轻松自研嵌入式日志框架，6大功能亮点一文读懂

#define LOGD(tag, fmt, args...)     SprLog::GetInstance()->d(tag, "%4d " fmt, __LINE__, ##args)
#define LOGI(tag, fmt, args...)     SprLog::GetInstance()->i(tag, "%4d " fmt, __LINE__, ##args)
#define LOGW(tag, fmt, args...)     SprLog::GetInstance()->w(tag, "%4d " fmt, __LINE__, ##args)
#define LOGE(tag, fmt, args...)     SprLog::GetInstance()->e(tag, "%4d " fmt, __LINE__, ##args)

int LogManager::MainLoop()
{
    while (mRunning)
    {
        if (pLogMCacheMem->AvailData() <= 0) {
            usleep(10000);
            continue;
        }

        int32_t len = 0;
        int ret = pLogMCacheMem->read(&len, sizeof(int32_t));
        if (ret != 0 || len < 0) {
            SPR_LOGE("read memory failed! len = %d, ret = %d\n", len, ret);
            usleep(10000);
            continue;
        }

        std::string value;
        value.resize(len);
        char* data = const_cast<char*>(value.c_str());
        ret = pLogMCacheMem->read(data, len);
        if (ret != 0) {
            SPR_LOGE("read failed! len = %d\n", len);
        }

        RotateLogsIfNecessary(len);
        WriteToLogFile(value);
    }

    return 0;
}

// E.g: sparrow.log sparrow.log.1 sparrow.log.2 ...
int LogManager::RotateLogsIfNecessary(uint32_t logDataSize)
{
    uint32_t curFileSize = static_cast<uint32_t>(mLogFileStream.tellp());
    if (curFileSize + logDataSize > mMaxFileSize) {
        mLogFileStream.close();

        UpdateSuffixOfAllFiles();
        mLogFileStream.open(mLogsDirPath + '/' + mCurrentLogFile, std::ios_base::app | std::ios_base::out);
        if (!mLogFileStream.is_open()) {
            SPR_LOGE("Open %s failed!", mCurrentLogFile.c_str());
        }
    }

    return 0;
}

class SharedRingBuffer
{
public:
    /**
     * @brief Constructs a master Shared Ring Buffer object.
     * @param path  The path to the shared memory.
     * @param capacity The buffer's capacity.
     *
     * Intended for use in master mode with shared memory refreshing.
     */
    SharedRingBuffer(std::string path, uint32_t capacity);

    /**
     * @brief Constructs a slave Shared Ring Buffer object
     * @param path The path to the shared memory.
     *
     * This constructor creates an instance of a slave Shared Ring Buffer, typically used by client applications.
     * It facilitates access and utilization of the shared buffer by referencing it through the specified path.
     */
    SharedRingBuffer(std::string path);
    ~SharedRingBuffer();

    bool    IsReadable()    const noexcept;
    bool    IsWriteable()   const noexcept;
    int     write(const void* data, int32_t len);
    int     read(void* data, int32_t len);
    int     DumpBuffer(void* data, int32_t len) const noexcept;

    int32_t AvailSpace()    const noexcept;
    int32_t AvailData()     const noexcept;


private:
    void    AdjustPosIfOverflow(uint32_t* pos, int32_t size) const noexcept;
    void    SetRWStatus(ECmdType type) const noexcept;
    void    DumpMemory(const char* pAddr, uint32_t size);
    void    DumpErrorInfo();

private:
    Root*       mRoot;
    void*       mData;
    uint32_t    mCapacity;
    std::mutex  mMutex;
    std::string mShmPath;
};

$ tail -f /tmp/sprlog/sparrow.log
04-12 23:53:26.048  51958       TimerM D:   76 [0x0 -> 0x5] msg.GetMsgId() = SIG_ID_SYSTEM_TIMER_NOTIFY
04-12 23:53:26.048  51958       TimerM D:   76 [0x0 -> 0x0] msg.GetMsgId() = SIG_ID_TIMER_START_SYSTEM_TIMER
04-12 23:53:26.057  51958       TimerM D:   76 [0x0 -> 0x5] msg.GetMsgId() = SIG_ID_SYSTEM_TIMER_NOTIFY
04-12 23:53:26.058  51958       TimerM D:   76 [0x0 -> 0x0] msg.GetMsgId() = SIG_ID_TIMER_START_SYSTEM_TIMER
04-12 23:53:26.068  51958       TimerM D:   76 [0x0 -> 0x5] msg.GetMsgId() = SIG_ID_SYSTEM_TIMER_NOTIFY
04-12 23:53:26.068  51958       TimerM D:   76 [0x0 -> 0x0] msg.GetMsgId() = SIG_ID_TIMER_START_SYSTEM_TIMER
04-12 23:53:26.078  51958       TimerM D:   76 [0x0 -> 0x5] msg.GetMsgId() = SIG_ID_SYSTEM_TIMER_NOTIFY
04-12 23:53:26.078  51958       TimerM D:   76 [0x0 -> 0x0] msg.GetMsgId() = SIG_ID_TIMER_START_SYSTEM_TIMER
04-12 23:53:26.088  51958       TimerM D:   76 [0x0 -> 0x5] msg.GetMsgId() = SIG_ID_SYSTEM_TIMER_NOTIFY
04-12 23:53:26.088  51958       TimerM D:   76 [0x0 -> 0x0] msg.GetMsgId() = SIG_ID_TIMER_START_SYSTEM_TIMER
04-12 23:53:26.098  51958       TimerM D:   76 [0x0 -> 0x5] msg.GetMsgId() = SIG_ID_SYSTEM_TIMER_NOTIFY

$ ls /tmp/sprlog/ -lh
total 10M
-rw-r--r-- 1 dx dx 995K Apr 12 23:56 sparrow.log
-rw-r--r-- 1 dx dx 1.0M Apr 12 23:55 sparrow.log.1
-rw-r--r-- 1 dx dx 1.0M Apr 12 23:54 sparrow.log.2
-rw-r--r-- 1 dx dx 1.0M Apr 12 23:54 sparrow.log.3
-rw-r--r-- 1 dx dx 1.0M Apr 12 23:53 sparrow.log.4
-rw-r--r-- 1 dx dx 1.0M Apr 12 23:52 sparrow.log.5
-rw-r--r-- 1 dx dx 1.0M Apr 12 23:51 sparrow.log.6
-rw-r--r-- 1 dx dx 1.0M Apr 12 23:50 sparrow.log.7
-rw-r--r-- 1 dx dx 1.0M Apr 12 23:50 sparrow.log.8
-rw-r--r-- 1 dx dx 1.0M Apr 12 23:49 sparrow.log.9