Software /
code /
prosody
File
net/resolvers/service.lua @ 10228:e77bf4222fae
net.server_epoll: Add support for opportunistic writes
This tries to flush data to the underlying sockets when receiving
writes. This should lead to fewer timer objects being around. On the
other hand, this leads to more and smaller writes which may translate to
more TCP/IP packets being sent, depending on how the kernel handles
this. This trades throughput for lower latency.
author | Kim Alvefur <zash@zash.se> |
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date | Wed, 28 Aug 2019 01:41:00 +0200 |
parent | 10121:33f287519bf6 |
child | 10386:cf93a951da37 |
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local adns = require "net.adns"; local basic = require "net.resolvers.basic"; local unpack = table.unpack or unpack; -- luacheck: ignore 113 local methods = {}; local resolver_mt = { __index = methods }; -- Find the next target to connect to, and -- pass it to cb() function methods:next(cb) if self.targets then if #self.targets == 0 then cb(nil); return; end local next_target = table.remove(self.targets, 1); self.resolver = basic.new(unpack(next_target, 1, 4)); self.resolver:next(function (...) if ... == nil then self:next(cb); else cb(...); end end); return; end local targets = {}; local function ready() self.targets = targets; self:next(cb); end -- Resolve DNS to target list local dns_resolver = adns.resolver(); dns_resolver:lookup(function (answer, err) if not answer and not err then -- net.adns returns nil if there are zero records or nxdomain answer = {}; end if answer then if #answer == 0 then if self.extra and self.extra.default_port then table.insert(targets, { self.hostname, self.extra.default_port, self.conn_type, self.extra }); end ready(); return; end if #answer == 1 and answer[1].srv.target == "." then -- No service here ready(); return; end table.sort(answer, function (a, b) return a.srv.priority < b.srv.priority end); for _, record in ipairs(answer) do table.insert(targets, { record.srv.target, record.srv.port, self.conn_type, self.extra }); end end ready(); end, "_" .. self.service .. "._" .. self.conn_type .. "." .. self.hostname, "SRV", "IN"); end local function new(hostname, service, conn_type, extra) return setmetatable({ hostname = hostname; service = service; conn_type = conn_type or "tcp"; extra = extra; }, resolver_mt); end return { new = new; };