Allow user to trigger full rescan with a .force-rescan file

src/db.c

@@ -651,6 +651,36 @@ db_purge_cruft(time_t ref)
 
 }
 
+void
+db_purge_all(void)
+{
+  char *queries[4] =
+    {
+      "DELETE FROM inotify;",
+      "DELETE FROM playlistitems;",
+      "DELETE FROM playlists WHERE type <> 1;",
+      "DELETE FROM files;"
+    };
+  char *errmsg;
+  int i;
+  int ret;
+
+  for (i = 0; i < (sizeof(queries) / sizeof(queries[0])); i++)
+    {
+      DPRINTF(E_DBG, L_DB, "Running purge query '%s'\n", queries[i]);
+
+      ret = db_exec(queries[i], &errmsg);
+      if (ret != SQLITE_OK)
+	{
+	  DPRINTF(E_LOG, L_DB, "Purge query %d error: %s\n", i, errmsg);
+
+	  sqlite3_free(errmsg);
+	}
+      else
+	DPRINTF(E_DBG, L_DB, "Purged %d rows\n", sqlite3_changes(hdl));
+    }
+}
+
 static int
 db_get_count(char *query)
 {

src/db.h

@@ -295,6 +295,9 @@ db_hook_post_scan(void);
 void
 db_purge_cruft(time_t ref);
 
+void
+db_purge_all(void);
+
 /* Queries */
 int
 db_query_start(struct query_params *qp);

src/filescanner.c

@@ -90,6 +90,9 @@ static pthread_t tid_scan;
 static struct deferred_pl *playlists;
 static struct stacked_dir *dirstack;
 
+/* Forward */
+static void
+bulk_scan(void);
 
 static int
 push_dir(struct stacked_dir **s, char *path)
@@ -560,6 +563,19 @@ process_file(char *file, time_t mtime, off_t size, int type, int flags)
 
 	  return;
 	}
+      else if (strcmp(ext, ".force-rescan") == 0)
+	{
+	  if (flags & F_SCAN_BULK)
+	    return;
+	  else
+	    {
+	      DPRINTF(E_LOG, L_SCAN, "Forcing full rescan, found force-rescan file: %s\n", file);
+	      db_purge_all();
+	      bulk_scan();
+
+	      return;
+	    }
+	}
     }
 
   /* Not any kind of special file, so let's see if it's a media file */