From ee018de76f07d0e0da433913966708d01476aa48 Mon Sep 17 00:00:00 2001 From: Aleš Mrázek Date: Wed, 17 Apr 2024 15:55:02 +0200 Subject: modules: prefetch: new module for prefetching expiring records --- modules/prefetch/prefetch.lua | 21 +++++++++++++++++++++ 1 file changed, 21 insertions(+) create mode 100644 modules/prefetch/prefetch.lua (limited to 'modules/prefetch/prefetch.lua') diff --git a/modules/prefetch/prefetch.lua b/modules/prefetch/prefetch.lua new file mode 100644 index 00000000..673cf3e5 --- /dev/null +++ b/modules/prefetch/prefetch.lua @@ -0,0 +1,21 @@ +-- SPDX-License-Identifier: GPL-3.0-or-later +-- Speculative prefetching for repetitive and soon-expiring records to reduce latency. +-- @module prefetch +local prefetch = {} + + +prefetch.layer = { + -- Prefetch all expiring (sub-)queries immediately after the request finishes. + -- Doing that immediately is simplest and avoids creating (new) large bursts of activity. + finish = function (_, req) + local qrys = req.rplan.resolved + for i = 0, (tonumber(qrys.len) - 1) do -- size_t doesn't work for some reason + local qry = qrys.at[i] + if qry.flags.EXPIRING == true then + resolve(kres.dname2str(qry.sname), qry.stype, qry.sclass, {'NO_CACHE'}) + end + end + end +} + +return prefetch -- cgit v1.2.3