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xdiff: post-process hunks to make them consistent.

maint
Davide Libenzi 19 years ago committed by Junio C Hamano
parent
commit
295ba2fb89
  1. 114
      xdiff/xdiffi.c
  2. 1
      xdiff/xmacros.h

114
xdiff/xdiffi.c

@ -45,6 +45,8 @@ static long xdl_split(unsigned long const *ha1, long off1, long lim1, @@ -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, @@ -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, @@ -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, @@ -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;

1
xdiff/xmacros.h

@ -33,6 +33,7 @@ @@ -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); \

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