Module: Redis::Objects::Locks::ClassMethods

Defined in:
lib/redis/objects/locks.rb

Overview

Class methods that appear in your class when you include Redis::Objects.

Instance Method Summary collapse

Instance Method Details

#clear_lock(name, id) ⇒ Object

Clear the lock. Use with care - usually only in an Admin page to clear stale locks (a stale lock should only happen if a server crashes.)



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# File 'lib/redis/objects/locks.rb', line 57

def clear_lock(name, id)
  verify_lock_defined!(name)
  lock_name = field_key("#{name}_lock", id)
  redis.del(lock_name)
end

#lock(name, options = {}) ⇒ Object

Define a new lock. It will function like a model attribute, so it can be used alongside ActiveRecord/DataMapper, etc.



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# File 'lib/redis/objects/locks.rb', line 17

def lock(name, options={})
  options[:timeout] ||= 5  # seconds
  options[:init] = false if options[:init].nil? # default :init to false
  @redis_objects[name] = options.merge(:type => :lock)
  if options[:global]
    instance_eval "      def \#{name}_lock(&block)\n        @\#{name} ||= Redis::Lock.new(field_key(:\#{name}_lock, ''), redis, @redis_objects[:\#{name}])\n      end\n    EndMethods\n    class_eval <<-EndMethods\n      def \#{name}_lock(&block)\n        self.class.\#{name}(block)\n      end\n    EndMethods\n  else\n    class_eval <<-EndMethods\n      def \#{name}_lock(&block)\n        raise(ActiveRedis::Errors::NotSavedError) if self.new?\n        @\#{name} ||= Redis::Lock.new(field_key(:\#{name}_lock), redis, self.class.redis_objects[:\#{name}])\n      end\n    EndMethods\n  end\n\n  \n  \nend\n"

#obtain_lock(name, id, &block) ⇒ Object

Obtain a lock, and execute the block synchronously. Any other code (on any server) will spin waiting for the lock up to the :timeout that was specified when the lock was defined.

Raises:

  • (ArgumentError) 


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# File 'lib/redis/objects/locks.rb', line 48

def obtain_lock(name, id, &block)
  verify_lock_defined!(name)
  raise ArgumentError, "Missing block to #{self.name}.obtain_lock" unless block_given?
  lock_name = field_key("#{name}_lock", id)
  Redis::Lock.new(lock_name, redis, self.redis_objects[name]).lock(&block)
end