From 26e44b1d5584a61da564b725396cbba0a0e919f7 Mon Sep 17 00:00:00 2001
From: Daniel Borchmann <daniel@algebra20.de>
Date: Fri, 27 Oct 2017 20:47:34 +0200
Subject: [PATCH] [Helm] Speed up recursive directory traversal in helm
 shortcut
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By copying and adapting the code of ‘directory-files-recursively’
---
 site-lisp/db-utils.el | 35 ++++++++++++++++++++++++++---------
 1 file changed, 26 insertions(+), 9 deletions(-)

diff --git a/site-lisp/db-utils.el b/site-lisp/db-utils.el
index 657973e..f1146e8 100644
--- a/site-lisp/db-utils.el
+++ b/site-lisp/db-utils.el
@@ -291,15 +291,32 @@ If FILE is not given, prompt for one."
   :type 'string)
 
 (defun db/important-documents ()
-  "Recursively return paths of all important documents found in `db/important-documents-path’."
-  (when (file-directory-p db/important-documents-path)
-    (delete-if                          ; FIXME: dump, make better
-     (lambda (spec)
-       (eq ?. (elt (car spec) 0)))
-     (mapcar (lambda (path)
-               (cons (string-remove-prefix db/important-documents-path path)
-                     path))
-             (directory-files-recursively db/important-documents-path "")))))
+  "Recursively return paths of all files found in `db/important-documents-path’.
+The result will be a list of cons cells, where the car is the
+path relative to `db/important-documents’ and the cdr is the full
+path."
+  ;; code adapted from `directory-files-recursively’
+  (cl-labels ((all-files-in-dir (dir)
+                (let ((result nil)
+                      (files nil))
+                  (dolist (file (sort (file-name-all-completions "" dir)
+                                      'string<))
+                    (unless (eq ?. (aref file 0)) ; omit hidden files
+                      (if (directory-name-p file)
+                          (let* ((leaf (substring file 0 (1- (length file))))
+                                 (full-file (expand-file-name leaf dir)))
+                            ;; Don't follow symlinks to other directories.
+                            (unless (file-symlink-p full-file)
+                              (setq result
+                                    (nconc result (all-files-in-dir full-file)))))
+                          (push (cons
+                                 (string-remove-prefix db/important-documents-path
+                                                       (expand-file-name file dir))
+                                 (expand-file-name file dir))
+                                files))))
+                  (nconc result (nreverse files)))))
+    (when (file-directory-p db/important-documents-path)
+      (all-files-in-dir db/important-documents-path))))
 
 (defun db/system-open (path)
   "Open PATH with default program as defined by the underlying system."