shvets / design_patterns_in_ruby

# flyweight.bsh
 
# Uses sharing to support large numbers of fine grained objects efficiently.
 
# 1. type interface
 
class Item 
  def process
  end
end 
 
# 2. type implementations
 
class MyItem1 < Item 
  def process
    puts "my item1 process"
  end
end
 
class MyItem2 < Item 
  def process
    puts "my item2 process"
  end
end
 
# 3. type factory; some kind of cache
 
class ItemCache 
  def initialize
    @item1 = MyItem1.new
    @item2 = MyItem2.new
  end
 
  def item(type) 
    if(type == 1) 
      return item1
    elsif(type == 2) 
      return item2
    end
  end
end
 
//4. test
 
cache = ItemCache.new
 
items = [ 
  cache.item(1), 
  cache.item(2),
  cache.item(2),
  cache.item(2),
  cache.item(1),
  cache.item(2),
  cache.item(1),
  cache.item(2)
]
 
for(item in items) do 
  item.process
end