【数据存储】备份保留策略：七天滚动与月度归档的双层设计** <!--TAGS: 数据存储,备份,保留

local function backupTag(dateStr)
    local day = tonumber(string.sub(dateStr, 7, 8))
    if day == 1 then
        return "ARCHIVE_" .. dateStr
    end
    return "DAILY_" .. dateStr
end
local function expired(tag, nowDays)
    if string.sub(tag, 1, 8) == "ARCHIVE_" then
        return false
    end
    local ts = tonumber(getsysvar("BACKUP_DAYS_" .. string.sub(tag, 7, 14)) or "0")
    return nowDays - ts > 7
end

setontimerex(80, 86400)
function ontimer80()
    local nowDays = math.floor(os.time() / 86400)
    local kill = {}
    for tag, _ in pairs(backupIndex()) do
        if expired(tag, nowDays) then
            kill[#kill + 1] = tag
        end
    end
    setsysvarex("BACKUP_KILL_LIST", table.concat(kill, ";"), 1)
end