+/**
+ * Get the number of files served between database transactions.
+ *
+ * This is used as an optimization to database access: doing database commits
+ * take some time and can slow things down too much, so you can choose to just
+ * commit after some number of files are processed, this is the commit_interval.
+ *
+ * @param lms previously allocated Light Media Scanner instance.
+ * @return (unsigned int)-1 on error, value otherwise.
+ * @ingroup LMS_API
+ */