[thirdparty/git.git] / diffcore-rename.c

/*
 * Copyright (C) 2005 Junio C Hamano
 */
#include "cache.h"
#include "diff.h"
#include "diffcore.h"
#include "delta.h"
#include "count-delta.h"

/* Table of rename/copy destinations */

static struct diff_rename_dst {
	struct diff_filespec *two;
	struct diff_filepair *pair;
} *rename_dst;
static int rename_dst_nr, rename_dst_alloc;

static struct diff_rename_dst *locate_rename_dst(struct diff_filespec *two,
						 int insert_ok)
{
	int first, last;

	first = 0;
	last = rename_dst_nr;
	while (last > first) {
		int next = (last + first) >> 1;
		struct diff_rename_dst *dst = &(rename_dst[next]);
		int cmp = strcmp(two->path, dst->two->path);
		if (!cmp)
			return dst;
		if (cmp < 0) {
			last = next;
			continue;
		}
		first = next+1;
	}
	/* not found */
	if (!insert_ok)
		return NULL;
	/* insert to make it at "first" */
	if (rename_dst_alloc <= rename_dst_nr) {
		rename_dst_alloc = alloc_nr(rename_dst_alloc);
		rename_dst = xrealloc(rename_dst,
				      rename_dst_alloc * sizeof(*rename_dst));
	}
	rename_dst_nr++;
	if (first < rename_dst_nr)
		memmove(rename_dst + first + 1, rename_dst + first,
			(rename_dst_nr - first - 1) * sizeof(*rename_dst));
	rename_dst[first].two = two;
	rename_dst[first].pair = NULL;
	return &(rename_dst[first]);
}

/* Table of rename/copy src files */
static struct diff_rename_src {
	struct diff_filespec *one;
	unsigned src_stays : 1;
} *rename_src;
static int rename_src_nr, rename_src_alloc;

static struct diff_rename_src *register_rename_src(struct diff_filespec *one,
						   int src_stays)
{
	int first, last;

	first = 0;
	last = rename_src_nr;
	while (last > first) {
		int next = (last + first) >> 1;
		struct diff_rename_src *src = &(rename_src[next]);
		int cmp = strcmp(one->path, src->one->path);
		if (!cmp)
			return src;
		if (cmp < 0) {
			last = next;
			continue;
		}
		first = next+1;
	}

	/* insert to make it at "first" */
	if (rename_src_alloc <= rename_src_nr) {
		rename_src_alloc = alloc_nr(rename_src_alloc);
		rename_src = xrealloc(rename_src,
				      rename_src_alloc * sizeof(*rename_src));
	}
	rename_src_nr++;
	if (first < rename_src_nr)
		memmove(rename_src + first + 1, rename_src + first,
			(rename_src_nr - first - 1) * sizeof(*rename_src));
	rename_src[first].one = one;
	rename_src[first].src_stays = src_stays;
	return &(rename_src[first]);
}

static int is_exact_match(struct diff_filespec *src, struct diff_filespec *dst)
{
	if (src->sha1_valid && dst->sha1_valid &&
	    !memcmp(src->sha1, dst->sha1, 20))
		return 1;
	if (diff_populate_filespec(src, 1) || diff_populate_filespec(dst, 1))
		return 0;
	if (src->size != dst->size)
		return 0;
	if (diff_populate_filespec(src, 0) || diff_populate_filespec(dst, 0))
		return 0;
	if (src->size == dst->size &&
	    !memcmp(src->data, dst->data, src->size))
		return 1;
	return 0;
}

struct diff_score {
	int src; /* index in rename_src */
	int dst; /* index in rename_dst */
	int score;
};

static int estimate_similarity(struct diff_filespec *src,
			       struct diff_filespec *dst,
			       int minimum_score)
{
	/* src points at a file that existed in the original tree (or
	 * optionally a file in the destination tree) and dst points
	 * at a newly created file.  They may be quite similar, in which
	 * case we want to say src is renamed to dst or src is copied into
	 * dst, and then some edit has been applied to dst.
	 *
	 * Compare them and return how similar they are, representing
	 * the score as an integer between 0 and MAX_SCORE.
	 *
	 * When there is an exact match, it is considered a better
	 * match than anything else; the destination does not even
	 * call into this function in that case.
	 */
	void *delta;
	unsigned long delta_size, base_size;
	int score;

	/* We deal only with regular files.  Symlink renames are handled
	 * only when they are exact matches --- in other words, no edits
	 * after renaming.
	 */
	if (!S_ISREG(src->mode) || !S_ISREG(dst->mode))
		return 0;

	delta_size = ((src->size < dst->size) ?
		      (dst->size - src->size) : (src->size - dst->size));
	base_size = ((src->size < dst->size) ? src->size : dst->size);

	/* We would not consider edits that change the file size so
	 * drastically.  delta_size must be smaller than
	 * (MAX_SCORE-minimum_score)/MAX_SCORE * min(src->size, dst->size).
	 *
	 * Note that base_size == 0 case is handled here already
	 * and the final score computation below would not have a
	 * divide-by-zero issue.
	 */
	if (base_size * (MAX_SCORE-minimum_score) < delta_size * MAX_SCORE)
		return 0;

	if (diff_populate_filespec(src, 0) || diff_populate_filespec(dst, 0))
		return 0; /* error but caught downstream */

	delta = diff_delta(src->data, src->size,
			   dst->data, dst->size,
			   &delta_size);

	/* A delta that has a lot of literal additions would have
	 * big delta_size no matter what else it does.
	 */
	if (base_size * (MAX_SCORE-minimum_score) < delta_size * MAX_SCORE)
		return 0;

	/* Estimate the edit size by interpreting delta. */
	delta_size = count_delta(delta, delta_size);
	free(delta);
	if (delta_size == UINT_MAX)
		return 0;

	/*
	 * Now we will give some score to it.  100% edit gets 0 points
	 * and 0% edit gets MAX_SCORE points.
	 */
	score = MAX_SCORE - (MAX_SCORE * delta_size / base_size); 
	if (score < 0) return 0;
	if (MAX_SCORE < score) return MAX_SCORE;
	return score;
}

static void record_rename_pair(struct diff_queue_struct *renq,
			       int dst_index, int src_index, int score)
{
	struct diff_filespec *one, *two, *src, *dst;
	struct diff_filepair *dp;

	if (rename_dst[dst_index].pair)
		die("internal error: dst already matched.");

	src = rename_src[src_index].one;
	one = alloc_filespec(src->path);
	fill_filespec(one, src->sha1, src->mode);

	dst = rename_dst[dst_index].two;
	two = alloc_filespec(dst->path);
	fill_filespec(two, dst->sha1, dst->mode);

	dp = diff_queue(renq, one, two);
	dp->score = score;
	dp->source_stays = rename_src[src_index].src_stays;
	rename_dst[dst_index].pair = dp;
}

/*
 * We sort the rename similarity matrix with the score, in descending
 * order (the most similar first).
 */
static int score_compare(const void *a_, const void *b_)
{
	const struct diff_score *a = a_, *b = b_;
	return b->score - a->score;
}

int diff_scoreopt_parse(const char *opt)
{
	int diglen, num, scale, i;
	if (opt[0] != '-' || (opt[1] != 'M' && opt[1] != 'C'))
		return -1; /* that is not a -M nor -C option */
	diglen = strspn(opt+2, "0123456789");
	if (diglen == 0 || strlen(opt+2) != diglen)
		return 0; /* use default */
	sscanf(opt+2, "%d", &num);
	for (i = 0, scale = 1; i < diglen; i++)
		scale *= 10;

	/* user says num divided by scale and we say internally that
	 * is MAX_SCORE * num / scale.
	 */
	return MAX_SCORE * num / scale;
}

void diffcore_rename(int detect_rename, int minimum_score)
{
	struct diff_queue_struct *q = &diff_queued_diff;
	struct diff_queue_struct renq, outq;
	struct diff_score *mx;
	int i, j;
	int num_create, num_src, dst_cnt;

	if (!minimum_score)
		minimum_score = DEFAULT_MINIMUM_SCORE;
	renq.queue = NULL;
	renq.nr = renq.alloc = 0;

	for (i = 0; i < q->nr; i++) {
		struct diff_filepair *p = q->queue[i];
		if (!DIFF_FILE_VALID(p->one))
			if (!DIFF_FILE_VALID(p->two))
				continue; /* unmerged */
			else
				locate_rename_dst(p->two, 1);
		else if (!DIFF_FILE_VALID(p->two))
			register_rename_src(p->one, 0);
		else if (detect_rename == DIFF_DETECT_COPY)
			register_rename_src(p->one, 1);
	}
	if (rename_dst_nr == 0)
		goto cleanup; /* nothing to do */

	/* We really want to cull the candidates list early
	 * with cheap tests in order to avoid doing deltas.
	 */
	for (i = 0; i < rename_dst_nr; i++) {
		struct diff_filespec *two = rename_dst[i].two;
		for (j = 0; j < rename_src_nr; j++) {
			struct diff_filespec *one = rename_src[j].one;
			if (!is_exact_match(one, two))
				continue;
			record_rename_pair(&renq, i, j, MAX_SCORE);
			break; /* we are done with this entry */
		}
	}
	diff_debug_queue("done detecting exact", &renq);

	/* Have we run out the created file pool?  If so we can avoid
	 * doing the delta matrix altogether.
	 */
	if (renq.nr == rename_dst_nr)
		goto cleanup;

	num_create = (rename_dst_nr - renq.nr);
	num_src = rename_src_nr;
	mx = xmalloc(sizeof(*mx) * num_create * num_src);
	for (dst_cnt = i = 0; i < rename_dst_nr; i++) {
		int base = dst_cnt * num_src;
		struct diff_filespec *two = rename_dst[i].two;
		if (rename_dst[i].pair)
			continue; /* dealt with exact match already. */
		for (j = 0; j < rename_src_nr; j++) {
			struct diff_filespec *one = rename_src[j].one;
			struct diff_score *m = &mx[base+j];
			m->src = j;
			m->dst = i;
			m->score = estimate_similarity(one, two,
						       minimum_score);
		}
		dst_cnt++;
	}
	/* cost matrix sorted by most to least similar pair */
	qsort(mx, num_create * num_src, sizeof(*mx), score_compare);
	for (i = 0; i < num_create * num_src; i++) {
		struct diff_rename_dst *dst = &rename_dst[mx[i].dst];
		if (dst->pair)
			continue; /* already done, either exact or fuzzy. */
		if (mx[i].score < minimum_score)
			break; /* there is no more usable pair. */
		record_rename_pair(&renq, mx[i].dst, mx[i].src, mx[i].score);
	}
	free(mx);
	diff_debug_queue("done detecting fuzzy", &renq);

 cleanup:
	/* At this point, we have found some renames and copies and they
	 * are kept in renq.  The original list is still in *q.
	 */
	outq.queue = NULL;
	outq.nr = outq.alloc = 0;
	for (i = 0; i < q->nr; i++) {
		struct diff_filepair *p = q->queue[i];
		struct diff_rename_dst *dst = locate_rename_dst(p->two, 0);
		struct diff_filepair *pair_to_free = NULL;

		if (dst) {
			/* creation */
			if (dst->pair) {
				/* renq has rename/copy to produce
				 * this file already, so we do not
				 * emit the creation record in the
				 * output.
				 */
				diff_q(&outq, dst->pair);
				pair_to_free = p;
			}
			else
				/* no matching rename/copy source, so record
				 * this as a creation.
				 */
				diff_q(&outq, p);
		}
		else if (!diff_unmodified_pair(p))
			/* all the usual ones need to be kept */
			diff_q(&outq, p);
		else
			/* no need to keep unmodified pairs */
			pair_to_free = p;

		if (pair_to_free)
			diff_free_filepair(pair_to_free);
	}
	diff_debug_queue("done copying original", &outq);

	free(renq.queue);
	free(q->queue);
	*q = outq;
	diff_debug_queue("done collapsing", q);

	free(rename_dst);
	rename_dst = NULL;
	rename_dst_nr = rename_dst_alloc = 0;
	free(rename_src);
	rename_src = NULL;
	rename_src_nr = rename_src_alloc = 0;
	return;
}
Commit	Line	Data
427dcb4b JH	1	/*
	2	* Copyright (C) 2005 Junio C Hamano
	3	*/
	4	#include "cache.h"
	5	#include "diff.h"
	6	#include "diffcore.h"
	7	#include "delta.h"
85976974	8	#include "count-delta.h"
427dcb4b	9
25d5ea41 JH	10	/* Table of rename/copy destinations */
	11
	12	static struct diff_rename_dst {
	13	struct diff_filespec *two;
	14	struct diff_filepair *pair;
	15	} *rename_dst;
	16	static int rename_dst_nr, rename_dst_alloc;
427dcb4b	17
25d5ea41 JH	18	static struct diff_rename_dst locate_rename_dst(struct diff_filespec two,
25d5ea41 JH	19	int insert_ok)
427dcb4b	20	{
25d5ea41 JH	21	int first, last;
	22
	23	first = 0;
	24	last = rename_dst_nr;
	25	while (last > first) {
	26	int next = (last + first) >> 1;
	27	struct diff_rename_dst *dst = &(rename_dst[next]);
	28	int cmp = strcmp(two->path, dst->two->path);
	29	if (!cmp)
	30	return dst;
	31	if (cmp < 0) {
	32	last = next;
	33	continue;
	34	}
	35	first = next+1;
	36	}
	37	/* not found */
	38	if (!insert_ok)
	39	return NULL;
	40	/* insert to make it at "first" */
	41	if (rename_dst_alloc <= rename_dst_nr) {
	42	rename_dst_alloc = alloc_nr(rename_dst_alloc);
	43	rename_dst = xrealloc(rename_dst,
	44	rename_dst_alloc * sizeof(*rename_dst));
	45	}
	46	rename_dst_nr++;
	47	if (first < rename_dst_nr)
	48	memmove(rename_dst + first + 1, rename_dst + first,
	49	(rename_dst_nr - first - 1) * sizeof(*rename_dst));
	50	rename_dst[first].two = two;
	51	rename_dst[first].pair = NULL;
	52	return &(rename_dst[first]);
427dcb4b JH	53	}
427dcb4b JH	54
15d061b4	55	/* Table of rename/copy src files */
25d5ea41 JH	56	static struct diff_rename_src {
25d5ea41 JH	57	struct diff_filespec *one;
15d061b4	58	unsigned src_stays : 1;
25d5ea41 JH	59	} *rename_src;
25d5ea41 JH	60	static int rename_src_nr, rename_src_alloc;
427dcb4b	61
15d061b4 JH	62	static struct diff_rename_src register_rename_src(struct diff_filespec one,
15d061b4 JH	63	int src_stays)
25d5ea41 JH	64	{
	65	int first, last;
	66
	67	first = 0;
	68	last = rename_src_nr;
	69	while (last > first) {
	70	int next = (last + first) >> 1;
	71	struct diff_rename_src *src = &(rename_src[next]);
	72	int cmp = strcmp(one->path, src->one->path);
	73	if (!cmp)
	74	return src;
	75	if (cmp < 0) {
	76	last = next;
	77	continue;
	78	}
	79	first = next+1;
	80	}
15d061b4	81
25d5ea41 JH	82	/* insert to make it at "first" */
	83	if (rename_src_alloc <= rename_src_nr) {
	84	rename_src_alloc = alloc_nr(rename_src_alloc);
	85	rename_src = xrealloc(rename_src,
	86	rename_src_alloc * sizeof(*rename_src));
427dcb4b	87	}
25d5ea41 JH	88	rename_src_nr++;
	89	if (first < rename_src_nr)
	90	memmove(rename_src + first + 1, rename_src + first,
	91	(rename_src_nr - first - 1) * sizeof(*rename_src));
	92	rename_src[first].one = one;
15d061b4	93	rename_src[first].src_stays = src_stays;
25d5ea41	94	return &(rename_src[first]);
427dcb4b JH	95	}
	96
	97	static int is_exact_match(struct diff_filespec src, struct diff_filespec dst)
	98	{
	99	if (src->sha1_valid && dst->sha1_valid &&
	100	!memcmp(src->sha1, dst->sha1, 20))
	101	return 1;
f0c6b2a2 JH	102	if (diff_populate_filespec(src, 1) \|\| diff_populate_filespec(dst, 1))
	103	return 0;
	104	if (src->size != dst->size)
	105	return 0;
	106	if (diff_populate_filespec(src, 0) \|\| diff_populate_filespec(dst, 0))
427dcb4b JH	107	return 0;
	108	if (src->size == dst->size &&
	109	!memcmp(src->data, dst->data, src->size))
	110	return 1;
	111	return 0;
	112	}
	113
	114	struct diff_score {
25d5ea41 JH	115	int src; /* index in rename_src */
25d5ea41 JH	116	int dst; /* index in rename_dst */
427dcb4b	117	int score;
427dcb4b JH	118	};
	119
	120	static int estimate_similarity(struct diff_filespec *src,
	121	struct diff_filespec *dst,
	122	int minimum_score)
	123	{
	124	/* src points at a file that existed in the original tree (or
	125	* optionally a file in the destination tree) and dst points
	126	* at a newly created file. They may be quite similar, in which
	127	* case we want to say src is renamed to dst or src is copied into
	128	* dst, and then some edit has been applied to dst.
	129	*
	130	* Compare them and return how similar they are, representing
f0c6b2a2 JH	131	* the score as an integer between 0 and MAX_SCORE.
	132	*
	133	* When there is an exact match, it is considered a better
	134	* match than anything else; the destination does not even
	135	* call into this function in that case.
427dcb4b JH	136	*/
427dcb4b JH	137	void *delta;
58b103f5	138	unsigned long delta_size, base_size;
427dcb4b JH	139	int score;
427dcb4b JH	140
60896c7b JH	141	/* We deal only with regular files. Symlink renames are handled
	142	* only when they are exact matches --- in other words, no edits
	143	* after renaming.
	144	*/
	145	if (!S_ISREG(src->mode) \|\| !S_ISREG(dst->mode))
	146	return 0;
	147
427dcb4b JH	148	delta_size = ((src->size < dst->size) ?
427dcb4b JH	149	(dst->size - src->size) : (src->size - dst->size));
58b103f5	150	base_size = ((src->size < dst->size) ? src->size : dst->size);
427dcb4b	151
58b103f5 JH	152	/* We would not consider edits that change the file size so
58b103f5 JH	153	* drastically. delta_size must be smaller than
cd1870ed	154	* (MAX_SCORE-minimum_score)/MAX_SCORE * min(src->size, dst->size).
f0c6b2a2	155	*
58b103f5 JH	156	* Note that base_size == 0 case is handled here already
	157	* and the final score computation below would not have a
	158	* divide-by-zero issue.
427dcb4b	159	*/
cd1870ed	160	if (base_size * (MAX_SCORE-minimum_score) < delta_size * MAX_SCORE)
427dcb4b JH	161	return 0;
427dcb4b JH	162
f0c6b2a2 JH	163	if (diff_populate_filespec(src, 0) \|\| diff_populate_filespec(dst, 0))
	164	return 0; /* error but caught downstream */
	165
427dcb4b JH	166	delta = diff_delta(src->data, src->size,
	167	dst->data, dst->size,
	168	&delta_size);
85976974 JH	169
	170	/* A delta that has a lot of literal additions would have
	171	* big delta_size no matter what else it does.
58b103f5	172	*/
a00d7d10	173	if (base_size * (MAX_SCORE-minimum_score) < delta_size * MAX_SCORE)
85976974 JH	174	return 0;
	175
	176	/* Estimate the edit size by interpreting delta. */
	177	delta_size = count_delta(delta, delta_size);
427dcb4b	178	free(delta);
85976974 JH	179	if (delta_size == UINT_MAX)
85976974 JH	180	return 0;
427dcb4b	181
58b103f5 JH	182	/*
	183	* Now we will give some score to it. 100% edit gets 0 points
	184	* and 0% edit gets MAX_SCORE points.
427dcb4b	185	*/
58b103f5	186	score = MAX_SCORE - (MAX_SCORE * delta_size / base_size);
427dcb4b JH	187	if (score < 0) return 0;
	188	if (MAX_SCORE < score) return MAX_SCORE;
	189	return score;
	190	}
	191
25d5ea41 JH	192	static void record_rename_pair(struct diff_queue_struct *renq,
25d5ea41 JH	193	int dst_index, int src_index, int score)
427dcb4b	194	{
25d5ea41 JH	195	struct diff_filespec one, two, src, dst;
25d5ea41 JH	196	struct diff_filepair *dp;
f7c1512a	197
25d5ea41 JH	198	if (rename_dst[dst_index].pair)
25d5ea41 JH	199	die("internal error: dst already matched.");
427dcb4b	200
25d5ea41 JH	201	src = rename_src[src_index].one;
	202	one = alloc_filespec(src->path);
	203	fill_filespec(one, src->sha1, src->mode);
427dcb4b	204
25d5ea41 JH	205	dst = rename_dst[dst_index].two;
	206	two = alloc_filespec(dst->path);
	207	fill_filespec(two, dst->sha1, dst->mode);
427dcb4b	208
25d5ea41	209	dp = diff_queue(renq, one, two);
01c4e70f	210	dp->score = score;
15d061b4	211	dp->source_stays = rename_src[src_index].src_stays;
25d5ea41	212	rename_dst[dst_index].pair = dp;
427dcb4b JH	213	}
	214
	215	/*
	216	* We sort the rename similarity matrix with the score, in descending
15d061b4	217	* order (the most similar first).
427dcb4b JH	218	*/
	219	static int score_compare(const void a_, const void b_)
	220	{
	221	const struct diff_score a = a_, b = b_;
	222	return b->score - a->score;
	223	}
	224
6b14d7fa JH	225	int diff_scoreopt_parse(const char *opt)
	226	{
	227	int diglen, num, scale, i;
	228	if (opt[0] != '-' \|\| (opt[1] != 'M' && opt[1] != 'C'))
	229	return -1; /* that is not a -M nor -C option */
	230	diglen = strspn(opt+2, "0123456789");
	231	if (diglen == 0 \|\| strlen(opt+2) != diglen)
	232	return 0; /* use default */
	233	sscanf(opt+2, "%d", &num);
	234	for (i = 0, scale = 1; i < diglen; i++)
	235	scale *= 10;
	236
	237	/* user says num divided by scale and we say internally that
	238	* is MAX_SCORE * num / scale.
	239	*/
	240	return MAX_SCORE * num / scale;
	241	}
	242
	243	void diffcore_rename(int detect_rename, int minimum_score)
427dcb4b	244	{
38c6f780	245	struct diff_queue_struct *q = &diff_queued_diff;
25d5ea41	246	struct diff_queue_struct renq, outq;
427dcb4b	247	struct diff_score *mx;
25d5ea41 JH	248	int i, j;
25d5ea41 JH	249	int num_create, num_src, dst_cnt;
427dcb4b	250
26dee0ad JH	251	if (!minimum_score)
26dee0ad JH	252	minimum_score = DEFAULT_MINIMUM_SCORE;
25d5ea41 JH	253	renq.queue = NULL;
25d5ea41 JH	254	renq.nr = renq.alloc = 0;
427dcb4b	255
427dcb4b	256	for (i = 0; i < q->nr; i++) {
52e95789	257	struct diff_filepair *p = q->queue[i];
81e50eab JH	258	if (!DIFF_FILE_VALID(p->one))
81e50eab JH	259	if (!DIFF_FILE_VALID(p->two))
60896c7b	260	continue; /* unmerged */
427dcb4b	261	else
25d5ea41	262	locate_rename_dst(p->two, 1);
81e50eab	263	else if (!DIFF_FILE_VALID(p->two))
15d061b4 JH	264	register_rename_src(p->one, 0);
	265	else if (detect_rename == DIFF_DETECT_COPY)
	266	register_rename_src(p->one, 1);
427dcb4b	267	}
25d5ea41	268	if (rename_dst_nr == 0)
427dcb4b JH	269	goto cleanup; /* nothing to do */
	270
	271	/* We really want to cull the candidates list early
	272	* with cheap tests in order to avoid doing deltas.
427dcb4b	273	*/
25d5ea41 JH	274	for (i = 0; i < rename_dst_nr; i++) {
	275	struct diff_filespec *two = rename_dst[i].two;
	276	for (j = 0; j < rename_src_nr; j++) {
	277	struct diff_filespec *one = rename_src[j].one;
	278	if (!is_exact_match(one, two))
	279	continue;
	280	record_rename_pair(&renq, i, j, MAX_SCORE);
	281	break; /* we are done with this entry */
427dcb4b JH	282	}
427dcb4b JH	283	}
25d5ea41	284	diff_debug_queue("done detecting exact", &renq);
427dcb4b JH	285
	286	/* Have we run out the created file pool? If so we can avoid
	287	* doing the delta matrix altogether.
	288	*/
25d5ea41	289	if (renq.nr == rename_dst_nr)
15d061b4	290	goto cleanup;
427dcb4b	291
25d5ea41 JH	292	num_create = (rename_dst_nr - renq.nr);
25d5ea41 JH	293	num_src = rename_src_nr;
427dcb4b	294	mx = xmalloc(sizeof(mx) num_create * num_src);
25d5ea41	295	for (dst_cnt = i = 0; i < rename_dst_nr; i++) {
427dcb4b	296	int base = dst_cnt * num_src;
25d5ea41 JH	297	struct diff_filespec *two = rename_dst[i].two;
25d5ea41 JH	298	if (rename_dst[i].pair)
427dcb4b	299	continue; /* dealt with exact match already. */
25d5ea41 JH	300	for (j = 0; j < rename_src_nr; j++) {
	301	struct diff_filespec *one = rename_src[j].one;
	302	struct diff_score *m = &mx[base+j];
	303	m->src = j;
	304	m->dst = i;
	305	m->score = estimate_similarity(one, two,
	306	minimum_score);
427dcb4b JH	307	}
	308	dst_cnt++;
	309	}
	310	/* cost matrix sorted by most to least similar pair */
	311	qsort(mx, num_create * num_src, sizeof(*mx), score_compare);
	312	for (i = 0; i < num_create * num_src; i++) {
25d5ea41 JH	313	struct diff_rename_dst *dst = &rename_dst[mx[i].dst];
	314	if (dst->pair)
	315	continue; /* already done, either exact or fuzzy. */
427dcb4b	316	if (mx[i].score < minimum_score)
15d061b4	317	break; /* there is no more usable pair. */
25d5ea41	318	record_rename_pair(&renq, mx[i].dst, mx[i].src, mx[i].score);
427dcb4b JH	319	}
427dcb4b JH	320	free(mx);
25d5ea41	321	diff_debug_queue("done detecting fuzzy", &renq);
427dcb4b	322
15d061b4	323	cleanup:
427dcb4b	324	/* At this point, we have found some renames and copies and they
25d5ea41	325	* are kept in renq. The original list is still in *q.
427dcb4b	326	*/
25d5ea41 JH	327	outq.queue = NULL;
25d5ea41 JH	328	outq.nr = outq.alloc = 0;
427dcb4b	329	for (i = 0; i < q->nr; i++) {
25d5ea41	330	struct diff_filepair *p = q->queue[i];
25d5ea41 JH	331	struct diff_rename_dst *dst = locate_rename_dst(p->two, 0);
	332	struct diff_filepair *pair_to_free = NULL;
	333
	334	if (dst) {
	335	/* creation */
	336	if (dst->pair) {
15d061b4 JH	337	/* renq has rename/copy to produce
	338	* this file already, so we do not
	339	* emit the creation record in the
	340	* output.
25d5ea41 JH	341	*/
	342	diff_q(&outq, dst->pair);
	343	pair_to_free = p;
	344	}
	345	else
	346	/* no matching rename/copy source, so record
	347	* this as a creation.
	348	*/
	349	diff_q(&outq, p);
427dcb4b	350	}
25d5ea41	351	else if (!diff_unmodified_pair(p))
15d061b4	352	/* all the usual ones need to be kept */
25d5ea41	353	diff_q(&outq, p);
15d061b4 JH	354	else
	355	/* no need to keep unmodified pairs */
	356	pair_to_free = p;
	357
226406f6 JH	358	if (pair_to_free)
226406f6 JH	359	diff_free_filepair(pair_to_free);
427dcb4b	360	}
25d5ea41	361	diff_debug_queue("done copying original", &outq);
427dcb4b	362
25d5ea41 JH	363	free(renq.queue);
	364	free(q->queue);
	365	*q = outq;
	366	diff_debug_queue("done collapsing", q);
427dcb4b	367
25d5ea41 JH	368	free(rename_dst);
	369	rename_dst = NULL;
	370	rename_dst_nr = rename_dst_alloc = 0;
	371	free(rename_src);
	372	rename_src = NULL;
	373	rename_src_nr = rename_src_alloc = 0;
427dcb4b JH	374	return;
427dcb4b JH	375	}