gistfile1.rb

#

require 'rubygems'
require 'spec'
require 'lru_cache'

describe LruCache, 'when Lru called' do
  before(:all) do
    puts 'Test Kaisi'
  end

#  before do
#    @lrucache = LruCache.new
#  end

  it 'should be construct.' do
    @lrucache = LruCache.new(2)
    @lrucache.size.should == 2
  end

  it 'size 3 no construct.' do
    @lrucache = LruCache.new(3)
    @lrucache.size.should == 3
  end

  it 'if put' do
    @lrucache = LruCache.new(3)
    @lrucache.put("a", "dataA")
  end
  it 'if get' do
    @lrucache = LruCache.new(3)
    @lrucache.get("a")
  end
  it 'if put and get ' do
    @lrucache = LruCache.new(3)
    @lrucache.put("a", "dataA")
    @lrucache.get("a").should == "dataA"
  end
  it 'if put and get ' do
    @lrucache = LruCache.new(3)
    @lrucache.put("b", "dataB")
    @lrucache.get("b").should == "dataB"
  end

  it 'if put put and get get' do
    @lrucache = LruCache.new(3)
    @lrucache.put("a", "dataA")
    @lrucache.put("b", "dataB")
    @lrucache.get("a").should == "dataA"
    @lrucache.get("b").should == "dataB"
  end

  it 'if put put put and get get get' do
    @lrucache = LruCache.new(3)
    @lrucache.put("a", "dataA")
    @lrucache.put("b", "dataB")
    @lrucache.put("c", "dataC")
    @lrucache.get("a").should == "dataA"
    @lrucache.get("b").should == "dataB"
    @lrucache.get("c").should == "dataC"
  end

  it 'if put put put and which is oldest' do
    @lrucache = LruCache.new(3)
    @lrucache.put("a", "dataA")
    @lrucache.put("b", "dataB")
    @lrucache.put("c", "dataC")
    @lrucache.elder().should == "a"
  end

  it 'if put put put and which is oldest' do
    @lrucache = LruCache.new(3)
    @lrucache.put("a", "dataA")
    @lrucache.put("b", "dataB")
    @lrucache.put("c", "dataC")
    @lrucache.elder().should == "a"
  end

  it 'if put put put and which is oldest' do
    @lrucache = LruCache.new(3)
    @lrucache.put("b", "dataB")
    @lrucache.put("c", "dataC")
    @lrucache.put("a", "dataA")
    @lrucache.elder().should == "b"
  end

  it 'if put put put and which is oldest' do
    @lrucache = LruCache.new(2)
    @lrucache.put("a", "dataA")
    @lrucache.put("b", "dataB")
    @lrucache.put("c", "dataC")
    @lrucache.elder().should == "b"
  end

  it 'if put put put and which is oldest' do
    @lrucache = LruCache.new(3)
    @lrucache.put("a", "dataA")
    @lrucache.put("b", "dataB")
    @lrucache.put("c", "dataC")
    @lrucache.put("d", "dataD")
    @lrucache.elder().should == "b"
  end

  after(:all) do
    puts 'Test Owari'
  end
end

gistfile2.rb

#
class LruCache
  attr_accessor :size
  def initialize(size)
    @size = size
    @cache = {}
    @oldest = nil
    @age = {}
  end
  def put(key, value)
    @cache[key] =  value
    @age.each do |k, v|
      @age[k] += 1
    end
    @age[key] = 0
    if @oldest == nil
      @oldest = key
    end
  end
  def get(key)
    @cache[key]
  end
  def elder
    ret = nil
    old = 0
    @age.each do |k, v|
      if old > v
        old = v
        ret = k
      end
    end
    ret
  end
end