From 4601833e4ed98aaaaf90c0ddab2bfebfae42db7c Mon Sep 17 00:00:00 2001
From: Sam Saffron <sam.saffron@gmail.com>
Date: Fri, 15 May 2020 14:01:54 +1000
Subject: [PATCH] PERF: ensure we run full GC on contexts

Prior to this change we would never clear memory from contexts and
rely on V8 reacting to pressure

This could lead to bloating of PrettyText and Transpiler contexts

This optimisations ensures that we will clear memory 2 seconds after
the last eval on the context
---
 Gemfile.lock                  | 2 +-
 lib/discourse_js_processor.rb | 2 +-
 lib/js_locale_helper.rb       | 2 +-
 lib/pretty_text.rb            | 2 +-
 4 files changed, 4 insertions(+), 4 deletions(-)

diff --git a/Gemfile.lock b/Gemfile.lock
index ce187c888d8..2a195eeebbd 100644
--- a/Gemfile.lock
+++ b/Gemfile.lock
@@ -188,7 +188,7 @@ GEM
     method_source (1.0.0)
     mini_mime (1.0.2)
     mini_portile2 (2.4.0)
-    mini_racer (0.2.11)
+    mini_racer (0.2.14)
       libv8 (> 7.3)
     mini_scheduler (0.12.2)
       sidekiq
diff --git a/lib/discourse_js_processor.rb b/lib/discourse_js_processor.rb
index 94e39d0d82f..df5e35c6972 100644
--- a/lib/discourse_js_processor.rb
+++ b/lib/discourse_js_processor.rb
@@ -79,7 +79,7 @@ class DiscourseJsProcessor
 
     def self.create_new_context
       # timeout any eval that takes longer than 15 seconds
-      ctx = MiniRacer::Context.new(timeout: 15000)
+      ctx = MiniRacer::Context.new(timeout: 15000, ensure_gc_after_idle: 2000)
       ctx.eval("var self = this; #{File.read("#{Rails.root}/vendor/assets/javascripts/babel.js")}")
       ctx.eval(File.read(Ember::Source.bundled_path_for('ember-template-compiler.js')))
       ctx.eval("module = {}; exports = {};")
diff --git a/lib/js_locale_helper.rb b/lib/js_locale_helper.rb
index 99d344ef8c9..8864eca71a2 100644
--- a/lib/js_locale_helper.rb
+++ b/lib/js_locale_helper.rb
@@ -282,7 +282,7 @@ module JsLocaleHelper
   def self.with_context
     @mutex.synchronize do
       yield @ctx ||= begin
-        ctx = MiniRacer::Context.new(timeout: 15000)
+        ctx = MiniRacer::Context.new(timeout: 15000, ensure_gc_after_idle: 2000)
         ctx.load("#{Rails.root}/lib/javascripts/messageformat.js")
         ctx
       end
diff --git a/lib/pretty_text.rb b/lib/pretty_text.rb
index 1e4775d1214..0f114c51694 100644
--- a/lib/pretty_text.rb
+++ b/lib/pretty_text.rb
@@ -65,7 +65,7 @@ module PrettyText
   end
 
   def self.create_es6_context
-    ctx = MiniRacer::Context.new(timeout: 25000)
+    ctx = MiniRacer::Context.new(timeout: 25000, ensure_gc_after_idle: 2000)
 
     ctx.eval("window = {}; window.devicePixelRatio = 2;") # hack to make code think stuff is retina