git/builtin-diff.c
Linus Torvalds 885a86abe2 Shrink "struct object" a bit
This shrinks "struct object" by a small amount, by getting rid of the
"struct type *" pointer and replacing it with a 3-bit bitfield instead.

In addition, we merge the bitfields and the "flags" field, which
incidentally should also remove a useless 4-byte padding from the object
when in 64-bit mode.

Now, our "struct object" is still too damn large, but it's now less
obviously bloated, and of the remaining fields, only the "util" (which is
not used by most things) is clearly something that should be eventually
discarded.

This shrinks the "git-rev-list --all" memory use by about 2.5% on the
kernel archive (and, perhaps more importantly, on the larger mozilla
archive). That may not sound like much, but I suspect it's more on a
64-bit platform.

There are other remaining inefficiencies (the parent lists, for example,
probably have horrible malloc overhead), but this was pretty obvious.

Most of the patch is just changing the comparison of the "type" pointer
from one of the constant string pointers to the appropriate new TYPE_xxx
small integer constant.

Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Signed-off-by: Junio C Hamano <junkio@cox.net>
2006-06-17 18:49:18 -07:00

371 lines
9.2 KiB
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[] =
"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 if (!strcmp(arg, "--raw"))
revs->diffopt.output_format = DIFF_FORMAT_RAW;
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_objects ||
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;
while (1 < argc) {
const char *arg = argv[1];
if (!strcmp(arg, "--raw"))
revs->diffopt.output_format = DIFF_FORMAT_RAW;
else
usage(builtin_diff_usage);
argv++; argc--;
}
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)
{
/* Blobs: the arguments are reversed when setup_revisions()
* picked them up.
*/
unsigned mode = canon_mode(S_IFREG | 0644);
while (1 < argc) {
const char *arg = argv[1];
if (!strcmp(arg, "--raw"))
revs->diffopt.output_format = DIFF_FORMAT_RAW;
else
usage(builtin_diff_usage);
argv++; argc--;
}
stuff_change(&revs->diffopt,
mode, mode,
blob[1].sha1, blob[0].sha1,
blob[0].name, blob[0].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 if (!strcmp(arg, "--raw"))
revs->diffopt.output_format = DIFF_FORMAT_RAW;
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_objects || revs->pending_objects->next ||
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_list *ent)
{
const unsigned char *(sha1[2]);
int swap = 1;
while (1 < argc) {
const char *arg = argv[1];
if (!strcmp(arg, "--raw"))
revs->diffopt.output_format = DIFF_FORMAT_RAW;
else
usage(builtin_diff_usage);
argv++; argc--;
}
/* We saw two trees, ent[0] and ent[1].
* unless ent[0] is unintesting, they are swapped
*/
if (ent[0].item->flags & UNINTERESTING)
swap = 0;
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_list *ent,
int ents)
{
const unsigned char (*parent)[20];
int i;
while (1 < argc) {
const char *arg = argv[1];
if (!strcmp(arg, "--raw"))
revs->diffopt.output_format = DIFF_FORMAT_RAW;
else
usage(builtin_diff_usage);
argv++; argc--;
}
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_object(obj, &revs->pending_objects, NULL, "HEAD");
}
int cmd_diff(int argc, const char **argv, char **envp)
{
struct rev_info rev;
struct object_list *list, 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_config);
init_revisions(&rev);
rev.diffopt.output_format = DIFF_FORMAT_PATCH;
argc = setup_revisions(argc, argv, &rev, NULL);
/* Do we have --cached and not have a pending object, then
* default to HEAD by hand. Eek.
*/
if (!rev.pending_objects) {
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 (list = rev.pending_objects; list; list = list->next) {
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 == TYPE_COMMIT)
obj = &((struct commit *)obj)->tree->object;
if (obj->type == TYPE_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 == TYPE_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
return builtin_diff_combined(&rev, argc, argv, ent, ents);
usage(builtin_diff_usage);
}