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}-#{sprintf('%012x', counter)}".freeze end end end end