header组装性能问题

[siddontang]

local h = ""
for i, v in pairs(nreqt.headers) do
-- fix cookie is a table value
if type(v) == "table" and i == "cookie" then
v = table.concat(v, "; ")
end
h = i .. ": " .. v .. "\r\n" .. h
end

h = i .. ": " .. v .. "\r\n" .. h 如果headers比较多是否会有性能问题，为什么不考虑使用table.concat?

[wendal]

欢迎提交pull req