git/builtin/range-diff.c
Johannes Schindelin b75747829f range-diff: optionally accept pathspecs
The `git range-diff` command can be quite expensive, which is not a
surprise given that the underlying algorithm to match up pairs of
commits between the provided two commit ranges has a cubic runtime.

Therefore it makes sense to restrict the commit ranges as much as
possible, to reduce the amount of input to that O(N^3) algorithm.

In chatty repositories with wide trees, this is not necessarily
possible merely by choosing commit ranges wisely.

Let's give users another option to restrict the commit ranges: by
providing a pathspec. That helps in repositories with wide trees because
it is likely that the user has a good idea which subset of the tree they
are actually interested in.

Example:

	git range-diff upstream/main upstream/seen HEAD -- range-diff.c

This shows commits that are either in the local branch or in `seen`, but
not in `main`, skipping all commits that do not touch `range-diff.c`.

Note: Since we piggy-back the pathspecs onto the `other_arg` mechanism
that was introduced to be able to pass through the `--notes` option to
the revision machinery, we must now ensure that the `other_arg` array is
appended at the end (the revision range must come before the pathspecs,
if any).

Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2022-08-26 09:49:26 -07:00

157 lines
4.6 KiB
C

#include "cache.h"
#include "builtin.h"
#include "parse-options.h"
#include "range-diff.h"
#include "config.h"
#include "revision.h"
static const char * const builtin_range_diff_usage[] = {
N_("git range-diff [<options>] <old-base>..<old-tip> <new-base>..<new-tip>"),
N_("git range-diff [<options>] <old-tip>...<new-tip>"),
N_("git range-diff [<options>] <base> <old-tip> <new-tip>"),
NULL
};
int cmd_range_diff(int argc, const char **argv, const char *prefix)
{
struct diff_options diffopt = { NULL };
struct strvec other_arg = STRVEC_INIT;
struct range_diff_options range_diff_opts = {
.creation_factor = RANGE_DIFF_CREATION_FACTOR_DEFAULT,
.diffopt = &diffopt,
.other_arg = &other_arg
};
int simple_color = -1, left_only = 0, right_only = 0;
struct option range_diff_options[] = {
OPT_INTEGER(0, "creation-factor",
&range_diff_opts.creation_factor,
N_("percentage by which creation is weighted")),
OPT_BOOL(0, "no-dual-color", &simple_color,
N_("use simple diff colors")),
OPT_PASSTHRU_ARGV(0, "notes", &other_arg,
N_("notes"), N_("passed to 'git log'"),
PARSE_OPT_OPTARG),
OPT_BOOL(0, "left-only", &left_only,
N_("only emit output related to the first range")),
OPT_BOOL(0, "right-only", &right_only,
N_("only emit output related to the second range")),
OPT_END()
};
struct option *options;
int i, dash_dash = -1, res = 0;
struct strbuf range1 = STRBUF_INIT, range2 = STRBUF_INIT;
struct object_id oid;
const char *three_dots = NULL;
git_config(git_diff_ui_config, NULL);
repo_diff_setup(the_repository, &diffopt);
options = parse_options_concat(range_diff_options, diffopt.parseopts);
argc = parse_options(argc, argv, prefix, options,
builtin_range_diff_usage, PARSE_OPT_KEEP_DASHDASH);
diff_setup_done(&diffopt);
/* force color when --dual-color was used */
if (!simple_color)
diffopt.use_color = 1;
for (i = 0; i < argc; i++)
if (!strcmp(argv[i], "--")) {
dash_dash = i;
break;
}
if (dash_dash == 3 ||
(dash_dash < 0 && argc > 2 &&
!get_oid_committish(argv[0], &oid) &&
!get_oid_committish(argv[1], &oid) &&
!get_oid_committish(argv[2], &oid))) {
if (dash_dash < 0)
; /* already validated arguments */
else if (get_oid_committish(argv[0], &oid))
usage_msg_optf(_("not a revision: '%s'"),
builtin_range_diff_usage, options,
argv[0]);
else if (get_oid_committish(argv[1], &oid))
usage_msg_optf(_("not a revision: '%s'"),
builtin_range_diff_usage, options,
argv[1]);
else if (get_oid_committish(argv[2], &oid))
usage_msg_optf(_("not a revision: '%s'"),
builtin_range_diff_usage, options,
argv[2]);
strbuf_addf(&range1, "%s..%s", argv[0], argv[1]);
strbuf_addf(&range2, "%s..%s", argv[0], argv[2]);
strvec_pushv(&other_arg, argv +
(dash_dash < 0 ? 3 : dash_dash));
} else if (dash_dash == 2 ||
(dash_dash < 0 && argc > 1 &&
is_range_diff_range(argv[0]) &&
is_range_diff_range(argv[1]))) {
if (dash_dash < 0)
; /* already validated arguments */
else if (!is_range_diff_range(argv[0]))
usage_msg_optf(_("not a commit range: '%s'"),
builtin_range_diff_usage, options,
argv[0]);
else if (!is_range_diff_range(argv[1]))
usage_msg_optf(_("not a commit range: '%s'"),
builtin_range_diff_usage, options,
argv[1]);
strbuf_addstr(&range1, argv[0]);
strbuf_addstr(&range2, argv[1]);
strvec_pushv(&other_arg, argv +
(dash_dash < 0 ? 2 : dash_dash));
} else if (dash_dash == 1 ||
(dash_dash < 0 && argc > 0 &&
(three_dots = strstr(argv[0], "...")))) {
const char *a, *b;
int a_len;
if (dash_dash < 0)
; /* already validated arguments */
else if (!(three_dots = strstr(argv[0], "...")))
usage_msg_optf(_("not a symmetric range: '%s'"),
builtin_range_diff_usage, options,
argv[0]);
if (three_dots == argv[0]) {
a = "HEAD";
a_len = strlen(a);
} else {
a = argv[0];
a_len = (int)(three_dots - a);
}
if (three_dots[3])
b = three_dots + 3;
else
b = "HEAD";
strbuf_addf(&range1, "%s..%.*s", b, a_len, a);
strbuf_addf(&range2, "%.*s..%s", a_len, a, b);
strvec_pushv(&other_arg, argv +
(dash_dash < 0 ? 1 : dash_dash));
} else
usage_msg_opt(_("need two commit ranges"),
builtin_range_diff_usage, options);
FREE_AND_NULL(options);
range_diff_opts.dual_color = simple_color < 1;
range_diff_opts.left_only = left_only;
range_diff_opts.right_only = right_only;
res = show_range_diff(range1.buf, range2.buf, &range_diff_opts);
strvec_clear(&other_arg);
strbuf_release(&range1);
strbuf_release(&range2);
return res;
}