Revision 9de0834663f28bee9e6b2c4647ed6128241ed26f authored by Linus Torvalds on 17 October 2006, 02:58:54 UTC, committed by Junio C Hamano on 17 October 2006, 04:27:44 UTC
Jim Mayering noticed that xdiff library took insanely long time when comparing files with many identical lines. This was because the hash function used in the library is broken on 64-bit architectures and caused too many collisions. http://thread.gmane.org/gmane.comp.version-control.git/28962/focus=28994 Acked-by: Davide Libenzi <davidel@xmaliserver.org> Signed-off-by: Junio C Hamano <junkio@cox.net>
1 parent 6fe5b7f
builtin-diff.c
/*
* Builtin "git diff"
*
* Copyright (c) 2006 Junio C Hamano
*/
#include "cache.h"
#include "commit.h"
#include "blob.h"
#include "tag.h"
#include "diff.h"
#include "diffcore.h"
#include "revision.h"
#include "log-tree.h"
#include "builtin.h"
/* NEEDSWORK: struct object has place for name but we _do_
* know mode when we extracted the blob out of a tree, which
* we currently lose.
*/
struct blobinfo {
unsigned char sha1[20];
const char *name;
};
static const char builtin_diff_usage[] =
"git-diff <options> <rev>{0,2} -- <path>*";
static int builtin_diff_files(struct rev_info *revs,
int argc, const char **argv)
{
int silent = 0;
while (1 < argc) {
const char *arg = argv[1];
if (!strcmp(arg, "--base"))
revs->max_count = 1;
else if (!strcmp(arg, "--ours"))
revs->max_count = 2;
else if (!strcmp(arg, "--theirs"))
revs->max_count = 3;
else if (!strcmp(arg, "-q"))
silent = 1;
else
usage(builtin_diff_usage);
argv++; argc--;
}
/*
* Make sure there are NO revision (i.e. pending object) parameter,
* specified rev.max_count is reasonable (0 <= n <= 3), and
* there is no other revision filtering parameter.
*/
if (revs->pending.nr ||
revs->min_age != -1 ||
revs->max_age != -1 ||
3 < revs->max_count)
usage(builtin_diff_usage);
if (revs->max_count < 0 &&
(revs->diffopt.output_format & DIFF_FORMAT_PATCH))
revs->combine_merges = revs->dense_combined_merges = 1;
/*
* Backward compatibility wart - "diff-files -s" used to
* defeat the common diff option "-s" which asked for
* DIFF_FORMAT_NO_OUTPUT.
*/
if (revs->diffopt.output_format == DIFF_FORMAT_NO_OUTPUT)
revs->diffopt.output_format = DIFF_FORMAT_RAW;
return run_diff_files(revs, silent);
}
static void stuff_change(struct diff_options *opt,
unsigned old_mode, unsigned new_mode,
const unsigned char *old_sha1,
const unsigned char *new_sha1,
const char *old_name,
const char *new_name)
{
struct diff_filespec *one, *two;
if (memcmp(null_sha1, old_sha1, 20) &&
memcmp(null_sha1, new_sha1, 20) &&
!memcmp(old_sha1, new_sha1, 20))
return;
if (opt->reverse_diff) {
unsigned tmp;
const unsigned char *tmp_u;
const char *tmp_c;
tmp = old_mode; old_mode = new_mode; new_mode = tmp;
tmp_u = old_sha1; old_sha1 = new_sha1; new_sha1 = tmp_u;
tmp_c = old_name; old_name = new_name; new_name = tmp_c;
}
one = alloc_filespec(old_name);
two = alloc_filespec(new_name);
fill_filespec(one, old_sha1, old_mode);
fill_filespec(two, new_sha1, new_mode);
/* NEEDSWORK: shouldn't this part of diffopt??? */
diff_queue(&diff_queued_diff, one, two);
}
static int builtin_diff_b_f(struct rev_info *revs,
int argc, const char **argv,
struct blobinfo *blob,
const char *path)
{
/* Blob vs file in the working tree*/
struct stat st;
if (argc > 1)
usage(builtin_diff_usage);
if (lstat(path, &st))
die("'%s': %s", path, strerror(errno));
if (!(S_ISREG(st.st_mode) || S_ISLNK(st.st_mode)))
die("'%s': not a regular file or symlink", path);
stuff_change(&revs->diffopt,
canon_mode(st.st_mode), canon_mode(st.st_mode),
blob[0].sha1, null_sha1,
path, path);
diffcore_std(&revs->diffopt);
diff_flush(&revs->diffopt);
return 0;
}
static int builtin_diff_blobs(struct rev_info *revs,
int argc, const char **argv,
struct blobinfo *blob)
{
unsigned mode = canon_mode(S_IFREG | 0644);
if (argc > 1)
usage(builtin_diff_usage);
stuff_change(&revs->diffopt,
mode, mode,
blob[0].sha1, blob[1].sha1,
blob[0].name, blob[1].name);
diffcore_std(&revs->diffopt);
diff_flush(&revs->diffopt);
return 0;
}
static int builtin_diff_index(struct rev_info *revs,
int argc, const char **argv)
{
int cached = 0;
while (1 < argc) {
const char *arg = argv[1];
if (!strcmp(arg, "--cached"))
cached = 1;
else
usage(builtin_diff_usage);
argv++; argc--;
}
/*
* Make sure there is one revision (i.e. pending object),
* and there is no revision filtering parameters.
*/
if (revs->pending.nr != 1 ||
revs->max_count != -1 || revs->min_age != -1 ||
revs->max_age != -1)
usage(builtin_diff_usage);
return run_diff_index(revs, cached);
}
static int builtin_diff_tree(struct rev_info *revs,
int argc, const char **argv,
struct object_array_entry *ent)
{
const unsigned char *(sha1[2]);
int swap = 0;
if (argc > 1)
usage(builtin_diff_usage);
/* We saw two trees, ent[0] and ent[1].
* if ent[1] is uninteresting, they are swapped
*/
if (ent[1].item->flags & UNINTERESTING)
swap = 1;
sha1[swap] = ent[0].item->sha1;
sha1[1-swap] = ent[1].item->sha1;
diff_tree_sha1(sha1[0], sha1[1], "", &revs->diffopt);
log_tree_diff_flush(revs);
return 0;
}
static int builtin_diff_combined(struct rev_info *revs,
int argc, const char **argv,
struct object_array_entry *ent,
int ents)
{
const unsigned char (*parent)[20];
int i;
if (argc > 1)
usage(builtin_diff_usage);
if (!revs->dense_combined_merges && !revs->combine_merges)
revs->dense_combined_merges = revs->combine_merges = 1;
parent = xmalloc(ents * sizeof(*parent));
/* Again, the revs are all reverse */
for (i = 0; i < ents; i++)
memcpy(parent + i, ent[ents - 1 - i].item->sha1, 20);
diff_tree_combined(parent[0], parent + 1, ents - 1,
revs->dense_combined_merges, revs);
return 0;
}
void add_head(struct rev_info *revs)
{
unsigned char sha1[20];
struct object *obj;
if (get_sha1("HEAD", sha1))
return;
obj = parse_object(sha1);
if (!obj)
return;
add_pending_object(revs, obj, "HEAD");
}
int cmd_diff(int argc, const char **argv, const char *prefix)
{
int i;
struct rev_info rev;
struct object_array_entry ent[100];
int ents = 0, blobs = 0, paths = 0;
const char *path = NULL;
struct blobinfo blob[2];
/*
* We could get N tree-ish in the rev.pending_objects list.
* Also there could be M blobs there, and P pathspecs.
*
* N=0, M=0:
* cache vs files (diff-files)
* N=0, M=2:
* compare two random blobs. P must be zero.
* N=0, M=1, P=1:
* compare a blob with a working tree file.
*
* N=1, M=0:
* tree vs cache (diff-index --cached)
*
* N=2, M=0:
* tree vs tree (diff-tree)
*
* Other cases are errors.
*/
git_config(git_diff_ui_config);
init_revisions(&rev, prefix);
argc = setup_revisions(argc, argv, &rev, NULL);
if (!rev.diffopt.output_format) {
rev.diffopt.output_format = DIFF_FORMAT_PATCH;
if (diff_setup_done(&rev.diffopt) < 0)
die("diff_setup_done failed");
}
/* Do we have --cached and not have a pending object, then
* default to HEAD by hand. Eek.
*/
if (!rev.pending.nr) {
int i;
for (i = 1; i < argc; i++) {
const char *arg = argv[i];
if (!strcmp(arg, "--"))
break;
else if (!strcmp(arg, "--cached")) {
add_head(&rev);
break;
}
}
}
for (i = 0; i < rev.pending.nr; i++) {
struct object_array_entry *list = rev.pending.objects+i;
struct object *obj = list->item;
const char *name = list->name;
int flags = (obj->flags & UNINTERESTING);
if (!obj->parsed)
obj = parse_object(obj->sha1);
obj = deref_tag(obj, NULL, 0);
if (!obj)
die("invalid object '%s' given.", name);
if (obj->type == OBJ_COMMIT)
obj = &((struct commit *)obj)->tree->object;
if (obj->type == OBJ_TREE) {
if (ARRAY_SIZE(ent) <= ents)
die("more than %d trees given: '%s'",
(int) ARRAY_SIZE(ent), name);
obj->flags |= flags;
ent[ents].item = obj;
ent[ents].name = name;
ents++;
continue;
}
if (obj->type == OBJ_BLOB) {
if (2 <= blobs)
die("more than two blobs given: '%s'", name);
memcpy(blob[blobs].sha1, obj->sha1, 20);
blob[blobs].name = name;
blobs++;
continue;
}
die("unhandled object '%s' given.", name);
}
if (rev.prune_data) {
const char **pathspec = rev.prune_data;
while (*pathspec) {
if (!path)
path = *pathspec;
paths++;
pathspec++;
}
}
/*
* Now, do the arguments look reasonable?
*/
if (!ents) {
switch (blobs) {
case 0:
return builtin_diff_files(&rev, argc, argv);
break;
case 1:
if (paths != 1)
usage(builtin_diff_usage);
return builtin_diff_b_f(&rev, argc, argv, blob, path);
break;
case 2:
if (paths)
usage(builtin_diff_usage);
return builtin_diff_blobs(&rev, argc, argv, blob);
break;
default:
usage(builtin_diff_usage);
}
}
else if (blobs)
usage(builtin_diff_usage);
else if (ents == 1)
return builtin_diff_index(&rev, argc, argv);
else if (ents == 2)
return builtin_diff_tree(&rev, argc, argv, ent);
else if ((ents == 3) && (ent[0].item->flags & UNINTERESTING)) {
/* diff A...B where there is one sane merge base between
* A and B. We have ent[0] == merge-base, ent[1] == A,
* and ent[2] == B. Show diff between the base and B.
*/
ent[1] = ent[2];
return builtin_diff_tree(&rev, argc, argv, ent);
}
else
return builtin_diff_combined(&rev, argc, argv,
ent, ents);
usage(builtin_diff_usage);
}
![swh spinner](/static/img/swh-spinner.gif)
Computing file changes ...