Cache logger instance.

src/fiber_orm.nim

@@ -309,14 +309,16 @@ type
     ## Error type raised when no record matches a given ID
 
 var logService {.threadvar.}: Option[LogService]
+var logger {.threadvar.}: Option[Logger]
 
 proc logQuery*(methodName: string, sqlStmt: string, args: openArray[(string, string)] = []) =
   # namespaced_logging would do this check for us, but we don't want to even
   # build the log object if we're not actually logging
   if logService.isNone: return
+  if logger.isNone: logger = logService.getLogger("fiber_orm/query")
   var log = %*{ "method": methodName, "sql": sqlStmt }
   for (k, v) in args: log[k] = %v
-  logService.getLogger("fiber_orm/query").debug(log)
+  logger.debug(log)
 
 proc enableDbLogging*(svc: LogService) =
   logService = some(svc)