From: erik quanstrom <quanstro@quanstro.net>
To: 9fans@cse.psu.edu
Subject: [9fans] snap checksum
Date: Fri, 11 Jan 2008 14:39:08 -0500 [thread overview]
Message-ID: <0d43ff0b0f3fc5742f94b963c508be10@quanstro.net> (raw)
does anyone know if the function /sys/src/cmd/snap/take.c:/^sumr
can return 0 for a buffer that is not all zeros?
i think it can not, since for sum&1, the next sum at least
has 0x8000 set and otherwise if (sum&1) == 0, then either
sum == 0 or sum>>1 != 0.
fletcher-16 seems similar except for the extra sum. does anyone
know of any writeups on this algorithm? or at least an example
that shows that sum can return 0 for a non-zeroed buffer?
- erik
next reply other threads:[~2008-01-11 19:39 UTC|newest]
Thread overview: 4+ messages / expand[flat|nested] mbox.gz Atom feed top
2008-01-11 19:39 erik quanstrom [this message]
2008-01-12 19:06 Russ Cox
2008-01-12 19:30 ` erik quanstrom
2008-01-16 9:43 ` Douglas A. Gwyn
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