very fast binary search in files

Question

I have to search fast for patterns in a binary file. Does anybody know how to find a byte sequence like %%EOF
 fast in a binary file ? Textreader does not work use of Encoding class makes the probleme even worser and therefore string.Find does not work. ArrayLists are cool but there i can only search for a single byte. Additionaly the extra performance cost for boxing/unboxing is not acceptable. Any hints highly appreciated.

spgilmore · Answer

You can do this in a single scan. Use a filestream and read one byte at a time. Just search for the first byte in teh sequence. When you find it compare the rest of sequence to the contents of the file at that location. If not a match continue. Reading only one byte at a time is not efficient but the filestream buffers the reads I think. If it's still too slow just modify the code to read and test 512 bytes at a time (which is good for NTFS) or 2048 at a time (which is good for CDs or FAT).