lib: document config metadata

[notmuch] / lib / database.cc

diff --git a/lib/database.cc b/lib/database.cc
index 0b60410226137e9ec5117a368bfb647524185b18..2b2d8219d29e5e963517b2a9c5219dec56be83dc 100644 (file)
--- a/lib/database.cc
+++ b/lib/database.cc
@@ -13,7 +13,7 @@
  * GNU General Public License for more details.
  *
  * You should have received a copy of the GNU General Public License
- * along with this program.  If not, see http://www.gnu.org/licenses/ .
+ * along with this program.  If not, see https://www.gnu.org/licenses/ .
  *
  * Author: Carl Worth <cworth@cworth.org>
  */
@@ -185,6 +185,14 @@ typedef struct {
  *                     generated is 1 and the value will be
  *                     incremented for each thread ID.
  *
+ *     C*              metadata keys starting with C indicate
+ *                     configuration data. It can be managed with the
+ *                     n_database_*config* API.  There is a convention
+ *                     of hierarchical keys separated by '.' (e.g.
+ *                     query.notmuch stores the value for the named
+ *                     query 'notmuch'), but it is not enforced by the
+ *                     API.
+ *
  * Obsolete metadata
  * -----------------
  *
@@ -217,7 +225,7 @@ typedef struct {
 
 /* With these prefix values we follow the conventions published here:
  *
- * http://xapian.org/docs/omega/termprefixes.html
+ * https://xapian.org/docs/omega/termprefixes.html
  *
  * as much as makes sense. Note that I took some liberty in matching
  * the reserved prefix values to notmuch concepts, (for example, 'G'