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/* -*- Mode: C; c-basic-offset: 4; indent-tabs-mode: nil -*- */
/*
Copyright (C) 2009 Red Hat, Inc.
This library 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 library 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 library; if not, see <http://www.gnu.org/licenses/>.
*/
#include <config.h>
#ifdef QUIC_FAMILY_8BPC
#undef QUIC_FAMILY_8BPC
#define FNAME(name) name##_8bpc
#define VNAME(name) name##_8bpc
#define BPC 8
#endif
#ifdef QUIC_FAMILY_5BPC
#undef QUIC_FAMILY_5BPC
#define FNAME(name) name##_5bpc
#define VNAME(name) name##_5bpc
#define BPC 5
#endif
static inline unsigned int FNAME(golomb_code)(const BYTE n, const unsigned int l)
{
return VNAME(family).golomb_code[n][l];
}
static inline unsigned int FNAME(golomb_code_len)(const BYTE n, const unsigned int l)
{
return VNAME(family).golomb_code_len[n][l];
}
static void FNAME(golomb_coding)(Encoder *encoder, const BYTE n, const unsigned int l)
{
encode(encoder, FNAME(golomb_code)(n, l), FNAME(golomb_code_len)(n, l));
}
static unsigned int FNAME(golomb_decoding)(const unsigned int l, const unsigned int bits,
unsigned int * const codewordlen)
{
if (bits > VNAME(family).notGRprefixmask[l]) { /*GR*/
const unsigned int zeroprefix = cnt_l_zeroes(bits); /* leading zeroes in codeword */
const unsigned int cwlen = zeroprefix + 1 + l; /* codeword length */
(*codewordlen) = cwlen;
return (zeroprefix << l) | ((bits >> (32 - cwlen)) & bppmask[l]);
} else { /* not-GR */
const unsigned int cwlen = VNAME(family).notGRcwlen[l];
(*codewordlen) = cwlen;
return VNAME(family).nGRcodewords[l] + ((bits) >> (32 - cwlen) &
bppmask[VNAME(family).notGRsuffixlen[l]]);
}
}
/* update the bucket using just encoded curval */
static void FNAME(update_model)(CommonState *state, s_bucket * const bucket,
const BYTE curval)
{
SPICE_VERIFY(BPC >= 1);
spice_return_if_fail (bucket != NULL);
const unsigned int bpp = BPC;
COUNTER * const pcounters = bucket->pcounters;
unsigned int i;
unsigned int bestcode;
unsigned int bestcodelen;
/* update counters, find minimum */
bestcode = bpp - 1;
bestcodelen = (pcounters[bestcode] += FNAME(golomb_code_len)(curval, bestcode));
for (i = bpp - 2; i < bpp; i--) { /* NOTE: expression i<bpp for signed int i would be: i>=0 */
const unsigned int ithcodelen = (pcounters[i] += FNAME(golomb_code_len)(curval, i));
if (ithcodelen < bestcodelen) {
bestcode = i;
bestcodelen = ithcodelen;
}
}
bucket->bestcode = bestcode; /* store the found minimum */
if (bestcodelen > state->wm_trigger) { /* halving counters? */
for (i = 0; i < bpp; i++) {
pcounters[i] >>= 1;
}
}
}
static s_bucket *FNAME(find_bucket)(Channel *channel, const unsigned int val)
{
spice_extra_assert(val < (0x1U << BPC));
/* The and (&) here is to avoid buffer overflows in case of garbage or malicious
* attempts. Is much faster then using comparisons and save us from such situations.
* Note that on normal build the check above won't be compiled as this code path
* is pretty hot and would cause speed regressions.
*/
return channel->_buckets_ptrs[val & ((1U << BPC) - 1)];
}
#undef FNAME
#undef VNAME
#undef BPC
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