dRubyで遊んでみよう

client.rb

require 'drb/drb'
require 'logger'
require_relative './user'

URL = 'druby://localhost:8787'

server = DRbObject.new_with_uri(URL)
logger = Logger.new(STDOUT)
3.times do
  logger.info "call server"
  user = server.fetch
  logger.info "user = #{user}, name = #{user.name}, created_at = #{user.created_at}"
  sleep 3
end

server.rb

require 'drb/drb'
require_relative './user'
require 'logger'

URL = 'druby://localhost:8787'

class Server
  def initialize(logger)
    @logger = logger
  end

  def fetch
    logger.info "call fetch"
    name = %w(芹沢鴨 近藤勇 新見錦 斎藤一 土方歳三 大野右仲 相馬主計).sample
    ::User.new(name: name, created_at: Time.now)
  end

  def logger
    @logger
  end
end

logger = Logger.new(STDOUT)

DRb.start_service(URL, Server.new(logger), :start_level => 1)
logger.info "start server"
DRb.thread.join
logger.info "end server"

user.rb

class User
  attr_reader :name, :created_at
  def initialize(name:, created_at:)
    @name = name
    @created_at = created_at
  end
end

ターミナルでserverを実行しつつ

% ruby server.rb

別のターミナルでclientを動かす
そうすると、serverで生成されたオブジェクトがclientで扱えて便利〜〜

% ruby client.rb
I, [2022-09-10T16:39:12.605202 #76033]  INFO -- : call server
I, [2022-09-10T16:39:12.610869 #76033]  INFO -- : user = #<User:0x00000001031b2408>, name = 新見錦, created_at = 2022-09-10 16:39:12 +0900
I, [2022-09-10T16:39:15.611280 #76033]  INFO -- : call server
I, [2022-09-10T16:39:15.613116 #76033]  INFO -- : user = #<User:0x00000001031b1300>, name = 近藤勇, created_at = 2022-09-10 16:39:15 +0900
I, [2022-09-10T16:39:18.614358 #76033]  INFO -- : call server
I, [2022-09-10T16:39:18.619264 #76033]  INFO -- : user = #<User:0x00000001031b0540>, name = 芹沢鴨, created_at = 2022-09-10 16:39:18 +0900