Build additional titles cache

org-roam.el

@@ -169,8 +169,11 @@ If `ABSOLUTE', return the absolute file-path. Else, return the relative file-pat
       ,(async-inject-variables "org-roam-files")
       ,(async-inject-variables "org-roam-directory")
       (let ((backward-links (make-hash-table :test #'equal))
-            (forward-links (make-hash-table :test #'equal)))
+            (forward-links (make-hash-table :test #'equal))
-        (cl-flet* ((org-roam--parse-content (file) (with-temp-buffer
+            (file-titles (make-hash-table :test #'equal)))
+        (cl-flet* ((org-roam--parse-content
+                    (file)
+                    (with-temp-buffer
                       (insert-file-contents file)
                       (with-current-buffer (current-buffer)
                         (org-element-map (org-element-parse-buffer) 'link
@@ -191,7 +194,9 @@ If `ABSOLUTE', return the absolute file-path. Else, return the relative file-pat
                                   (list :from file
                                         :to (file-truename (expand-file-name path org-roam-directory))
                                         :content (string-trim content))))))))))
-                   (org-roam--process-items (items) (mapcar
+                   (org-roam--process-items
+                    (items)
+                    (mapcar
                      (lambda (item)
                        (pcase-let ((`(:from ,p-from :to ,p-to :content ,content) item))
                          ;; Build forward-links
@@ -215,14 +220,32 @@ If `ABSOLUTE', return the absolute file-path. Else, return the relative file-pat
                              (let ((contents-hash (make-hash-table :test #'equal)))
                                (puthash p-from (list content) contents-hash)
                                (puthash p-to contents-hash backward-links))))))
-                                                     items)))
+                     items))
+                   (org-roam--extract-title
+                    (buffer)
+                    (with-current-buffer buffer
+                      (org-element-map
+                          (org-element-parse-buffer)
+                          'keyword
+                        (lambda (kw)
+                          (when (string= (org-element-property :key kw) "TITLE")
+                            (org-element-property :value kw)))
+                        :first-match t))))
           (mapcar #'org-roam--process-items
-                  (mapcar #'org-roam--parse-content org-roam-files)))
+                  (mapcar #'org-roam--parse-content org-roam-files))
+          (mapcar (lambda (file)
+                    (with-temp-buffer
+                      (insert-file-contents file)
+                      (when-let ((title (org-roam--extract-title (current-buffer))))
+                        (puthash file title file-titles))))
+                  org-roam-files))
         (list
          :forward forward-links
-         :backward backward-links)))
+         :backward backward-links
+         :titles file-titles)))
    (lambda (cache)
-     (setq org-roam-cache cache))))
+     (setq org-roam-cache cache)
+     (message "Org-roam cache built!"))))
 
 (defun org-roam--insert-item (item)
   "Insert `ITEM' into `org-roam-cache'.
@@ -231,7 +254,8 @@ If `ABSOLUTE', return the absolute file-path. Else, return the relative file-pat
 
 Before calling this function, `org-roam-cache' should be already populated."
   (let ((forward-cache (plist-get org-roam-cache :forward))
-        (backward-cache (plist-get org-roam-cache :backward)))
+        (backward-cache (plist-get org-roam-cache :backward))
+        (title-cache (plist-get org-roam-cache :titles)))
     (pcase-let ((`(:from ,p-from :to ,p-to :content ,content) item))
       ;; Build forward-links
       (let ((links (gethash p-from forward-cache)))
@@ -255,7 +279,8 @@ Before calling this function, `org-roam-cache' should be already populated."
             (puthash p-from (list content) contents-hash)
             (puthash p-to contents-hash backward-cache))))
       (setq org-roam-cache (list :forward forward-cache
-                                 :backward backward-cache)))))
+                                 :backward backward-cache
+                                 :titles title-cache)))))
 
 (defun org-roam--parse-content ()
   "Parse the current buffer, and return a list of items for processing."
@@ -286,8 +311,9 @@ This is equivalent to removing the node from the graph."
   (with-current-buffer (current-buffer)
     (let ((file (file-truename (buffer-file-name buffer)))
           (forward-cache (plist-get org-roam-cache :forward))
-          (backward-cache (plist-get org-roam-cache :backward)))
+          (backward-cache (plist-get org-roam-cache :backward))
-      ;; Setup 1: Remove all existing links for file
+          (titles-cache (plist-get org-roam-cache :titles)))
+      ;; Step 1: Remove all existing links for file
       (when-let ((forward-links (gethash file forward-cache)))
         ;; Delete backlinks to file
         (dolist (link forward-links)
@@ -296,12 +322,28 @@ This is equivalent to removing the node from the graph."
             (puthash link backward-links backward-cache)))
         ;; Clean out forward links
         (remhash file forward-cache))
-      (setq org-roam-cache (list :forward forward-cache :backward backward-cache)))))
+      ;; Step 2: Remove from the title cache
+      (remhash file titles-cache)
+      (setq org-roam-cache (list :forward forward-cache
+                                 :backward backward-cache
+                                 :titles titles-cache)))))
+
+(defun org-roam--update-cache-title (buffer)
+  "Inserts the `TITLE' of file in buffer into the cache."
+  (when-let ((titles-cache (plist-get org-roam-cache :titles))
+             (title (org-roam--extract-title buffer)))
+    (puthash (file-truename (buffer-file-name buffer))
+             title
+             titles-cache)
+    (setq org-roam-cache (plist-put org-roam-cache :titles titles-cache))))
 
 (defun org-roam--update-cache ()
   "Update `org-roam-cache' for the current buffer file."
   (save-excursion
     (org-roam--clear-cache-for-buffer (current-buffer))
+    ;; Insert into title cache
+    (org-roam--update-cache-title (current-buffer))
+    ;; Insert new items
     (let ((items (org-roam--parse-content)))
       (dolist (item items)
         (org-roam--insert-item item)))))