[PATCH] diff overhaul
This cleans up the way calls are made into the diff core from diff-tree
family and diff-helper. Earlier, these programs had "if
(generating_patch)" sprinkled all over the place, but those ugliness are
gone and handled uniformly from the diff core, even when not generating
patch format.
This also allowed diff-cache and diff-files to acquire -R
(reverse) option to generate diff in reverse. Users of
diff-tree can swap two trees easily so I did not add -R there.
[ Linus' note: I'll add -R to "diff-tree" too, since a "commit
diff" doesn't have another tree to switch around: the other
tree is always the parent(s) of the commit ]
Also -M<digits-as-mantissa> suggestion made by Linus has been
implemented.
Documentation updates are also included.
Signed-off-by: Junio C Hamano <junkio@cox.net>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
diff --git a/diff.c b/diff.c
index 92fcc67..c4b6b76 100644
--- a/diff.c
+++ b/diff.c
@@ -11,6 +11,8 @@
static const char *diff_opts = "-pu";
static unsigned char null_sha1[20] = { 0, };
+#define MAX_SCORE 10000
+#define DEFAULT_MINIMUM_SCORE 5000
static const char *external_diff(void)
{
@@ -55,7 +57,7 @@
const char *cp;
char *bp;
- /* count bytes needed to store the quoted string. */
+ /* count bytes needed to store the quoted string. */
for (cnt = 1, cp = src; *cp; cnt++, cp++)
if (*cp == '\'')
cnt += 3;
@@ -93,7 +95,8 @@
static void builtin_diff(const char *name_a,
const char *name_b,
- struct diff_tempfile *temp)
+ struct diff_tempfile *temp,
+ int rename_score)
{
int i, next_at, cmd_size;
const char *diff_cmd = "diff -L'%s%s' -L'%s%s'";
@@ -149,6 +152,10 @@
printf("new mode %s\n", temp[1].mode);
}
if (strcmp(name_a, name_b)) {
+ if (0 < rename_score)
+ printf("rename similarity index %d%%\n",
+ (int)(0.5+
+ rename_score*100.0/MAX_SCORE));
printf("rename old %s\n", name_a);
printf("rename new %s\n", name_b);
}
@@ -184,7 +191,7 @@
* file. Practically, this code only helps when we are used
* by diff-cache --cached, which does read the cache before
* calling us.
- */
+ */
if (!active_cache)
return 0;
@@ -302,9 +309,10 @@
static int detect_rename;
static int reverse_diff;
+static int diff_raw_output = -1;
static const char **pathspec;
static int speccnt;
-static int diff_rename_minimum_score;
+static int minimum_score;
static int matches_pathspec(const char *name)
{
@@ -334,7 +342,8 @@
static void run_external_diff(const char *name,
const char *other,
struct diff_spec *one,
- struct diff_spec *two)
+ struct diff_spec *two,
+ int rename_score)
{
struct diff_tempfile *temp = diff_temp;
pid_t pid;
@@ -395,7 +404,7 @@
* otherwise we use the built-in one.
*/
if (one && two)
- builtin_diff(name, other ? : name, temp);
+ builtin_diff(name, other ? : name, temp, rename_score);
else
printf("* Unmerged path %s\n", name);
exit(0);
@@ -446,7 +455,7 @@
die("internal error");
if (!detect_rename) {
- run_external_diff(name, NULL, one, two);
+ run_external_diff(name, NULL, one, two, -1);
return;
}
elem = xmalloc(sizeof(*elem) + strlen(name));
@@ -519,10 +528,10 @@
continue;
if (on_created_list)
run_external_diff(elem->path, NULL,
- &null_file_spec, &elem->it);
+ &null_file_spec, &elem->it, -1);
else
run_external_diff(elem->path, NULL,
- &elem->it, &null_file_spec);
+ &elem->it, &null_file_spec, -1);
}
}
@@ -541,7 +550,6 @@
return 0;
}
-#define MINIMUM_SCORE 5000
int estimate_similarity(struct diff_spec_hold *src, struct diff_spec_hold *dst)
{
/* src points at a deleted file and dst points at a created
@@ -549,20 +557,24 @@
* say src is renamed to dst.
*
* Compare them and return how similar they are, representing
- * the score as an integer between 0 and 10000. 10000 is
- * reserved for the case where they match exactly.
+ * the score as an integer between 0 and 10000, except
+ * where they match exactly it is considered better than anything
+ * else.
*/
void *delta;
unsigned long delta_size;
+ int score;
delta_size = ((src->size < dst->size) ?
(dst->size - src->size) : (src->size - dst->size));
/* We would not consider rename followed by more than
- * 20% edits; that is, delta_size must be smaller than
- * (src->size + dst->size)/2 * 0.2, which means...
+ * minimum_score/MAX_SCORE edits; that is, delta_size must be smaller
+ * than (src->size + dst->size)/2 * minimum_score/MAX_SCORE,
+ * which means...
*/
- if ((src->size + dst->size) < delta_size * 10)
+
+ if ((src->size+dst->size)*minimum_score < delta_size*MAX_SCORE*2)
return 0;
delta = diff_delta(src->data, src->size,
@@ -573,14 +585,17 @@
/* This "delta" is really xdiff with adler32 and all the
* overheads but it is a quick and dirty approximation.
*
- * Now we will give some score to it. Let's say 20% edit gets
- * 5000 points and 0% edit gets 9000 points. That is, every
- * 1/20000 edit gets 1 point penalty. The amount of penalty is:
+ * Now we will give some score to it. 100% edit gets
+ * 0 points and 0% edit gets MAX_SCORE points. That is, every
+ * 1/MAX_SCORE edit gets 1 point penalty. The amount of penalty is:
*
- * (delta_size * 2 / (src->size + dst->size)) * 20000
+ * (delta_size * 2 / (src->size + dst->size)) * MAX_SCORE
*
*/
- return 9000 - (40000 * delta_size / (src->size+dst->size));
+ score = MAX_SCORE-(MAX_SCORE*2*delta_size/(src->size+dst->size));
+ if (score < 0) return 0;
+ if (MAX_SCORE < score) return MAX_SCORE;
+ return score;
}
struct diff_score {
@@ -596,14 +611,15 @@
}
static void flush_rename_pair(struct diff_spec_hold *src,
- struct diff_spec_hold *dst)
+ struct diff_spec_hold *dst,
+ int rename_score)
{
src->flags |= MATCHED;
dst->flags |= MATCHED;
free_data(src);
free_data(dst);
run_external_diff(src->path, dst->path,
- &src->it, &dst->it);
+ &src->it, &dst->it, rename_score);
}
static void free_held_diff(struct diff_spec_hold *list)
@@ -637,7 +653,7 @@
continue;
if (! is_exact_match(src, dst))
continue;
- flush_rename_pair(src, dst);
+ flush_rename_pair(src, dst, MAX_SCORE);
break;
}
}
@@ -670,7 +686,7 @@
}
c++;
}
- qsort(mx, num_create*num_delete, sizeof(*mx), score_compare);
+ qsort(mx, num_create*num_delete, sizeof(*mx), score_compare);
#if 0
for (c = 0; c < num_create * num_delete; c++) {
@@ -689,9 +705,9 @@
dst = mx[c].dst;
if ((src->flags & MATCHED) || (dst->flags & MATCHED))
continue;
- if (mx[c].score < diff_rename_minimum_score)
+ if (mx[c].score < minimum_score)
break;
- flush_rename_pair(src, dst);
+ flush_rename_pair(src, dst, mx[c].score);
}
free(mx);
@@ -703,7 +719,26 @@
createdfile = deletedfile = NULL;
}
+int diff_scoreopt_parse(const char *opt)
+{
+ int diglen, num, scale, i;
+ if (opt[0] != '-' || opt[1] != 'M')
+ return -1; /* that is not -M 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 diff_setup(int detect_rename_, int minimum_score_, int reverse_diff_,
+ int diff_raw_output_,
const char **pathspec_, int speccnt_)
{
free_held_diff(createdfile);
@@ -713,8 +748,14 @@
detect_rename = detect_rename_;
reverse_diff = reverse_diff_;
pathspec = pathspec_;
+ diff_raw_output = diff_raw_output_;
speccnt = speccnt_;
- diff_rename_minimum_score = minimum_score_ ? : MINIMUM_SCORE;
+ minimum_score = minimum_score_ ? : DEFAULT_MINIMUM_SCORE;
+}
+
+static const char *git_object_type(unsigned mode)
+{
+ return S_ISDIR(mode) ? "tree" : "blob";
}
void diff_addremove(int addremove, unsigned mode,
@@ -724,6 +765,21 @@
char concatpath[PATH_MAX];
struct diff_spec spec[2], *one, *two;
+ if (0 <= diff_raw_output) {
+ if (!path)
+ path = "";
+ if (reverse_diff)
+ addremove = (addremove == '+' ? '-' : '+');
+ printf("%c%06o %s %s %s%s%c",
+ addremove,
+ mode,
+ git_object_type(mode), sha1_to_hex(sha1),
+ base, path, diff_raw_output);
+ return;
+ }
+ if (S_ISDIR(mode))
+ return;
+
memcpy(spec[0].blob_sha1, sha1, 20);
spec[0].mode = mode;
spec[0].sha1_valid = !!memcmp(sha1, null_sha1, 20);
@@ -750,6 +806,29 @@
char concatpath[PATH_MAX];
struct diff_spec spec[2];
+ if (0 <= diff_raw_output) {
+ char old_hex[41];
+ strcpy(old_hex, sha1_to_hex(old_sha1));
+
+ if (!path)
+ path = "";
+ if (reverse_diff)
+ printf("*%06o->%06o %s %s->%s %s%s%c",
+ new_mode, old_mode,
+ git_object_type(new_mode),
+ sha1_to_hex(new_sha1), old_hex,
+ base, path, diff_raw_output);
+ else
+ printf("*%06o->%06o %s %s->%s %s%s%c",
+ old_mode, new_mode,
+ git_object_type(new_mode),
+ old_hex, sha1_to_hex(new_sha1),
+ base, path, diff_raw_output);
+ return;
+ }
+ if (S_ISDIR(new_mode))
+ return;
+
if (path) {
strcpy(concatpath, base);
strcat(concatpath, path);
@@ -766,10 +845,15 @@
/* We do not look at changed files as candidate for
* rename detection ever.
*/
- run_external_diff(path ? concatpath : base, NULL, &spec[0], &spec[1]);
+ run_external_diff(path ? concatpath : base, NULL,
+ &spec[0], &spec[1], -1);
}
void diff_unmerge(const char *path)
{
- run_external_diff(path, NULL, NULL, NULL);
+ if (0 <= diff_raw_output) {
+ printf("U %s%c", path, diff_raw_output);
+ return;
+ }
+ run_external_diff(path, NULL, NULL, NULL, -1);
}
