Add derailed_benchmarks gem.

Gemfile

@@ -69,6 +69,7 @@ group :development do
   gem 'benchmark-ips', require: "benchmark/ips"
   gem 'listen'
   gem 'solargraph'
+  gem 'derailed_benchmarks'
 end
 
 group :test do

Gemfile.lock

@@ -132,6 +132,7 @@ GEM
     crass (1.0.6)
     daemons (1.4.1)
     dante (0.2.0)
+    dead_end (3.1.0)
     debug_inspector (1.1.0)
     declarative (0.0.20)
     delayed_job (4.1.9)
@@ -139,6 +140,18 @@ GEM
     delayed_job_active_record (4.1.6)
       activerecord (>= 3.0, < 6.2)
       delayed_job (>= 3.0, < 5)
+    derailed_benchmarks (2.1.1)
+      benchmark-ips (~> 2)
+      dead_end
+      get_process_mem (~> 0)
+      heapy (~> 0)
+      memory_profiler (>= 0, < 2)
+      mini_histogram (>= 0.3.0)
+      rack (>= 1)
+      rack-test
+      rake (> 10, < 14)
+      ruby-statistics (>= 2.1)
+      thor (>= 0.19, < 2)
     diff-lcs (1.4.4)
     digest-crc (0.6.4)
       rake (>= 12.0.0, < 14.0.0)
@@ -225,6 +238,8 @@ GEM
       multi_json (~> 1.11)
       os (>= 0.9, < 2.0)
       signet (>= 0.16, < 2.a)
+    heapy (0.2.0)
+      thor
     hsluv (1.0.1)
     http (4.4.1)
       addressable (~> 2.3)
@@ -262,6 +277,7 @@ GEM
       rack-contrib (>= 1.1, < 3)
       railties (>= 3.0.0, < 7)
     method_source (1.0.0)
+    mini_histogram (0.3.1)
     mini_mime (1.1.2)
     mini_portile2 (2.6.1)
     minitest (5.15.0)
@@ -389,6 +405,7 @@ GEM
       rack (>= 1.1)
       rubocop (>= 1.7.0, < 2.0)
     ruby-progressbar (1.11.0)
+    ruby-statistics (3.0.0)
     ruby-vips (2.1.4)
       ffi (~> 1.12)
     ruby2_keywords (0.0.5)
@@ -502,6 +519,7 @@ DEPENDENCIES
   daemons
   delayed_job
   delayed_job_active_record
+  derailed_benchmarks
   diff-lcs
   dotenv-rails
   dtext_rb!

app/assets/config/manifest.js

@@ -0,0 +1,8 @@
+// This is the config file for Sprockets. Danbooru doesn't use Sprockets, but
+// we still need this file anyway because the derailed_benchmarks gem doesn't
+// work without it. derailed_benchmarks does `require "rails/all"`, which loads
+// Sprockets, which fails if this config file isn't present.
+//
+// https://github.com/rails/sprockets-rails/issues/444
+// https://github.com/zombocom/derailed_benchmarks
+{}

config/storage.yml

@@ -0,0 +1,7 @@
+# This is the config file for Active Storage. Danbooru doesn't use Active
+# Storage, but we still need this file anyway because the derailed_benchmarks
+# gem doesn't work without it. derailed_benchmarks does `require "rails/all"`,
+# which loads Active Storage, which fails if this config file isn't present.
+#
+# https://edgeguides.rubyonrails.org/active_storage_overview.html#setup
+# https://github.com/zombocom/derailed_benchmarks