fixes #3066: add bootsnap support

Gemfile

@@ -43,6 +43,7 @@ gem 'memcache_mock'
 gem 'memoist'
 gem 'daemons'
 gem 'oauth2'
+gem 'bootsnap'
 
 # needed for looser jpeg header compat
 gem 'ruby-imagespec', :require => "image_spec", :git => "https://github.com/r888888888/ruby-imagespec.git", :branch => "exif-fixes"

Gemfile.lock

@@ -82,6 +82,8 @@ GEM
       bcrypt (>= 3.1.3)
     bcrypt-ruby (3.1.5-x64-mingw32)
       bcrypt (>= 3.1.3)
+    bootsnap (1.0.0)
+      msgpack (~> 1.0)
     buftok (0.2.0)
     builder (3.2.3)
     byebug (9.0.6)
@@ -201,6 +203,8 @@ GEM
     minitest (5.10.1)
     mocha (1.2.1)
       metaclass (~> 0.0.1)
+    msgpack (1.1.0)
+    msgpack (1.1.0-x64-mingw32)
     multi_json (1.12.1)
     multi_xml (0.6.0)
     multipart-post (2.0.0)
@@ -385,6 +389,7 @@ DEPENDENCIES
   aws-sdk (~> 2)
   bcrypt-ruby
   bigquery!
+  bootsnap
   capistrano (~> 3.4.0)
   capistrano-deploytags (~> 1.0.0)
   capistrano-rails

config/boot.rb

@@ -1,3 +1,14 @@
 ENV['BUNDLE_GEMFILE'] ||= File.expand_path('../../Gemfile', __FILE__)
 
 require 'bundler/setup' # Set up gems listed in the Gemfile.
+require 'bootsnap'
+require 'tmpdir'
+Bootsnap.setup(
+  cache_dir: File.join(Dir.tmpdir, 'bootsnap-cache'), # Path to your cache
+  development_mode: ENV['MY_ENV'] == 'development',
+  load_path_cache: true, # Should we optimize the LOAD_PATH with a cache?
+  autoload_paths_cache: true, # Should we optimize ActiveSupport autoloads with cache?
+  disable_trace: false, # Sets `RubyVM::InstructionSequence.compile_option = { trace_instruction: false }`
+  compile_cache_iseq: true, # Should compile Ruby code into ISeq cache?
+  compile_cache_yaml: true # Should compile YAML into a cache?
+)