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Merge branch 'en/xdiff-cleanup-3' into pw/xdiff-shrink-memory-consumption 

* en/xdiff-cleanup-3:
  xdiff/xdl_cleanup_records: make execution of action easier to follow
  xdiff/xdl_cleanup_records: make setting action easier to follow
  xdiff/xdl_cleanup_records: make limits more clear
  xdiff/xdl_cleanup_records: use unambiguous types
  xdiff: use unambiguous types in xdl_bogo_sqrt()
  xdiff/xdl_cleanup_records: delete local recs pointer
main
Junio C Hamano 2026-05-05 16:19:59 +09:00
parent 94f057755b f87808b701
commit bfd057b2dd
4 changed files with 73 additions and 32 deletions
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2
xdiff/xdiffi.c
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@ -348,7 +348,7 @@ int xdl_do_diff(mmfile_t *mf1, mmfile_t *mf2, xpparam_t const *xpp,
kvdf += xe->xdf2.nreff + 1;
kvdb += xe->xdf2.nreff + 1;

xenv.mxcost = xdl_bogosqrt(ndiags);
xenv.mxcost = (long)xdl_bogosqrt((uint64_t)ndiags);
if (xenv.mxcost < XDL_MAX_COST_MIN)
xenv.mxcost = XDL_MAX_COST_MIN;
xenv.snake_cnt = XDL_SNAKE_CNT;

97
xdiff/xprepare.c
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@ -197,8 +197,8 @@ void xdl_free_env(xdfenv_t *xe) {
}


static bool xdl_clean_mmatch(uint8_t const *action, long i, long s, long e) {
long r, rdis0, rpdis0, rdis1, rpdis1;
static bool xdl_clean_mmatch(uint8_t const *action, ptrdiff_t i, ptrdiff_t s, ptrdiff_t e) {
ptrdiff_t r, rdis0, rpdis0, rdis1, rpdis1;

/*
* Limits the window that is examined during the similar-lines
@ -268,8 +268,7 @@ static bool xdl_clean_mmatch(uint8_t const *action, long i, long s, long e) {
* might be potentially discarded if they appear in a run of discardable.
*/
static int xdl_cleanup_records(xdlclassifier_t *cf, xdfile_t *xdf1, xdfile_t *xdf2) {
long i, nm, mlim;
xrecord_t *recs;
ptrdiff_t i, nm, mlim1, mlim2;
xdlclass_t *rcrec;
uint8_t *action1 = NULL, *action2 = NULL;
bool need_min = !!(cf->flags & XDF_NEED_MINIMAL);
@ -291,20 +290,44 @@ static int xdl_cleanup_records(xdlclassifier_t *cf, xdfile_t *xdf1, xdfile_t *xd
/*
* Initialize temporary arrays with DISCARD, KEEP, or INVESTIGATE.
*/
if ((mlim = xdl_bogosqrt((long)xdf1->nrec)) > XDL_MAX_EQLIMIT)
mlim = XDL_MAX_EQLIMIT;
for (i = xdf1->dstart, recs = &xdf1->recs[xdf1->dstart]; i <= xdf1->dend; i++, recs++) {
rcrec = cf->rcrecs[recs->minimal_perfect_hash];
if (need_min) {
/* i.e. infinity */
mlim1 = PTRDIFF_MAX;
} else {
mlim1 = xdl_bogosqrt((uint64_t)xdf1->nrec);
if (mlim1 > XDL_MAX_EQLIMIT)
mlim1 = XDL_MAX_EQLIMIT;
}
for (i = xdf1->dstart; i <= xdf1->dend; i++) {
size_t mph1 = xdf1->recs[i].minimal_perfect_hash;
rcrec = cf->rcrecs[mph1];
nm = rcrec ? rcrec->len2 : 0;
action1[i] = (nm == 0) ? DISCARD: (nm >= mlim && !need_min) ? INVESTIGATE: KEEP;
if (nm == 0)
action1[i] = DISCARD;
else if (nm < mlim1)
action1[i] = KEEP;
else /* nm >= mlim1 */
action1[i] = INVESTIGATE;
}

if ((mlim = xdl_bogosqrt((long)xdf2->nrec)) > XDL_MAX_EQLIMIT)
mlim = XDL_MAX_EQLIMIT;
for (i = xdf2->dstart, recs = &xdf2->recs[xdf2->dstart]; i <= xdf2->dend; i++, recs++) {
rcrec = cf->rcrecs[recs->minimal_perfect_hash];
if (need_min) {
/* i.e. infinity */
mlim2 = PTRDIFF_MAX;
} else {
mlim2 = xdl_bogosqrt((uint64_t)xdf2->nrec);
if (mlim2 > XDL_MAX_EQLIMIT)
mlim2 = XDL_MAX_EQLIMIT;
}
for (i = xdf2->dstart; i <= xdf2->dend; i++) {
size_t mph2 = xdf2->recs[i].minimal_perfect_hash;
rcrec = cf->rcrecs[mph2];
nm = rcrec ? rcrec->len1 : 0;
action2[i] = (nm == 0) ? DISCARD: (nm >= mlim && !need_min) ? INVESTIGATE: KEEP;
if (nm == 0)
action2[i] = DISCARD;
else if (nm < mlim2)
action2[i] = KEEP;
else /* nm >= mlim2 */
action2[i] = INVESTIGATE;
}

/*
@ -312,27 +335,45 @@ static int xdl_cleanup_records(xdlclassifier_t *cf, xdfile_t *xdf1, xdfile_t *xd
* false, or become true.
*/
xdf1->nreff = 0;
for (i = xdf1->dstart, recs = &xdf1->recs[xdf1->dstart];
i <= xdf1->dend; i++, recs++) {
if (action1[i] == KEEP ||
(action1[i] == INVESTIGATE && !xdl_clean_mmatch(action1, i, xdf1->dstart, xdf1->dend))) {
for (i = xdf1->dstart; i <= xdf1->dend; i++) {
uint8_t action = action1[i];

if (action == INVESTIGATE) {
if (!xdl_clean_mmatch(action1, i, xdf1->dstart, xdf1->dend))
action = KEEP;
else
action = DISCARD;
}

if (action == KEEP) {
xdf1->reference_index[xdf1->nreff++] = i;
/* changed[i] remains false, i.e. keep */
} else
/* changed[i] remains false */
} else if (action == DISCARD) {
xdf1->changed[i] = true;
/* i.e. discard */
} else {
BUG("Illegal state for action");
}
}

xdf2->nreff = 0;
for (i = xdf2->dstart, recs = &xdf2->recs[xdf2->dstart];
i <= xdf2->dend; i++, recs++) {
if (action2[i] == KEEP ||
(action2[i] == INVESTIGATE && !xdl_clean_mmatch(action2, i, xdf2->dstart, xdf2->dend))) {
for (i = xdf2->dstart; i <= xdf2->dend; i++) {
uint8_t action = action2[i];

if (action == INVESTIGATE) {
if (!xdl_clean_mmatch(action2, i, xdf2->dstart, xdf2->dend))
action = KEEP;
else
action = DISCARD;
}

if (action == KEEP) {
xdf2->reference_index[xdf2->nreff++] = i;
/* changed[i] remains false, i.e. keep */
} else
/* changed[i] remains false */
} else if (action == DISCARD) {
xdf2->changed[i] = true;
/* i.e. discard */
} else {
BUG("Illegal state for action");
}
}

cleanup:

4
xdiff/xutils.c
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@ -23,8 +23,8 @@
#include "xinclude.h"


long xdl_bogosqrt(long n) {
long i;
uint64_t xdl_bogosqrt(uint64_t n) {
uint64_t i;

/*
* Classical integer square root approximation using shifts.

2
xdiff/xutils.h
View File

@ -25,7 +25,7 @@



long xdl_bogosqrt(long n);
uint64_t xdl_bogosqrt(uint64_t n);
int xdl_emit_diffrec(char const *rec, long size, char const *pre, long psize,
xdemitcb_t *ecb);
int xdl_cha_init(chastore_t *cha, long isize, long icount);