(feature): use sqlite as backing database (#200)

All org-roam related information will now be stored in the database. Henceforth, the cache needs to be built synchronously once (via `M-x org-roam-build-cache`), which is then incrementally updated.
2025-09-26 16:40:56 -05:00 · 2020-02-29 15:56:08 +08:00
parent d086d1675d
commit 0c2aaad3df
25 changed files with 738 additions and 839 deletions
--- a/org-roam-db.el
+++ b/org-roam-db.el
@@ -0,0 +1,146 @@
+;;; org-roam-db.el --- Roam Research replica with Org-mode -*- coding: utf-8; lexical-binding: t -*-
+
+;; Copyright © 2020 Jethro Kuan <jethrokuan95@gmail.com>
+
+;; Author: Jethro Kuan <jethrokuan95@gmail.com>
+
+;; This file is NOT part of GNU Emacs.
+
+;; This program is free software; you can redistribute it and/or modify
+;; it under the terms of the GNU General Public License as published by
+;; the Free Software Foundation; either version 3, or (at your option)
+;; any later version.
+;;
+;; This program is distributed in the hope that it will be useful,
+;; but WITHOUT ANY WARRANTY; without even the implied warranty of
+;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+;; GNU General Public License for more details.
+;;
+;; You should have received a copy of the GNU General Public License
+;; along with GNU Emacs; see the file COPYING.  If not, write to the
+;; Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor,
+;; Boston, MA 02110-1301, USA.
+
+;;; Commentary:
+;;
+;; This code is heavily referenced from https://github.com/magit/forge.
+;;
+;;; Code:
+
+(require 'emacsql)
+(require 'emacsql-sqlite)
+
+;;; Options
+
+(defcustom org-roam-directory (expand-file-name "~/org-roam/")
+  "Default path to Org-roam files.
+
+All Org files, at any level of nesting, is considered part of the Org-roam."
+  :type 'directory
+  :group 'org-roam)
+
+(defconst org-roam-db-filename "org-roam.db"
+  "Name of the Org-roam database file.")
+
+(defconst org-roam--db-version 1)
+(defconst org-roam--sqlite-available-p
+  (with-demoted-errors "Org-roam initialization: %S"
+    (emacsql-sqlite-ensure-binary)
+    t))
+
+(defvar org-roam--db-connection (make-hash-table :test #'equal)
+  "Database connection to Org-roam database.")
+
+;;; Core
+
+(defun org-roam--get-db ()
+  "Return the sqlite db file."
+  (interactive "P")
+  (expand-file-name org-roam-db-filename org-roam-directory))
+
+(defun org-roam--get-db-connection ()
+  "Return the database connection, if any."
+  (gethash (file-truename org-roam-directory)
+           org-roam--db-connection))
+
+(defun org-roam-db ()
+  (unless (and (org-roam--get-db-connection)
+               (emacsql-live-p (org-roam--get-db-connection)))
+    (let* ((db-file (org-roam--get-db))
+           (init-db (not (file-exists-p db-file))))
+      (make-directory (file-name-directory db-file) t)
+      (let ((conn (emacsql-sqlite db-file)))
+        (puthash (file-truename org-roam-directory)
+                 conn
+                 org-roam--db-connection)
+        (when init-db
+          (org-roam--db-init conn))
+        (let* ((version (caar (emacsql conn "PRAGMA user_version")))
+               (version (org-roam--db-maybe-update conn version)))
+          (cond
+           ((> version org-roam--db-version)
+            (emacsql-close conn)
+            (user-error
+             "The Org-roam database was created with a newer Org-roam version. %s"
+             "You need to update the Org-roam package.")
+            ((< version org-roam--db-version)
+             (emacsql-close conn)
+             (error "BUG: The Org-roam database scheme changed %s"
+                    "and there is no upgrade path"))))))))
+  (org-roam--get-db-connection))
+
+;;; Api
+
+(defun org-roam-sql (sql &rest args)
+  (if  (stringp sql)
+      (emacsql (org-roam-db) (apply #'format sql args))
+    (apply #'emacsql (org-roam-db) sql args)))
+
+;;; Schemata
+
+(defconst org-roam--db-table-schemata
+  '((files
+     [(file :unique :primary-key)
+      (hash :not-null)
+      (last-modified :not-null)
+      ])
+
+    (file-links
+     [(file-from :not-null)
+      (file-to :not-null)
+      (properties :not-null)])
+
+    (titles
+     [
+      (file :not-null)
+      titles])
+
+    (refs
+     [(ref :unique :not-null)
+      (file :not-null)])))
+
+(defun org-roam--db-init (db)
+  (emacsql-with-transaction db
+    (pcase-dolist (`(,table . ,schema) org-roam--db-table-schemata)
+      (emacsql db [:create-table $i1 $S2] table schema))
+    (emacsql db (format "PRAGMA user_version = %s" org-roam--db-version))))
+
+(defun org-roam--db-maybe-update (db version)
+  (emacsql-with-transaction db
+    'ignore
+    ;; Do nothing now
+    version))
+
+(defun org-roam--db-close (&optional db)
+  (unless db
+    (setq db (org-roam--get-db-connection)))
+  (when (and db (emacsql-live-p db))
+    (emacsql-close db)))
+
+(defun org-roam--db-close-all ()
+  (dolist (conn (hash-table-values org-roam--db-connection))
+    (org-roam--db-close conn)))
+
+(provide 'org-roam-db)
+
+;;; org-roam-db.el ends here