[thirdparty/git.git] / xdiff / xutils.c

/*
 *  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 <limits.h>
#include <assert.h>
#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 = 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 > 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;
}
Commit	Line	Data
3443546f LT	1	/*
	2	* LibXDiff by Davide Libenzi ( File Differential Library )
	3	* Copyright (C) 2003 Davide Libenzi
	4	*
	5	* This library is free software; you can redistribute it and/or
	6	* modify it under the terms of the GNU Lesser General Public
	7	* License as published by the Free Software Foundation; either
	8	* version 2.1 of the License, or (at your option) any later version.
	9	*
	10	* This library is distributed in the hope that it will be useful,
	11	* but WITHOUT ANY WARRANTY; without even the implied warranty of
	12	* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
	13	* Lesser General Public License for more details.
	14	*
	15	* You should have received a copy of the GNU Lesser General Public
48425792 TZ	16	* License along with this library; if not, see
48425792 TZ	17	* <http://www.gnu.org/licenses/>.
3443546f LT	18	*
	19	* Davide Libenzi <davidel@xmailserver.org>
	20	*
	21	*/
	22
6942efcf TR	23	#include <limits.h>
6942efcf TR	24	#include <assert.h>
3443546f LT	25	#include "xinclude.h"
	26
	27
	28
3443546f	29
ca557aff DL	30	long xdl_bogosqrt(long n) {
	31	long i;
	32
	33	/*
	34	* Classical integer square root approximation using shifts.
	35	*/
	36	for (i = 1; n > 0; n >>= 2)
	37	i <<= 1;
	38
	39	return i;
	40	}
	41
	42
3443546f LT	43	int xdl_emit_diffrec(char const rec, long size, char const pre, long psize,
3443546f LT	44	xdemitcb_t *ecb) {
d281786f	45	int i = 2;
621c53cc	46	mmbuffer_t mb[3];
3443546f LT	47
	48	mb[0].ptr = (char *) pre;
	49	mb[0].size = psize;
	50	mb[1].ptr = (char *) rec;
	51	mb[1].size = size;
d281786f JH	52	if (size > 0 && rec[size - 1] != '\n') {
d281786f JH	53	mb[2].ptr = (char *) "\n\\ No newline at end of file\n";
621c53cc	54	mb[2].size = strlen(mb[2].ptr);
d281786f	55	i++;
621c53cc	56	}
611e42a5	57	if (ecb->out_line(ecb->priv, mb, i) < 0) {
3443546f LT	58
	59	return -1;
	60	}
	61
	62	return 0;
	63	}
	64
	65	void xdl_mmfile_first(mmfile_t mmf, long *size)
	66	{
	67	*size = mmf->size;
	68	return mmf->ptr;
	69	}
	70
	71
3443546f LT	72	long xdl_mmfile_size(mmfile_t *mmf)
	73	{
	74	return mmf->size;
	75	}
	76
	77
	78	int xdl_cha_init(chastore_t *cha, long isize, long icount) {
	79
	80	cha->head = cha->tail = NULL;
	81	cha->isize = isize;
	82	cha->nsize = icount * isize;
	83	cha->ancur = cha->sncur = NULL;
	84	cha->scurr = 0;
	85
	86	return 0;
	87	}
	88
	89
	90	void xdl_cha_free(chastore_t *cha) {
	91	chanode_t cur, tmp;
	92
	93	for (cur = cha->head; (tmp = cur) != NULL;) {
	94	cur = cur->next;
	95	xdl_free(tmp);
	96	}
	97	}
	98
	99
	100	void xdl_cha_alloc(chastore_t cha) {
	101	chanode_t *ancur;
	102	void *data;
	103
	104	if (!(ancur = cha->ancur) \|\| ancur->icurr == cha->nsize) {
	105	if (!(ancur = (chanode_t *) xdl_malloc(sizeof(chanode_t) + cha->nsize))) {
	106
	107	return NULL;
	108	}
	109	ancur->icurr = 0;
	110	ancur->next = NULL;
	111	if (cha->tail)
	112	cha->tail->next = ancur;
	113	if (!cha->head)
	114	cha->head = ancur;
	115	cha->tail = ancur;
	116	cha->ancur = ancur;
	117	}
	118
	119	data = (char *) ancur + sizeof(chanode_t) + ancur->icurr;
	120	ancur->icurr += cha->isize;
	121
	122	return data;
	123	}
	124
86abba80	125	long xdl_guess_lines(mmfile_t *mf, long sample) {
3443546f LT	126	long nl = 0, size, tsize = 0;
	127	char const data, cur, *top;
	128
	129	if ((cur = data = xdl_mmfile_first(mf, &size)) != NULL) {
739864b1	130	for (top = data + size; nl < sample && cur < top; ) {
3443546f LT	131	nl++;
	132	if (!(cur = memchr(cur, '\n', top - cur)))
	133	cur = top;
	134	else
	135	cur++;
	136	}
	137	tsize += (long) (cur - data);
	138	}
	139
	140	if (nl && tsize)
	141	nl = xdl_mmfile_size(mf) / (tsize / nl);
	142
	143	return nl + 1;
	144	}
	145
36617af7 AP	146	int xdl_blankline(const char *line, long size, long flags)
	147	{
	148	long i;
	149
	150	if (!(flags & XDF_WHITESPACE_FLAGS))
	151	return (size <= 1);
	152
	153	for (i = 0; i < size && XDL_ISSPACE(line[i]); i++)
	154	;
	155
	156	return (i == size);
	157	}
	158
e9282f02 JH	159	/*
	160	* Have we eaten everything on the line, except for an optional
	161	* CR at the very end?
	162	*/
	163	static int ends_with_optional_cr(const char *l, long s, long i)
	164	{
	165	int complete = s && l[s-1] == '\n';
	166
	167	if (complete)
	168	s--;
	169	if (s == i)
	170	return 1;
	171	/* do not ignore CR at the end of an incomplete line */
	172	if (complete && s == i + 1 && l[i] == '\r')
	173	return 1;
	174	return 0;
	175	}
	176
0d21efa5 JS	177	int xdl_recmatch(const char l1, long s1, const char l2, long s2, long flags)
	178	{
	179	int i1, i2;
	180
b4cf0f17 DR	181	if (s1 == s2 && !memcmp(l1, l2, s1))
b4cf0f17 DR	182	return 1;
3b5ef0e2	183	if (!(flags & XDF_WHITESPACE_FLAGS))
b4cf0f17	184	return 0;
3b5ef0e2 JH	185
	186	i1 = 0;
	187	i2 = 0;
	188
	189	/*
	190	* -w matches everything that matches with -b, and -b in turn
e9282f02 JH	191	* matches everything that matches with --ignore-space-at-eol,
e9282f02 JH	192	* which in turn matches everything that matches with --ignore-cr-at-eol.
3b5ef0e2 JH	193	*
	194	* Each flavor of ignoring needs different logic to skip whitespaces
	195	* while we have both sides to compare.
	196	*/
0d21efa5	197	if (flags & XDF_IGNORE_WHITESPACE) {
3b5ef0e2 JH	198	goto skip_ws;
	199	while (i1 < s1 && i2 < s2) {
	200	if (l1[i1++] != l2[i2++])
2344d47f	201	return 0;
3b5ef0e2	202	skip_ws:
349362cc	203	while (i1 < s1 && XDL_ISSPACE(l1[i1]))
3b5ef0e2	204	i1++;
349362cc	205	while (i2 < s2 && XDL_ISSPACE(l2[i2]))
3b5ef0e2	206	i2++;
0d21efa5	207	}
0d21efa5	208	} else if (flags & XDF_IGNORE_WHITESPACE_CHANGE) {
3b5ef0e2	209	while (i1 < s1 && i2 < s2) {
349362cc	210	if (XDL_ISSPACE(l1[i1]) && XDL_ISSPACE(l2[i2])) {
3b5ef0e2	211	/* Skip matching spaces and try again */
349362cc	212	while (i1 < s1 && XDL_ISSPACE(l1[i1]))
859f9c45	213	i1++;
349362cc	214	while (i2 < s2 && XDL_ISSPACE(l2[i2]))
859f9c45	215	i2++;
3b5ef0e2	216	continue;
859f9c45	217	}
3b5ef0e2 JH	218	if (l1[i1++] != l2[i2++])
	219	return 0;
	220	}
	221	} else if (flags & XDF_IGNORE_WHITESPACE_AT_EOL) {
044fb190 JS	222	while (i1 < s1 && i2 < s2 && l1[i1] == l2[i2]) {
	223	i1++;
	224	i2++;
	225	}
e9282f02 JH	226	} else if (flags & XDF_IGNORE_CR_AT_EOL) {
	227	/* Find the first difference and see how the line ends */
	228	while (i1 < s1 && i2 < s2 && l1[i1] == l2[i2]) {
	229	i1++;
	230	i2++;
	231	}
	232	return (ends_with_optional_cr(l1, s1, i1) &&
	233	ends_with_optional_cr(l2, s2, i2));
3b5ef0e2 JH	234	}
	235
	236	/*
	237	* After running out of one side, the remaining side must have
	238	* nothing but whitespace for the lines to match. Note that
	239	* ignore-whitespace-at-eol case may break out of the loop
	240	* while there still are characters remaining on both lines.
	241	*/
	242	if (i1 < s1) {
349362cc	243	while (i1 < s1 && XDL_ISSPACE(l1[i1]))
859f9c45	244	i1++;
3b5ef0e2 JH	245	if (s1 != i1)
	246	return 0;
	247	}
	248	if (i2 < s2) {
349362cc	249	while (i2 < s2 && XDL_ISSPACE(l2[i2]))
859f9c45	250	i2++;
3b5ef0e2 JH	251	return (s2 == i2);
	252	}
	253	return 1;
0d21efa5	254	}
3443546f	255
824f782c JS	256	static unsigned long xdl_hash_record_with_whitespace(char const **data,
824f782c JS	257	char const *top, long flags) {
3443546f LT	258	unsigned long ha = 5381;
3443546f LT	259	char const ptr = data;
e9282f02	260	int cr_at_eol_only = (flags & XDF_WHITESPACE_FLAGS) == XDF_IGNORE_CR_AT_EOL;
3443546f LT	261
3443546f LT	262	for (; ptr < top && *ptr != '\n'; ptr++) {
e9282f02 JH	263	if (cr_at_eol_only) {
	264	/* do not ignore CR at the end of an incomplete line */
	265	if (*ptr == '\r' &&
	266	(ptr + 1 < top && ptr[1] == '\n'))
	267	continue;
	268	}
	269	else if (XDL_ISSPACE(*ptr)) {
859f9c45	270	const char *ptr2 = ptr;
78ed710f	271	int at_eol;
349362cc	272	while (ptr + 1 < top && XDL_ISSPACE(ptr[1])
2344d47f	273	&& ptr[1] != '\n')
0d21efa5	274	ptr++;
78ed710f	275	at_eol = (top <= ptr + 1 \|\| ptr[1] == '\n');
6d12acef KC	276	if (flags & XDF_IGNORE_WHITESPACE)
	277	; /* already handled */
	278	else if (flags & XDF_IGNORE_WHITESPACE_CHANGE
78ed710f	279	&& !at_eol) {
0d21efa5 JS	280	ha += (ha << 5);
	281	ha ^= (unsigned long) ' ';
	282	}
6d12acef	283	else if (flags & XDF_IGNORE_WHITESPACE_AT_EOL
78ed710f	284	&& !at_eol) {
859f9c45 JS	285	while (ptr2 != ptr + 1) {
	286	ha += (ha << 5);
	287	ha ^= (unsigned long) *ptr2;
	288	ptr2++;
	289	}
	290	}
0d21efa5 JS	291	continue;
0d21efa5 JS	292	}
3443546f LT	293	ha += (ha << 5);
	294	ha ^= (unsigned long) *ptr;
	295	}
	296	*data = ptr < top ? ptr + 1: ptr;
	297
	298	return ha;
	299	}
	300
824f782c JS	301	unsigned long xdl_hash_record(char const *data, char const top, long flags) {
	302	unsigned long ha = 5381;
	303	char const ptr = data;
	304
	305	if (flags & XDF_WHITESPACE_FLAGS)
	306	return xdl_hash_record_with_whitespace(data, top, flags);
	307
	308	for (; ptr < top && *ptr != '\n'; ptr++) {
	309	ha += (ha << 5);
	310	ha ^= (unsigned long) *ptr;
	311	}
	312	*data = ptr < top ? ptr + 1: ptr;
	313
	314	return ha;
	315	}
	316
3443546f LT	317	unsigned int xdl_hashbits(unsigned int size) {
	318	unsigned int val = 1, bits = 0;
	319
	320	for (; val < size && bits < CHAR_BIT * sizeof(unsigned int); val <<= 1, bits++);
	321	return bits ? bits: 1;
	322	}
	323
	324
	325	int xdl_num_out(char *out, long val) {
	326	char ptr, str = out;
	327	char buf[32];
	328
	329	ptr = buf + sizeof(buf) - 1;
	330	*ptr = '\0';
	331	if (val < 0) {
	332	*--ptr = '-';
	333	val = -val;
	334	}
	335	for (; val && ptr > buf; val /= 10)
	336	*--ptr = "0123456789"[val % 10];
	337	if (*ptr)
	338	for (; *ptr; ptr++, str++)
	339	str = ptr;
	340	else
	341	*str++ = '0';
	342	*str = '\0';
	343
	344	return str - out;
	345	}
	346
611e42a5 JK	347	static int xdl_format_hunk_hdr(long s1, long c1, long s2, long c2,
	348	const char *func, long funclen,
	349	xdemitcb_t *ecb) {
3443546f LT	350	int nb = 0;
	351	mmbuffer_t mb;
	352	char buf[128];
	353
	354	memcpy(buf, "@@ -", 4);
	355	nb += 4;
	356
ca557aff	357	nb += xdl_num_out(buf + nb, c1 ? s1: s1 - 1);
3443546f	358
3ce8f089 JH	359	if (c1 != 1) {
	360	memcpy(buf + nb, ",", 1);
	361	nb += 1;
3443546f	362
3ce8f089 JH	363	nb += xdl_num_out(buf + nb, c1);
3ce8f089 JH	364	}
3443546f LT	365
	366	memcpy(buf + nb, " +", 2);
	367	nb += 2;
	368
ca557aff	369	nb += xdl_num_out(buf + nb, c2 ? s2: s2 - 1);
3443546f	370
3ce8f089 JH	371	if (c2 != 1) {
	372	memcpy(buf + nb, ",", 1);
	373	nb += 1;
3443546f	374
3ce8f089 JH	375	nb += xdl_num_out(buf + nb, c2);
3ce8f089 JH	376	}
3443546f	377
acb72577 MW	378	memcpy(buf + nb, " @@", 3);
	379	nb += 3;
	380	if (func && funclen) {
	381	buf[nb++] = ' ';
	382	if (funclen > sizeof(buf) - nb - 1)
	383	funclen = sizeof(buf) - nb - 1;
	384	memcpy(buf + nb, func, funclen);
	385	nb += funclen;
	386	}
	387	buf[nb++] = '\n';
3443546f LT	388
	389	mb.ptr = buf;
	390	mb.size = nb;
611e42a5	391	if (ecb->out_line(ecb->priv, &mb, 1) < 0)
3443546f	392	return -1;
611e42a5 JK	393	return 0;
611e42a5 JK	394	}
3443546f	395
611e42a5 JK	396	int xdl_emit_hunk_hdr(long s1, long c1, long s2, long c2,
	397	const char *func, long funclen,
	398	xdemitcb_t *ecb) {
	399	if (!ecb->out_hunk)
	400	return xdl_format_hunk_hdr(s1, c1, s2, c2, func, funclen, ecb);
	401	if (ecb->out_hunk(ecb->priv,
	402	c1 ? s1 : s1 - 1, c1,
	403	c2 ? s2 : s2 - 1, c2,
	404	func, funclen) < 0)
	405	return -1;
3443546f LT	406	return 0;
3443546f LT	407	}
1d26b252 TRC	408
	409	int xdl_fall_back_diff(xdfenv_t diff_env, xpparam_t const xpp,
	410	int line1, int count1, int line2, int count2)
	411	{
	412	/*
	413	* This probably does not work outside Git, since
	414	* we have a very simple mmfile structure.
	415	*
	416	* Note: ideally, we would reuse the prepared environment, but
	417	* the libxdiff interface does not (yet) allow for diffing only
	418	* ranges of lines instead of the whole files.
	419	*/
	420	mmfile_t subfile1, subfile2;
	421	xdfenv_t env;
	422
	423	subfile1.ptr = (char *)diff_env->xdf1.recs[line1 - 1]->ptr;
	424	subfile1.size = diff_env->xdf1.recs[line1 + count1 - 2]->ptr +
	425	diff_env->xdf1.recs[line1 + count1 - 2]->size - subfile1.ptr;
	426	subfile2.ptr = (char *)diff_env->xdf2.recs[line2 - 1]->ptr;
	427	subfile2.size = diff_env->xdf2.recs[line2 + count2 - 2]->ptr +
	428	diff_env->xdf2.recs[line2 + count2 - 2]->size - subfile2.ptr;
	429	if (xdl_do_diff(&subfile1, &subfile2, xpp, &env) < 0)
	430	return -1;
	431
	432	memcpy(diff_env->xdf1.rchg + line1 - 1, env.xdf1.rchg, count1);
	433	memcpy(diff_env->xdf2.rchg + line2 - 1, env.xdf2.rchg, count2);
	434
	435	xdl_free_env(&env);
	436
	437	return 0;
	438	}