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.
Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
In particular on Windows, where shell scripts are even more expensive
than on MacOSX or Linux, it makes sense to move a loop that forks
Git at least once for every line in the todo list into a builtin.
Note: The original code did not try to skip unnecessary picks of root
commits but punts instead (probably --root was not considered common
enough of a use case to bother optimizing). We do the same, for now.
Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
In particular on Windows, where shell scripts are even more expensive
than on MacOSX or Linux, it makes sense to move a loop that forks
Git at least once for every line in the todo list into a builtin.
Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
This is crucial to improve performance on Windows, as the speed is now
mostly dominated by the SHA-1 transformation (because it spawns a new
rev-parse process for *every* line, and spawning processes is pretty
slow from Git for Windows' MSYS2 Bash).
Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
The first step of an interactive rebase is to generate the so-called "todo
script", to be stored in the state directory as "git-rebase-todo" and to
be edited by the user.
Originally, we adjusted the output of `git log <options>` using a simple
sed script. Over the course of the years, the code became more
complicated. We now use shell scripting to edit the output of `git log`
conditionally, depending whether to keep "empty" commits (i.e. commits
that do not change any files).
On platforms where shell scripting is not native, this can be a serious
drag. And it opens the door for incompatibilities between platforms when
it comes to shell scripting or to Unix-y commands.
Let's just re-implement the todo script generation in plain C, using the
revision machinery directly.
This is substantially faster, improving the speed relative to the
shell script version of the interactive rebase from 2x to 3x on Windows.
Note that the rearrange_squash() function in git-rebase--interactive
relied on the fact that we set the "format" variable to the config setting
rebase.instructionFormat. Relying on a side effect like this is no good,
hence we explicitly perform that assignment (possibly again) in
rearrange_squash().
Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
The shell script version of the interactive rebase has a very specific
final message. Teach the sequencer to print the same.
Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
For the benefit of e.g. the shell prompt, the interactive rebase not
only displays the progress for the user to see, but also writes it into
the msgnum/end files in the state directory.
Teach the sequencer this new trick.
Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
The interactive rebase keeps the user informed about its progress.
If the sequencer wants to do the grunt work of the interactive
rebase, it also needs to show that progress.
Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
This is the behavior of the shell script version of the interactive
rebase, by using the `output` function defined in `git-rebase.sh`.
Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
This is the behavior of the shell script version of the interactive
rebase, by using the `output` function defined in `git-rebase.sh`.
Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
In the upcoming patch, we will support rebase -i's progress
reporting. The progress skips comments but counts 'noop's.
Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
The parsing part of a 'drop' command is almost identical to parsing a
'pick', while the operation is the same as that of a 'noop'.
Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
The interactive rebase has the very special magic that a cherry-pick
that exits with a status different from 0 and 1 signifies a failure to
even record that a cherry-pick was started.
This can happen e.g. when a fast-forward fails because it would
overwrite untracked files.
In that case, we must reschedule the command that we thought we already
had at least started successfully.
Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
The sequencer already has an idea about using different merge
strategies. We just piggy-back on top of that, using rebase -i's
own settings, when running the sequencer in interactive rebase mode.
Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
Git's `rebase` command inspects the `rebase.autostash` config setting
to determine whether it should stash any uncommitted changes before
rebasing and re-apply them afterwards.
As we introduce more bits and pieces to let the sequencer act as
interactive rebase's backend, here is the part that adds support for
the autostash feature.
Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
When continuing after a `pick` command failed, we want that commit
to show up in the rewritten-list (and its notes to be rewritten), too.
Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
When rebasing commits that have commit notes attached, the interactive
rebase rewrites those notes faithfully at the end. The sequencer must
do this, too, if it wishes to do interactive rebase's job.
Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
We already used the same reflog message as the scripted version of rebase
-i when finishing. With this commit, we do that also for all the commands
before that.
Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
This makes the code DRYer, with the obvious benefit that we can enhance
the code further in a single place.
We can also reuse the functionality elsewhere by calling this new
function.
Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
The sequencer already knew how to fast-forward instead of
cherry-picking, if possible.
We want to continue to do this, of course, but in case of the 'reword'
command, we will need to call `git commit` after fast-forwarding.
Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
This is now trivial, as all the building blocks are in place: all we need
to do is to flip the "edit" switch when committing.
Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
When doing an interactive rebase, we want to leave a 'patch' file for
further inspection by the user (even if we never tried to actually apply
that patch, since we're cherry-picking instead).
Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
An interactive rebase operates on a detached HEAD (to keep the reflog
of the original branch relatively clean), and updates the branch only
at the end.
Now that the sequencer learns to perform interactive rebases, it also
needs to learn the trick to update the branch before removing the
directory containing the state of the interactive rebase.
Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
When the last command of an interactive rebase fails, the user needs to
resolve the problem and then continue the interactive rebase. Naturally,
the todo script is empty by then. So let's not complain about that!
To that end, let's move that test out of the function that parses the
todo script, and into the more high-level function read_populate_todo().
This is also necessary by now because the lower-level parse_insn_buffer()
has no idea whether we are performing an interactive rebase or not.
Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
When a cherry-pick continues without a "todo script", the intention is
simply to pick a single commit.
However, when an interactive rebase is continued without a "todo
script", it means that the last command has been completed and that we
now need to clean up.
This commit guards the revert/cherry-pick specific steps so that they
are not executed in rebase -i mode.
Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
When an interactive rebase is interrupted, the user may stage changes
before continuing, and we need to commit those changes in that case.
Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
When the interactive rebase aborts, it writes out an author-script file
to record the author information for the current commit. As we are about
to teach the sequencer how to perform the actions behind an interactive
rebase, it needs to write those author-script files, too.
Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
For users' convenience, most rebase commands can be abbreviated, e.g.
'p' instead of 'pick' and 'x' instead of 'exec'. Let's teach the
sequencer to handle those abbreviated commands just fine.
Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
This is a huge patch, and at the same time a huge step forward to
execute the performance-critical parts of the interactive rebase in a
builtin command.
Since 'fixup' and 'squash' are not only similar, but also need to know
about each other (we want to reduce a series of fixups/squashes into a
single, final commit message edit, from the user's point of view), we
really have to implement them both at the same time.
Most of the actual work is done by the existing code path that already
handles the "pick" and the "edit" commands; We added support for other
features (e.g. to amend the commit message) in the patches leading up to
this one, yet there are still quite a few bits in this patch that simply
would not make sense as individual patches (such as: determining whether
there was anything to "fix up" in the "todo" script, etc).
In theory, it would be possible to reuse the fast-forward code path also
for the fixup and the squash code paths, but in practice this would make
the code less readable. The end result cannot be fast-forwarded anyway,
therefore let's just extend the cherry-picking code path for now.
Since the sequencer parses the entire `git-rebase-todo` script in one go,
fixup or squash commands without a preceding pick can be reported early
(in git-rebase--interactive, we could only report such errors just before
executing the fixup/squash).
Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
In the interactive rebase, commands that were successfully processed are
not simply discarded, but appended to the 'done' file instead. This is
used e.g. to display the current state to the user in the output of
`git status` or the progress.
Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
When calling `git rebase -i -v`, the user wants to see some statistics
after the commits were rebased. Let's show some.
The strbuf we use to perform that task will be used for other things
in subsequent commits, hence it is declared and initialized in a wider
scope than strictly needed here.
Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
The 'exec' command is a little special among rebase -i's commands, as it
does *not* have a SHA-1 as first parameter. Instead, everything after the
`exec` command is treated as command-line to execute.
Let's reuse the arg/arg_len fields of the todo_item structure (which hold
the oneline for pick/edit commands) to point to the command-line.
Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
This patch is a straight-forward reimplementation of the `edit`
operation of the interactive rebase command.
Well, not *quite* straight-forward: when stopping, the `edit`
command wants to write the `patch` file (which is not only the
patch, but includes the commit message and author information). To
that end, this patch requires the earlier work that taught the
log-tree machinery to respect the `file` setting of
rev_info->diffopt to write to a file stream different than stdout.
Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
The 'noop' command is probably the most boring of all rebase -i commands
to support in the sequencer.
Which makes it an excellent candidate for this first stab to add support
for rebase -i's commands to the sequencer.
For the moment, let's also treat empty lines and commented-out lines as
'noop'; We will refine that handling later in this patch series.
To make it easier to identify "classes" of todo_commands (such as:
determine whether a command is pick-like, i.e. handles a single commit),
let's enforce a certain order of said commands.
Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
This patch introduces a new action for the sequencer. It really does not
do a whole lot of its own right now, but lays the ground work for
patches to come. The intention, of course, is to finally make the
sequencer the work horse of the interactive rebase (the original idea
behind the "sequencer" concept).
Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
When translating error messages, we need to be careful *not* to translate
the todo commands such as "pick", "reword", etc because they are commands,
and Git would not understand translated versions of those commands.
Therefore, translating the commands in the error messages would simply be
misleading.
Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
This makes the code consistent by fixing quite a couple of error messages.
Suggested by Jakub Narębski.
Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
The definition of this function goes back all the way to 043a449
(sequencer: factor code out of revert builtin, 2012-01-11), long before a
serious effort was made to translate all the error messages.
It is slightly out of the context of the current patch series (whose
purpose it is to re-implement the performance critical parts of the
interactive rebase in C) to make the error messages in the sequencer
translatable, but what the heck. We'll just do it while we're looking at
this part of the code.
Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
The sequencer was introduced to make the cherry-pick and revert
functionality available as library function, with the original idea
being to extend the sequencer to also implement the rebase -i
functionality.
The test to ensure that all of the commands in the script are identical
to the overall operation does not mesh well with that.
Therefore let's disable the test in rebase -i mode.
While at it, error out early if the "instruction sheet" (i.e. the todo
script) could not be parsed.
Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
The write_message() function safely writes an strbuf to a file.
Sometimes it is inconvenient to require an strbuf, though: the text to
be written may not be stored in a strbuf, or the strbuf should not be
released after writing.
Let's refactor "safely writing string to a file" into
write_with_lock_file(), and make write_message() use it. The new
function makes it easy to create new convenience function
write_file_gently(); as some of the upcoming callers of this new
function would want to append a newline character, add a flag for it in
write_file_gently(), and thus in write_with_lock_file().
Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
Interactive rebase's scripts may be indented; we need to handle this
case, too, now that we prepare the sequencer to process interactive
rebases.
Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
The return value of do_recursive_merge() may be positive (indicating merge
conflicts), so let's OR later error conditions so as not to overwrite them
with 0.
This is not yet a problem, but preparing for the patches to come: we will
teach the sequencer to do rebase -i's job.
Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
The sequencer_commit() function already knows how to amend commits, and
with this new option, it can also clean up commit messages (i.e. strip
out commented lines). This is needed to implement rebase -i's 'fixup'
and 'squash' commands as sequencer commands.
Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
This teaches the sequencer_commit() function to take an argument that
will allow us to implement "todo" commands that need to amend the commit
messages ("fixup", "squash" and "reword").
Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
In the upcoming commits, we will implement more and more of rebase
-i's functionality. One particular feature of the commands to come is
that some of them allow editing the commit message while others don't,
i.e. we cannot define in the replay_opts whether the commit message
should be edited or not.
Let's add a new parameter to the sequencer_commit() function. Previously,
it was the duty of the caller to ensure that the opts->edit setting
indicates whether to let the user edit the commit message or not,
indicating that it is an "all or nothing" setting, i.e. that the sequencer
wants to let the user edit *all* commit message, or none at all. In the
upcoming rebase -i mode, it will depend on the particular command that is
currently executed, though.
Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
The rebase command sports a `--gpg-sign` option that is heeded by the
interactive rebase.
This patch teaches the sequencer that trick, as part of the bigger
effort to make the sequencer the work horse of the interactive rebase.
Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
As we are slowly teaching the sequencer to perform the hard work for
the interactive rebase, we need to read files that were written by
shell scripts.
These files typically contain a single line and are invariably ended
by a line feed (and possibly a carriage return before that). Let's use
a helper to read such files and to remove the line ending.
Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
