From e9e65f9d9fdbf86b77b5f6ec95303cc3d73d61e7 Mon Sep 17 00:00:00 2001
From: Jim Myhrberg <contact@jimeh.me>
Date: Sat, 15 Feb 2020 18:10:08 +0000
Subject: [PATCH] perf(startup): Improve startup speed by borrowing from
 doom-emacs

Shameless borrow various methods of improving Emacs startup time from
doom-emacs:

https://github.com/hlissner/doom-emacs/blob/b0978a4526cfd78bb18e5279909c19bee97e9878/docs/faq.org#how-does-doom-start-up-so-quickly
---
 core/siren-core-init.el        |  1 +
 core/siren-core-performance.el | 20 ++++++++++++++++++++
 early-init.el                  | 14 ++++++++++++++
 3 files changed, 35 insertions(+)
 create mode 100644 core/siren-core-performance.el

diff --git a/core/siren-core-init.el b/core/siren-core-init.el
index 4d98918..cf1b2af 100644
--- a/core/siren-core-init.el
+++ b/core/siren-core-init.el
@@ -36,6 +36,7 @@
 
 ;; Continue core stuff
 (require 'siren-core-packages)
+(require 'siren-core-performance)
 (require 'siren-core-env)
 (require 'siren-core-ui)
 (require 'siren-core-editor)
diff --git a/core/siren-core-performance.el b/core/siren-core-performance.el
new file mode 100644
index 0000000..f0de02e
--- /dev/null
+++ b/core/siren-core-performance.el
@@ -0,0 +1,20 @@
+;;; siren-core-performance.el --- jimeh's Emacs Siren: Performance tweaks
+
+;;; Commentary:
+
+;; Performance tweaks.
+
+;;; Code:
+
+;; Setup and use gcmh-mode for improved garbage collection.
+(use-package gcmh
+  :hook
+  (emacs-startup . (lambda() (gcmh-mode +1)))
+  (focus-out-hook . gcmh-idle-garbage-collect)
+
+  :custom
+  (gcmh-idle-delay 10)
+  (gcmh-high-cons-threshold 16777216))
+
+(provide 'siren-core-performance)
+;;; siren-core-performance.el ends here
diff --git a/early-init.el b/early-init.el
index 9ebdb46..e16720d 100644
--- a/early-init.el
+++ b/early-init.el
@@ -6,8 +6,22 @@
 
 ;;; Code:
 
+;; Defer garbage collection further back in the startup process
+(setq gc-cons-threshold most-positive-fixnum)
+
 ;; Disable Emacs 27's automatic package.el initialization before the init.el
 ;; file is loaded. I use straight.el instead of package.el.
 (setq package-enable-at-startup nil)
 
+;; Prevent the glimpse of un-styled Emacs by disabling these UI elements early.
+(setq tool-bar-mode nil
+      menu-bar-mode nil)
+(when (fboundp 'set-scroll-bar-mode)
+  (set-scroll-bar-mode nil))
+
+;; Resizing the Emacs frame can be a terribly expensive part of changing the
+;; font. By inhibiting this, we easily halve startup times with fonts that are
+;; larger than the system default.
+(setq frame-inhibit-implied-resize t)
+
 ;;; early-init.el ends here