lib/celluloid/internals/uuid.rb
require "securerandom"
module Celluloid
module Internals
# Clearly Ruby doesn't have enough UUID libraries
# This one aims to be fast and simple with good support for multiple threads
# If there's a better UUID library I can use with similar multithreaded
# performance, I certainly wouldn't mind using a gem for this!
module UUID
values = SecureRandom.hex(9).match(/(.{8})(.{4})(.{3})(.{3})/)
PREFIX = "#{values[1]}-#{values[2]}-4#{values[3]}-8#{values[4]}".freeze
BLOCK_SIZE = 0x10000
@counter = 0
@counter_mutex = Mutex.new
def self.generate
thread = Thread.current
unless thread.uuid_limit
@counter_mutex.synchronize do
block_base = @counter
@counter += BLOCK_SIZE
thread.uuid_counter = block_base
thread.uuid_limit = @counter - 1
end
end
counter = thread.uuid_counter
if thread.uuid_counter >= thread.uuid_limit
thread.uuid_counter = thread.uuid_limit = nil
else
thread.uuid_counter += 1
end
"#{PREFIX}-#{format('%012x', counter)}".freeze
end
end
end
end