neovim

xutils.c (9887B)

---

/*
*  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"


long xdl_bogosqrt(long n) {
long i;

/*
 * Classical integer square root approximation using shifts.
 */
for (i = 1; n > 0; n >>= 2)
	i <<= 1;

return i;
}


int xdl_emit_diffrec(char const *rec, long size, char const *pre, long psize,
	     xdemitcb_t *ecb) {
int i = 2;
mmbuffer_t mb[3];

mb[0].ptr = (char *) pre;
mb[0].size = psize;
mb[1].ptr = (char *) rec;
mb[1].size = size;
if (size > 0 && rec[size - 1] != '\n') {
	mb[2].ptr = (char *) "\n\\ No newline at end of file\n";
	mb[2].size = (long)strlen(mb[2].ptr);
	i++;
}
if (ecb->out_line(ecb->priv, mb, i) < 0) {

	return -1;
}

return 0;
}

void *xdl_mmfile_first(mmfile_t *mmf, long *size)
{
*size = mmf->size;
return mmf->ptr;
}


long xdl_mmfile_size(mmfile_t *mmf)
{
return mmf->size;
}


int xdl_cha_init(chastore_t *cha, long isize, long icount) {

cha->head = cha->tail = NULL;
cha->isize = isize;
cha->nsize = icount * isize;
cha->ancur = cha->sncur = NULL;
cha->scurr = 0;

return 0;
}


void xdl_cha_free(chastore_t *cha) {
chanode_t *cur, *tmp;

for (cur = cha->head; (tmp = cur) != NULL;) {
	cur = cur->next;
	xdl_free(tmp);
}
}


void *xdl_cha_alloc(chastore_t *cha) {
chanode_t *ancur;
void *data;

if (!(ancur = cha->ancur) || ancur->icurr == cha->nsize) {
	if (!(ancur = (chanode_t *) xdl_malloc(sizeof(chanode_t) + cha->nsize))) {

		return NULL;
	}
	ancur->icurr = 0;
	ancur->next = NULL;
	if (cha->tail)
		cha->tail->next = ancur;
	if (!cha->head)
		cha->head = ancur;
	cha->tail = ancur;
	cha->ancur = ancur;
}

data = (char *) ancur + sizeof(chanode_t) + ancur->icurr;
ancur->icurr += cha->isize;

return data;
}

long xdl_guess_lines(mmfile_t *mf, long sample) {
long nl = 0, size, tsize = 0;
char const *data, *cur, *top;

if ((cur = data = xdl_mmfile_first(mf, &size)) != NULL) {
	for (top = data + size; nl < sample && cur < top; ) {
		nl++;
		if (!(cur = memchr(cur, '\n', top - cur)))
			cur = top;
		else
			cur++;
	}
	tsize += (long) (cur - data);
}

if (nl && tsize)
	nl = xdl_mmfile_size(mf) / (tsize / nl);

return nl + 1;
}

int xdl_blankline(const char *line, long size, long flags)
{
long i;

if (!(flags & XDF_WHITESPACE_FLAGS))
	return (size <= 1);

for (i = 0; i < size && XDL_ISSPACE(line[i]); i++)
	;

return (i == size);
}

/*
* Have we eaten everything on the line, except for an optional
* CR at the very end?
*/
static int ends_with_optional_cr(const char *l, long s, long i)
{
int complete = s && l[s-1] == '\n';

if (complete)
	s--;
if (s == i)
	return 1;
/* do not ignore CR at the end of an incomplete line */
if (complete && s == i + 1 && l[i] == '\r')
	return 1;
return 0;
}

int xdl_recmatch(const char *l1, long s1, const char *l2, long s2, long flags)
{
int i1, i2;

if (s1 == s2 && !memcmp(l1, l2, s1))
	return 1;
if (!(flags & XDF_WHITESPACE_FLAGS))
	return 0;

i1 = 0;
i2 = 0;

/*
 * -w matches everything that matches with -b, and -b in turn
 * matches everything that matches with --ignore-space-at-eol,
 * which in turn matches everything that matches with --ignore-cr-at-eol.
 *
 * Each flavor of ignoring needs different logic to skip whitespaces
 * while we have both sides to compare.
 */
if (flags & XDF_IGNORE_WHITESPACE) {
	goto skip_ws;
	while (i1 < s1 && i2 < s2) {
		if (l1[i1++] != l2[i2++])
			return 0;
	skip_ws:
		while (i1 < s1 && XDL_ISSPACE(l1[i1]))
			i1++;
		while (i2 < s2 && XDL_ISSPACE(l2[i2]))
			i2++;
	}
} else if (flags & XDF_IGNORE_WHITESPACE_CHANGE) {
	while (i1 < s1 && i2 < s2) {
		if (XDL_ISSPACE(l1[i1]) && XDL_ISSPACE(l2[i2])) {
			/* Skip matching spaces and try again */
			while (i1 < s1 && XDL_ISSPACE(l1[i1]))
				i1++;
			while (i2 < s2 && XDL_ISSPACE(l2[i2]))
				i2++;
			continue;
		}
		if (l1[i1++] != l2[i2++])
			return 0;
	}
} else if (flags & XDF_IGNORE_WHITESPACE_AT_EOL) {
	while (i1 < s1 && i2 < s2 && l1[i1] == l2[i2]) {
		i1++;
		i2++;
	}
} else if (flags & XDF_IGNORE_CR_AT_EOL) {
	/* Find the first difference and see how the line ends */
	while (i1 < s1 && i2 < s2 && l1[i1] == l2[i2]) {
		i1++;
		i2++;
	}
	return (ends_with_optional_cr(l1, s1, i1) &&
		ends_with_optional_cr(l2, s2, i2));
}

/*
 * After running out of one side, the remaining side must have
 * nothing but whitespace for the lines to match.  Note that
 * ignore-whitespace-at-eol case may break out of the loop
 * while there still are characters remaining on both lines.
 */
if (i1 < s1) {
	while (i1 < s1 && XDL_ISSPACE(l1[i1]))
		i1++;
	if (s1 != i1)
		return 0;
}
if (i2 < s2) {
	while (i2 < s2 && XDL_ISSPACE(l2[i2]))
		i2++;
	return (s2 == i2);
}
return 1;
}

static unsigned long xdl_hash_record_with_whitespace(char const **data,
	char const *top, long flags) {
unsigned long ha = 5381;
char const *ptr = *data;
int cr_at_eol_only = (flags & XDF_WHITESPACE_FLAGS) == XDF_IGNORE_CR_AT_EOL;

for (; ptr < top && *ptr != '\n'; ptr++) {
	if (cr_at_eol_only) {
		/* do not ignore CR at the end of an incomplete line */
		if (*ptr == '\r' &&
		    (ptr + 1 < top && ptr[1] == '\n'))
			continue;
	}
	else if (XDL_ISSPACE(*ptr)) {
		const char *ptr2 = ptr;
		int at_eol;
		while (ptr + 1 < top && XDL_ISSPACE(ptr[1])
				&& ptr[1] != '\n')
			ptr++;
		at_eol = (top <= ptr + 1 || ptr[1] == '\n');
		if (flags & XDF_IGNORE_WHITESPACE)
			; /* already handled */
		else if (flags & XDF_IGNORE_WHITESPACE_CHANGE
			 && !at_eol) {
			ha += (ha << 5);
			ha ^= (unsigned long) ' ';
		}
		else if (flags & XDF_IGNORE_WHITESPACE_AT_EOL
			 && !at_eol) {
			while (ptr2 != ptr + 1) {
				ha += (ha << 5);
				ha ^= (unsigned long) *ptr2;
				ptr2++;
			}
		}
		continue;
	}
	ha += (ha << 5);
	ha ^= (unsigned long) *ptr;
}
*data = ptr < top ? ptr + 1: ptr;

return ha;
}

unsigned long xdl_hash_record(char const **data, char const *top, long flags) {
unsigned long ha = 5381;
char const *ptr = *data;

if (flags & XDF_WHITESPACE_FLAGS)
	return xdl_hash_record_with_whitespace(data, top, flags);

for (; ptr < top && *ptr != '\n'; ptr++) {
	ha += (ha << 5);
	ha ^= (unsigned long) *ptr;
}
*data = ptr < top ? ptr + 1: ptr;

return ha;
}

unsigned int xdl_hashbits(unsigned int size) {
unsigned int val = 1, bits = 0;

for (; val < size && bits < CHAR_BIT * sizeof(unsigned int); val <<= 1, bits++);
return bits ? bits: 1;
}


int xdl_num_out(char *out, long val) {
char *ptr, *str = out;
char buf[32];

ptr = buf + sizeof(buf) - 1;
*ptr = '\0';
if (val < 0) {
	*--ptr = '-';
	val = -val;
}
for (; val && ptr > buf; val /= 10)
	*--ptr = "0123456789"[val % 10];
if (*ptr)
	for (; *ptr; ptr++, str++)
		*str = *ptr;
else
	*str++ = '0';
*str = '\0';

return str - out;
}

static int xdl_format_hunk_hdr(long s1, long c1, long s2, long c2,
		       const char *func, long funclen,
		       xdemitcb_t *ecb) {
int nb = 0;
mmbuffer_t mb;
char buf[128];

memcpy(buf, "@@ -", 4);
nb += 4;

nb += xdl_num_out(buf + nb, c1 ? s1: s1 - 1);

if (c1 != 1) {
	memcpy(buf + nb, ",", 1);
	nb += 1;

	nb += xdl_num_out(buf + nb, c1);
}

memcpy(buf + nb, " +", 2);
nb += 2;

nb += xdl_num_out(buf + nb, c2 ? s2: s2 - 1);

if (c2 != 1) {
	memcpy(buf + nb, ",", 1);
	nb += 1;

	nb += xdl_num_out(buf + nb, c2);
}

memcpy(buf + nb, " @@", 3);
nb += 3;
if (func && funclen) {
	buf[nb++] = ' ';
	if (funclen > (long)sizeof(buf) - nb - 1)
		funclen = sizeof(buf) - nb - 1;
	memcpy(buf + nb, func, funclen);
	nb += funclen;
}
buf[nb++] = '\n';

mb.ptr = buf;
mb.size = nb;
if (ecb->out_line(ecb->priv, &mb, 1) < 0)
	return -1;
return 0;
}

int xdl_emit_hunk_hdr(long s1, long c1, long s2, long c2,
	      const char *func, long funclen,
	      xdemitcb_t *ecb) {
if (!ecb->out_hunk)
	return xdl_format_hunk_hdr(s1, c1, s2, c2, func, funclen, ecb);
if (ecb->out_hunk(ecb->priv,
		  c1 ? s1 : s1 - 1, c1,
		  c2 ? s2 : s2 - 1, c2,
		  func, funclen) < 0)
	return -1;
return 0;
}

int xdl_fall_back_diff(xdfenv_t *diff_env, xpparam_t const *xpp,
	int line1, int count1, int line2, int count2)
{
/*
 * This probably does not work outside Git, since
 * we have a very simple mmfile structure.
 *
 * Note: ideally, we would reuse the prepared environment, but
 * the libxdiff interface does not (yet) allow for diffing only
 * ranges of lines instead of the whole files.
 */
mmfile_t subfile1, subfile2;
xdfenv_t env;

subfile1.ptr = (char *)diff_env->xdf1.recs[line1 - 1]->ptr;
subfile1.size = diff_env->xdf1.recs[line1 + count1 - 2]->ptr +
	diff_env->xdf1.recs[line1 + count1 - 2]->size - subfile1.ptr;
subfile2.ptr = (char *)diff_env->xdf2.recs[line2 - 1]->ptr;
subfile2.size = diff_env->xdf2.recs[line2 + count2 - 2]->ptr +
	diff_env->xdf2.recs[line2 + count2 - 2]->size - subfile2.ptr;
if (xdl_do_diff(&subfile1, &subfile2, xpp, &env) < 0)
	return -1;

memcpy(diff_env->xdf1.rchg + line1 - 1, env.xdf1.rchg, count1);
memcpy(diff_env->xdf2.rchg + line2 - 1, env.xdf2.rchg, count2);

xdl_free_env(&env);

return 0;
}