Generating tokens the priam way

gen_tokens.py

#!/usr/bin/env python

import sys
import decimal
from decimal import Decimal
# Translated from netflix/priam

# MINIMUM_TOKEN = Decimal(0)
# MAXIMUM_TOKEN = Decimal(2) ** Decimal(127)

MINIMUM_TOKEN = 0
MAXIMUM_TOKEN = 2 ** 127

decimal.getcontext().prec = 40


def initial_token(size, position, offset):
    return ((MAXIMUM_TOKEN / size) * position) + offset


#*
# Creates a token given the following parameter
#
# @param my_slot
#            -- Slot where this instance has to be.
# @param rac_count
#            -- Rac count is the numeber of RAC's
# @param rac_size
#            -- number of memberships in the rac
# @param region
#            -- name of the DC where it this token is created.
#/
#
# def create_token(my_slot, total_count, region_name):
#     return initial_token(Decimal(total_count), Decimal(my_slot), Decimal(region_offset(region_name))).normalize()

def create_token(my_slot, total_count, region_name):
    return initial_token(total_count, my_slot, region_offset(region_name))



def region_offset(region):
    return java_string_hashcode(region)


def java_string_hashcode(s):
    h = 0
    for c in s:
        h = (31 * h + ord(c)) & 0xFFFFFFFF
    return ((h + 0x80000000) & 0xFFFFFFFF) - 0x80000000

def create_n_nodes_tokens_in(argv = sys.argv[:]):
    count  = int(argv[1])
    region = argv[2]
    for position in range(count):
        print "{0}: {1:.0f}".format(region, create_token(position, count, region))



def main():
    create_n_nodes_tokens_in()


if __name__ == '__main__':
    main()

how_java_looks

user> (pprint_token_list 12 "us-east-1")
("us-east-1 0: 1808575600"
 "us-east-1 1: 14178431955039102644307275311465584410"
 "us-east-1 2: 28356863910078205288614550621122593220"
 "us-east-1 3: 42535295865117307932921825930779602030"
 "us-east-1 4: 56713727820156410577229101240436610840"
 "us-east-1 5: 70892159775195513221536376550093619650"
 "us-east-1 6: 85070591730234615865843651859750628460"
 "us-east-1 7: 99249023685273718510150927169407637270"
 "us-east-1 8: 113427455640312821154458202479064646080"
 "us-east-1 9: 127605887595351923798765477788721654890"
 "us-east-1 10: 141784319550391026443072753098378663700"
 "us-east-1 11: 155962751505430129087380028408035672510")
nil
user> 

how_this_looks

12 node:

(sedeploy)753 pn@pn-mbp 00:40 ~/dvcs/github/netflix/Priam $ python ~/tmp/assign_token.py 12 us-east-1
us-east-1: 1808575600
us-east-1: 14178431955039101857246194831382806528
us-east-1: 28356863910078203714492389662765613056
us-east-1: 42535295865117307932921825928971026432
us-east-1: 56713727820156407428984779325531226112
us-east-1: 70892159775195516369780698461381853184
us-east-1: 85070591730234615865843651857942052864
us-east-1: 99249023685273724806639570993792679936
us-east-1: 113427455640312814857969558651062452224
us-east-1: 127605887595351923798765477786913079296
us-east-1: 141784319550391032739561396922763706368
us-east-1: 155962751505430122790891384580033478656

λ ~/Downloads/ java -jar jython-standalone-2.5.3.jar get_tokens.py 12 us-east-1
us-east-1: 1808575600
us-east-1: 14178431955039102644307275311465584410
us-east-1: 28356863910078205288614550621122593220
us-east-1: 42535295865117307932921825930779602030
us-east-1: 56713727820156410577229101240436610840
us-east-1: 70892159775195513221536376550093619650
us-east-1: 85070591730234615865843651859750628460
us-east-1: 99249023685273718510150927169407637270
us-east-1: 113427455640312821154458202479064646080
us-east-1: 127605887595351923798765477788721654890
us-east-1: 141784319550391026443072753098378663700
us-east-1: 155962751505430129087380028408035672510