net.server_epoll: Add support for systemd socket activation
Allows creating listening sockets and accepting client connections
before Prosody starts.
This is unlike normal Prosody dynamic resource management, where ports
may added and removed at any time, and the ports defined by the config.
Weird things happen if these are closed (e.g. due to reload) so here we
prevent closing and ensure sockets are reused when opened again.
local queue = require("prosody.util.queue");
local lib = { smqueue = {} }
local smqueue = lib.smqueue;
function smqueue:push(v)
self._head = self._head + 1;
assert(self._queue:push(v));
end
function smqueue:ack(h)
if h < self._tail then
return nil, "tail"
elseif h > self._head then
return nil, "head"
end
local acked = {};
self._tail = h;
local expect = self._head - self._tail;
while expect < self._queue:count() do
local v = self._queue:pop();
if not v then return nil, "pop" end
table.insert(acked, v);
end
return acked
end
function smqueue:count_unacked() return self._head - self._tail end
function smqueue:count_acked() return self._tail end
function smqueue:resumable() return self._queue:count() >= (self._head - self._tail) end
function smqueue:resume() return self._queue:items() end
function smqueue:consume() return self._queue:consume() end
function smqueue:table()
local t = {};
for i, v in self:resume() do t[i] = v; end
return t
end
local function freeze(q) return { head = q._head; tail = q._tail } end
local queue_mt = { __name = "smqueue"; __index = smqueue; __len = smqueue.count_unacked; __freeze = freeze }
function lib.new(size)
assert(size > 0);
return setmetatable({ _head = 0; _tail = 0; _queue = queue.new(size, true) }, queue_mt)
end
return lib