[thirdparty/git.git] / xdiff-interface.c

#include "cache.h"
#include "xdiff-interface.h"

static int parse_num(char **cp_p, int *num_p)
{
	char *cp = *cp_p;
	int num = 0;
	int read_some;

	while ('0' <= *cp && *cp <= '9')
		num = num * 10 + *cp++ - '0';
	if (!(read_some = cp - *cp_p))
		return -1;
	*cp_p = cp;
	*num_p = num;
	return 0;
}

int parse_hunk_header(char *line, int len,
		      int *ob, int *on,
		      int *nb, int *nn)
{
	char *cp;
	cp = line + 4;
	if (parse_num(&cp, ob)) {
	bad_line:
		return error("malformed diff output: %s", line);
	}
	if (*cp == ',') {
		cp++;
		if (parse_num(&cp, on))
			goto bad_line;
	}
	else
		*on = 1;
	if (*cp++ != ' ' || *cp++ != '+')
		goto bad_line;
	if (parse_num(&cp, nb))
		goto bad_line;
	if (*cp == ',') {
		cp++;
		if (parse_num(&cp, nn))
			goto bad_line;
	}
	else
		*nn = 1;
	return -!!memcmp(cp, " @@", 3);
}

static void consume_one(void *priv_, char *s, unsigned long size)
{
	struct xdiff_emit_state *priv = priv_;
	char *ep;
	while (size) {
		unsigned long this_size;
		ep = memchr(s, '\n', size);
		this_size = (ep == NULL) ? size : (ep - s + 1);
		priv->consume(priv, s, this_size);
		size -= this_size;
		s += this_size;
	}
}

static int xdiff_outf(void *priv_, mmbuffer_t *mb, int nbuf)
{
	struct xdiff_emit_state *priv = priv_;
	int i;

	for (i = 0; i < nbuf; i++) {
		if (mb[i].ptr[mb[i].size-1] != '\n') {
			/* Incomplete line */
			priv->remainder = xrealloc(priv->remainder,
						   priv->remainder_size +
						   mb[i].size);
			memcpy(priv->remainder + priv->remainder_size,
			       mb[i].ptr, mb[i].size);
			priv->remainder_size += mb[i].size;
			continue;
		}

		/* we have a complete line */
		if (!priv->remainder) {
			consume_one(priv, mb[i].ptr, mb[i].size);
			continue;
		}
		priv->remainder = xrealloc(priv->remainder,
					   priv->remainder_size +
					   mb[i].size);
		memcpy(priv->remainder + priv->remainder_size,
		       mb[i].ptr, mb[i].size);
		consume_one(priv, priv->remainder,
			    priv->remainder_size + mb[i].size);
		free(priv->remainder);
		priv->remainder = NULL;
		priv->remainder_size = 0;
	}
	if (priv->remainder) {
		consume_one(priv, priv->remainder, priv->remainder_size);
		free(priv->remainder);
		priv->remainder = NULL;
		priv->remainder_size = 0;
	}
	return 0;
}

/*
 * Trim down common substring at the end of the buffers,
 * but leave at least ctx lines at the end.
 */
static void trim_common_tail(mmfile_t *a, mmfile_t *b, long ctx)
{
	const int blk = 1024;
	long trimmed = 0, recovered = 0;
	char *ap = a->ptr + a->size;
	char *bp = b->ptr + b->size;
	long smaller = (a->size < b->size) ? a->size : b->size;

	if (ctx)
		return;

	while (blk + trimmed <= smaller && !memcmp(ap - blk, bp - blk, blk)) {
		trimmed += blk;
		ap -= blk;
		bp -= blk;
	}

	while (recovered < trimmed)
		if (ap[recovered++] == '\n')
			break;
	a->size -= trimmed - recovered;
	b->size -= trimmed - recovered;
}

int xdi_diff(mmfile_t *mf1, mmfile_t *mf2, xpparam_t const *xpp, xdemitconf_t const *xecfg, xdemitcb_t *xecb)
{
	mmfile_t a = *mf1;
	mmfile_t b = *mf2;

	trim_common_tail(&a, &b, xecfg->ctxlen);

	return xdl_diff(&a, &b, xpp, xecfg, xecb);
}

int xdi_diff_outf(mmfile_t *mf1, mmfile_t *mf2,
		  struct xdiff_emit_state *state, xpparam_t const *xpp,
		  xdemitconf_t const *xecfg, xdemitcb_t *xecb)
{
	int ret;
	xecb->outf = xdiff_outf;
	xecb->priv = state;
	ret = xdi_diff(mf1, mf2, xpp, xecfg, xecb);
	return ret;
}

int read_mmfile(mmfile_t *ptr, const char *filename)
{
	struct stat st;
	FILE *f;
	size_t sz;

	if (stat(filename, &st))
		return error("Could not stat %s", filename);
	if ((f = fopen(filename, "rb")) == NULL)
		return error("Could not open %s", filename);
	sz = xsize_t(st.st_size);
	ptr->ptr = xmalloc(sz ? sz : 1);
	if (sz && fread(ptr->ptr, sz, 1, f) != 1)
		return error("Could not read %s", filename);
	fclose(f);
	ptr->size = sz;
	return 0;
}

#define FIRST_FEW_BYTES 8000
int buffer_is_binary(const char *ptr, unsigned long size)
{
	if (FIRST_FEW_BYTES < size)
		size = FIRST_FEW_BYTES;
	return !!memchr(ptr, 0, size);
}

struct ff_regs {
	int nr;
	struct ff_reg {
		regex_t re;
		int negate;
	} *array;
};

static long ff_regexp(const char *line, long len,
		char *buffer, long buffer_size, void *priv)
{
	char *line_buffer = xstrndup(line, len); /* make NUL terminated */
	struct ff_regs *regs = priv;
	regmatch_t pmatch[2];
	int result = 0, i;

	for (i = 0; i < regs->nr; i++) {
		struct ff_reg *reg = regs->array + i;
		if (reg->negate ^ !!regexec(&reg->re,
					line_buffer, 2, pmatch, 0)) {
			free(line_buffer);
			return -1;
		}
	}
	i = pmatch[1].rm_so >= 0 ? 1 : 0;
	line += pmatch[i].rm_so;
	result = pmatch[i].rm_eo - pmatch[i].rm_so;
	if (result > buffer_size)
		result = buffer_size;
	else
		while (result > 0 && (isspace(line[result - 1]) ||
					line[result - 1] == '\n'))
			result--;
	memcpy(buffer, line, result);
	free(line_buffer);
	return result;
}

void xdiff_set_find_func(xdemitconf_t *xecfg, const char *value)
{
	int i;
	struct ff_regs *regs;

	xecfg->find_func = ff_regexp;
	regs = xecfg->find_func_priv = xmalloc(sizeof(struct ff_regs));
	for (i = 0, regs->nr = 1; value[i]; i++)
		if (value[i] == '\n')
			regs->nr++;
	regs->array = xmalloc(regs->nr * sizeof(struct ff_reg));
	for (i = 0; i < regs->nr; i++) {
		struct ff_reg *reg = regs->array + i;
		const char *ep = strchr(value, '\n'), *expression;
		char *buffer = NULL;

		reg->negate = (*value == '!');
		if (reg->negate && i == regs->nr - 1)
			die("Last expression must not be negated: %s", value);
		if (*value == '!')
			value++;
		if (ep)
			expression = buffer = xstrndup(value, ep - value);
		else
			expression = value;
		if (regcomp(&reg->re, expression, 0))
			die("Invalid regexp to look for hunk header: %s", expression);
		free(buffer);
		value = ep + 1;
	}
}
Commit	Line	Data
d9ea73e0 JH	1	#include "cache.h"
	2	#include "xdiff-interface.h"
	3
a0fd3146	4	static int parse_num(char *cp_p, int num_p)
c1e335a4 JH	5	{
c1e335a4 JH	6	char cp = cp_p;
a0fd3146	7	int num = 0;
c1e335a4 JH	8	int read_some;
	9
	10	while ('0' <= cp && cp <= '9')
	11	num = num * 10 + *cp++ - '0';
	12	if (!(read_some = cp - *cp_p))
	13	return -1;
	14	*cp_p = cp;
	15	*num_p = num;
	16	return 0;
	17	}
	18
	19	int parse_hunk_header(char *line, int len,
a0fd3146 JH	20	int ob, int on,
a0fd3146 JH	21	int nb, int nn)
c1e335a4 JH	22	{
	23	char *cp;
	24	cp = line + 4;
	25	if (parse_num(&cp, ob)) {
	26	bad_line:
	27	return error("malformed diff output: %s", line);
	28	}
	29	if (*cp == ',') {
	30	cp++;
	31	if (parse_num(&cp, on))
	32	goto bad_line;
	33	}
	34	else
	35	*on = 1;
	36	if (cp++ != ' ' \|\| cp++ != '+')
	37	goto bad_line;
	38	if (parse_num(&cp, nb))
	39	goto bad_line;
	40	if (*cp == ',') {
	41	cp++;
	42	if (parse_num(&cp, nn))
	43	goto bad_line;
	44	}
	45	else
	46	*nn = 1;
	47	return -!!memcmp(cp, " @@", 3);
	48	}
	49
d9ea73e0 JH	50	static void consume_one(void priv_, char s, unsigned long size)
	51	{
	52	struct xdiff_emit_state *priv = priv_;
	53	char *ep;
	54	while (size) {
	55	unsigned long this_size;
	56	ep = memchr(s, '\n', size);
	57	this_size = (ep == NULL) ? size : (ep - s + 1);
	58	priv->consume(priv, s, this_size);
	59	size -= this_size;
	60	s += this_size;
	61	}
	62	}
	63
c99db9d2	64	static int xdiff_outf(void priv_, mmbuffer_t mb, int nbuf)
d9ea73e0 JH	65	{
	66	struct xdiff_emit_state *priv = priv_;
	67	int i;
	68
	69	for (i = 0; i < nbuf; i++) {
	70	if (mb[i].ptr[mb[i].size-1] != '\n') {
	71	/* Incomplete line */
83572c1a JF	72	priv->remainder = xrealloc(priv->remainder,
	73	priv->remainder_size +
	74	mb[i].size);
d9ea73e0 JH	75	memcpy(priv->remainder + priv->remainder_size,
	76	mb[i].ptr, mb[i].size);
	77	priv->remainder_size += mb[i].size;
	78	continue;
	79	}
	80
	81	/* we have a complete line */
	82	if (!priv->remainder) {
	83	consume_one(priv, mb[i].ptr, mb[i].size);
	84	continue;
	85	}
83572c1a JF	86	priv->remainder = xrealloc(priv->remainder,
	87	priv->remainder_size +
	88	mb[i].size);
d9ea73e0 JH	89	memcpy(priv->remainder + priv->remainder_size,
	90	mb[i].ptr, mb[i].size);
	91	consume_one(priv, priv->remainder,
	92	priv->remainder_size + mb[i].size);
	93	free(priv->remainder);
	94	priv->remainder = NULL;
	95	priv->remainder_size = 0;
	96	}
	97	if (priv->remainder) {
	98	consume_one(priv, priv->remainder, priv->remainder_size);
	99	free(priv->remainder);
	100	priv->remainder = NULL;
	101	priv->remainder_size = 0;
	102	}
	103	return 0;
	104	}
7cab5883	105
913b45f5 JH	106	/*
	107	* Trim down common substring at the end of the buffers,
	108	* but leave at least ctx lines at the end.
	109	*/
29ab27f4	110	static void trim_common_tail(mmfile_t a, mmfile_t b, long ctx)
913b45f5 JH	111	{
913b45f5 JH	112	const int blk = 1024;
52499977	113	long trimmed = 0, recovered = 0;
913b45f5 JH	114	char *ap = a->ptr + a->size;
	115	char *bp = b->ptr + b->size;
	116	long smaller = (a->size < b->size) ? a->size : b->size;
	117
d2f82950 LT	118	if (ctx)
	119	return;
	120
913b45f5 JH	121	while (blk + trimmed <= smaller && !memcmp(ap - blk, bp - blk, blk)) {
	122	trimmed += blk;
	123	ap -= blk;
	124	bp -= blk;
	125	}
	126
d2f82950	127	while (recovered < trimmed)
52499977	128	if (ap[recovered++] == '\n')
d2f82950 LT	129	break;
	130	a->size -= trimmed - recovered;
	131	b->size -= trimmed - recovered;
913b45f5 JH	132	}
913b45f5 JH	133
c279d7e9 JH	134	int xdi_diff(mmfile_t mf1, mmfile_t mf2, xpparam_t const xpp, xdemitconf_t const xecfg, xdemitcb_t *xecb)
c279d7e9 JH	135	{
913b45f5 JH	136	mmfile_t a = *mf1;
	137	mmfile_t b = *mf2;
	138
	139	trim_common_tail(&a, &b, xecfg->ctxlen);
	140
	141	return xdl_diff(&a, &b, xpp, xecfg, xecb);
c279d7e9 JH	142	}
c279d7e9 JH	143
c99db9d2 BD	144	int xdi_diff_outf(mmfile_t mf1, mmfile_t mf2,
	145	struct xdiff_emit_state state, xpparam_t const xpp,
	146	xdemitconf_t const xecfg, xdemitcb_t xecb)
	147	{
	148	int ret;
	149	xecb->outf = xdiff_outf;
	150	xecb->priv = state;
	151	ret = xdi_diff(mf1, mf2, xpp, xecfg, xecb);
	152	return ret;
	153	}
	154
7cab5883 JS	155	int read_mmfile(mmfile_t ptr, const char filename)
	156	{
	157	struct stat st;
	158	FILE *f;
dc49cd76	159	size_t sz;
7cab5883 JS	160
	161	if (stat(filename, &st))
	162	return error("Could not stat %s", filename);
	163	if ((f = fopen(filename, "rb")) == NULL)
	164	return error("Could not open %s", filename);
dc49cd76	165	sz = xsize_t(st.st_size);
381b851c JS	166	ptr->ptr = xmalloc(sz ? sz : 1);
381b851c JS	167	if (sz && fread(ptr->ptr, sz, 1, f) != 1)
7cab5883 JS	168	return error("Could not read %s", filename);
7cab5883 JS	169	fclose(f);
dc49cd76	170	ptr->size = sz;
7cab5883 JS	171	return 0;
	172	}
	173
6bfce93e JS	174	#define FIRST_FEW_BYTES 8000
	175	int buffer_is_binary(const char *ptr, unsigned long size)
	176	{
	177	if (FIRST_FEW_BYTES < size)
	178	size = FIRST_FEW_BYTES;
	179	return !!memchr(ptr, 0, size);
	180	}
f258475a JH	181
	182	struct ff_regs {
	183	int nr;
	184	struct ff_reg {
	185	regex_t re;
	186	int negate;
	187	} *array;
	188	};
	189
	190	static long ff_regexp(const char *line, long len,
	191	char buffer, long buffer_size, void priv)
	192	{
	193	char line_buffer = xstrndup(line, len); / make NUL terminated */
	194	struct ff_regs *regs = priv;
	195	regmatch_t pmatch[2];
	196	int result = 0, i;
	197
	198	for (i = 0; i < regs->nr; i++) {
	199	struct ff_reg *reg = regs->array + i;
	200	if (reg->negate ^ !!regexec(&reg->re,
	201	line_buffer, 2, pmatch, 0)) {
	202	free(line_buffer);
	203	return -1;
	204	}
	205	}
	206	i = pmatch[1].rm_so >= 0 ? 1 : 0;
	207	line += pmatch[i].rm_so;
	208	result = pmatch[i].rm_eo - pmatch[i].rm_so;
	209	if (result > buffer_size)
	210	result = buffer_size;
	211	else
	212	while (result > 0 && (isspace(line[result - 1]) \|\|
	213	line[result - 1] == '\n'))
	214	result--;
	215	memcpy(buffer, line, result);
	216	free(line_buffer);
	217	return result;
	218	}
	219
	220	void xdiff_set_find_func(xdemitconf_t xecfg, const char value)
	221	{
	222	int i;
	223	struct ff_regs *regs;
	224
	225	xecfg->find_func = ff_regexp;
	226	regs = xecfg->find_func_priv = xmalloc(sizeof(struct ff_regs));
	227	for (i = 0, regs->nr = 1; value[i]; i++)
	228	if (value[i] == '\n')
	229	regs->nr++;
	230	regs->array = xmalloc(regs->nr * sizeof(struct ff_reg));
	231	for (i = 0; i < regs->nr; i++) {
	232	struct ff_reg *reg = regs->array + i;
	233	const char ep = strchr(value, '\n'), expression;
	234	char *buffer = NULL;
	235
	236	reg->negate = (*value == '!');
	237	if (reg->negate && i == regs->nr - 1)
	238	die("Last expression must not be negated: %s", value);
	239	if (*value == '!')
	240	value++;
	241	if (ep)
	242	expression = buffer = xstrndup(value, ep - value);
	243	else
	244	expression = value;
245	if (regcomp(&reg->re, expression, 0))
246	die("Invalid regexp to look for hunk header: %s", expression);
8e0f7003	247	free(buffer);
f258475a JH	248	value = ep + 1;
	249	}
	250	}