将lua配置表设置成只读

setconst.lua

local rawnext = next
function next(t,k)
    local m = getmetatable(t)
    local n = m and m.__next or rawnext
    return n(t,k)
end
function pairs(t) return next, t, nil end

function readonly(t)
    local proxy = {}
    local mt = {
        __index = t,
        __next = function(_, k) return next(t, k) end,
        __newindex = function(t, k, v)
            error("attempt to update a read-only table", 2)
        end,
    }
    for k,v in pairs(t) do
        if type(v)=="table" then
            t[k] = readonly(v)
        end
    end
    setmetatable(proxy, mt)
    return proxy
end

function setconst()
    for k,v in pairs(_G) do
        if k~="naruto_assert" and (string.find(k,"naruto_") or k=="DropDB") then
            _G[k] = readonly(v)
        end
    end
end

-------------test-------------
function read(t)
    for k,v in pairs(t) do
        if type(v)=="table" then
            read(v)
        end
    end
end
function test()
    local t1=os.time()
    print("time:start1",t1)
    for k,v in pairs(_G) do
        if string.find(k,"naruto") or string.find(k,"Drop") then
            read(v)
        end
    end
    local t2=os.time()
    print("time:end1",t2,t2-t1)

    setconst()
    local t3=os.time()
    print("time:start2",t3)
    for k,v in pairs(_G) do
        if string.find(k,"naruto") or string.find(k,"Drop") then
            read(v)
        end
    end
    local t4=os.time()
    print("time:end2",t4,t4-t3)
end