Module: Redlock::Scripts

Included in:

Redlock

Defined in:

lib/redlock/scripts.rb

Constant Summary

UNLOCK_SCRIPT =

"  if redis.call(\"get\",KEYS[1]) == ARGV[1] then\n    return redis.call(\"del\",KEYS[1])\n  else\n    return 0\n  end\n"

LOCK_SCRIPT =

thanks to github.com/sbertrang/redis-distlock/blob/master/lib/Redis/DistLock.pm also github.com/sbertrang/redis-distlock/issues/2 which proposes the value-checking and @maltoe for github.com/leandromoreira/redlock-rb/pull/20#discussion_r38903633

"  if (redis.call(\"exists\", KEYS[1]) == 0 and ARGV[3] == \"yes\") or redis.call(\"get\", KEYS[1]) == ARGV[1] then\n    return redis.call(\"set\", KEYS[1], ARGV[1], \"PX\", ARGV[2])\n  end\n"

PTTL_SCRIPT =

"  return { redis.call(\"get\", KEYS[1]), redis.call(\"pttl\", KEYS[1]) }\n"

UNLOCK_SCRIPT_SHA =

We do not want to load the scripts on every Redlock::Client initialization. Hence, we rely on Redis handing out SHA1 hashes of the cached scripts and pre-calculate them instead of loading the scripts unconditionally. If the scripts have not been cached on Redis, ‘recover_from_script_flush` has our backs.

Digest::SHA1.hexdigest(UNLOCK_SCRIPT)

LOCK_SCRIPT_SHA =

Digest::SHA1.hexdigest(LOCK_SCRIPT)

PTTL_SCRIPT_SHA =

Digest::SHA1.hexdigest(PTTL_SCRIPT)