fd2bbdd238
This splits Geert's similarity fingerprint code into main program and fingerprinting function. The next step would be to try using this in pack-objects.c::try_delta() -- which would be a good evaluation. Signed-off-by: Junio C Hamano <junkio@cox.net>
29 lines
1.0 KiB
C
29 lines
1.0 KiB
C
#ifndef GSIMM_H
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#define GSIMM_H
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/* Length of file message digest (MD) in bytes. Longer MD's are
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better, but increase processing time for diminishing returns.
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Must be multiple of NUM_HASHES_PER_CHAR / 8, and at least 24
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for good results
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*/
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#define MD_LENGTH 32
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#define MD_BITS (MD_LENGTH * 8)
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/* The MIN_FILE_SIZE indicates the absolute minimal file size that
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can be processed. As indicated above, the first and last
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RABIN_WINDOW_SIZE - 1 bytes are skipped.
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In order to get at least an average of 12 samples
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per bit in the final message digest, require at least 3 * MD_LENGTH
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complete windows in the file. */
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#define MIN_FILE_SIZE (3 * MD_LENGTH + 2 * (RABIN_WINDOW_SIZE - 1))
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/* Limit matching algorithm to files less than 256 MB, so we can use
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32 bit integers everywhere without fear of overflow. For larger
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files we should add logic to mmap the file by piece and accumulate
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the frequency counts. */
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#define MAX_FILE_SIZE (256*1024*1024 - 1)
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void gb_simm_process(u_char *data, unsigned len, u_char *md);
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#endif
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