#include "diff.h"
#include "diffcore.h"
#include "delta.h"
+#include "count-delta.h"
/* Table of rename/copy destinations */
return &(rename_dst[first]);
}
+/* Table of rename/copy src files */
static struct diff_rename_src {
struct diff_filespec *one;
- unsigned src_used : 1;
+ unsigned src_stays : 1;
} *rename_src;
static int rename_src_nr, rename_src_alloc;
-static struct diff_rename_src *locate_rename_src(struct diff_filespec *one,
- int insert_ok)
+static struct diff_rename_src *register_rename_src(struct diff_filespec *one,
+ int src_stays)
{
int first, last;
}
first = next+1;
}
- /* not found */
- if (!insert_ok)
- return NULL;
+
/* insert to make it at "first" */
if (rename_src_alloc <= rename_src_nr) {
rename_src_alloc = alloc_nr(rename_src_alloc);
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_used = 0;
+ rename_src[first].src_stays = src_stays;
return &(rename_src[first]);
}
if (src->sha1_valid && dst->sha1_valid &&
!memcmp(src->sha1, dst->sha1, 20))
return 1;
- if (diff_populate_filespec(src) || diff_populate_filespec(dst))
- /* this is an error but will be caught downstream */
+ 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))
int src; /* index in rename_src */
int dst; /* index in rename_dst */
int score;
- int rank;
};
static int estimate_similarity(struct diff_filespec *src,
* 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 10000, except
- * where they match exactly it is considered better than anything
- * else.
+ * 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;
/* 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);
- /*
- * We currently punt here, but we may later end up parsing the
- * delta to really assess the extent of damage. A big consecutive
- * remove would produce small delta_size that affects quite a
- * big portion of the file.
+
+ /* 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
fill_filespec(two, dst->sha1, dst->mode);
dp = diff_queue(renq, one, two);
- dp->score = score;
-
- rename_src[src_index].src_used = 1;
+ dp->score = score ? : 1; /* make sure it is at least 1 */
+ 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 (more similar first).
+ * order (the most similar first).
*/
static int score_compare(const void *a_, const void *b_)
{
else
locate_rename_dst(p->two, 1);
else if (!DIFF_FILE_VALID(p->two))
- locate_rename_src(p->one, 1);
- else if (1 < detect_rename) /* find copy, too */
- locate_rename_src(p->one, 1);
+ 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 */
* doing the delta matrix altogether.
*/
if (renq.nr == rename_dst_nr)
- goto flush_rest;
+ goto cleanup;
num_create = (rename_dst_nr - renq.nr);
num_src = rename_src_nr;
if (dst->pair)
continue; /* already done, either exact or fuzzy. */
if (mx[i].score < minimum_score)
- break; /* there is not any more diffs applicable. */
+ 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);
- flush_rest:
+ cleanup:
/* At this point, we have found some renames and copies and they
* are kept in renq. The original list is still in *q.
- *
- * Scan the original list and move them into the outq; we will sort
- * outq and swap it into the queue supplied to pass that to
- * downstream, so we assign the sort keys in this loop.
- *
- * See comments at the top of record_rename_pair for numbers used
- * to assign rename_rank.
*/
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_src *src = locate_rename_src(p->one, 0);
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 already to produce
- * this file, so we do not emit the creation
- * record in the output.
+ /* 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;
diff_q(&outq, p);
}
else if (!diff_unmodified_pair(p))
- /* all the other cases need to be recorded as is */
+ /* all the usual ones need to be kept */
diff_q(&outq, p);
- else {
- /* unmodified pair needs to be recorded only if
- * it is used as the source of rename/copy
- */
- if (src && src->src_used)
- diff_q(&outq, p);
- else
- pair_to_free = p;
- }
- if (pair_to_free) {
- diff_free_filespec_data(pair_to_free->one);
- diff_free_filespec_data(pair_to_free->two);
- free(pair_to_free);
- }
+ 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);
*q = outq;
diff_debug_queue("done collapsing", q);
- cleanup:
free(rename_dst);
rename_dst = NULL;
rename_dst_nr = rename_dst_alloc = 0;
projects / git.git / blobdiff