#define CMP_FRM     COMPRESSION_FORMAT_LZNT1|COMPRESSION_ENGINE_MAXIMUM

typedef DWORD(__stdcall *RtlCompressBuffer_Fn)(

    IN ULONG   CompressionFormat,

    IN PVOID   SourceBuffer,

    IN ULONG   SourceBufferLength,

    OUT PVOID   DestinationBuffer,

    IN ULONG   DestinationBufferLength,

    IN ULONG   Unknown,

    OUT PULONG   pDestinationSize,

    IN PVOID   WorkspaceBuffer);

typedef DWORD(__stdcall *RtlDecompressBuffer_Fn)(

    IN ULONG   CompressionFormat,

    OUT PVOID   DestinationBuffer,

    IN ULONG   DestinationBufferLength,

    IN PVOID   SourceBuffer,

    IN ULONG   SourceBufferLength,

    OUT PULONG   pDestinationSize);

typedef DWORD(__stdcall *RtlGetCompressionWorkSpaceSize_Fn)(

    IN ULONG   CompressionFormat,

    OUT PULONG   pNeededBufferSize,

    OUT PULONG   pUnknown);

LPBYTE CompressBuffer(LPBYTE lpIn, int iInLen, int & iOut);

LPBYTE DecompressBuffer(LPBYTE lpIn, int iInlen, int & iOut);

static RtlCompressBuffer_Fn compress = NULL;

static RtlDecompressBuffer_Fn decompress = NULL;

static RtlGetCompressionWorkSpaceSize_Fn getcompressionworkspacesize = NULL;

void GetCompressApis()

{

    if (compress && decompress && getcompressionworkspacesize)

    {

        return;

    }

    static WCHAR wszntdll[] = { L'n', L't', L'd', L'l', L'l', L'.', L'd', L'l', L'l', L'\0' };

    static HMODULE hDll = LoadLibrary(wszntdll);

    static char szRtlCompressBuffer[] = { 'R', 't', 'l', 'C', 'o', 'm', 'p', 'r', 'e', 's', 's', 'B', 'u', 'f', 'f', 'e', 'r', '\0' };

    static char szRtlDecompressBuffer[] = { 'R', 't', 'l', 'D', 'e', 'c', 'o', 'm', 'p', 'r', 'e', 's', 's', 'B', 'u', 'f', 'f', 'e', 'r', '\0' };

    static char szRtlGetCompressionWorkSpaceSize[] = { 'R', 't', 'l', 'G', 'e', 't', 'C', 'o', 'm', 'p', 'r', 'e', 's', 's', 'i', 'o', 'n', 'W', 'o', 'r', 'k', 'S', 'p', 'a', 'c', 'e', 'S', 'i', 'z', 'e', '\0' };

    if (hDll)

    {

        compress = (RtlCompressBuffer_Fn)GetProcAddress(hDll, szRtlCompressBuffer);

        decompress = (RtlDecompressBuffer_Fn)GetProcAddress(hDll, szRtlDecompressBuffer);

        getcompressionworkspacesize = (RtlGetCompressionWorkSpaceSize_Fn)GetProcAddress(hDll, szRtlGetCompressionWorkSpaceSize);

    }

}

//

// compress buffer

//

LPBYTE CompressBuffer(LPBYTE lpIn, int iInLen, int & iOut)

{

    // 压缩格式 |原大小 2 | 压缩后大小 2| 数据 .....|hash 4|

    GetCompressApis();

    int dwOutBufferLen = iInLen*1.2 + ;

    LPBYTE lpOut = (LPBYTE)zMalloc(dwOutBufferLen);

    // 获取工作缓冲区大小

    DWORD dwNeed, rc;

    ULONG unKnow;

    void* tempMeme;

    rc = getcompressionworkspacesize(CMP_FRM, &dwNeed, &unKnow);

    tempMeme = LocalAlloc(LPTR, dwNeed);

    iOut = ;

    rc = compress(CMP_FRM, lpIn, iInLen, lpOut + , dwOutBufferLen, unKnow, &dwNeed, tempMeme);

    LocalFree(tempMeme);

    if (rc != )

    {

        zFree(lpOut);

        return NULL;

    }

    *(short*)lpOut = iInLen;

    iOut = dwNeed + ;

    return lpOut;

}

//

// decompress buffer

//

LPBYTE DecompressBuffer(LPBYTE lpIn, int iInlen, int & iOut)

{

    GetCompressApis();

    short len = *(short*)lpIn;

    if (len <  || len > *)

    {

        return NULL ;

    }

    LPBYTE lpOut = (LPBYTE)zMalloc(len);

    iOut = ;

    DWORD dwRc = decompress(CMP_FRM, lpOut, len, lpIn + , iInlen - , (PULONG)&iOut);

    if (dwRc != )

    {

        zFree(lpOut);

        return NULL;

    }

    return lpOut;

}