【数据存储】日志切割归档：按天滚动与压缩

---日志的按天切割
function LogRotate.checkAndRotate(logName)
    local today = os.date("%Y-%m-%d")
    local file = logName .. "_" .. today .. ".log"
    local size = QF_FileSize(file)
    if size > 500 * 1024 * 1024 then
        -- 超过 500MB 按序号切割
        local seq = 1
        while QF_FileExists(logName .. "_" .. today .. "_" .. seq .. ".log") do
            seq = seq + 1
        end
        QF_RenameFile(file, logName .. "_" .. today .. "_" .. seq .. ".log")
    end
end

---日志的压缩归档
function LogArchive.compress(logName, date)
    local src = logName .. "_" .. date .. ".log"
    local dst = logName .. "_" .. date .. ".gz"
    QF_GzipCompress(src, dst)
    QF_DeleteFile(src)
end

function LogArchive.purge(logName, keepDays)
    local cutoff = os.date("%Y-%m-%d", os.time() - keepDays * 86400)
    local files = QF_ListFiles(logName .. "_*.gz")
    for _, f in ipairs(files) do
        local fileDate = f:match("(%d{4}-%d{2}-%d{2})")
        if fileDate < cutoff then
            QF_DeleteFile(f)
        end
    end
end