limits
def id_at(time)
  ms_since_twepoch = ((time.utc.to_i*1000)-TWEPOCH)
  ms_since_twepoch << SHIFT
end

# Rough estimate (doesn't account for leap years, etc) of years from now that an id will occur
def years_from_now(id)
  seconds = ((id >> SHIFT)+TWEPOCH)/1000
  seconds_from_now = seconds-Time.now.to_i
  seconds_from_now/60.0/60/24/365
end

Doesn't Time.at use seconds? (you need ms)

nevermind, i misread it.

@ryanking Not surprised. It's not the most readable code ever. Just something I hacked together after looking at your Scala IdWorker.

here's the mock we use: http://gist.github.com/637737