neovim

xemit.c (8278B)

---

/*
*  LibXDiff by Davide Libenzi ( File Differential Library )
*  Copyright (C) 2003	Davide Libenzi
*
*  This library is free software; you can redistribute it and/or
*  modify it under the terms of the GNU Lesser General Public
*  License as published by the Free Software Foundation; either
*  version 2.1 of the License, or (at your option) any later version.
*
*  This library is distributed in the hope that it will be useful,
*  but WITHOUT ANY WARRANTY; without even the implied warranty of
*  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
*  Lesser General Public License for more details.
*
*  You should have received a copy of the GNU Lesser General Public
*  License along with this library; if not, see
*  <http://www.gnu.org/licenses/>.
*
*  Davide Libenzi <davidel@xmailserver.org>
*
*/

#include "xinclude.h"

static long xdl_get_rec(xdfile_t *xdf, long ri, char const **rec) {

*rec = xdf->recs[ri]->ptr;

return xdf->recs[ri]->size;
}


static int xdl_emit_record(xdfile_t *xdf, long ri, char const *pre, xdemitcb_t *ecb) {
long size, psize = (long)strlen(pre);
char const *rec;

size = xdl_get_rec(xdf, ri, &rec);
if (xdl_emit_diffrec(rec, size, pre, psize, ecb) < 0) {

	return -1;
}

return 0;
}


/*
* Starting at the passed change atom, find the latest change atom to be included
* inside the differential hunk according to the specified configuration.
* Also advance xscr if the first changes must be discarded.
*/
xdchange_t *xdl_get_hunk(xdchange_t **xscr, xdemitconf_t const *xecfg)
{
xdchange_t *xch, *xchp, *lxch;
long max_common = 2 * xecfg->ctxlen + xecfg->interhunkctxlen;
long max_ignorable = xecfg->ctxlen;
unsigned long ignored = 0; /* number of ignored blank lines */

/* remove ignorable changes that are too far before other changes */
for (xchp = *xscr; xchp && xchp->ignore; xchp = xchp->next) {
	xch = xchp->next;

	if (xch == NULL ||
	    xch->i1 - (xchp->i1 + xchp->chg1) >= max_ignorable)
		*xscr = xch;
}

if (*xscr == NULL)
	return NULL;

lxch = *xscr;

for (xchp = *xscr, xch = xchp->next; xch; xchp = xch, xch = xch->next) {
	long distance = xch->i1 - (xchp->i1 + xchp->chg1);
	if (distance > max_common)
		break;

	if (distance < max_ignorable && (!xch->ignore || lxch == xchp)) {
		lxch = xch;
		ignored = 0;
	} else if (distance < max_ignorable && xch->ignore) {
		ignored += xch->chg2;
	} else if (lxch != xchp &&
		   xch->i1 + (long)ignored - (lxch->i1 + lxch->chg1) > max_common) {
		break;
	} else if (!xch->ignore) {
		lxch = xch;
		ignored = 0;
	} else {
		ignored += xch->chg2;
	}
}

return lxch;
}


#if 0
static long def_ff(const char *rec, long len, char *buf, long sz, void *priv UNUSED)
{
if (len > 0 &&
		(isalpha((unsigned char)*rec) || /* identifier? */
		 *rec == '_' || /* also identifier? */
		 *rec == '$')) { /* identifiers from VMS and other esoterico */
	if (len > sz)
		len = sz;
	while (0 < len && isspace((unsigned char)rec[len - 1]))
		len--;
	memcpy(buf, rec, len);
	return len;
}
return -1;
}
#endif

#if 0
static long match_func_rec(xdfile_t *xdf, xdemitconf_t const *xecfg, long ri,
		   char *buf, long sz)
{
const char *rec;
long len = xdl_get_rec(xdf, ri, &rec);
if (!xecfg->find_func)
	return def_ff(rec, len, buf, sz, xecfg->find_func_priv);
return xecfg->find_func(rec, len, buf, sz, xecfg->find_func_priv);
}
#endif

#if 0
static int is_func_rec(xdfile_t *xdf, xdemitconf_t const *xecfg, long ri)
{
char dummy[1];
return match_func_rec(xdf, xecfg, ri, dummy, sizeof(dummy)) >= 0;
}
#endif

struct func_line {
long len;
char buf[80];
};

#if 0
static long get_func_line(xdfenv_t *xe, xdemitconf_t const *xecfg,
		  struct func_line *func_line, long start, long limit)
{
long l, size, step = (start > limit) ? -1 : 1;
char *buf, dummy[1];

buf = func_line ? func_line->buf : dummy;
size = func_line ? sizeof(func_line->buf) : sizeof(dummy);

for (l = start; l != limit && 0 <= l && l < xe->xdf1.nrec; l += step) {
	long len = match_func_rec(&xe->xdf1, xecfg, l, buf, size);
	if (len >= 0) {
		if (func_line)
			func_line->len = len;
		return l;
	}
}
return -1;
}
#endif

#if 0
static int is_empty_rec(xdfile_t *xdf, long ri)
{
const char *rec;
long len = xdl_get_rec(xdf, ri, &rec);

while (len > 0 && XDL_ISSPACE(*rec)) {
	rec++;
	len--;
}
return !len;
}
#endif

int xdl_emit_diff(xdfenv_t *xe, xdchange_t *xscr, xdemitcb_t *ecb,
	  xdemitconf_t const *xecfg) {
long s1, s2, e1, e2, lctx;
xdchange_t *xch, *xche;
#if 0
long funclineprev = -1;
#endif
struct func_line func_line;

func_line.len = 0;

for (xch = xscr; xch; xch = xche->next) {
	xche = xdl_get_hunk(&xch, xecfg);
	if (!xch)
		break;

	s1 = XDL_MAX(xch->i1 - xecfg->ctxlen, 0);
	s2 = XDL_MAX(xch->i2 - xecfg->ctxlen, 0);

#if 0
	if (xecfg->flags & XDL_EMIT_FUNCCONTEXT) {
		long fs1, i1 = xch->i1;

		/* Appended chunk? */
		if (i1 >= xe->xdf1.nrec) {
			long i2 = xch->i2;

			/*
			 * We don't need additional context if
			 * a whole function was added.
			 */
			while (i2 < xe->xdf2.nrec) {
				if (is_func_rec(&xe->xdf2, xecfg, i2))
					goto post_context_calculation;
				i2++;
			}

			/*
			 * Otherwise get more context from the
			 * pre-image.
			 */
			i1 = xe->xdf1.nrec - 1;
		}

		fs1 = get_func_line(xe, xecfg, NULL, i1, -1);
		while (fs1 > 0 && !is_empty_rec(&xe->xdf1, fs1 - 1) &&
		       !is_func_rec(&xe->xdf1, xecfg, fs1 - 1))
			fs1--;
		if (fs1 < 0)
			fs1 = 0;
		if (fs1 < s1) {
			s2 = XDL_MAX(s2 - (s1 - fs1), 0);
			s1 = fs1;

			/*
			 * Did we extend context upwards into an
			 * ignored change?
			 */
			while (xchp != xch &&
			       xchp->i1 + xchp->chg1 <= s1 &&
			       xchp->i2 + xchp->chg2 <= s2)
				xchp = xchp->next;

			/* If so, show it after all. */
			if (xchp != xch) {
				xch = xchp;
				goto pre_context_calculation;
			}
		}
	}

post_context_calculation:
#endif
	lctx = xecfg->ctxlen;
	lctx = XDL_MIN(lctx, xe->xdf1.nrec - (xche->i1 + xche->chg1));
	lctx = XDL_MIN(lctx, xe->xdf2.nrec - (xche->i2 + xche->chg2));

	e1 = xche->i1 + xche->chg1 + lctx;
	e2 = xche->i2 + xche->chg2 + lctx;

#if 0
	if (xecfg->flags & XDL_EMIT_FUNCCONTEXT) {
		long fe1 = get_func_line(xe, xecfg, NULL,
					 xche->i1 + xche->chg1,
					 xe->xdf1.nrec);
		while (fe1 > 0 && is_empty_rec(&xe->xdf1, fe1 - 1))
			fe1--;
		if (fe1 < 0)
			fe1 = xe->xdf1.nrec;
		if (fe1 > e1) {
			e2 = XDL_MIN(e2 + (fe1 - e1), xe->xdf2.nrec);
			e1 = fe1;
		}

		/*
		 * Overlap with next change?  Then include it
		 * in the current hunk and start over to find
		 * its new end.
		 */
		if (xche->next) {
			long l = XDL_MIN(xche->next->i1,
					 xe->xdf1.nrec - 1);
			if (l - xecfg->ctxlen <= e1 ||
			    get_func_line(xe, xecfg, NULL, l, e1) < 0) {
				xche = xche->next;
				goto post_context_calculation;
			}
		}
	}
#endif

	/*
	 * Emit current hunk header.
	 */

#if 0
	if (xecfg->flags & XDL_EMIT_FUNCNAMES) {
		get_func_line(xe, xecfg, &func_line,
			      s1 - 1, funclineprev);
		funclineprev = s1 - 1;
	}
#endif
	if (!(xecfg->flags & XDL_EMIT_NO_HUNK_HDR) &&
	    xdl_emit_hunk_hdr(s1 + 1, e1 - s1, s2 + 1, e2 - s2,
			      func_line.buf, func_line.len, ecb) < 0)
		return -1;

	/*
	 * Emit pre-context.
	 */
	for (; s2 < xch->i2; s2++)
		if (xdl_emit_record(&xe->xdf2, s2, " ", ecb) < 0)
			return -1;

	for (s1 = xch->i1, s2 = xch->i2;; xch = xch->next) {
		/*
		 * Merge previous with current change atom.
		 */
		for (; s1 < xch->i1 && s2 < xch->i2; s1++, s2++)
			if (xdl_emit_record(&xe->xdf2, s2, " ", ecb) < 0)
				return -1;

		/*
		 * Removes lines from the first file.
		 */
		for (s1 = xch->i1; s1 < xch->i1 + xch->chg1; s1++)
			if (xdl_emit_record(&xe->xdf1, s1, "-", ecb) < 0)
				return -1;

		/*
		 * Adds lines from the second file.
		 */
		for (s2 = xch->i2; s2 < xch->i2 + xch->chg2; s2++)
			if (xdl_emit_record(&xe->xdf2, s2, "+", ecb) < 0)
				return -1;

		if (xch == xche)
			break;
		s1 = xch->i1 + xch->chg1;
		s2 = xch->i2 + xch->chg2;
	}

	/*
	 * Emit post-context.
	 */
	for (s2 = xche->i2 + xche->chg2; s2 < e2; s2++)
		if (xdl_emit_record(&xe->xdf2, s2, " ", ecb) < 0)
			return -1;
}

return 0;
}