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Slow BinaryReader Position Change Time

Posted By:      Posted Date: September 24, 2010    Points: 0   Category :.NET Framework

Hello, I have a question about basically a laggy position change time with a large file (actually, in this case I'm using a 20GB or so disk drive).  Basically what I'm doing is writing my own class that uses the CreateFile function to read raw data from a local disk drive, and then have an extract file class that allows me to seek to blocks (the file system is FAT) that the file occupies, then read the data, piece it together, etc.  I noticed though, that when extracting an 800KB file, it took about 10 seconds to do the process, and the main cause was that changing my reader's position took anywhere from 250 milliseconds to one complete second.

The short version: When extracting a file using my own classes, it took way longer than it should have, and the cause is changing the IO's position.


The code is exactly as you'd probably imagine:

for (int i = 0; i < f.BlocksOccupied.Length - 1; i++)
          br.BaseStream.Position = m.GetBlockOffset(f.BlocksOccupied[i], f.PartInfo);
So what I am asking is if there is any way to speed up the process of moving my posit

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