xdiff: post-process hunks to make them consistent.

This commit is contained in:
Davide Libenzi 2006-04-13 16:45:13 -07:00 коммит произвёл Junio C Hamano
Родитель f327dbced2
Коммит 295ba2fb89
2 изменённых файлов: 110 добавлений и 5 удалений

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@ -45,6 +45,8 @@ static long xdl_split(unsigned long const *ha1, long off1, long lim1,
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 int xdl_change_compact(xdfile_t *xdf, xdfile_t *xdfo);
@ -395,6 +397,110 @@ static xdchange_t *xdl_add_change(xdchange_t *xscr, long i1, long i2, long chg1,
}
static int xdl_change_compact(xdfile_t *xdf, xdfile_t *xdfo) {
long ix, ixo, ixs, ixref, grpsiz, nrec = xdf->nrec;
char *rchg = xdf->rchg, *rchgo = xdfo->rchg;
xrecord_t **recs = xdf->recs;
/*
* This is the same of what GNU diff does. Move back and forward
* change groups for a consistent and pretty diff output. This also
* helps in finding joineable change groups and reduce the diff size.
*/
for (ix = ixo = 0;;) {
/*
* Find the first changed line in the to-be-compacted file.
* We need to keep track of both indexes, so if we find a
* changed lines group on the other file, while scanning the
* to-be-compacted file, we need to skip it properly. Note
* that loops that are testing for changed lines on rchg* do
* not need index bounding since the array is prepared with
* a zero at position -1 and N.
*/
for (; ix < nrec && !rchg[ix]; ix++)
while (rchgo[ixo++]);
if (ix == nrec)
break;
/*
* Record the start of a changed-group in the to-be-compacted file
* and find the end of it, on both to-be-compacted and other file
* indexes (ix and ixo).
*/
ixs = ix;
for (ix++; rchg[ix]; ix++);
for (; rchgo[ixo]; ixo++);
do {
grpsiz = ix - ixs;
/*
* If the line before the current change group, is equal to
* the last line of the current change group, shift backward
* the group.
*/
while (ixs > 0 && recs[ixs - 1]->ha == recs[ix - 1]->ha &&
XDL_RECMATCH(recs[ixs - 1], recs[ix - 1])) {
rchg[--ixs] = 1;
rchg[--ix] = 0;
/*
* This change might have joined two change groups,
* so we try to take this scenario in account by moving
* the start index accordingly (and so the other-file
* end-of-group index).
*/
for (; rchg[ixs - 1]; ixs--);
while (rchgo[--ixo]);
}
/*
* Record the end-of-group position in case we are matched
* with a group of changes in the other file (that is, the
* change record before the enf-of-group index in the other
* file is set).
*/
ixref = rchgo[ixo - 1] ? ix: nrec;
/*
* If the first line of the current change group, is equal to
* the line next of the current change group, shift forward
* the group.
*/
while (ix < nrec && recs[ixs]->ha == recs[ix]->ha &&
XDL_RECMATCH(recs[ixs], recs[ix])) {
rchg[ixs++] = 0;
rchg[ix++] = 1;
/*
* This change might have joined two change groups,
* so we try to take this scenario in account by moving
* the start index accordingly (and so the other-file
* end-of-group index). Keep tracking the reference
* index in case we are shifting together with a
* corresponding group of changes in the other file.
*/
for (; rchg[ix]; ix++);
while (rchgo[++ixo])
ixref = ix;
}
} while (grpsiz != ix - ixs);
/*
* Try to move back the possibly merged group of changes, to match
* the recorded postion in the other file.
*/
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;
@ -440,13 +546,13 @@ int xdl_diff(mmfile_t *mf1, mmfile_t *mf2, xpparam_t const *xpp,
return -1;
}
if (xdl_build_script(&xe, &xscr) < 0) {
if (xdl_change_compact(&xe.xdf1, &xe.xdf2) < 0 ||
xdl_change_compact(&xe.xdf2, &xe.xdf1) < 0 ||
xdl_build_script(&xe, &xscr) < 0) {
xdl_free_env(&xe);
return -1;
}
if (xscr) {
if (xdl_emit_diff(&xe, xscr, ecb, xecfg) < 0) {
@ -454,10 +560,8 @@ int xdl_diff(mmfile_t *mf1, mmfile_t *mf2, xpparam_t const *xpp,
xdl_free_env(&xe);
return -1;
}
xdl_free_script(xscr);
}
xdl_free_env(&xe);
return 0;

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@ -33,6 +33,7 @@
#define XDL_ISDIGIT(c) ((c) >= '0' && (c) <= '9')
#define XDL_HASHLONG(v, b) (((unsigned long)(v) * GR_PRIME) >> ((CHAR_BIT * sizeof(unsigned long)) - (b)))
#define XDL_PTRFREE(p) do { if (p) { xdl_free(p); (p) = NULL; } } while (0)
#define XDL_RECMATCH(r1, r2) ((r1)->size == (r2)->size && memcmp((r1)->ptr, (r2)->ptr, (r1)->size) == 0)
#define XDL_LE32_PUT(p, v) \
do { \
unsigned char *__p = (unsigned char *) (p); \