git/builtin/range-diff.c
Johannes Schindelin d9c66f0b5b range-diff: first rudimentary implementation
At this stage, `git range-diff` can determine corresponding commits
of two related commit ranges. This makes use of the recently introduced
implementation of the linear assignment algorithm.

The core of this patch is a straight port of the ideas of tbdiff, the
apparently dormant project at https://github.com/trast/tbdiff.

The output does not at all match `tbdiff`'s output yet, as this patch
really concentrates on getting the patch matching part right.

Note: due to differences in the diff algorithm (`tbdiff` uses the Python
module `difflib`, Git uses its xdiff fork), the cost matrix calculated
by `range-diff` is different (but very similar) to the one calculated
by `tbdiff`. Therefore, it is possible that they find different matching
commits in corner cases (e.g. when a patch was split into two patches of
roughly equal length).

Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2018-08-13 10:44:50 -07:00

69 lines
1.8 KiB
C

#include "cache.h"
#include "builtin.h"
#include "parse-options.h"
#include "range-diff.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)
{
int creation_factor = 60;
struct option options[] = {
OPT_INTEGER(0, "creation-factor", &creation_factor,
N_("Percentage by which creation is weighted")),
OPT_END()
};
int res = 0;
struct strbuf range1 = STRBUF_INIT, range2 = STRBUF_INIT;
argc = parse_options(argc, argv, NULL, options,
builtin_range_diff_usage, 0);
if (argc == 2) {
if (!strstr(argv[0], ".."))
die(_("no .. in range: '%s'"), argv[0]);
strbuf_addstr(&range1, argv[0]);
if (!strstr(argv[1], ".."))
die(_("no .. in range: '%s'"), argv[1]);
strbuf_addstr(&range2, argv[1]);
} else if (argc == 3) {
strbuf_addf(&range1, "%s..%s", argv[0], argv[1]);
strbuf_addf(&range2, "%s..%s", argv[0], argv[2]);
} else if (argc == 1) {
const char *b = strstr(argv[0], "..."), *a = argv[0];
int a_len;
if (!b) {
error(_("single arg format must be symmetric range"));
usage_with_options(builtin_range_diff_usage, options);
}
a_len = (int)(b - a);
if (!a_len) {
a = "HEAD";
a_len = strlen(a);
}
b += 3;
if (!*b)
b = "HEAD";
strbuf_addf(&range1, "%s..%.*s", b, a_len, a);
strbuf_addf(&range2, "%.*s..%s", a_len, a, b);
} else {
error(_("need two commit ranges"));
usage_with_options(builtin_range_diff_usage, options);
}
res = show_range_diff(range1.buf, range2.buf, creation_factor);
strbuf_release(&range1);
strbuf_release(&range2);
return res;
}