Module: Redis::Objects::Counters::ClassMethods

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

Overview

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

Instance Attribute Summary collapse

Instance Method Summary collapse

Instance Attribute Details

#initialized_counters ⇒ Object (readonly)

Returns the value of attribute initialized_counters.



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# File 'lib/redis/objects/counters.rb', line 18

def initialized_counters
  @initialized_counters
end

Instance Method Details

#counter(name, options = {}) ⇒ Object

Define a new counter. It will function like a regular instance method, so it can be used alongside ActiveRecord, DataMapper, etc.



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# File 'lib/redis/objects/counters.rb', line 22

def counter(name, options={})
  options[:start] ||= 0
  options[:type]  ||= options[:start] == 0 ? :increment : :decrement
  @redis_objects[name.to_sym] = options.merge(:type => :counter)
  klass_name = '::' + self.name
  if options[:global]
    instance_eval <<-EndMethods
      def #{name}
        @#{name} ||= Redis::Counter.new(redis_field_key(:#{name}), #{klass_name}.redis, #{klass_name}.redis_objects[:#{name}])
      end
    EndMethods
    class_eval <<-EndMethods
      def #{name}
        self.class.#{name}
      end
    EndMethods
  else
    class_eval <<-EndMethods
      def #{name}
        @#{name} ||= Redis::Counter.new(redis_field_key(:#{name}), #{klass_name}.redis, #{klass_name}.redis_objects[:#{name}])
      end
    EndMethods
  end
end

#decrement_counter(name, id = nil, by = 1, &block) ⇒ Object

Decrement a counter with the specified name and id. Accepts a block like the instance method. See Redis::Objects::Counter for details.



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# File 'lib/redis/objects/counters.rb', line 67

def decrement_counter(name, id=nil, by=1, &block)
  return super(name, id) unless counter_defined?(name)
  verify_counter_defined!(name, id)
  initialize_counter!(name, id)
  value = redis.decrby(redis_field_key(name, id), by).to_i
  block_given? ? rewindable_block(:increment_counter, name, id, value, &block) : value
end

#get_counter(name, id = nil) ⇒ Object

Get the current value of the counter. It is more efficient to use the instance method if possible.



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# File 'lib/redis/objects/counters.rb', line 49

def get_counter(name, id=nil)
  verify_counter_defined!(name, id)
  initialize_counter!(name, id)
  redis.get(redis_field_key(name, id)).to_i
end

#getset_counter(name, id = nil, to = nil) ⇒ Object

Set a counter to its starting value and return the old value.



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# File 'lib/redis/objects/counters.rb', line 84

def getset_counter(name, id=nil, to=nil)
  verify_counter_defined!(name, id)
  to = @redis_objects[name][:start] if to.nil?
  redis.getset(redis_field_key(name, id), to.to_i).to_i
end

#increment_counter(name, id = nil, by = 1, &block) ⇒ Object

Increment a counter with the specified name and id. Accepts a block like the instance method. See Redis::Objects::Counter for details.



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

def increment_counter(name, id=nil, by=1, &block)
  return super(name, id) unless counter_defined?(name)
  verify_counter_defined!(name, id)
  initialize_counter!(name, id)
  value = redis.incrby(redis_field_key(name, id), by).to_i
  block_given? ? rewindable_block(:decrement_counter, name, id, value, &block) : value
end

#reset_counter(name, id = nil, to = nil) ⇒ Object

Reset a counter to its starting value.



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# File 'lib/redis/objects/counters.rb', line 76

def reset_counter(name, id=nil, to=nil)
  verify_counter_defined!(name, id)
  to = @redis_objects[name][:start] if to.nil?
  redis.set(redis_field_key(name, id), to.to_i)
  true
end