Profile memory usage from processing HTML contents

.github/workflows/actions/munge_gemfile.rb

@@ -0,0 +1,8 @@
+# frozen_string_literal: true
+
+CONTENTS = <<~RUBY
+  source 'https://rubygems.org'
+  gemspec
+RUBY
+
+File.open('Gemfile', 'wb') { |f| f.puts CONTENTS }

.github/workflows/memprof.yml

@@ -0,0 +1,38 @@
+name: Memory Profile
+on:
+  push:
+    branches:
+      - master
+  pull_request:
+    branches:
+      - master
+
+jobs:
+  memory_profile:
+    if: "!contains(github.event.commits[0].message, '[ci skip]')"
+    runs-on: "ubuntu-latest"
+    steps:
+      - uses: actions/checkout@master
+      - uses: actions/setup-ruby@v1
+        with:
+          ruby-version: '2.7'
+      - name: Set up Dependencies Cache
+        uses: actions/cache@v1
+        with:
+          path: vendor/bundle
+          key: ubuntu-latest-gems
+          restore-keys: |
+            ubuntu-latest-gems-
+      - name: Install dependencies
+        run: |
+          bundle config path vendor/bundle
+          bundle install -j8
+          bundle exec rake gem:spec
+          bundle exec ruby .github/workflows/actions/munge_gemfile.rb
+          bundle install -j8
+      - name: Compile Nokogiri
+        run: bundle exec rake compile
+      - name: Memory Profile of parsing and serializing HTML Document
+        run: bundle exec rake memprof:html_doc
+      - name: Memory Profile of parsing and serializing HTML Document Fragment
+        run: bundle exec rake memprof:html_doc_frag

Gemfile

@@ -13,6 +13,7 @@ gem "hoe-debugging", "~>2.0", :group => [:development, :test]
 gem "hoe-gemspec", "~>1.0", :group => [:development, :test]
 gem "hoe-git", "~>1.6", :group => [:development, :test]
 gem "hoe-markdown", "~>1.1", :group => [:development, :test]
+gem "memory_profiler", "~>0.9", :group => [:development, :test]
 gem "minitest", "~>5.8", :group => [:development, :test]
 gem "racc", "~>1.5.0", :group => [:development, :test]
 gem "rake", "~>13.0", :group => [:development, :test]

Rakefile

@@ -54,6 +54,7 @@ HOE = Hoe.spec 'nokogiri' do
     ["hoe-gemspec", "~> 1.0"],
     ["hoe-git", "~> 1.6"],
     ["hoe-markdown", "~> 1.1"],
+    ["memory_profiler", "~> 0.9"],
     ["minitest", "~> 5.8"],
     ["racc", "~> 1.5.0"],
     ["rake", "~> 13.0"],
@@ -80,6 +81,7 @@ require_relative "tasks/debug"
 require_relative "tasks/docker"
 require_relative "tasks/docs-linkify"
 require_relative "tasks/rubocop"
+require_relative "tasks/memprof"
 require_relative "tasks/set-version-to-timestamp"
 
 # work around Hoe's inflexibility about the default tasks

tasks/memprof.rb

@@ -0,0 +1,34 @@
+# frozen_string_literal: true
+
+namespace :memprof do
+  require "memory_profiler"
+  module NokoMemProf
+    def self.profile abs_path
+      puts "\nTesting with Nokogiri v" + Nokogiri::VERSION.to_s
+      puts
+      contents = File.read abs_path
+      MemoryProfiler.report do
+        1000.times { yield contents  }
+      end.pretty_print(scale_bytes: true, normalize_paths: true)
+    end
+  end
+
+
+  task :html_doc do
+    require "nokogiri"
+
+    abs_path = File.expand_path("../test/files/fixture.html", __dir__)
+    NokoMemProf.profile(abs_path) do |contents|
+      Nokogiri::HTML::Document.parse(contents).to_html
+    end
+  end
+
+  task :html_doc_frag do
+    require "nokogiri"
+
+    abs_path = File.expand_path("../test/files/fixture_body.html", __dir__)
+    NokoMemProf.profile(abs_path) do |contents|
+      Nokogiri::HTML::DocumentFragment.parse(contents).to_html
+    end
+  end
+end