Function SFileReadFile

extern/StormLib/src/SFileReadFile.cpp:678–764

// SFileReadFile

bool WINAPI SFileReadFile(HANDLE hFile, void * pvBuffer, DWORD dwToRead, LPDWORD pdwRead, LPOVERLAPPED lpOverlapped)
{
    TFileEntry * pFileEntry;
    TMPQFile * hf;
    DWORD dwBytesRead = 0;                      // Number of bytes read
    DWORD dwErrCode = ERROR_SUCCESS;

    // Always zero the result
    if(pdwRead != NULL)
        *pdwRead = 0;
    lpOverlapped = lpOverlapped;

    // Check valid parameters
    if((hf = IsValidFileHandle(hFile)) == NULL)
    {
        SetLastError(ERROR_INVALID_HANDLE);
        return false;
    }

    if(pvBuffer == NULL)
    {
        SetLastError(ERROR_INVALID_PARAMETER);
        return false;
    }

    // If we didn't load the patch info yet, do it now
    if(hf->pFileEntry != NULL && (hf->pFileEntry->dwFlags & MPQ_FILE_PATCH_FILE) && hf->pPatchInfo == NULL)
    {
        dwErrCode = AllocatePatchInfo(hf, true);
        if(dwErrCode != ERROR_SUCCESS || hf->pPatchInfo == NULL)
        {
            SetLastError(dwErrCode);
            return false;
        }
    }

    // Clear the last used compression
    pFileEntry = hf->pFileEntry;
    hf->dwCompression0 = 0;

    // If the file is local file, read the data directly from the stream
    if(hf->pStream != NULL)
    {
        dwErrCode = ReadMpqFileLocalFile(hf, pvBuffer, hf->dwFilePos, dwToRead, &dwBytesRead);
    }

    // If the file is a patch file, we have to read it special way
    else if(hf->hfPatch != NULL && (pFileEntry->dwFlags & MPQ_FILE_PATCH_FILE) == 0)
    {
        dwErrCode = ReadMpqFilePatchFile(hf, pvBuffer, hf->dwFilePos, dwToRead, &dwBytesRead);
    }

    // If the archive is a MPK archive, we need special way to read the file
    else if(hf->ha->dwSubType == MPQ_SUBTYPE_MPK)
    {
        dwErrCode = ReadMpkFileSingleUnit(hf, pvBuffer, hf->dwFilePos, dwToRead, &dwBytesRead);
    }