From 194d6b5b2e112d62f8be90b92411603ab48fa8f5 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Alex=20Benn=C3=A9e?= <alex@bennee.com>
Date: Thu, 11 Apr 2013 04:22:11 +0100
Subject: [PATCH] Add the option to shortcut eproject file searching if project
 already open.

When working remotely over something like TRAMP performance can be
severely impacted as eproject checks against all possible eproject
types. This optimisation will assume that if a file is opened in a
subdirectory of an existing loaded project then we can use that
definition.

This breaks sub-projects although this could be mitigated if we sort
the existing roots by length and the user opens sub-projects before
the main project.
---
 eproject.el | 44 ++++++++++++++++++++++++++++++++++----------
 1 file changed, 34 insertions(+), 10 deletions(-)

diff --git a/eproject.el b/eproject.el
index e16733a..9931c5b 100644
--- a/eproject.el
+++ b/eproject.el
@@ -221,6 +221,17 @@
   :link '(emacs-library-link :tag "Optional extras" "eproject-extras.el")
   :link '(url-link :tag "Github wiki" "http://wiki.github.com/jrockway/eproject"))
 
+(defcustom eproject-shortcut-search nil
+  "If not nil, shortcut searches if a file already in an open eproject
+directory.
+
+Setting to true will cause confusion if you have sub-projects inside
+your projects. However it will be a lot faster if you are working
+remotely over things like TRAMP."
+  :group 'eproject
+  :type 'boolean)
+
+
 (defvar eproject-root nil
   "A buffer-local variable set to the root of its eproject
   project.  NIL if it isn't in an eproject.  Your code should
@@ -542,17 +553,29 @@ else through unchanged."
 (defun eproject-maybe-turn-on ()
   "Turn on eproject for the current buffer, if it is in a project."
   (interactive)
-  (let (bestroot besttype (set-before (mapcar #'car eproject-attributes-alist)))
-    (loop for type in (eproject--all-types)
-          do (let ((root (eproject--run-project-selector type)))
-               (when (and root
-                          (or (not bestroot)
-                              ;; longest filename == best match (XXX:
-                              ;; need to canonicalize?)
-                              (> (length root) (length bestroot))))
-                 (setq bestroot root)
-                 (setq besttype type))))
+  (message "eproject searching for potential roots")
+  (let* ((set-before (eproject--known-project-roots))
+	 (filename (buffer-file-name))
+	 (bestroot (find-if '(lambda(x) (string-match x filename))
+			   set-before))
+	 (besttype (if bestroot (getf (cdr (assoc bestroot eproject-attributes-alist))
+			 :type))))
+    (message (format "bestroot=%s besttype=%s set-before=%s" bestroot
+		     besttype set-before))
+    (unless (and eproject-shortcut-search
+		 bestroot
+		 besttype)
+      (loop for type in (eproject--all-types)
+	    do (let ((root (eproject--run-project-selector type)))
+		 (when (and root
+			    (or (not bestroot)
+				;; longest filename == best match (XXX:
+				;; need to canonicalize?)
+				(> (length root) (length bestroot))))
+		   (setq bestroot root)
+		   (setq besttype type)))))
     (when bestroot
+      (message (format "eproject found: %s as bestroot" bestroot))
       (setq eproject-root (file-name-as-directory bestroot))
 
       ;; read .eproject file (etc.) and initialize at least :name and
@@ -647,6 +670,7 @@ No check is done to ensure that the root subsumes FILE or even
 that FILE is an absolute path."
   ;; XXX: this logic is sort of copied from search-directory-tree.
   ;; maybe combine?
+  ;; AJB: broken? I get the same regexps whatever project root applied?
   (destructuring-bind (matcher . ignore) (eproject--file-check-regexps root)
     (and (not (string-match ignore file))
          (not (string-match ignore (file-name-nondirectory file)))