[thirdparty/git.git] / tree-diff.c

/*
 * Helper functions for tree diff generation
 */
#include "cache.h"
#include "diff.h"
#include "tree.h"

static char *malloc_base(const char *base, const char *path, int pathlen)
{
	int baselen = strlen(base);
	char *newbase = xmalloc(baselen + pathlen + 2);
	memcpy(newbase, base, baselen);
	memcpy(newbase + baselen, path, pathlen);
	memcpy(newbase + baselen + pathlen, "/", 2);
	return newbase;
}

static void show_entry(struct diff_options *opt, const char *prefix, struct tree_desc *desc,
		       const char *base);

static int compare_tree_entry(struct tree_desc *t1, struct tree_desc *t2, const char *base, struct diff_options *opt)
{
	unsigned mode1, mode2;
	const char *path1, *path2;
	const unsigned char *sha1, *sha2;
	int cmp, pathlen1, pathlen2;

	sha1 = tree_entry_extract(t1, &path1, &mode1);
	sha2 = tree_entry_extract(t2, &path2, &mode2);

	pathlen1 = strlen(path1);
	pathlen2 = strlen(path2);
	cmp = base_name_compare(path1, pathlen1, mode1, path2, pathlen2, mode2);
	if (cmp < 0) {
		show_entry(opt, "-", t1, base);
		return -1;
	}
	if (cmp > 0) {
		show_entry(opt, "+", t2, base);
		return 1;
	}
	if (!opt->find_copies_harder && !hashcmp(sha1, sha2) && mode1 == mode2)
		return 0;

	/*
	 * If the filemode has changed to/from a directory from/to a regular
	 * file, we need to consider it a remove and an add.
	 */
	if (S_ISDIR(mode1) != S_ISDIR(mode2)) {
		show_entry(opt, "-", t1, base);
		show_entry(opt, "+", t2, base);
		return 0;
	}

	if (opt->recursive && S_ISDIR(mode1)) {
		int retval;
		char *newbase = malloc_base(base, path1, pathlen1);
		if (opt->tree_in_recursive)
			opt->change(opt, mode1, mode2,
				    sha1, sha2, base, path1);
		retval = diff_tree_sha1(sha1, sha2, newbase, opt);
		free(newbase);
		return retval;
	}

	opt->change(opt, mode1, mode2, sha1, sha2, base, path1);
	return 0;
}

static int interesting(struct tree_desc *desc, const char *base, struct diff_options *opt)
{
	const char *path;
	unsigned mode;
	int i;
	int baselen, pathlen;

	if (!opt->nr_paths)
		return 1;

	(void)tree_entry_extract(desc, &path, &mode);

	pathlen = strlen(path);
	baselen = strlen(base);

	for (i=0; i < opt->nr_paths; i++) {
		const char *match = opt->paths[i];
		int matchlen = opt->pathlens[i];

		if (baselen >= matchlen) {
			/* If it doesn't match, move along... */
			if (strncmp(base, match, matchlen))
				continue;

			/* The base is a subdirectory of a path which was specified. */
			return 1;
		}

		/* Does the base match? */
		if (strncmp(base, match, baselen))
			continue;

		match += baselen;
		matchlen -= baselen;

		if (pathlen > matchlen)
			continue;

		if (matchlen > pathlen) {
			if (match[pathlen] != '/')
				continue;
			if (!S_ISDIR(mode))
				continue;
		}

		if (strncmp(path, match, pathlen))
			continue;

		return 1;
	}
	return 0; /* No matches */
}

/* A whole sub-tree went away or appeared */
static void show_tree(struct diff_options *opt, const char *prefix, struct tree_desc *desc, const char *base)
{
	while (desc->size) {
		if (interesting(desc, base, opt))
			show_entry(opt, prefix, desc, base);
		update_tree_entry(desc);
	}
}

/* A file entry went away or appeared */
static void show_entry(struct diff_options *opt, const char *prefix, struct tree_desc *desc,
		       const char *base)
{
	unsigned mode;
	const char *path;
	const unsigned char *sha1 = tree_entry_extract(desc, &path, &mode);

	if (opt->recursive && S_ISDIR(mode)) {
		char type[20];
		char *newbase = malloc_base(base, path, strlen(path));
		struct tree_desc inner;
		void *tree;

		tree = read_sha1_file(sha1, type, &inner.size);
		if (!tree || strcmp(type, tree_type))
			die("corrupt tree sha %s", sha1_to_hex(sha1));

		inner.buf = tree;
		show_tree(opt, prefix, &inner, newbase);

		free(tree);
		free(newbase);
	} else {
		opt->add_remove(opt, prefix[0], mode, sha1, base, path);
	}
}

int diff_tree(struct tree_desc *t1, struct tree_desc *t2, const char *base, struct diff_options *opt)
{
	while (t1->size | t2->size) {
		if (opt->nr_paths && t1->size && !interesting(t1, base, opt)) {
			update_tree_entry(t1);
			continue;
		}
		if (opt->nr_paths && t2->size && !interesting(t2, base, opt)) {
			update_tree_entry(t2);
			continue;
		}
		if (!t1->size) {
			show_entry(opt, "+", t2, base);
			update_tree_entry(t2);
			continue;
		}
		if (!t2->size) {
			show_entry(opt, "-", t1, base);
			update_tree_entry(t1);
			continue;
		}
		switch (compare_tree_entry(t1, t2, base, opt)) {
		case -1:
			update_tree_entry(t1);
			continue;
		case 0:
			update_tree_entry(t1);
			/* Fallthrough */
		case 1:
			update_tree_entry(t2);
			continue;
		}
		die("git-diff-tree: internal error");
	}
	return 0;
}

int diff_tree_sha1(const unsigned char *old, const unsigned char *new, const char *base, struct diff_options *opt)
{
	void *tree1, *tree2;
	struct tree_desc t1, t2;
	int retval;

	tree1 = read_object_with_reference(old, tree_type, &t1.size, NULL);
	if (!tree1)
		die("unable to read source tree (%s)", sha1_to_hex(old));
	tree2 = read_object_with_reference(new, tree_type, &t2.size, NULL);
	if (!tree2)
		die("unable to read destination tree (%s)", sha1_to_hex(new));
	t1.buf = tree1;
	t2.buf = tree2;
	retval = diff_tree(&t1, &t2, base, opt);
	free(tree1);
	free(tree2);
	return retval;
}

int diff_root_tree_sha1(const unsigned char *new, const char *base, struct diff_options *opt)
{
	int retval;
	void *tree;
	struct tree_desc empty, real;

	tree = read_object_with_reference(new, tree_type, &real.size, NULL);
	if (!tree)
		die("unable to read root tree (%s)", sha1_to_hex(new));
	real.buf = tree;

	empty.size = 0;
	empty.buf = "";
	retval = diff_tree(&empty, &real, base, opt);
	free(tree);
	return retval;
}

static int count_paths(const char **paths)
{
	int i = 0;
	while (*paths++)
		i++;
	return i;
}

void diff_tree_release_paths(struct diff_options *opt)
{
	free(opt->pathlens);
}

void diff_tree_setup_paths(const char **p, struct diff_options *opt)
{
	opt->nr_paths = 0;
	opt->pathlens = NULL;
	opt->paths = NULL;

	if (p) {
		int i;

		opt->paths = p;
		opt->nr_paths = count_paths(p);
		if (opt->nr_paths == 0) {
			opt->pathlens = NULL;
			return;
		}
		opt->pathlens = xmalloc(opt->nr_paths * sizeof(int));
		for (i=0; i < opt->nr_paths; i++)
			opt->pathlens[i] = strlen(p[i]);
	}
}
Commit	Line	Data
ac1b3d12 LT	1	/*
	2	* Helper functions for tree diff generation
	3	*/
	4	#include "cache.h"
	5	#include "diff.h"
8e440259	6	#include "tree.h"
ac1b3d12	7
ac1b3d12 LT	8	static char malloc_base(const char base, const char *path, int pathlen)
	9	{
	10	int baselen = strlen(base);
	11	char *newbase = xmalloc(baselen + pathlen + 2);
	12	memcpy(newbase, base, baselen);
	13	memcpy(newbase + baselen, path, pathlen);
	14	memcpy(newbase + baselen + pathlen, "/", 2);
	15	return newbase;
	16	}
	17
cf995ede DR	18	static void show_entry(struct diff_options opt, const char prefix, struct tree_desc *desc,
cf995ede DR	19	const char *base);
ac1b3d12 LT	20
	21	static int compare_tree_entry(struct tree_desc t1, struct tree_desc t2, const char base, struct diff_options opt)
	22	{
	23	unsigned mode1, mode2;
	24	const char path1, path2;
	25	const unsigned char sha1, sha2;
	26	int cmp, pathlen1, pathlen2;
	27
50f9a858 LT	28	sha1 = tree_entry_extract(t1, &path1, &mode1);
50f9a858 LT	29	sha2 = tree_entry_extract(t2, &path2, &mode2);
ac1b3d12 LT	30
	31	pathlen1 = strlen(path1);
	32	pathlen2 = strlen(path2);
	33	cmp = base_name_compare(path1, pathlen1, mode1, path2, pathlen2, mode2);
	34	if (cmp < 0) {
	35	show_entry(opt, "-", t1, base);
	36	return -1;
	37	}
	38	if (cmp > 0) {
	39	show_entry(opt, "+", t2, base);
	40	return 1;
	41	}
a89fccd2	42	if (!opt->find_copies_harder && !hashcmp(sha1, sha2) && mode1 == mode2)
ac1b3d12 LT	43	return 0;
	44
	45	/*
	46	* If the filemode has changed to/from a directory from/to a regular
	47	* file, we need to consider it a remove and an add.
	48	*/
	49	if (S_ISDIR(mode1) != S_ISDIR(mode2)) {
	50	show_entry(opt, "-", t1, base);
	51	show_entry(opt, "+", t2, base);
	52	return 0;
	53	}
	54
	55	if (opt->recursive && S_ISDIR(mode1)) {
	56	int retval;
	57	char *newbase = malloc_base(base, path1, pathlen1);
	58	if (opt->tree_in_recursive)
	59	opt->change(opt, mode1, mode2,
	60	sha1, sha2, base, path1);
	61	retval = diff_tree_sha1(sha1, sha2, newbase, opt);
	62	free(newbase);
	63	return retval;
	64	}
	65
	66	opt->change(opt, mode1, mode2, sha1, sha2, base, path1);
	67	return 0;
	68	}
	69
a8baa7b9	70	static int interesting(struct tree_desc desc, const char base, struct diff_options *opt)
ac1b3d12 LT	71	{
	72	const char *path;
	73	unsigned mode;
	74	int i;
	75	int baselen, pathlen;
	76
a8baa7b9	77	if (!opt->nr_paths)
ac1b3d12 LT	78	return 1;
ac1b3d12 LT	79
50f9a858	80	(void)tree_entry_extract(desc, &path, &mode);
ac1b3d12 LT	81
	82	pathlen = strlen(path);
	83	baselen = strlen(base);
	84
a8baa7b9 JH	85	for (i=0; i < opt->nr_paths; i++) {
	86	const char *match = opt->paths[i];
	87	int matchlen = opt->pathlens[i];
ac1b3d12 LT	88
	89	if (baselen >= matchlen) {
	90	/* If it doesn't match, move along... */
	91	if (strncmp(base, match, matchlen))
	92	continue;
	93
	94	/* The base is a subdirectory of a path which was specified. */
	95	return 1;
	96	}
	97
	98	/* Does the base match? */
	99	if (strncmp(base, match, baselen))
	100	continue;
	101
	102	match += baselen;
	103	matchlen -= baselen;
	104
	105	if (pathlen > matchlen)
	106	continue;
	107
	108	if (matchlen > pathlen) {
	109	if (match[pathlen] != '/')
	110	continue;
	111	if (!S_ISDIR(mode))
	112	continue;
	113	}
	114
	115	if (strncmp(path, match, pathlen))
	116	continue;
	117
	118	return 1;
	119	}
	120	return 0; /* No matches */
	121	}
	122
	123	/* A whole sub-tree went away or appeared */
	124	static void show_tree(struct diff_options opt, const char prefix, struct tree_desc desc, const char base)
	125	{
	126	while (desc->size) {
a8baa7b9	127	if (interesting(desc, base, opt))
ac1b3d12 LT	128	show_entry(opt, prefix, desc, base);
	129	update_tree_entry(desc);
	130	}
	131	}
	132
	133	/* A file entry went away or appeared */
cf995ede DR	134	static void show_entry(struct diff_options opt, const char prefix, struct tree_desc *desc,
cf995ede DR	135	const char *base)
ac1b3d12 LT	136	{
	137	unsigned mode;
	138	const char *path;
50f9a858	139	const unsigned char *sha1 = tree_entry_extract(desc, &path, &mode);
ac1b3d12 LT	140
	141	if (opt->recursive && S_ISDIR(mode)) {
	142	char type[20];
	143	char *newbase = malloc_base(base, path, strlen(path));
	144	struct tree_desc inner;
	145	void *tree;
	146
	147	tree = read_sha1_file(sha1, type, &inner.size);
8e440259	148	if (!tree \|\| strcmp(type, tree_type))
ac1b3d12 LT	149	die("corrupt tree sha %s", sha1_to_hex(sha1));
	150
	151	inner.buf = tree;
	152	show_tree(opt, prefix, &inner, newbase);
	153
	154	free(tree);
	155	free(newbase);
cf995ede DR	156	} else {
cf995ede DR	157	opt->add_remove(opt, prefix[0], mode, sha1, base, path);
ac1b3d12	158	}
ac1b3d12 LT	159	}
	160
	161	int diff_tree(struct tree_desc t1, struct tree_desc t2, const char base, struct diff_options opt)
	162	{
	163	while (t1->size \| t2->size) {
a8baa7b9	164	if (opt->nr_paths && t1->size && !interesting(t1, base, opt)) {
ac1b3d12 LT	165	update_tree_entry(t1);
	166	continue;
	167	}
a8baa7b9	168	if (opt->nr_paths && t2->size && !interesting(t2, base, opt)) {
ac1b3d12 LT	169	update_tree_entry(t2);
	170	continue;
	171	}
	172	if (!t1->size) {
	173	show_entry(opt, "+", t2, base);
	174	update_tree_entry(t2);
	175	continue;
	176	}
	177	if (!t2->size) {
	178	show_entry(opt, "-", t1, base);
	179	update_tree_entry(t1);
	180	continue;
	181	}
	182	switch (compare_tree_entry(t1, t2, base, opt)) {
	183	case -1:
	184	update_tree_entry(t1);
	185	continue;
	186	case 0:
	187	update_tree_entry(t1);
	188	/* Fallthrough */
	189	case 1:
	190	update_tree_entry(t2);
	191	continue;
	192	}
	193	die("git-diff-tree: internal error");
	194	}
	195	return 0;
	196	}
	197
	198	int diff_tree_sha1(const unsigned char old, const unsigned char new, const char base, struct diff_options opt)
	199	{
	200	void tree1, tree2;
	201	struct tree_desc t1, t2;
	202	int retval;
	203
8e440259	204	tree1 = read_object_with_reference(old, tree_type, &t1.size, NULL);
ac1b3d12 LT	205	if (!tree1)
ac1b3d12 LT	206	die("unable to read source tree (%s)", sha1_to_hex(old));
8e440259	207	tree2 = read_object_with_reference(new, tree_type, &t2.size, NULL);
ac1b3d12 LT	208	if (!tree2)
	209	die("unable to read destination tree (%s)", sha1_to_hex(new));
	210	t1.buf = tree1;
	211	t2.buf = tree2;
	212	retval = diff_tree(&t1, &t2, base, opt);
	213	free(tree1);
	214	free(tree2);
	215	return retval;
	216	}
	217
2b60356d RS	218	int diff_root_tree_sha1(const unsigned char new, const char base, struct diff_options *opt)
	219	{
	220	int retval;
	221	void *tree;
	222	struct tree_desc empty, real;
	223
	224	tree = read_object_with_reference(new, tree_type, &real.size, NULL);
	225	if (!tree)
	226	die("unable to read root tree (%s)", sha1_to_hex(new));
	227	real.buf = tree;
	228
	229	empty.size = 0;
	230	empty.buf = "";
	231	retval = diff_tree(&empty, &real, base, opt);
	232	free(tree);
	233	return retval;
	234	}
	235
ac1b3d12 LT	236	static int count_paths(const char **paths)
	237	{
	238	int i = 0;
	239	while (*paths++)
	240	i++;
	241	return i;
	242	}
	243
a8baa7b9	244	void diff_tree_release_paths(struct diff_options *opt)
ac1b3d12	245	{
a8baa7b9 JH	246	free(opt->pathlens);
	247	}
	248
	249	void diff_tree_setup_paths(const char *p, struct diff_options opt)
	250	{
	251	opt->nr_paths = 0;
	252	opt->pathlens = NULL;
	253	opt->paths = NULL;
	254
ac1b3d12 LT	255	if (p) {
	256	int i;
	257
a8baa7b9 JH	258	opt->paths = p;
	259	opt->nr_paths = count_paths(p);
	260	if (opt->nr_paths == 0) {
	261	opt->pathlens = NULL;
7e4a2a84 JH	262	return;
7e4a2a84 JH	263	}
a8baa7b9 JH	264	opt->pathlens = xmalloc(opt->nr_paths * sizeof(int));
	265	for (i=0; i < opt->nr_paths; i++)
	266	opt->pathlens[i] = strlen(p[i]);
ac1b3d12 LT	267	}
ac1b3d12 LT	268	}