#include "xinclude.h"
#include "common.h"
#include "integer.h"
#define XDL_MAX_COST_MIN 256
#define XDL_HEUR_MIN_COST 256
#define XDL_LINE_MAX (long)((1UL << (CHAR_BIT * sizeof(long) - 1)) - 1)
#define XDL_SNAKE_CNT 20
#define XDL_K_HEUR 4
typedef
struct
s_xdpsplit {
long
i1, i2;
int
min_lo, min_hi;
} xdpsplit_t;
static
long
xdl_split(unsigned
long
const
*ha1,
long
off1,
long
lim1,
unsigned
long
const
*ha2,
long
off2,
long
lim2,
long
*kvdf,
long
*kvdb,
int
need_min, xdpsplit_t *spl,
xdalgoenv_t *xenv);
static
xdchange_t *xdl_add_change(xdchange_t *xscr,
long
i1,
long
i2,
long
chg1,
long
chg2);
static
long
xdl_split(unsigned
long
const
*ha1,
long
off1,
long
lim1,
unsigned
long
const
*ha2,
long
off2,
long
lim2,
long
*kvdf,
long
*kvdb,
int
need_min, xdpsplit_t *spl,
xdalgoenv_t *xenv) {
long
dmin = off1 - lim2, dmax = lim1 - off2;
long
fmid = off1 - off2, bmid = lim1 - lim2;
long
odd = (fmid - bmid) & 1;
long
fmin = fmid, fmax = fmid;
long
bmin = bmid, bmax = bmid;
long
ec, d, i1, i2, prev1, best, dd, v, k;
kvdf[fmid] = off1;
kvdb[bmid] = lim1;
for
(ec = 1;; ec++) {
int
got_snake = 0;
if
(fmin > dmin)
kvdf[--fmin - 1] = -1;
else
++fmin;
if
(fmax < dmax)
kvdf[++fmax + 1] = -1;
else
--fmax;
for
(d = fmax; d >= fmin; d -= 2) {
if
(kvdf[d - 1] >= kvdf[d + 1])
i1 = kvdf[d - 1] + 1;
else
i1 = kvdf[d + 1];
prev1 = i1;
i2 = i1 - d;
for
(; i1 < lim1 && i2 < lim2 && ha1[i1] == ha2[i2]; i1++, i2++);
if
(i1 - prev1 > xenv->snake_cnt)
got_snake = 1;
kvdf[d] = i1;
if
(odd && bmin <= d && d <= bmax && kvdb[d] <= i1) {
spl->i1 = i1;
spl->i2 = i2;
spl->min_lo = spl->min_hi = 1;
return
ec;
}
}
if
(bmin > dmin)
kvdb[--bmin - 1] = XDL_LINE_MAX;
else
++bmin;
if
(bmax < dmax)
kvdb[++bmax + 1] = XDL_LINE_MAX;
else
--bmax;
for
(d = bmax; d >= bmin; d -= 2) {
if
(kvdb[d - 1] < kvdb[d + 1])
i1 = kvdb[d - 1];
else
i1 = kvdb[d + 1] - 1;
prev1 = i1;
i2 = i1 - d;
for
(; i1 > off1 && i2 > off2 && ha1[i1 - 1] == ha2[i2 - 1]; i1--, i2--);
if
(prev1 - i1 > xenv->snake_cnt)
got_snake = 1;
kvdb[d] = i1;
if
(!odd && fmin <= d && d <= fmax && i1 <= kvdf[d]) {
spl->i1 = i1;
spl->i2 = i2;
spl->min_lo = spl->min_hi = 1;
return
ec;
}
}
if
(need_min)
continue
;
if
(got_snake && ec > xenv->heur_min) {
for
(best = 0, d = fmax; d >= fmin; d -= 2) {
dd = d > fmid ? d - fmid: fmid - d;
i1 = kvdf[d];
i2 = i1 - d;
v = (i1 - off1) + (i2 - off2) - dd;
if
(v > XDL_K_HEUR * ec && v > best &&
off1 + xenv->snake_cnt <= i1 && i1 < lim1 &&
off2 + xenv->snake_cnt <= i2 && i2 < lim2) {
for
(k = 1; ha1[i1 - k] == ha2[i2 - k]; k++)
if
(k == xenv->snake_cnt) {
best = v;
spl->i1 = i1;
spl->i2 = i2;
break
;
}
}
}
if
(best > 0) {
spl->min_lo = 1;
spl->min_hi = 0;
return
ec;
}
for
(best = 0, d = bmax; d >= bmin; d -= 2) {
dd = d > bmid ? d - bmid: bmid - d;
i1 = kvdb[d];
i2 = i1 - d;
v = (lim1 - i1) + (lim2 - i2) - dd;
if
(v > XDL_K_HEUR * ec && v > best &&
off1 < i1 && i1 <= lim1 - xenv->snake_cnt &&
off2 < i2 && i2 <= lim2 - xenv->snake_cnt) {
for
(k = 0; ha1[i1 + k] == ha2[i2 + k]; k++)
if
(k == xenv->snake_cnt - 1) {
best = v;
spl->i1 = i1;
spl->i2 = i2;
break
;
}
}
}
if
(best > 0) {
spl->min_lo = 0;
spl->min_hi = 1;
return
ec;
}
}
if
(ec >= xenv->mxcost) {
long
fbest, fbest1, bbest, bbest1;
fbest = fbest1 = -1;
for
(d = fmax; d >= fmin; d -= 2) {
i1 = XDL_MIN(kvdf[d], lim1);
i2 = i1 - d;
if
(lim2 < i2)
i1 = lim2 + d, i2 = lim2;
if
(fbest < i1 + i2) {
fbest = i1 + i2;
fbest1 = i1;
}
}
bbest = bbest1 = XDL_LINE_MAX;
for
(d = bmax; d >= bmin; d -= 2) {
i1 = XDL_MAX(off1, kvdb[d]);
i2 = i1 - d;
if
(i2 < off2)
i1 = off2 + d, i2 = off2;
if
(i1 + i2 < bbest) {
bbest = i1 + i2;
bbest1 = i1;
}
}
if
((lim1 + lim2) - bbest < fbest - (off1 + off2)) {
spl->i1 = fbest1;
spl->i2 = fbest - fbest1;
spl->min_lo = 1;
spl->min_hi = 0;
}
else
{
spl->i1 = bbest1;
spl->i2 = bbest - bbest1;
spl->min_lo = 0;
spl->min_hi = 1;
}
return
ec;
}
}
}
int
xdl_recs_cmp(diffdata_t *dd1,
long
off1,
long
lim1,
diffdata_t *dd2,
long
off2,
long
lim2,
long
*kvdf,
long
*kvdb,
int
need_min, xdalgoenv_t *xenv) {
unsigned
long
const
*ha1 = dd1->ha, *ha2 = dd2->ha;
for
(; off1 < lim1 && off2 < lim2 && ha1[off1] == ha2[off2]; off1++, off2++);
for
(; off1 < lim1 && off2 < lim2 && ha1[lim1 - 1] == ha2[lim2 - 1]; lim1--, lim2--);
if
(off1 == lim1) {
char
*rchg2 = dd2->rchg;
long
*rindex2 = dd2->rindex;
for
(; off2 < lim2; off2++)
rchg2[rindex2[off2]] = 1;
}
else
if
(off2 == lim2) {
char
*rchg1 = dd1->rchg;
long
*rindex1 = dd1->rindex;
for
(; off1 < lim1; off1++)
rchg1[rindex1[off1]] = 1;
}
else
{
xdpsplit_t spl;
spl.i1 = spl.i2 = 0;
if
(xdl_split(ha1, off1, lim1, ha2, off2, lim2, kvdf, kvdb,
need_min, &spl, xenv) < 0) {
return
-1;
}
if
(xdl_recs_cmp(dd1, off1, spl.i1, dd2, off2, spl.i2,
kvdf, kvdb, spl.min_lo, xenv) < 0 ||
xdl_recs_cmp(dd1, spl.i1, lim1, dd2, spl.i2, lim2,
kvdf, kvdb, spl.min_hi, xenv) < 0) {
return
-1;
}
}
return
0;
}
int
xdl_do_diff(mmfile_t *mf1, mmfile_t *mf2, xpparam_t
const
*xpp,
xdfenv_t *xe) {
size_t
ndiags, allocsize;
long
*kvd, *kvdf, *kvdb;
xdalgoenv_t xenv;
diffdata_t dd1, dd2;
if
(XDF_DIFF_ALG(xpp->flags) == XDF_PATIENCE_DIFF)
return
xdl_do_patience_diff(mf1, mf2, xpp, xe);
if
(XDF_DIFF_ALG(xpp->flags) == XDF_HISTOGRAM_DIFF)
return
xdl_do_histogram_diff(mf1, mf2, xpp, xe);
if
(xdl_prepare_env(mf1, mf2, xpp, xe) < 0) {
return
-1;
}
GITERR_CHECK_ALLOC_ADD3(&ndiags, xe->xdf1.nreff, xe->xdf2.nreff, 3);
GITERR_CHECK_ALLOC_MULTIPLY(&allocsize, ndiags, 2);
GITERR_CHECK_ALLOC_ADD(&allocsize, allocsize, 2);
GITERR_CHECK_ALLOC_MULTIPLY(&allocsize, allocsize,
sizeof
(
long
));
if
(!(kvd = (
long
*) xdl_malloc(allocsize))) {
xdl_free_env(xe);
return
-1;
}
kvdf = kvd;
kvdb = kvdf + ndiags;
kvdf += xe->xdf2.nreff + 1;
kvdb += xe->xdf2.nreff + 1;
xenv.mxcost = xdl_bogosqrt(ndiags);
if
(xenv.mxcost < XDL_MAX_COST_MIN)
xenv.mxcost = XDL_MAX_COST_MIN;
xenv.snake_cnt = XDL_SNAKE_CNT;
xenv.heur_min = XDL_HEUR_MIN_COST;
dd1.nrec = xe->xdf1.nreff;
dd1.ha = xe->xdf1.ha;
dd1.rchg = xe->xdf1.rchg;
dd1.rindex = xe->xdf1.rindex;
dd2.nrec = xe->xdf2.nreff;
dd2.ha = xe->xdf2.ha;
dd2.rchg = xe->xdf2.rchg;
dd2.rindex = xe->xdf2.rindex;
if
(xdl_recs_cmp(&dd1, 0, dd1.nrec, &dd2, 0, dd2.nrec,
kvdf, kvdb, (xpp->flags & XDF_NEED_MINIMAL) != 0, &xenv) < 0) {
xdl_free(kvd);
xdl_free_env(xe);
return
-1;
}
xdl_free(kvd);
return
0;
}
static
xdchange_t *xdl_add_change(xdchange_t *xscr,
long
i1,
long
i2,
long
chg1,
long
chg2) {
xdchange_t *xch;
if
(!(xch = (xdchange_t *) xdl_malloc(
sizeof
(xdchange_t))))
return
NULL;
xch->next = xscr;
xch->i1 = i1;
xch->i2 = i2;
xch->chg1 = chg1;
xch->chg2 = chg2;
xch->ignore = 0;
return
xch;
}
int
xdl_change_compact(xdfile_t *xdf, xdfile_t *xdfo,
long
flags) {
long
ix, ixo, ixs, ixref, grpsiz, nrec = xdf->nrec;
char
*rchg = xdf->rchg, *rchgo = xdfo->rchg;
xrecord_t **recs = xdf->recs;
for
(ix = ixo = 0;;) {
for
(; ix < nrec && !rchg[ix]; ix++)
while
(rchgo[ixo++]);
if
(ix == nrec)
break
;
ixs = ix;
for
(ix++; rchg[ix]; ix++);
for
(; rchgo[ixo]; ixo++);
do
{
grpsiz = ix - ixs;
while
(ixs > 0 && recs[ixs - 1]->ha == recs[ix - 1]->ha &&
xdl_recmatch(recs[ixs - 1]->ptr, recs[ixs - 1]->size, recs[ix - 1]->ptr, recs[ix - 1]->size, flags)) {
rchg[--ixs] = 1;
rchg[--ix] = 0;
for
(; rchg[ixs - 1]; ixs--);
while
(rchgo[--ixo]);
}
ixref = rchgo[ixo - 1] ? ix: nrec;
while
(ix < nrec && recs[ixs]->ha == recs[ix]->ha &&
xdl_recmatch(recs[ixs]->ptr, recs[ixs]->size, recs[ix]->ptr, recs[ix]->size, flags)) {
rchg[ixs++] = 0;
rchg[ix++] = 1;
for
(; rchg[ix]; ix++);
while
(rchgo[++ixo])
ixref = ix;
}
}
while
(grpsiz != ix - ixs);
while
(ixref < ix) {
rchg[--ixs] = 1;
rchg[--ix] = 0;
while
(rchgo[--ixo]);
}
}
return
0;
}
int
xdl_build_script(xdfenv_t *xe, xdchange_t **xscr) {
xdchange_t *cscr = NULL, *xch;
char
*rchg1 = xe->xdf1.rchg, *rchg2 = xe->xdf2.rchg;
long
i1, i2, l1, l2;
for
(i1 = xe->xdf1.nrec, i2 = xe->xdf2.nrec; i1 >= 0 || i2 >= 0; i1--, i2--)
if
(rchg1[i1 - 1] || rchg2[i2 - 1]) {
for
(l1 = i1; rchg1[i1 - 1]; i1--);
for
(l2 = i2; rchg2[i2 - 1]; i2--);
if
(!(xch = xdl_add_change(cscr, i1, i2, l1 - i1, l2 - i2))) {
xdl_free_script(cscr);
return
-1;
}
cscr = xch;
}
*xscr = cscr;
return
0;
}
void
xdl_free_script(xdchange_t *xscr) {
xdchange_t *xch;
while
((xch = xscr) != NULL) {
xscr = xscr->next;
xdl_free(xch);
}
}
static
int
xdl_call_hunk_func(xdfenv_t *xe, xdchange_t *xscr, xdemitcb_t *ecb,
xdemitconf_t
const
*xecfg)
{
xdchange_t *xch, *xche;
(
void
)xe;
for
(xch = xscr; xch; xch = xche->next) {
xche = xdl_get_hunk(&xch, xecfg);
if
(!xch)
break
;
if
(xecfg->hunk_func(xch->i1, xche->i1 + xche->chg1 - xch->i1,
xch->i2, xche->i2 + xche->chg2 - xch->i2,
ecb->priv) < 0)
return
-1;
}
return
0;
}
static
void
xdl_mark_ignorable(xdchange_t *xscr, xdfenv_t *xe,
long
flags)
{
xdchange_t *xch;
for
(xch = xscr; xch; xch = xch->next) {
int
ignore = 1;
xrecord_t **rec;
long
i;
rec = &xe->xdf1.recs[xch->i1];
for
(i = 0; i < xch->chg1 && ignore; i++)
ignore = xdl_blankline(rec[i]->ptr, rec[i]->size, flags);
rec = &xe->xdf2.recs[xch->i2];
for
(i = 0; i < xch->chg2 && ignore; i++)
ignore = xdl_blankline(rec[i]->ptr, rec[i]->size, flags);
xch->ignore = ignore;
}
}
int
xdl_diff(mmfile_t *mf1, mmfile_t *mf2, xpparam_t
const
*xpp,
xdemitconf_t
const
*xecfg, xdemitcb_t *ecb) {
xdchange_t *xscr;
xdfenv_t xe;
emit_func_t ef = xecfg->hunk_func ? xdl_call_hunk_func : xdl_emit_diff;
if
(xdl_do_diff(mf1, mf2, xpp, &xe) < 0) {
return
-1;
}
if
(xdl_change_compact(&xe.xdf1, &xe.xdf2, xpp->flags) < 0 ||
xdl_change_compact(&xe.xdf2, &xe.xdf1, xpp->flags) < 0 ||
xdl_build_script(&xe, &xscr) < 0) {
xdl_free_env(&xe);
return
-1;
}
if
(xscr) {
if
(xpp->flags & XDF_IGNORE_BLANK_LINES)
xdl_mark_ignorable(xscr, &xe, xpp->flags);
if
(ef(&xe, xscr, ecb, xecfg) < 0) {
xdl_free_script(xscr);
xdl_free_env(&xe);
return
-1;
}
xdl_free_script(xscr);
}
xdl_free_env(&xe);
return
0;
}