Add Redis Functions: SETIFHIGHER, SETIFLOWER, ZADDIFHIGHER, ZADDIFLOWER

LUA Scripts that add these new functions for Redis.

These are very useful to me for things like analytics or "gamification". Use SCRIPT LOAD in the console to add these functions

SETIFHIGHER

Sset or update key if new value is higher than current. If not exists returns OK, if updated returns the increment , if not updated return 0

SCRIPT LOAD "local c = tonumber(redis.call('get', KEYS[1])); if c then if tonumber(ARGV[1]) > c then redis.call('set', KEYS[1], ARGV[1]) return tonumber(ARGV[1]) - c else return 0 end else return redis.call('set', KEYS[1], ARGV[1]) end"

# Use:
EVALSHA "2ab979bc4b89ab15c14805586c33d898f99a53d4" 1 key 245

 SETIFLOWER

Set or update key if new value is lower than current. If not exists returns OK, if updated returns the decrement , if not updated returns 0

SCRIPT LOAD "local c = tonumber(redis.call('get', KEYS[1])); if c then if tonumber(ARGV[1]) < c then redis.call('set', KEYS[1], ARGV[1]) return tonumber(ARGV[1]) - c else return 0 end else return redis.call('set', KEYS[1], ARGV[1]) end"

# Use:
EVALSHA "3b99f44a33619dca62593053ce4bf52f7b432880" 1 key 3535

ZADDIFHIGHER

Set or update sorted set if new value is higher than current. If not exists returns "OK", if updated returns the increment, if not updated returns 0

SCRIPT LOAD "local c = tonumber(redis.call('zscore', KEYS[1], ARGV[1])); if c then  if tonumber(KEYS[2]) > c then redis.call('zadd', KEYS[1], KEYS[2], ARGV[1]) return tonumber(KEYS[2]) - c else return 0 end else redis.call('zadd', KEYS[1], KEYS[2], ARGV[1]) return 'OK' end"

# Use:
EVALSHA "8d1c75ea83b6f8f9ba5f7f048188da7ee6c4b35f" 2 set 10 member

 ZADDIFLOWER

Set or update sorted set if new value is lower than current. If not exists returns "OK", if updated returns the decrement, if not updated returns 0

SCRIPT LOAD "local c = tonumber(redis.call('zscore', KEYS[1], ARGV[1])); if c then  if tonumber(KEYS[2]) < c then redis.call('zadd', KEYS[1], KEYS[2], ARGV[1]) return tonumber(KEYS[2]) - c else return 0 end else redis.call('zadd', KEYS[1], KEYS[2], ARGV[1]) return 'OK' end"

# Use:
EVALSHA "1f8b6cf618d14c48e23b483fc42df71b6bea582e" 2 set 10 member

 Basic Benchmarks

# SET key val # 87489.06
# SETRANGE key2 6 "Redis" # 75757.58 req/s
# INCR  key 245 # 70224.72 req/s
# INCRBY key 245 22 # 67114.09 req/s
# EVAL SET key val # 46296.29 req/s
# SETIFHIGHER # 41666.67 req/s
# SETIFLOWER # 41054.12 req/s
# ZADDIFHIGHER # 34952.81 req/s
# ZADDIFLOWER # 34831.07 req/s