【性能调优】掉落延迟：高峰掉落的缓冲发放

-- 掉落延迟：缓冲入队
local player = class(actor)
local dropQueue = {}
local function enqueueDrops(player, x, y, drops)
    local groupId = os.time() .. "_" .. math.random(1000)
    dropQueue[groupId] = {x = x, y = y, items = drops, born = os.time()}
    sendmsg(player, 1, 0, "掉落物正在散落……")
end

-- 掉落延迟：节拍发放
local player = class(actor)
local function flushDrops(player)
    local cnt = 0
    for groupId, group in pairs(dropQueue) do
        cnt = cnt + 1
        for _, item in ipairs(group.items) do
            giveitem(player, item.name, item.count)
        end
        dropQueue[groupId] = nil
        if cnt >= 8 then break end
    end
    if cnt > 0 then
        sendmsg(player, 1, 0, "本批发放 " .. cnt .. " 组掉落。")
    end
end