File

util/smqueue.lua @ 12590:5eaf77114fdb

compat: Use table.pack (there since Lua 5.2) over our util.table Added in d278a770eddc avoid having to deal with its absence in Lua 5.1. No longer needed when Lua 5.1 support is dropped.
author Kim Alvefur <zash@zash.se>
date Mon, 11 Jul 2022 19:15:24 +0200
parent 12058:4860da718e87
child 12975:d10957394a3c
line wrap: on
line source

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