Emacs(Elisp): Open large file quickly. 大きいファイルを早く開きたい

open-large-file-quickly.el

;;; ------------------------------------------------------------
;;; 大きいファイルを早く開きたい
;; gist-description: Emacs(Elisp): Open large file quickly. 大きいファイルを早く開きたい
;; gist-id: 96e00bd843c838f45ab8183e286150ec
;; gist-name: open-large-file-quickly.el
;; gist-private: nil
(defun open-large-file-quickly()
  "To read large file."
  (interactive)
  (progn
    (when (file-exists-p (buffer-file-name))
      (let* ((file-name (buffer-file-name (current-buffer)))
             (f-attr (file-attributes file-name))
             (f-size (nth 7 f-attr))
             (is-large (>= f-size 2000000)))
        (if (not (string= (substring (buffer-file-name) 0 1) "*"))
            (progn
              (setq-local ac-auto-start (not is-large))
              (setq-local show-paren-mode (not is-large))
              (setq-local linum-mode (not is-large))
              (when is-large
                (message "File Size: %s Bytes, Opened by less function mode" f-size))))))))
(add-hook 'find-file-hooks 'open-large-file-quickly)