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/* -*- c-file-style: "bsd" -*-
* rproxy -- dynamic caching and delta update in HTTP
* $Id: rollsum.h,v 1.7 2000/08/06 12:50:36 mbp Exp $
*
* Copyright (C) 2000 by Martin Pool <mbp@humbug.org.au>
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU Lesser General Public License as published by
* the Free Software Foundation; either version 2.1 of the License, or
* (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
*/
/* ROLLSUM_T contains the checksums that roll through the new version of the
file as we see it. We use this for two different things: searching for
matches in the old version of the file, and also generating new-signature
information to send down to the client. */
struct hs_rollsum {
int havesum; /* false if we've skipped & need to
recalculate */
uint32_t weak_sum, s1, s2; /* weak checksum */
};
/* Define this to check all weak checksums the slow way. As a debuggging
assertion, calculate the weak checksum *in full* at every byte, and make
sure it is the same. This will be really slow, but it will catch problems
with rolling. */
#define HS_PAINFUL_HONESTY
int _hs_trim_sums(byte_t const *p, hs_rollsum_t * rollsum,
size_t short_block);
int _hs_stretch_sums(byte_t const *p, size_t full_block,
size_t short_block, hs_rollsum_t * rollsum);
void _hs_roll_reset(hs_rollsum_t * rollsum);
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