333 int DiskIO::Read(void* buffer, int numBytes) {  in Read()  argument
345       if (numBytes <= blockSize) {  in Read()
349          numBlocks = numBytes / blockSize;  in Read()
350          if ((numBytes % blockSize) != 0)  in Read()
361       memcpy(buffer, tempSpace, numBytes);  in Read()
364       if (((numBlocks * blockSize) != numBytes) && (retval > 0))  in Read()
365          retval = numBytes;  in Read()
376 int DiskIO::Write(void* buffer, int numBytes) {  in Write()  argument
388       if (numBytes <= blockSize) {  in Write()
392          numBlocks = numBytes / blockSize;  in Write()
393          if ((numBytes % blockSize) != 0) numBlocks++;  in Write()
402       memcpy(tempSpace, buffer, numBytes);  in Write()
403       for (i = numBytes; i < numBlocks * blockSize; i++) {  in Write()
409       if (((numBlocks * blockSize) != numBytes) && (retval > 0))  in Write()
410          retval = numBytes;  in Write()