When uncompressing a zip file using xceed the decompression takes about 50 times longer than winzip if AVG anti-virus resident shield is enabled.  I assume the this is due to the anti-virus scanner checking each file as it is written to disk but Winzip is fast so....

My guess it winzip writes the extracted file at one time to disk (only one scan) or winzip writes the extracted file to a non scannable extension and then renames the file to the correct extension.

1.  Can I force the extraction to write more than 32k to disk at a time when extracting?

2.  What events are used to change a extracted file name?  and is there an event that is fired after a file has been extracted that I can use to change the filename back to the original name?  I assume this would result in only one scan by AVG.

BTW,  This compressed files have a large number of .bin and .dat extensions.

Thanks

Rob

Actually my profiler was incorrect.  Xceed is 8x slower than winzip.

Any thoughts?

First of all, a disclaimer. We do not know exactly how the AVG program operates. For all we know, the software could have built-in exceptions to let WinZip operate since it is a common, popular program.
 
Now, it is possible that AVG starts a virus check for every write operation the Xceed Zip Compression library makes.
 
To answer your questions:
 
1. No, the size of the write buffer is not configurable. You could, however, redirect unzipping to memory with the UnzipPreprocessingFile event and then use the UnzippingMemoryFile event to implement your own write operations.
 
2. The UnzipPreprocessingFile event allows you to change the filename if you want. There is no event triggered after a file has been written to disk but if you implement your own disk writing algorithm as suggested in above, you can control the file extensions yourself.