From be819f880bde3be26f6f5db2952016e950a1530f Mon Sep 17 00:00:00 2001 From: Johannes Schindelin Date: Tue, 12 Apr 2016 16:02:27 +0200 Subject: [PATCH 1/2] Add a builtin helper for interactive rebases Git's interactive rebase is still implemented as a shell script, despite its complexity. This implies that it suffers from the portability point of view, from lack of expressibility, and of course also from performance. The latter issue is particularly serious on Windows, where we pay a hefty price for relying so much on POSIX. Unfortunately, being such a huge shell script also means that we missed the train when it would have been relatively easy to port it to C, and instead piled feature upon feature onto that poor script that originally never intended to be more than a slightly pimped cherry-pick in a loop. To open the road toward better performance (in addition to all the other benefits of C over shell scripts), let's just start *somewhere*. The approach taken here is to add a builtin helper that at first intends to take care of the parts of the interactive rebase that are most affected by the performance penalties mentioned above. In particular, after we spent all those efforts on preparing the sequencer to process rebase -i's git-rebase-todo scripts, we implement the `git rebase -i --continue` functionality as a new builtin, git-rebase--helper. Once that is in place, we can work gradually on tackling the rest of the technical debt. Note that the rebase--helper needs to learn about the transient --ff/--no-ff options of git-rebase, as the corresponding flag is not persisted to, and re-read from, the state directory. Signed-off-by: Johannes Schindelin --- .gitignore | 1 + Makefile | 1 + builtin.h | 1 + builtin/rebase--helper.c | 40 ++++++++++++++++++++++++++++++++++++++++ git.c | 1 + 5 files changed, 44 insertions(+) create mode 100644 builtin/rebase--helper.c diff --git a/.gitignore b/.gitignore index 05cb58a3d4..a9b8c968c9 100644 --- a/.gitignore +++ b/.gitignore @@ -114,6 +114,7 @@ /git-read-tree /git-rebase /git-rebase--am +/git-rebase--helper /git-rebase--interactive /git-rebase--merge /git-receive-pack diff --git a/Makefile b/Makefile index 7a36af8665..e14744bc87 100644 --- a/Makefile +++ b/Makefile @@ -925,6 +925,7 @@ BUILTIN_OBJS += builtin/prune.o BUILTIN_OBJS += builtin/pull.o BUILTIN_OBJS += builtin/push.o BUILTIN_OBJS += builtin/read-tree.o +BUILTIN_OBJS += builtin/rebase--helper.o BUILTIN_OBJS += builtin/receive-pack.o BUILTIN_OBJS += builtin/reflog.o BUILTIN_OBJS += builtin/remote.o diff --git a/builtin.h b/builtin.h index 6b95006a0a..2e5de141eb 100644 --- a/builtin.h +++ b/builtin.h @@ -102,6 +102,7 @@ extern int cmd_prune_packed(int argc, const char **argv, const char *prefix); extern int cmd_pull(int argc, const char **argv, const char *prefix); extern int cmd_push(int argc, const char **argv, const char *prefix); extern int cmd_read_tree(int argc, const char **argv, const char *prefix); +extern int cmd_rebase__helper(int argc, const char **argv, const char *prefix); extern int cmd_receive_pack(int argc, const char **argv, const char *prefix); extern int cmd_reflog(int argc, const char **argv, const char *prefix); extern int cmd_remote(int argc, const char **argv, const char *prefix); diff --git a/builtin/rebase--helper.c b/builtin/rebase--helper.c new file mode 100644 index 0000000000..ca1ebb2fa1 --- /dev/null +++ b/builtin/rebase--helper.c @@ -0,0 +1,40 @@ +#include "builtin.h" +#include "cache.h" +#include "parse-options.h" +#include "sequencer.h" + +static const char * const builtin_rebase_helper_usage[] = { + N_("git rebase--helper []"), + NULL +}; + +int cmd_rebase__helper(int argc, const char **argv, const char *prefix) +{ + struct replay_opts opts = REPLAY_OPTS_INIT; + enum { + CONTINUE = 1, ABORT + } command = 0; + struct option options[] = { + OPT_BOOL(0, "ff", &opts.allow_ff, N_("allow fast-forward")), + OPT_CMDMODE(0, "continue", &command, N_("continue rebase"), + CONTINUE), + OPT_CMDMODE(0, "abort", &command, N_("abort rebase"), + ABORT), + 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); + usage_with_options(builtin_rebase_helper_usage, options); +} diff --git a/git.c b/git.c index 0f1937fd0c..26b4ad3bee 100644 --- a/git.c +++ b/git.c @@ -451,6 +451,7 @@ static struct cmd_struct commands[] = { { "pull", cmd_pull, RUN_SETUP | NEED_WORK_TREE }, { "push", cmd_push, RUN_SETUP }, { "read-tree", cmd_read_tree, RUN_SETUP }, + { "rebase--helper", cmd_rebase__helper, RUN_SETUP | NEED_WORK_TREE }, { "receive-pack", cmd_receive_pack }, { "reflog", cmd_reflog, RUN_SETUP }, { "remote", cmd_remote, RUN_SETUP }, From 09d4656ba1a69767c617bfc115b0cfac374a1207 Mon Sep 17 00:00:00 2001 From: Johannes Schindelin Date: Mon, 28 Mar 2016 13:34:50 +0200 Subject: [PATCH 2/2] rebase -i: use the rebase--helper builtin Now that the sequencer learned to process a "normal" interactive rebase, we use it. The original shell script is still used for "non-normal" interactive rebases, i.e. when --root or --preserve-merges was passed. Please note that the --root option (via the $squash_onto variable) needs special handling only for the very first command, hence it is still okay to use the helper upon continue/skip. Also please note that the --no-ff setting is volatile, i.e. when the interactive rebase is interrupted at any stage, there is no record of it. Therefore, we have to pass it from the shell script to the rebase--helper. Signed-off-by: Johannes Schindelin --- git-rebase--interactive.sh | 13 +++++++++++++ 1 file changed, 13 insertions(+) diff --git a/git-rebase--interactive.sh b/git-rebase--interactive.sh index ca994c5c54..88e6d97e0c 100644 --- a/git-rebase--interactive.sh +++ b/git-rebase--interactive.sh @@ -1059,6 +1059,10 @@ git_rebase__interactive () { case "$action" in continue) + if test ! -d "$rewritten" + then + exec git rebase--helper ${force_rebase:+--no-ff} --continue + fi # do we have anything to commit? if git diff-index --cached --quiet HEAD -- then @@ -1118,6 +1122,10 @@ first and then run 'git rebase --continue' again.")" skip) git rerere clear + if test ! -d "$rewritten" + then + exec git rebase--helper ${force_rebase:+--no-ff} --continue + fi do_rest return 0 ;; @@ -1304,6 +1312,11 @@ expand_todo_ids test -d "$rewritten" || test -n "$force_rebase" || skip_unnecessary_picks checkout_onto +if test -z "$rebase_root" && test ! -d "$rewritten" +then + require_clean_work_tree "rebase" + exec git rebase--helper ${force_rebase:+--no-ff} --continue +fi do_rest }