undef/git-commit-vandalism
1
0
Fork 0
Code Issues Pull Requests Packages Projects Releases Wiki Activity

[PATCH] Diff-helper update

Browse Source 
This patch adds a framework and a stub implementation of rename
detection to diff-helper program.

The current stub code is just enough to detect pure renames in
diff-tree output and not fancier.  The plan is perhaps to use
the same delta code when Nico's delta storage patch is merged
for similarity evaluation purposes.

Signed-off-by: Junio C Hamano <junkio@cox.net>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
This commit is contained in:
Junio C Hamano 2005-05-17 23:29:49 -07:00 committed by Linus Torvalds
parent e7bd907db6
commit 915838c3cb
4 changed files with 170 additions and 19 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

12
Documentation/git-diff-helper.txt
View File

@ -9,7 +9,7 @@ git-diff-helper - Generates patch format output for git-diff-*
SYNOPSIS
--------
'git-diff-helper' [-z] [-R]
'git-diff-helper' [-z] [-R] [-r]
DESCRIPTION
-----------
@ -28,7 +28,12 @@ OPTIONS
git-diff-cache <tree> | git-diff-helper -R file.c
would show a diff to bring the working file back to what is in the <tree>.
would show a diff to bring the working file back to what
is in the <tree>.
-r::
Detect renames.
See Also
--------
@ -37,7 +42,8 @@ The section on generating patches in link:git-diff-cache.html[git-diff-cache]
Author
------
Written by Linus Torvalds <torvalds@osdl.org>
Written by Junio C Hamano <junkio@cox.net>
Documentation
--------------

141
diff-helper.c
View File

@ -21,6 +21,129 @@ static int matches_pathspec(const char *name, const char **spec, int cnt)
return 0;
}
static int detect_rename = 0;
/*
* We do not detect circular renames. Just hold created and deleted
* entries and later attempt to match them up. If they do not match,
* then spit them out as deletes or creates as original.
*/
static struct diff_spec_hold {
struct diff_spec_hold *next;
struct diff_spec_hold *matched;
struct diff_spec old, new;
char path[1];
} *createdfile, *deletedfile;
static void hold_spec(const char *path,
struct diff_spec *old, struct diff_spec *new)
{
struct diff_spec_hold **list, *elem;
list = (! old->file_valid) ? &createdfile : &deletedfile;
elem = xmalloc(sizeof(*elem) + strlen(path));
strcpy(elem->path, path);
elem->next = *list;
*list = elem;
elem->old = *old;
elem->new = *new;
elem->matched = 0;
}
#define MINIMUM_SCORE 7000
int estimate_similarity(struct diff_spec *one, struct diff_spec *two)
{
/* Return how similar they are, representing the score as an
* integer between 0 and 10000.
*
* This version is very dumb and detects exact matches only.
* Wnen Nico's delta stuff gets in, I'll use the delta
* algorithm to estimate the similarity score in core.
*/
if (one->sha1_valid && two->sha1_valid &&
!memcmp(one->blob_sha1, two->blob_sha1, 20))
return 10000;
return 0;
}
static void flush_renames(const char **spec, int cnt, int reverse)
{
struct diff_spec_hold *rename_src, *rename_dst, *elem;
struct diff_spec_hold *leftover = NULL;
int score, best_score;
while (createdfile) {
rename_dst = createdfile;
createdfile = rename_dst->next;
best_score = MINIMUM_SCORE;
rename_src = NULL;
for (elem = deletedfile;
elem;
elem = elem->next) {
if (elem->matched)
continue;
score = estimate_similarity(&elem->old,
&rename_dst->new);
if (best_score < score) {
rename_src = elem;
best_score = score;
}
}
if (rename_src) {
rename_src->matched = rename_dst;
rename_dst->matched = rename_src;
if (!cnt ||
matches_pathspec(rename_src->path, spec, cnt) ||
matches_pathspec(rename_dst->path, spec, cnt)) {
if (reverse)
run_external_diff(rename_dst->path,
rename_src->path,
&rename_dst->new,
&rename_src->old);
else
run_external_diff(rename_src->path,
rename_dst->path,
&rename_src->old,
&rename_dst->new);
}
}
else {
rename_dst->next = leftover;
leftover = rename_dst;
}
}
/* unmatched deletes */
for (elem = deletedfile; elem; elem = elem->next) {
if (elem->matched)
continue;
if (!cnt ||
matches_pathspec(elem->path, spec, cnt)) {
if (reverse)
run_external_diff(elem->path, NULL,
&elem->new, &elem->old);
else
run_external_diff(elem->path, NULL,
&elem->old, &elem->new);
}
}
/* unmatched creates */
for (elem = leftover; elem; elem = elem->next) {
if (!cnt ||
matches_pathspec(elem->path, spec, cnt)) {
if (reverse)
run_external_diff(elem->path, NULL,
&elem->new, &elem->old);
else
run_external_diff(elem->path, NULL,
&elem->old, &elem->new);
}
}
}
static int parse_oneside_change(const char *cp, struct diff_spec *one,
char *path)
{
@ -100,17 +223,24 @@ static int parse_diff_raw_output(const char *buf,
default:
return -1;
}
if (detect_rename && old.file_valid != new.file_valid) {
/* hold these */
hold_spec(path, &old, &new);
return 0;
}
if (!cnt || matches_pathspec(path, spec, cnt)) {
if (reverse)
run_external_diff(path, &new, &old);
run_external_diff(path, NULL, &new, &old);
else
run_external_diff(path, &old, &new);
run_external_diff(path, NULL, &old, &new);
}
return 0;
}
static const char *diff_helper_usage =
"git-diff-helper [-R] [-z] paths...";
"git-diff-helper [-r] [-R] [-z] paths...";
int main(int ac, const char **av) {
struct strbuf sb;
@ -124,6 +254,8 @@ int main(int ac, const char **av) {
reverse = 1;
else if (av[1][1] == 'z')
line_termination = 0;
else if (av[1][1] == 'r')
detect_rename = 1;
else
usage(diff_helper_usage);
ac--; av++;
@ -139,5 +271,8 @@ int main(int ac, const char **av) {
if (status)
fprintf(stderr, "cannot parse %s\n", sb.buf);
}
if (detect_rename)
flush_renames(av+1, ac-1, reverse);
return 0;
}

34
diff.c
View File

@ -79,7 +79,8 @@ static struct diff_tempfile {
char tmp_path[50];
} diff_temp[2];
static void builtin_diff(const char *name,
static void builtin_diff(const char *name_a,
const char *name_b,
struct diff_tempfile *temp)
{
int i, next_at;
@ -88,9 +89,12 @@ static void builtin_diff(const char *name,
const char *input_name_sq[2];
const char *path0[2];
const char *path1[2];
const char *name_sq = sq_expand(name);
const char *name_sq[2];
char *cmd;
name_sq[0] = sq_expand(name_a);
name_sq[1] = sq_expand(name_b);
/* diff_cmd and diff_arg have 6 %s in total which makes
* the sum of these strings 12 bytes larger than required.
* we use 2 spaces around diff-opts, and we need to count
@ -105,7 +109,7 @@ static void builtin_diff(const char *name,
path1[i] = "";
} else {
path0[i] = i ? "b/" : "a/";
path1[i] = name_sq;
path1[i] = name_sq[i];
}
cmd_size += (strlen(path0[i]) + strlen(path1[i]) +
strlen(input_name_sq[i]));
@ -122,7 +126,7 @@ static void builtin_diff(const char *name,
next_at += snprintf(cmd+next_at, cmd_size-next_at,
diff_arg, input_name_sq[0], input_name_sq[1]);
printf("diff --git a/%s b/%s\n", name, name);
printf("diff --git a/%s b/%s\n", name_a, name_b);
if (!path1[0][0])
printf("new file mode %s\n", temp[1].mode);
else if (!path1[1][0])
@ -132,6 +136,10 @@ static void builtin_diff(const char *name,
printf("old mode %s\n", temp[0].mode);
printf("new mode %s\n", temp[1].mode);
}
if (strcmp(name_a, name_b)) {
printf("rename old %s\n", name_a);
printf("rename new %s\n", name_b);
}
if (strncmp(temp[0].mode, temp[1].mode, 3))
/* we do not run diff between different kind
* of objects.
@ -157,7 +165,7 @@ static int work_tree_matches(const char *name, const unsigned char *sha1)
* benchmark with my previous version that always reads cache
* shows that it makes things worse for diff-tree comparing
* two linux-2.6 kernel trees in an already checked out work
* tree. This is because most diff-tree comparison deals with
* tree. This is because most diff-tree comparisons deal with
* only a small number of files, while reading the cache is
* expensive for a large project, and its cost outweighs the
* savings we get by not inflating the object to a temporary
@ -294,6 +302,7 @@ static void remove_tempfile_on_signal(int signo)
*
*/
void run_external_diff(const char *name,
const char *other,
struct diff_spec *one,
struct diff_spec *two)
{
@ -304,7 +313,7 @@ void run_external_diff(const char *name,
if (one && two) {
prepare_temp_file(name, &temp[0], one);
prepare_temp_file(name, &temp[1], two);
prepare_temp_file(other ? : name, &temp[1], two);
if (! atexit_asked &&
(temp[0].name == temp[0].tmp_path ||
temp[1].name == temp[1].tmp_path)) {
@ -320,7 +329,8 @@ void run_external_diff(const char *name,
die("unable to fork");
if (!pid) {
const char *pgm = external_diff();
if (pgm) {
/* not passing rename patch to external ones */
if (!other && pgm) {
if (one && two)
execlp(pgm, pgm,
name,
@ -334,7 +344,7 @@ void run_external_diff(const char *name,
* otherwise we use the built-in one.
*/
if (one && two)
builtin_diff(name, temp);
builtin_diff(name, other ? : name, temp);
else
printf("* Unmerged path %s\n", name);
exit(0);
@ -379,7 +389,7 @@ void diff_addremove(int addremove, unsigned mode,
strcpy(concatpath, base);
strcat(concatpath, path);
}
run_external_diff(path ? concatpath : base, one, two);
run_external_diff(path ? concatpath : base, NULL, one, two);
}
void diff_change(unsigned old_mode, unsigned new_mode,
@ -400,10 +410,10 @@ void diff_change(unsigned old_mode, unsigned new_mode,
strcpy(concatpath, base);
strcat(concatpath, path);
}
run_external_diff(path ? concatpath : base, &spec[0], &spec[1]);
run_external_diff(path ? concatpath : base, NULL, &spec[0], &spec[1]);
}
void diff_unmerge(const char *path)
{
run_external_diff(path, NULL, NULL);
run_external_diff(path, NULL, NULL, NULL);
}

2
diff.h
View File

@ -31,7 +31,7 @@ struct diff_spec {
unsigned file_valid : 1; /* if false the file does not even exist */
};
extern void run_external_diff(const char *name,
extern void run_external_diff(const char *name, const char *other,
struct diff_spec *, struct diff_spec *);
#endif /* DIFF_H */