Add support for firefox profile viewer

Author: dalehamel

README.md

@@ -282,11 +282,16 @@ report = AppProfiler.run(mode: :cpu) do
   # ...
 end
 
-report.view # opens the profile locally in speedscope.
+report.view # opens the profile locally in speedscope or firefox profiler, as appropriate
 ```
 
 Profile files can be found locally in your rails app at `tmp/app_profiler/*.json`.
 
+**Note** In development, if using the SpeedscopeRemoteViewer for stackprof
+or if using Vernier, a route for `/app_profiler` will be added to the application.
+If using Vernier, a route for `/from-url` is also added. These will be handled
+in middlewares, before any application routing logic. There is a small chance
+that these could shadow existing routes in the application.
 
 ## Storage backends
 
@@ -328,6 +333,8 @@ Rails.application.config.app_profiler.backend = AppProfiler::StackprofBackend #
 
 By default, the stackprof backend will be used.
 
+In local development, changing the backend will change whether the profile is viewed in speedscope or firefox-profiler.
+
 ## Running tests
 
 ```

lib/app_profiler.rb

@@ -28,8 +28,9 @@ module Storage
 
   module Viewer
     autoload :BaseViewer, "app_profiler/viewer/base_viewer"
-    autoload :SpeedscopeViewer, "app_profiler/viewer/speedscope_viewer"
-    autoload :SpeedscopeRemoteViewer, "app_profiler/viewer/speedscope_remote_viewer"
+    autoload :SpeedscopeViewer, "app_profiler/viewer/speedscope"
+    autoload :SpeedscopeRemoteViewer, "app_profiler/viewer/remote/speedscope"
+    autoload :FirefoxRemoteViewer, "app_profiler/viewer/remote/firefox"
   end
 
   require "app_profiler/middleware"
@@ -51,8 +52,10 @@ module Viewer
   mattr_reader   :profile_url_formatter,
     default: DefaultProfileFormatter
 
+  mattr_accessor :gecko_viewer_package, default: "https://github.com/tenderlove/profiler#v0.0.2"
   mattr_accessor :storage, default: Storage::FileStorage
-  mattr_accessor :viewer, default: Viewer::SpeedscopeViewer
+  mattr_accessor :viewer, default: Viewer::SpeedscopeViewer # DEPRECATED
+  mattr_accessor :speedscope_viewer, default: Viewer::SpeedscopeViewer
   mattr_accessor :middleware, default: Middleware
   mattr_accessor :server, default: Server
   mattr_accessor :upload_queue_max_length, default: 10
@@ -186,6 +189,17 @@ def clear
       @backend.stop if @backend&.running?
       @backend = nil
     end
+
+    # DEPRECATIONS
+    def viewer
+      ActiveSupport::Deprecation.warn("viewer is deprecated, use speedscope_viewer instead")
+      @viewer
+    end
+
+    def viewer=(viewer)
+      ActiveSupport::Deprecation.warn("viewer= is deprecated, use speedscope_viewer= instead")
+      @viewer = viewer
+    end
   end
 
   require "app_profiler/railtie" if defined?(Rails::Railtie)

lib/app_profiler/profile/stackprof.rb

@@ -13,7 +13,7 @@ def format
     end
 
     def view(params = {})
-      AppProfiler.viewer.view(self, **params)
+      AppProfiler.speedscope_viewer.view(self, **params)
     end
   end
 end

lib/app_profiler/profile/vernier.rb

@@ -13,7 +13,7 @@ def format
     end
 
     def view(params = {})
-      raise NotImplementedError
+      Viewer::FirefoxRemoteViewer.view(self, **params)
     end
   end
 end

lib/app_profiler/railtie.rb

@@ -11,7 +11,8 @@ class Railtie < Rails::Railtie
       AppProfiler.logger = app.config.app_profiler.logger || Rails.logger
       AppProfiler.root = app.config.app_profiler.root || Rails.root
       AppProfiler.storage = app.config.app_profiler.storage || Storage::FileStorage
-      AppProfiler.viewer = app.config.app_profiler.viewer || Viewer::SpeedscopeViewer
+      AppProfiler.viewer = app.config.app_profiler.viewer || Viewer::SpeedscopeRemoteViewer
+      AppProfiler.speedscope_viewer = app.config.app_profiler.speedscope_viewer || AppProfiler.viewer
       AppProfiler.storage.bucket_name = app.config.app_profiler.storage_bucket_name || "profiles"
       AppProfiler.storage.credentials = app.config.app_profiler.storage_credentials || {}
       AppProfiler.middleware = app.config.app_profiler.middleware || Middleware
@@ -41,12 +42,16 @@ class Railtie < Rails::Railtie
       AppProfiler.profile_enqueue_failure = app.config.app_profiler.profile_enqueue_failure
       AppProfiler.after_process_queue = app.config.app_profiler.after_process_queue
       AppProfiler.backend = app.config.app_profiler.profiler_backend || :stackprof
+      AppProfiler.gecko_viewer_package = app.config.app_profiler.gecko_viewer_package || "https://github.com/firefox-devtools/profiler"
     end
 
     initializer "app_profiler.add_middleware" do |app|
       unless AppProfiler.middleware.disabled
-        if AppProfiler.viewer == Viewer::SpeedscopeRemoteViewer
-          app.middleware.insert_before(0, Viewer::SpeedscopeRemoteViewer::Middleware)
+        if Rails.env.development? || Rails.env.test?
+          if AppProfiler.speedscope_viewer == Viewer::SpeedscopeRemoteViewer
+            app.middleware.insert_before(0, Viewer::SpeedscopeRemoteViewer::Middleware)
+          end
+          app.middleware.insert_before(0, Viewer::FirefoxRemoteViewer::Middleware)
         end
         app.middleware.insert_before(0, AppProfiler.middleware)
       end

lib/app_profiler/viewer/base_viewer.rb

@@ -1,5 +1,8 @@
 # frozen_string_literal: true
 
+gem "rails-html-sanitizer", ">= 1.6.0"
+require "rails-html-sanitizer"
+
 module AppProfiler
   module Viewer
     class BaseViewer
@@ -12,6 +15,101 @@ def view(profile, params = {})
       def view(_params = {})
         raise NotImplementedError
       end
+
+      class BaseMiddleware
+        class Sanitizer < Rails::HTML::Sanitizer.best_supported_vendor.safe_list_sanitizer
+          self.allowed_tags = Set.new([
+            "strong", "em", "b", "i", "p", "code", "pre", "tt", "samp", "kbd", "var", "sub",
+            "sup", "dfn", "cite", "big", "small", "address", "hr", "br", "div", "span", "h1",
+            "h2", "h3", "h4", "h5", "h6", "ul", "ol", "li", "dl", "dt", "dd", "abbr", "acronym",
+            "a", "img", "blockquote", "del", "ins", "script",
+          ])
+        end
+
+        private_constant(:Sanitizer)
+
+        def self.id(file)
+          file.basename.to_s
+        end
+
+        def initialize(app)
+          @app = app
+        end
+
+        def call(env)
+          request = Rack::Request.new(env)
+
+          return index(env) if %r(\A/app_profiler/?\z).match?(request.path_info)
+
+          @app.call(env)
+        end
+
+        protected
+
+        def id(file)
+          self.class.id(file)
+        end
+
+        def profile_files
+          AppProfiler.profile_root.glob("**/*.json")
+        end
+
+        def render(html)
+          [
+            200,
+            { "Content-Type" => "text/html" },
+            [
+              +<<~HTML,
+                <!doctype html>
+                <html>
+                  <head>
+                    <title>App Profiler</title>
+                  </head>
+                  <body>
+                    #{sanitizer.sanitize(html)}
+                  </body>
+                </html>
+              HTML
+            ],
+          ]
+        end
+
+        def sanitizer
+          @sanitizer ||= Sanitizer.new
+        end
+
+        def viewer(_env, path)
+          raise NotImplementedError
+        end
+
+        def show(env, id)
+          raise NotImplementedError
+        end
+
+        def index(_env)
+          render(
+            (+"").tap do |content|
+              content << "<h1>Profiles</h1>"
+              profile_files.each do |file|
+                viewer = if file.to_s.end_with?(AppProfiler::VernierProfile::FILE_EXTENSION)
+                  AppProfiler::Viewer::FirefoxRemoteViewer::NAME
+                else
+                  AppProfiler::Viewer::SpeedscopeRemoteViewer::NAME
+                end
+                content << <<~HTML
+                  <p>
+                    <a href="/app_profiler/#{viewer}/viewer/#{id(file)}">
+                      #{id(file)}
+                    </a>
+                  </p>
+                HTML
+              end
+            end
+          )
+        end
+      end
+
+      private_constant(:BaseMiddleware)
     end
   end
 end

lib/app_profiler/viewer/middleware/firefox.rb

@@ -0,0 +1,68 @@
+# frozen_string_literal: true
+
+require "app_profiler/yarn/command"
+require "app_profiler/yarn/with_firefox_profiler"
+
+module AppProfiler
+  module Viewer
+    class FirefoxRemoteViewer < BaseViewer
+      class Middleware < BaseMiddleware
+        include Yarn::WithFirefoxProfile
+
+        def initialize(app)
+          super
+          @firefox_profiler = Rack::File.new(
+            File.join(AppProfiler.root, "node_modules/firefox-profiler/dist")
+          )
+        end
+
+        def call(env)
+          request = Rack::Request.new(env)
+          @app.call(env) if request.path_info.end_with?(AppProfiler::StackprofProfile::FILE_EXTENSION)
+          # Firefox profiler *really* doesn't like for /from-url/ to be at any other mount point
+          # so with this enabled, we take over both /app_profiler and /from-url in the app in development.
+          return from(env, Regexp.last_match(1))   if request.path_info =~ %r(\A/from-url(.*)\z)
+          return viewer(env, Regexp.last_match(1)) if request.path_info =~ %r(\A/app_profiler/firefox/viewer/(.*)\z)
+          return show(env, Regexp.last_match(1))   if request.path_info =~ %r(\A/app_profiler/firefox/(.*)\z)
+
+          super
+        end
+
+        protected
+
+        attr_reader(:firefox_profiler)
+
+        def viewer(env, path)
+          setup_yarn unless yarn_setup
+
+          if path.end_with?(AppProfiler::VernierProfile::FILE_EXTENSION)
+            proto = env["rack.url_scheme"]
+            host = env["HTTP_HOST"]
+            source = "#{proto}://#{host}/app_profiler/firefox/#{path}"
+
+            target = "/from-url/#{CGI.escape(source)}"
+
+            [302, { "Location" => target }, []]
+          else
+            env[Rack::PATH_INFO] = path.delete_prefix("/app_profiler")
+            firefox_profiler.call(env)
+          end
+        end
+
+        def from(env, path)
+          setup_yarn unless yarn_setup
+          index = File.read(File.join(AppProfiler.root, "node_modules/firefox-profiler/dist/index.html"))
+          [200, { "Content-Type" => "text/html" }, [index]]
+        end
+
+        def show(_env, name)
+          profile = profile_files.find do |file|
+            id(file) == name
+          end || raise(ArgumentError)
+
+          [200, { "Content-Type" => "application/json" }, [profile.read]]
+        end
+      end
+    end
+  end
+end

lib/app_profiler/viewer/middleware/speedscope.rb

@@ -0,0 +1,56 @@
+# frozen_string_literal: true
+
+require "app_profiler/yarn/command"
+require "app_profiler/yarn/with_speedscope"
+
+module AppProfiler
+  module Viewer
+    class SpeedscopeRemoteViewer < BaseViewer
+      class Middleware < BaseMiddleware
+        include Yarn::WithSpeedscope
+
+        def initialize(app)
+          super
+          @speedscope = Rack::File.new(
+            File.join(AppProfiler.root, "node_modules/speedscope/dist/release")
+          )
+        end
+
+        def call(env)
+          request = Rack::Request.new(env)
+          @app.call(env) if request.path_info.end_with?(AppProfiler::VernierProfile::FILE_EXTENSION)
+          return viewer(env, Regexp.last_match(1)) if request.path_info =~ %r(\A/app_profiler/speedscope/viewer/(.*)\z)
+          return show(env, Regexp.last_match(1))   if request.path_info =~ %r(\A/app_profiler/speedscope/(.*)\z)
+
+          super
+        end
+
+        protected
+
+        attr_reader(:speedscope)
+
+        def viewer(env, path)
+          setup_yarn unless yarn_setup
+
+          if path.end_with?(AppProfiler::StackprofProfile::FILE_EXTENSION)
+            source = "/app_profiler/speedscope/#{path}"
+            target = "/app_profiler/speedscope/viewer/index.html#profileURL=#{CGI.escape(source)}"
+
+            [302, { "Location" => target }, []]
+          else
+            env[Rack::PATH_INFO] = path.delete_prefix("/app_profiler/speedscope")
+            speedscope.call(env)
+          end
+        end
+
+        def show(_env, name)
+          profile = profile_files.find do |file|
+            id(file) == name
+          end || raise(ArgumentError)
+
+          [200, { "Content-Type" => "application/json" }, [profile.read]]
+        end
+      end
+    end
+  end
+end

lib/app_profiler/viewer/remote/firefox.rb

@@ -0,0 +1,33 @@
+# frozen_string_literal: true
+
+require "app_profiler/viewer/middleware/firefox"
+
+module AppProfiler
+  module Viewer
+    class FirefoxRemoteViewer < BaseViewer
+      NAME = "firefox"
+
+      class << self
+        def view(profile, params = {})
+          new(profile).view(**params)
+        end
+      end
+
+      def initialize(profile)
+        super()
+        @profile = profile
+      end
+
+      def view(response: nil, autoredirect: nil, async: false)
+        id = Middleware.id(@profile.file)
+
+        if response && response[0].to_i < 500
+          response[1]["Location"] = "/app_profiler/#{NAME}/viewer/#{id}"
+          response[0] = 303
+        else
+          AppProfiler.logger.info("[Profiler] Profile available at /app_profiler/#{id}\n")
+        end
+      end
+    end
+  end
+end