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Merge branch 'jc/rename' 

* 'jc/rename' (early part):
  Optimize rename detection for a huge diff
maint
Junio C Hamano 2008-04-09 00:46:40 -07:00
parent 018465d998 6d24ad971c
commit 2a5fe25458
1 changed files with 58 additions and 22 deletions
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80
diffcore-rename.c
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@ -112,8 +112,8 @@ static int basename_same(struct diff_filespec *src, struct diff_filespec *dst)
struct diff_score {
int src; /* index in rename_src */
int dst; /* index in rename_dst */
int score;
int name_score;
unsigned short score;
short name_score;
};

static int estimate_similarity(struct diff_filespec *src,
@ -223,6 +223,12 @@ static int score_compare(const void *a_, const void *b_)
{
const struct diff_score *a = a_, *b = b_;

/* sink the unused ones to the bottom */
if (a->dst < 0)
return (0 <= b->dst);
else if (b->dst < 0)
return -1;

if (a->score == b->score)
return b->name_score - a->name_score;

@ -387,6 +393,22 @@ static int find_exact_renames(void)
return i;
}

#define NUM_CANDIDATE_PER_DST 4
static void record_if_better(struct diff_score m[], struct diff_score *o)
{
int i, worst;

/* find the worst one */
worst = 0;
for (i = 1; i < NUM_CANDIDATE_PER_DST; i++)
if (score_compare(&m[i], &m[worst]) > 0)
worst = i;

/* is it better than the worst one? */
if (score_compare(&m[worst], o) > 0)
m[worst] = *o;
}

void diffcore_rename(struct diff_options *options)
{
int detect_rename = options->detect_rename;
@ -474,47 +496,61 @@ void diffcore_rename(struct diff_options *options)
goto cleanup;
}

mx = xmalloc(sizeof(*mx) * num_create * num_src);
mx = xcalloc(num_create * NUM_CANDIDATE_PER_DST, sizeof(*mx));
for (dst_cnt = i = 0; i < rename_dst_nr; i++) {
int base = dst_cnt * num_src;
struct diff_filespec *two = rename_dst[i].two;
struct diff_score *m;

if (rename_dst[i].pair)
continue; /* dealt with exact match already. */

m = &mx[dst_cnt * NUM_CANDIDATE_PER_DST];
for (j = 0; j < NUM_CANDIDATE_PER_DST; j++)
m[j].dst = -1;

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);
m->name_score = basename_same(one, two);
struct diff_score this_src;
this_src.score = estimate_similarity(one, two,
minimum_score);
this_src.name_score = basename_same(one, two);
this_src.dst = i;
this_src.src = j;
record_if_better(m, &this_src);
diff_free_filespec_blob(one);
}
/* We do not need the text anymore */
diff_free_filespec_blob(two);
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];
struct diff_filespec *src;
qsort(mx, dst_cnt * NUM_CANDIDATE_PER_DST, sizeof(*mx), score_compare);

for (i = 0; i < dst_cnt * NUM_CANDIDATE_PER_DST; i++) {
struct diff_rename_dst *dst;

if ((mx[i].dst < 0) ||
(mx[i].score < minimum_score))
break; /* there is no more usable pair. */
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. */
src = rename_src[mx[i].src].one;
if (src->rename_used)
if (rename_src[mx[i].src].one->rename_used)
continue;
record_rename_pair(mx[i].dst, mx[i].src, mx[i].score);
rename_count++;
}
for (i = 0; i < num_create * num_src; i++) {
struct diff_rename_dst *dst = &rename_dst[mx[i].dst];

for (i = 0; i < dst_cnt * NUM_CANDIDATE_PER_DST; i++) {
struct diff_rename_dst *dst;

if ((mx[i].dst < 0) ||
(mx[i].score < minimum_score))
break; /* there is no more usable pair. */
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(mx[i].dst, mx[i].src, mx[i].score);
rename_count++;
}