cristiancmoises/zupt
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Release v2.0.0: VaptVupt codec integration, auto codec detection, Jasmin and VaptVupt fixes, multi-arch & performance enhancements, security hardening, ACSL annotations

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Cristian Cezar Moisés 2026-04-05 15:35:49 -03:00
commit c42251f0a2
15 changed files with 380 additions and 407 deletions
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43
src/vv_encoder.c
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@ -6,6 +6,7 @@
#if !defined(_DEFAULT_SOURCE) && !defined(_GNU_SOURCE)
#define _DEFAULT_SOURCE 1
#endif
/*
* VaptVupt — Encoder v2 (Sprint 1)
*
@ -442,11 +443,8 @@ int64_t vv_compress(const uint8_t *src, size_t src_len,
if (wlog == 0) {
switch (opts->mode) {
case VV_MODE_ULTRA_FAST: wlog = 16; break;
case VV_MODE_BALANCED: wlog = 16; break;
case VV_MODE_EXTREME: wlog = 16; break;
/* TRADEOFF: wlog=16 default avoids 3-byte offset overhead on small data.
* Users can set opts.window_log=20 (1MB) or 22 (4MB) for large files
* with long-range patterns. Zupt sets wlog=20 for backup chunks >1MB. */
case VV_MODE_BALANCED: wlog = 16; break; /* may be overridden below */
case VV_MODE_EXTREME: wlog = 16; break; /* may be overridden below */
}
}
switch (opts->mode) {
@ -456,6 +454,41 @@ int64_t vv_compress(const uint8_t *src, size_t src_len,
default: depth = 48;
}
/* ─── ADAPTIVE WINDOW (Item 2): trial-compress first block at wlog=16
* and wlog=20. If wlog=20 produces ≥3% smaller output, use it.
* Only for balanced/extreme with auto wlog (opts->window_log == 0).
* Cost: one extra compression of the first block (~10ms for 1MB).
* TRADEOFF: encode speed vs automatic ratio optimization.
* Zupt benefits because backup data characteristics are unknown. ─── */
if (opts->window_log == 0 && opts->mode >= VV_MODE_BALANCED && src_len > 65536) {
size_t trial_len = src_len;
if (trial_len > VV_MAX_BLOCK_SIZE) trial_len = VV_MAX_BLOCK_SIZE;
size_t trial_cap = trial_len + trial_len / 255 + 1024;
uint8_t *trial_buf = (uint8_t *)malloc(trial_cap);
if (trial_buf) {
/* Trial at wlog=16 */
matcher_t m16;
matcher_init(&m16, 16, depth);
size_t sz16 = compress_block(src, trial_len, trial_buf, trial_cap, &m16, opts->mode);
matcher_free(&m16);
/* Trial at wlog=20 */
matcher_t m20;
matcher_init(&m20, 20, depth);
size_t sz20 = compress_block(src, trial_len, trial_buf, trial_cap, &m20, opts->mode);
matcher_free(&m20);
free(trial_buf);
/* Pick winner: wlog=20 must save ≥3% to justify 3-byte offsets */
if (sz20 > 0 && sz16 > 0 && sz20 < (sz16 * 97 / 100)) {
wlog = 20;
}
/* Otherwise stay at wlog=16 (no regression on short-offset data) */
}
}
/* Frame header */
uint8_t *op = dst;
vv_frame_header_t fh;