chg: Reduce startup time of GNU Emacs

bin/backpack

@@ -22,7 +22,7 @@ fi
 
 if [ "$ACTION" = "ensure" ]; then
     echo "✅ Running Emacs in batch mode..."
-    emacs -nw --eval '(load (expand-file-name "ensure.el" user-emacs-directory))'
+    emacs -nw -l $INIT_DIR/ensure.el
     exit $?
 else
     echo "❌ Error: unknown action '$ACTION'" >&2

devenv.nix

@@ -58,7 +58,6 @@ in
     pkgs.enchant.dev # for jinx
   ];
   enterTest = ''
-    mkdir -p $DEVENV_ROOT/artifacts
     for-each-emacs $DEVENV_ROOT/.
     exit $?
   '';

early-init.el

@@ -1,137 +1,20 @@
 ;; -*- no-byte-compile: t; -*-
 
-(when (version< emacs-version "29.1")
-  (error "Backpack is only compatible with Emacs version 29.1 and up"))
-
-(setq package-enable-at-startup nil)
-(setq load-prefer-newer t)
-(setq native-comp-deferred-compilation nil)
-
-;; directories
-(defvar backpack--base-packages-dir (expand-file-name "base-packages" user-emacs-directory))
-(defvar backpack--leaf (expand-file-name "leaf.el" backpack--base-packages-dir))
-(defvar backpack--leaf-keywords (expand-file-name "leaf-keywords.el" backpack--base-packages-dir))
-(defvar backpack--cache-emacs (expand-file-name ".cache/emacs" user-emacs-directory))
-
-(let ((colors-file (expand-file-name "default-colors.el" backpack--cache-emacs)))
-  (when (file-exists-p colors-file)
-    (load colors-file)))
-
-(add-to-list 'load-path backpack--leaf)
-(add-to-list 'load-path backpack--leaf-keywords)
-(add-to-list 'load-path (expand-file-name "pouch" user-emacs-directory))
-
-;; shamelessly copied from Emacs Bedrock
-(setq backpack--initial-gc-threshold gc-cons-threshold)
-(setq gc-cons-threshold 10000000)
-
-(setq byte-compile-warnings '(not obsolete))
-(setq warning-suppress-log-types '((comp) (bytecomp)))
-(setq native-comp-async-report-warnings-errors 'silent)
-
-(setq inhibit-startup-echo-area-message (user-login-name))
-
-;; move auto-save-list to another location
-(setq auto-save-list-directory (expand-file-name "auto-save-list/" backpack--cache-emacs))
-
-(unless (file-directory-p auto-save-list-directory)
-  (make-directory auto-save-list-directory t))
-
-(setq auto-save-list-file-prefix
-      (expand-file-name ".saves-" auto-save-list-directory))
-
-;; move eln-cache to another location
-(setq backpack--eln-cache-dir (expand-file-name "eln-cache/" backpack--cache-emacs))
-
-(unless (file-directory-p backpack--eln-cache-dir)
-  (make-directory backpack--eln-cache-dir t))
-
-(setq native-comp-eln-load-path (list backpack--eln-cache-dir))
-
-;; configuration variables for elpaca
-(defvar elpaca-installer-version 0.11)
-(defvar elpaca-directory (expand-file-name ".cache/elpaca/" user-emacs-directory))
-(defvar elpaca-builds-directory (expand-file-name "builds/" elpaca-directory))
-(defvar elpaca-repos-directory (expand-file-name "repos/" elpaca-directory))
-(defvar elpaca-order '(elpaca :repo "https://github.com/progfolio/elpaca.git"
-                              :ref nil :depth 1 :inherit ignore
-                              :files (:defaults "elpaca-test.el" (:exclude "extensions"))
-                              :build (:not elpaca--activate-package)))
-(let* ((repo  (expand-file-name "elpaca/" elpaca-repos-directory))
-       (build (expand-file-name "elpaca/" elpaca-builds-directory))
-       (order (cdr elpaca-order))
-       (default-directory repo))
-  (add-to-list 'load-path (if (file-exists-p build) build repo))
-  (unless (file-exists-p repo)
-    (make-directory repo t)
-    (when (<= emacs-major-version 28) (require 'subr-x))
-    (condition-case-unless-debug err
-        (if-let* ((buffer (pop-to-buffer-same-window "*elpaca-bootstrap*"))
-                  ((zerop (apply #'call-process `("git" nil ,buffer t "clone"
-                                                  ,@(when-let* ((depth (plist-get order :depth)))
-                                                      (list (format "--depth=%d" depth) "--no-single-branch"))
-                                                  ,(plist-get order :repo) ,repo))))
-                  ((zerop (call-process "git" nil buffer t "checkout"
-                                        (or (plist-get order :ref) "--"))))
-                  (emacs (concat invocation-directory invocation-name))
-                  ((zerop (call-process emacs nil buffer nil "-Q" "-L" "." "--batch"
-                                        "--eval" "(byte-recompile-directory \".\" 0 'force)")))
-                  ((require 'elpaca))
-                  ((elpaca-generate-autoloads "elpaca" repo)))
-            (progn (message "%s" (buffer-string)) (kill-buffer buffer))
-          (error "%s" (with-current-buffer buffer (buffer-string))))
-      ((error) (warn "%s" err) (delete-directory repo 'recursive))))
-  (unless (require 'elpaca-autoloads nil t)
-    (require 'elpaca)
-    (elpaca-generate-autoloads "elpaca" repo)
-    (let ((load-source-file-function nil)) (load "./elpaca-autoloads"))))
-(add-hook 'after-init-hook #'elpaca-process-queues -100)
-(elpaca `(,@elpaca-order))
-
-(require 'leaf)
-(require 'leaf-keywords)
-(leaf-keywords-init)
-
-;;; add additional keywords to leaf block
-;; :doctor defines binaries to check on the user's system
-;; :fonts check what if the fonts needed by a package are installed
-(plist-put leaf-keywords :doctor '`(,@leaf--body))
-(plist-put leaf-keywords :fonts '`(,@leaf--body))
-
-;; alias :ensure to :elpaca
-(setq leaf-alias-keyword-alist '((:ensure . :elpaca)))
-
-(defun save-default-bg-fg-colors ()
-  "Save the current theme's foreground and background colors into a file."
-  (let ((bg (face-attribute 'default :background))
-	(fg (face-attribute 'default :foreground)))
-    (with-temp-file (expand-file-name "default-colors.el" backpack--cache-emacs)
-      (insert (format "(setq default-frame-alist '((background-color . \"%s\") (foreground-color . \"%s\")))"
-                      bg fg)))))
-
-(leaf benchmark-init
-  :ensure t
-  :config
-  (add-hook 'after-init-hook  #'benchmark-init/deactivate 100)
-  (benchmark-init/activate))
-
-(leaf no-littering
-  :ensure t
-  :pre-setq
-  `(no-littering-etc-directory . ,(expand-file-name "etc" backpack--cache-emacs))
-  `(no-littering-var-directory . ,(expand-file-name "var" backpack--cache-emacs))
-  :config
-  (with-eval-after-load "recentf"
-    (add-to-list 'recentf-exclude
-		 (recentf-expand-file-name no-littering-var-directory))
-    (add-to-list 'recentf-exclude
-		 (recentf-expand-file-name no-littering-etc-directory)))
-
-  (no-littering-theme-backups)
-
-  (defvar backpack-tree-sitter-installation-directory
-    (no-littering-expand-var-file-name "tree-sitter")
-    "Directory for installing tree-sitter grammars")
-
-  (unless (file-exists-p backpack-tree-sitter-installation-directory)
-    (make-directory backpack-tree-sitter-installation-directory t)))
+(let (file-name-handler-alist)
+  (if noninteractive
+      (setq gc-cons-threshold (* 128 1024 1024)
+	    gc-cons-percentage 1.0)
+    (setq gc-cons-threshold most-positive-fixnum))
+
+  (setq load-prefer-newer noninteractive)
+
+  (let ((load-suffixes '(".elc" ".el"))
+	(backpack (expand-file-name "lisp/backpack" user-emacs-directory)))
+    (when (file-exists-p (concat backpack ".el"))
+      ;; load backpack
+      (load backpack nil nil nil t))
+    (setq user-init-file (expand-file-name "early-init" user-emacs-directory))
+    (setq load-prefer-newer t)
+    (setq gc-cons-threshold (* 16 1024 1024))))
+
+(backpack-start (not noninteractive))

ensure.el

@@ -1,7 +1,48 @@
+(defvar elpaca-order '(elpaca :repo "https://github.com/progfolio/elpaca.git"
+				:ref nil :depth 1 :inherit ignore
+				:files (:defaults "elpaca-test.el" (:exclude "extensions"))
+				:build (:not elpaca--activate-package)))
+
 (progn
-  (elpaca-wait)
-  (save-default-bg-fg-colors)
-  (unless (gearp! :ui -treesit)
-    (let ((treesit-auto-install t))
-      (treesit-auto-install-all)))
-  (kill-emacs 0))
+  (let* ((repo  (expand-file-name "elpaca/" elpaca-repos-directory))
+	 (build (expand-file-name "elpaca/" elpaca-builds-directory))
+	 (order (cdr elpaca-order))
+	 (default-directory repo))
+    (unless (file-exists-p repo)
+      (make-directory repo t)
+      (condition-case-unless-debug err
+          (if-let* ((buffer (pop-to-buffer-same-window "*elpaca-bootstrap*"))
+                    ((zerop (apply #'call-process
+				   `("git" nil ,buffer t "clone"
+                                     ,@(when-let* ((depth (plist-get order :depth)))
+					 (list (format "--depth=%d" depth) "--no-single-branch"))
+                                     ,(plist-get order :repo) ,repo))))
+                    ((zerop (call-process "git" nil buffer t "checkout"
+                                          (or (plist-get order :ref) "--"))))
+                    (emacs (concat invocation-directory invocation-name))
+                    ((zerop (call-process emacs nil buffer nil "-Q" "-L" "." "--batch"
+                                          "--eval" "(byte-recompile-directory \".\" 0 'force)")))
+                    ((require 'elpaca))
+                    ((elpaca-generate-autoloads "elpaca" repo)))
+              (progn (message "%s" (buffer-string)) (kill-buffer buffer))
+            (error "%s" (with-current-buffer buffer (buffer-string))))
+	((error) (warn "%s" err) (delete-directory repo 'recursive))))
+    (unless (require 'elpaca-autoloads nil t)
+      (require 'elpaca)
+      (elpaca-generate-autoloads "elpaca" repo)
+      (let ((load-source-file-function nil)) (load "./elpaca-autoloads"))))
+
+  (elpaca `(,@elpaca-order))
+
+  (add-hook 'elpaca-post-queue-hook
+	    (lambda ()
+	      ;; (save-default-bg-fg-colors)
+	      (unless (gearp! :ui -treesit)
+		(when (fboundp 'treesit-auto-install-all)
+		  (message "compiling tree-sitter grammars")
+		  (let ((treesit-auto-install t))
+		    (treesit-auto-install-all))))
+	      (kill-emacs 0)))
+
+  (backpack-load-gear-files)
+  (elpaca-wait))

etc/scripts/prepare-and-run.sh

@@ -16,6 +16,6 @@ rsync -a --filter=':- .gitignore' --filter='- .git/' --filter='- .github/' $2 "$
 
 $1 --version | head -n 1
 
-$1 --init-directory $TEST_HOME/.emacs.d -batch -l ert -l $TEST_HOME/.emacs.d/test/all-tests.el -f ert-run-tests-batch-and-exit
+$1 --init-directory $TEST_HOME/.emacs.d -batch -l $TEST_HOME/.emacs.d/early-init.el -l ert -l $TEST_HOME/.emacs.d/test/all-tests.el -f ert-run-tests-batch-and-exit
 
 rm -rf $TEST_HOME