util/smqueue.lua
author Matthew Wild <mwild1@gmail.com>
Mon, 20 Feb 2023 18:10:15 +0000
branch0.12
changeset 12898 0598d822614f
parent 12062 4860da718e87
child 12979 d10957394a3c
permissions -rw-r--r--
mod_websocket: Fire pre-session-close event (fixes #1800) This event was added in a7c183bb4e64 and is required to make mod_smacks know that a session was intentionally closed and shouldn't be hibernated (see fcea4d9e7502). Because this was missing from mod_websocket's session.close(), mod_smacks would always attempt to hibernate websocket sessions even if they closed cleanly. That mod_websocket has its own copy of session.close() is something to fix another day (probably not in the stable branch). So for now this commit makes the minimal change to get things working again. Thanks to Damian and the Jitsi team for reporting.

local queue = require("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