git/builtin/rebase--helper.c
Johannes Schindelin c44a4c650c rebase -i: rearrange fixup/squash lines using the rebase--helper
This operation has quadratic complexity, which is especially painful
on Windows, where shell scripts are *already* slow (mainly due to the
overhead of the POSIX emulation layer).

Let's reimplement this with linear complexity (using a hash map to
match the commits' subject lines) for the common case; Sadly, the
fixup/squash feature's design neglected performance considerations,
allowing arbitrary prefixes (read: `fixup! hell` will match the
commit subject `hello world`), which means that we are stuck with
quadratic performance in the worst case.

The reimplemented logic also happens to fix a bug where commented-out
lines (representing empty patches) were dropped by the previous code.

While at it, clarify how the fixup/squash feature works in `git rebase
-i`'s man page.

Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2017-07-27 15:35:06 -07:00

68 lines
2.3 KiB
C

#include "builtin.h"
#include "cache.h"
#include "config.h"
#include "parse-options.h"
#include "sequencer.h"
static const char * const builtin_rebase_helper_usage[] = {
N_("git rebase--helper [<options>]"),
NULL
};
int cmd_rebase__helper(int argc, const char **argv, const char *prefix)
{
struct replay_opts opts = REPLAY_OPTS_INIT;
int keep_empty = 0;
enum {
CONTINUE = 1, ABORT, MAKE_SCRIPT, SHORTEN_SHA1S, EXPAND_SHA1S,
CHECK_TODO_LIST, SKIP_UNNECESSARY_PICKS, REARRANGE_SQUASH
} command = 0;
struct option options[] = {
OPT_BOOL(0, "ff", &opts.allow_ff, N_("allow fast-forward")),
OPT_BOOL(0, "keep-empty", &keep_empty, N_("keep empty commits")),
OPT_CMDMODE(0, "continue", &command, N_("continue rebase"),
CONTINUE),
OPT_CMDMODE(0, "abort", &command, N_("abort rebase"),
ABORT),
OPT_CMDMODE(0, "make-script", &command,
N_("make rebase script"), MAKE_SCRIPT),
OPT_CMDMODE(0, "shorten-ids", &command,
N_("shorten SHA-1s in the todo list"), SHORTEN_SHA1S),
OPT_CMDMODE(0, "expand-ids", &command,
N_("expand SHA-1s in the todo list"), EXPAND_SHA1S),
OPT_CMDMODE(0, "check-todo-list", &command,
N_("check the todo list"), CHECK_TODO_LIST),
OPT_CMDMODE(0, "skip-unnecessary-picks", &command,
N_("skip unnecessary picks"), SKIP_UNNECESSARY_PICKS),
OPT_CMDMODE(0, "rearrange-squash", &command,
N_("rearrange fixup/squash lines"), REARRANGE_SQUASH),
OPT_END()
};
git_config(git_default_config, NULL);
opts.action = REPLAY_INTERACTIVE_REBASE;
opts.allow_ff = 1;
opts.allow_empty = 1;
argc = parse_options(argc, argv, NULL, options,
builtin_rebase_helper_usage, PARSE_OPT_KEEP_ARGV0);
if (command == CONTINUE && argc == 1)
return !!sequencer_continue(&opts);
if (command == ABORT && argc == 1)
return !!sequencer_remove_state(&opts);
if (command == MAKE_SCRIPT && argc > 1)
return !!sequencer_make_script(keep_empty, stdout, argc, argv);
if (command == SHORTEN_SHA1S && argc == 1)
return !!transform_todo_ids(1);
if (command == EXPAND_SHA1S && argc == 1)
return !!transform_todo_ids(0);
if (command == CHECK_TODO_LIST && argc == 1)
return !!check_todo_list();
if (command == SKIP_UNNECESSARY_PICKS && argc == 1)
return !!skip_unnecessary_picks();
if (command == REARRANGE_SQUASH && argc == 1)
return !!rearrange_squash();
usage_with_options(builtin_rebase_helper_usage, options);
}