Class: Redlock::Client::RedisInstance

Inherits:
Object
  • Object
show all
Defined in:
lib/redlock/client.rb,
lib/redlock/testing.rb

Constant Summary collapse

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"

Instance Method Summary collapse

Constructor Details

#initialize(connection) ⇒ RedisInstance

Returns a new instance of RedisInstance.



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# File 'lib/redlock/client.rb', line 115

def initialize(connection)
  if connection.respond_to?(:client)
    @redis = connection
  else
    @redis = Redis.new(connection)
  end
end

Instance Method Details

#load_scripts ⇒ Object 



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# File 'lib/redlock/client.rb', line 141

def load_scripts
  @unlock_script_sha = @redis.script(:load, UNLOCK_SCRIPT)
  @lock_script_sha = @redis.script(:load, LOCK_SCRIPT)
end

#load_scripts_without_testing ⇒ Object 



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# File 'lib/redlock/testing.rb', line 28

def load_scripts
  @unlock_script_sha = @redis.script(:load, UNLOCK_SCRIPT)
  @lock_script_sha = @redis.script(:load, LOCK_SCRIPT)
end

#lock(resource, val, ttl, allow_new_lock) ⇒ Object 



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# File 'lib/redlock/client.rb', line 123

def lock(resource, val, ttl, allow_new_lock)
  recover_from_script_flush do
    @redis.evalsha @lock_script_sha, keys: [resource], argv: [val, ttl, allow_new_lock]
  end
rescue Redis::BaseConnectionError
  false
end

#unlock(resource, val) ⇒ Object 



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# File 'lib/redlock/client.rb', line 131

def unlock(resource, val)
  recover_from_script_flush do
    @redis.evalsha @unlock_script_sha, keys: [resource], argv: [val]
  end
rescue
  # Nothing to do, unlocking is just a best-effort attempt.
end