【高级技巧】双写校验：关键数值的双份记账比对

local function setCoin(actor, value)
    actor = getplayerbyname(actor)
    if value < 0 or value > 2100000000 then
        sendmsg(actor, 1, "金币数值越界，写入被拒。")
        return
    end
    setplayvar(actor, "HUMAN", "CoinMain", value, 1)
    setplayvar(actor, "HUMAN", "CoinShadow", value, 1)
end
local function getCoin(actor)
    actor = getplayerbyname(actor)
    local main = getplayvar(actor, "HUMAN", "CoinMain")
    local shadow = getplayvar(actor, "HUMAN", "CoinShadow")
    if main ~= shadow then
        sendmsg(actor, 1, "金币账目异常，已封存待审。")
        setplayvar(actor, "HUMAN", "CoinLock", 1, 1)
        return tonumber(shadow) or 0
    end
    return tonumber(main) or 0
end

local function payCoin(actor, amount)
    actor = getplayerbyname(actor)
    local coin = getCoin(actor)
    if coin < amount then
        sendmsg(actor, 1, "金币不足。")
        return
    end
    setCoin(actor, coin - amount)
    sendmsg(actor, 1, "支付 " .. amount .. " 金币完成。")
end