Function WriteDataToMpqFile

extern/StormLib/src/SFileAddFile.cpp:124–272

// MPQ write data functions

static DWORD WriteDataToMpqFile(
    TMPQArchive * ha,
    TMPQFile * hf,
    LPBYTE pbFileData,
    DWORD dwDataSize,
    DWORD dwCompression)
{
    TFileEntry * pFileEntry = hf->pFileEntry;
    ULONGLONG ByteOffset;
    LPBYTE pbCompressed = NULL;             // Compressed (target) data
    LPBYTE pbToWrite = hf->pbFileSector;    // Data to write to the file
    DWORD dwErrCode = ERROR_SUCCESS;
    int nCompressionLevel;                  // ADPCM compression level (only used for wave files)

    // Make sure that the caller won't overrun the previously initiated file size
    assert(hf->dwFilePos + dwDataSize <= pFileEntry->dwFileSize);
    assert(hf->dwSectorCount != 0);
    assert(hf->pbFileSector != NULL);
    if((hf->dwFilePos + dwDataSize) > pFileEntry->dwFileSize)
        return ERROR_DISK_FULL;

    // Now write all data to the file sector buffer
    if(dwErrCode == ERROR_SUCCESS)
    {
        DWORD dwBytesInSector = hf->dwFilePos % hf->dwSectorSize;
        DWORD dwSectorIndex = hf->dwFilePos / hf->dwSectorSize;
        DWORD dwBytesToCopy;

        // Process all data.
        while(dwDataSize != 0)
        {
            dwBytesToCopy = dwDataSize;

            // Check for sector overflow
            if(dwBytesToCopy > (hf->dwSectorSize - dwBytesInSector))
                dwBytesToCopy = (hf->dwSectorSize - dwBytesInSector);

            // Copy the data to the file sector
            memcpy(hf->pbFileSector + dwBytesInSector, pbFileData, dwBytesToCopy);
            dwBytesInSector += dwBytesToCopy;
            pbFileData += dwBytesToCopy;
            dwDataSize -= dwBytesToCopy;

            // Update the file position
            hf->dwFilePos += dwBytesToCopy;

            // If the current sector is full, or if the file is already full,
            // then write the data to the MPQ
            if(dwBytesInSector >= hf->dwSectorSize || hf->dwFilePos >= pFileEntry->dwFileSize)
            {
                // Set the position in the file
                ByteOffset = hf->RawFilePos + pFileEntry->dwCmpSize;

                // Update MD5 and CRC32 of the file
                if(hf->hctx != NULL)
                    md5_process((hash_state *)hf->hctx, hf->pbFileSector, dwBytesInSector);
                hf->dwCrc32 = crc32(hf->dwCrc32, hf->pbFileSector, dwBytesInSector);