Although fast-import can take file changes in any order, trying to debug
by comparing the original fast-export stream to the filtered version is
difficult if the files are randomly reordered. Sometimes we aren't
comparing the filtered version to the original but just looking at the
stream passed to fast-import, in which case having the files in sorted
order may help.
Our accumulation of file_changes into a dict() in order to check for
collisions when renaming had the unfortunate side effect of sorting
files by internals of dictionary ordering. Although the files started
in sorted order, we don't in general want to use the original order
because renames can cause filenames to become out-of-order. Just apply
a simple sort at the end.
Signed-off-by: Elijah Newren <newren@gmail.com>
I suspect at some point someone will try to pass -M or -C to
fast-export; may as well leave a note in the code about another place
that's incompatible while I'm thinking about it.
Signed-off-by: Elijah Newren <newren@gmail.com>
Imperative form sounds better than --empty-pruning and
--degenerate-pruning, and it probably works better with command line
completion.
Signed-off-by: Elijah Newren <newren@gmail.com>
The reset directive can specify a commit hash for the 'from' directive,
which can be used to reset to a specify commit, or, if the hash is all
zeros, then it can be used to delete the ref. Support such operations.
Signed-off-by: Elijah Newren <newren@gmail.com>
For other programs importing git-filter-repo as a library and passing a
blob, commit, tag, or reset callback to RepoFilter, pass a second
parameter to these functions with extra metadata they might find useful.
For simplicity of implementation, this technically changes the calling
signature of the --*-callback functions passed on the command line, but
we hide that behind a _do_not_use_this_variable parameter for now, leave
it undocumented, and encourage folks who want to use it to write an
actual python program that imports git-filter-repo. In the future, we
may modify the --*-callback functions to not pass this extra parameter,
or if it is deemed sufficiently useful, then we'll rename the second
parameter and document it.
As already noted in our API compatibilty caveat near the top of
git-filter-repo, I am not guaranteeing API backwards compatibility.
That especially applies to this metadata argument, other than the fact
that it'll be a dict mapping strings to some kind of value. I might add
more keys, rename them, change the corresponding value, or even remove
keys that used to be part of metadata.
Signed-off-by: Elijah Newren <newren@gmail.com>
Location of filtering logic was previously split in a confusing fashion
between FastExportFilter and RepoFilter. Move all filtering logic from
FastExportFilter into RepoFilter, and rename the former to
FastExportParser to reflect this change.
One downside of this change is that FastExportParser's _parse_commit
holds two pieces of information (orig_parents and had_file_changes)
which are not part of the commit object but which are now needed by
RepoFilter. Adding those bits of info to the commit object does not
make sense, so for now we pass an auxiliary dict with the
commit_callback that has these two fields. This information is not
passed along to external commit_callbacks passed to RepoFilter, though,
which seems suboptimal. To be fair, though, commit_callbacks to
RepoFilter never had access to this information so this is not a new
shortcoming, it just seems more apparent now.
Signed-off-by: Elijah Newren <newren@gmail.com>
I introduced this over a decade ago thinking it would come in handy in
some special case, and the only place I used it was in a testcase that
existed almost solely to increase code coverage. Modify the testcase to
instead demonstrate how it is trivial to get the effects of the
everything_callback without it being present.
Signed-off-by: Elijah Newren <newren@gmail.com>
The specially constructed callbacks in RepoFilter.run() were
superfluous; we already had special callback functions. Instead of
creating new local functions that call the real callbacks and then do
one extra step, just put the extra wanted code into the real callbacks.
Signed-off-by: Elijah Newren <newren@gmail.com>
Using fast-import's feature done capability, any output sent to it after
the 'done' directive will be ignored. We do not intend to send any such
information, but there have been a couple cases where an accident while
refactoring the code resulted in some information being sent after the
done directive. To avoid having to debug that again, just close the
output stream after sending the 'done' directive to ensure that we get
an immediate and clear error if we ever run into such a situation again.
Signed-off-by: Elijah Newren <newren@gmail.com>
The upcoming git-2.22 release will not have the --reencode option to
fast-export; however, since we default to --reencode=yes and that was
the default behavior in all existing versions of git (only to change in
git-2.23), we can just silently leave the option off if we detect we are
running with this version. However, the diff-tree --combined-all-paths
option from git-2.22 is still mandatory; we cannot run with git versions
older than that (well, with -rc or built-from-source versions, but that
won't matter to most users).
Signed-off-by: Elijah Newren <newren@gmail.com>
Translating "Parsed %d commits" a hundred thousand times (once per
commit), turned out to be somewhat expensive -- especially since we
were only going to print it out once every few thousand commits.
Translate it once and cache the result, shaving off about 20% of
execution time for a simple rewrite of a test repository (rails).
Signed-off-by: Elijah Newren <newren@gmail.com>
This allows the user to put a whole bunch of paths they want to keep (or
want to remove) in a file and then just provide the path to it. They
can also use globs or regexes (similar to --replace-text) and can also
do renames. In fact, this allows regex renames, despite the fact that I
never added a --path-rename-regex option.
Signed-off-by: Elijah Newren <newren@gmail.com>
Using an exact path (file or directory) for --path-rename instead of a
prefix removes an ugly caveat from the documentation, makes it operate
similarly to --path, and will make it easier to reuse common code when I
add the --paths-from-file option. Switch over, and replace the
startswith() check by a call to filename_matches().
Signed-off-by: Elijah Newren <newren@gmail.com>
This new flag allows people to filter files solely based on their
basename rather than on their full path within the repo, making it
easier to e.g. remove all .DS_Store files or keep all README.md
files.
Signed-off-by: Elijah Newren <newren@gmail.com>
This class only represents one FileChange, so fix the misnomer and make
it clearer to others the purpose of this object.
Signed-off-by: Elijah Newren <newren@gmail.com>
For most repos, --fake-missing-tagger will be a no-op. But if a repo
out there has a missing tagger, then fast-import will choke on it unless
one is inserted; ask fast-export to do that.
Signed-off-by: Elijah Newren <newren@gmail.com>
This adds the ability to automatically add new replacement refs for each
rewritten commit (as well as delete or update replacement refs that
existed before the run). This will allow users to use either new or old
commit hashes to reference commits locally, though old commit hashes
will need to be unabbreviated. The only requirement for this to work,
is that the person who does the rewrite also needs to push the replace
refs up where other users can grab them, and users who want to use them
need to modify their fetch refspecs to grab the replace refs.
However, other tools external to git may not understand replace refs...
Tools like Gerrit and GitHub apparently do not yet natively understand
replace refs. Trying to view "commits" by the replacement ref will
yield various forms of "Not Found" in each tool. One has to instead try
to view it as a branch with an odd name (including "refs/replace/"), and
often branches are accessed via a different URL style than commits so it
becomes very non-obvious to users how to access the info associated with
an old commit hash.
* In Gerrit, instead of being able to search on the sha1sum or use a
pre-defined URL to search and auto-redirect to the appropriate code
review with
https://gerrit.SITE.COM/#/q/${OLD_SHA1SUM},n,z
one instead has to have a special plugin and go to a URL like
https://gerrit.SITE.COM/plugins/gitiles/ORG/REPO/+/refs/replace/${OLD_SHA1SUM}
but then the user isn't shown the actual code review and will need
to guess which link to click on to get to it (and it'll only be
there if the user included a Change-Id in the commit message).
* In GitHub, instead of being able to go to a URL like
https://github.SITE.COM/ORG/REPO/commit/${OLD_SHA1SUM}
one instead has to navigate based on branch using
https://github.SITE.COM/ORG/REPO/tree/refs/replace/${OLD_SHA1SUM}
but that will show a listing of commits instead of information about
a specific commit; the user has to manually click on the first commit
to get to the desired location.
For now, providing replace refs at least allows users to access
information locally using old IDs; perhaps in time as other external
tools will gain a better understanding of how to use replace refs, the
barrier to history rewrites will decrease enough that big projects that
really need it (e.g. those that have committed many sins by commiting
stupidly large useless binary blobs) can at least seriously contemplate
the undertaking. History rewrites will always have some drawbacks and
pain associated with them, as they should, but when warranted it's nice
to have transition plans that are more smooth than a massive flag day.
Signed-off-by: Elijah Newren <newren@gmail.com>
Keeping empty pruning as a single section likely makes users only think
about pruning of non-merge commits which become empty. Since merge
commits can lose parents or become degenerate, it is worth creating a
second section for this; besides, that matches the separate options we
provide to users to control the features.
Signed-off-by: Elijah Newren <newren@gmail.com>
We have a good default for pruning of empty commits and degenerate merge
commits: only pruning such commits that didn't start out that way (i.e.
that couldn't intentionally have been empty or degenerate). However,
users may have reasons to want to aggressively prune such commits (maybe
they used BFG repo filter or filter-branch previously and have lots of
cruft commits that they want remoed), and we may as well allow them to
specify that they don't want pruning too, just to be flexible.
Signed-off-by: Elijah Newren <newren@gmail.com>
If a commit was a merge in the original repo, and its ancestors on at
least one side have all been filtered away, and the commit has no
filechanges relative to its remaining parent (if any), then this commit
should be pruned. We had a small logic error preventing such pruning;
fix it by checking len(parents) instead of len(orig_parents).
Signed-off-by: Elijah Newren <newren@gmail.com>
fast-import syntax declares how to specify the parents of a commit with
'from' and possibly 'merge' directives, but it oddly also allows parents
to be implicitly specified via branch name. The documentation is easy
to misread:
"Omitting the from command in the first commit of a new branch will
cause fast-import to create that commit with no ancestor."
Note that the "in the first commit of a new branch" is key here. It is
reinforced later in the document with:
"Omitting the from command on existing branches is usually desired, as
the current commit on that branch is automatically assumed to be the
first ancestor of the new commit."
Desirability of operating this way aside, this raises an interesting
question: what if you only have one branch in some repository, but that
branch has more than one root commit? How does one use the fast-import
format to import such a repository? The fast-import documentation
doesn't state as far as I can tell, but using a 'reset' directive
without providing a 'from' reference for it is the way to go.
Modify filter-repo to understand implicit 'from' commits, and to
appropriately issue 'reset' directives when we need additional root
commits.
Signed-off-by: Elijah Newren <newren@gmail.com>
Notable items:
* We use bytestrings _everywhere_. This is incredibly annoying to
me, as I think users will be tempted to use "normal" strings in
callback functions and get surprised when things compare as
unequal, but I did like 3-4 python3 conversions with different
amounts in bytestrings and regular strings, and I always hit
real world repositories with alternate encodings on user names
and commit messages (despite commit messages not necessarily
having a special 'encoding' field). Further, I was always
risking munging data the user didn't want by trying to 'decode'
the bytestrings into unicode, and I was probably slowing down
performance. So, in the end I gave up and everything must be a
bytestring.
* The performance of the python2 version of filter-repo drifted
slightly over time with additional features and more robust
checking (particularly the become-empty and become-degenerate
pruning), though largely still providing the same performance
as I highlighted in my BFG/filter-branch/filter-repo comparison.
There certainly weren't any factors of 2 difference. A pleasant
surprise was that the python2->python3 conversion appears to have
only made a difference of a couple percent to performance and
some tests were faster and others slower than the python2 version.
So performance seems to be a wash.
* The individual commits on python3-conversion do not work
independently, but rather demonstrate separate aspects of what work
was needed in the large conversion to python3.
Signed-off-by: Elijah Newren <newren@gmail.com>
This is by far the largest python3 change; it consists basically of
* using b'<str>' instead of '<str>' in lots of places
* adding a .encode() if we really do work with a string but need to
get it converted to a bytestring
* replace uses of .format() with interpolation via the '%' operator,
since bytestrings don't have a .format() method.
Signed-off-by: Elijah Newren <newren@gmail.com>
Unlike how str works, if we grab an array index of a bytestr we get an
integer (corresponding to the ASCII value) instead of a bytestr of
length 1. Adjust code accordingly.
Signed-off-by: Elijah Newren <newren@gmail.com>
