Class: RedisRds::Mutex

Inherits:
String show all
Defined in:
lib/redis_rds/mutex.rb

Constant Summary collapse

DEFAULT_EXPIRY = 
60.seconds

Instance Attribute Summary collapse

Attributes inherited from Object

#redis_key

Class Method Summary collapse

Instance Method Summary collapse

Methods inherited from String

#append, #decr, #decrby, #get, #incr, #incrby, #length, #set, #setex, #setnx

Methods inherited from Object

configure, connection, #connection, #delete, #dump, #exists?, #expire, #expireat, flushdb, #namespace, #persist, #pttl, #ttl, #type

Constructor Details

#initialize(id, expiry = DEFAULT_EXPIRY, owner = '') ⇒ Mutex

Returns a new instance of Mutex.



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# File 'lib/redis_rds/mutex.rb', line 7

def initialize(id, expiry = DEFAULT_EXPIRY, owner = '')
  super("#{namespace}:mutex:#{id}")

  @id = id
  @expiry = expiry
  @owner = owner.blank? ? generate_owner : owner
end

Instance Attribute Details

#expiry ⇒ Object (readonly)

Returns the value of attribute expiry.



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# File 'lib/redis_rds/mutex.rb', line 5

def expiry
  @expiry
end

#id ⇒ Object (readonly)

Returns the value of attribute id.



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# File 'lib/redis_rds/mutex.rb', line 5

def id
  @id
end

Class Method Details

.unserialize(serialized) ⇒ Object 



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# File 'lib/redis_rds/mutex.rb', line 51

def unserialize(serialized)
  return self.new(*serialized)
end

Instance Method Details

#lock ⇒ Object 



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# File 'lib/redis_rds/mutex.rb', line 15

def lock
  connection.set(@redis_key, @owner, ex: @expiry, nx: true)
  return locked?
end

#locked? ⇒ Boolean Also known as: owned?

Returns:

  • (Boolean) 


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# File 'lib/redis_rds/mutex.rb', line 20

def locked?
  return connection.get(@redis_key) == @owner
end

#release ⇒ Object 



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# File 'lib/redis_rds/mutex.rb', line 25

def release
  self.delete if owned?
end

#serialize ⇒ Object 



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# File 'lib/redis_rds/mutex.rb', line 29

def serialize
  [@id, @expiry, @owner]
end

#synchronize ⇒ Object 



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# File 'lib/redis_rds/mutex.rb', line 33

def synchronize
  if self.lock
    begin
      yield if block_given?
    ensure
      self.release
    end
  end
end