1 TopGit - A different patch queue manager
7 TopGit aims to make handling of large amount of interdependent topic
8 branches easier. In fact, it is designed especially for the case
9 when you maintain a queue of third-party patches on top of another
10 (perhaps Git-controlled) project and want to easily organize, maintain
11 and submit them - TopGit achieves that by keeping a separate topic
12 branch for each patch and providing few tools to maintain the branches.
18 Why not use something like StGIT or Guilt or rebase -i for maintaining
19 your patch queue? The advantage of these tools is their simplicity;
20 they work with patch _series_ and defer to the reflog facility for
21 version control of patches (reordering of patches is not
22 version-controlled at all). But there are several disadvantages -
23 for one, these tools (especially StGIT) do not actually fit well
24 with plain Git at all: it is basically impossible to take advantage
25 of the index effectively when using StGIT. But more importantly,
26 these tools horribly fail in the face of distributed environment.
28 TopGit has been designed around three main tenets:
30 (i) TopGit is as thin layer on top of Git as possible.
31 You still maintain your index and commit using Git, TopGit will
32 only automate few indispensable tasks.
34 (ii) TopGit is anxious about _keeping_ your history. It will
35 never rewrite your history and all metadata is also tracked by Git,
36 smoothly and non-obnoxiously. It is good to have a _single_ point
37 when the history is cleaned up, and that is at the point of inclusion
38 in the upstream project; locally, you can see how your patch has evolved
39 and easily return to older versions.
41 (iii) TopGit is specifically designed to work in distributed
42 environment. You can have several instances of TopGit-aware repositories
43 and smoothly keep them all up-to-date and transfer your changes between
46 As mentioned above, the main intended use-case for TopGit is tracking
47 third-party patches, where each patch is effectively a single topic
48 branch. In order to flexibly accommodate even complex scenarios when
49 you track many patches where many are independent but some depend
50 on others, TopGit ignores the ancient Quilt heritage of patch series
51 and instead allows the patches to freely form graphs (DAGs just like
52 Git history itself, only "one level higher"). For now, you have
53 to manually specify which patches does the current one depend
54 on, but TopGit might help you with that in the future in a darcs-like
57 A glossary plug: The union (i.e. merge) of patch dependencies is
58 called a _base_ of the patch (topic branch).
60 Of course, TopGit is perhaps not the right tool for you:
62 (i) TopGit is not complicated, but StGIT et al. are somewhat
63 simpler, conceptually. If you just want to make a linear purely-local
64 patch queue, deferring to StGIT instead might make more sense.
66 (ii) When using TopGit, your history can get a little hairy
67 over time, especially with all the merges rippling through. ;-)
73 ## Create and evolve a topic branch
74 $ tg create t/gitweb/pathinfo-action
75 tg: Automatically marking dependency on master
76 tg: Creating t/gitweb/pathinfo-action base from master...
82 ## Create another topic branch on top of the former one
83 $ tg create t/gitweb/nifty-links
84 tg: Automatically marking dependency on t/gitweb/pathinfo-action
85 tg: Creating t/gitweb/nifty-links base from t/gitweb/pathinfo-action...
89 ## Create another topic branch on top of master and submit
90 ## the resulting patch upstream
91 $ tg create t/revlist/author-fixed master
92 tg: Creating t/revlist/author-fixed base from master...
96 tg: Sent t/revlist/author-fixed
98 To: git@vger.kernel.org
100 Subject: [PATCH] Fix broken revlist --author when --fixed-string
102 ## Create another topic branch depending on two others non-trivially
103 $ tg create t/whatever t/revlist/author-fixed t/gitweb/nifty-links
104 tg: Creating t/whatever base from t/revlist/author-fixed...
105 tg: Merging t/whatever base with t/gitweb/nifty-links...
107 tg: Please commit merge resolution and call: tg create
108 tg: It is also safe to abort this operation using `git reset --hard`
109 tg: but please remember you are on the base branch now;
110 tg: you will want to switch to a different branch.
114 tg: Resuming t/whatever setup...
118 ## Update a single topic branch and propagate the changes to
120 $ git checkout t/gitweb/nifty-links
123 $ git checkout t/whatever
125 Topic Branch: t/whatever (1 commit)
126 Subject: [PATCH] Whatever patch
128 Depends: t/revlist/author-fixed t/gitweb/nifty-links
130 t/gitweb/nifty-links (1 commit)
132 tg: Updating base with t/gitweb/nifty-links changes...
134 tg: Please commit merge resolution and call `tg update` again.
135 tg: It is also safe to abort this operation using `git reset --hard`,
136 tg: but please remember you are on the base branch now;
137 tg: you will want to switch to a different branch.
141 tg: Updating t/whatever against new base...
143 tg: Please resolve the merge and commit. No need to do anything else.
144 tg: You can abort this operation using `git reset --hard` now
145 tg: and retry this merge later using `tg update`.
149 ## Update a single topic branch and propagate the changes
150 ## further through the dependency chain
151 $ git checkout t/gitweb/pathinfo-action
154 $ git checkout t/whatever
156 Topic Branch: t/whatever (1/2 commits)
157 Subject: [PATCH] Whatever patch
159 Depends: t/revlist/author-fixed t/gitweb/nifty-links
161 t/gitweb/pathinfo-action (<= t/gitweb/nifty-links) (1 commit)
163 tg: Recursing to t/gitweb/nifty-links...
164 [t/gitweb/nifty-links] tg: Updating base with t/gitweb/pathinfo-action changes...
166 [t/gitweb/nifty-links] tg: Please commit merge resolution and call `tg update` again.
167 [t/gitweb/nifty-links] tg: It is also safe to abort this operation using `git reset --hard`,
168 [t/gitweb/nifty-links] tg: but please remember you are on the base branch now;
169 [t/gitweb/nifty-links] tg: you will want to switch to a different branch.
170 [t/gitweb/nifty-links] tg: You are in a subshell. If you abort the merge,
171 [t/gitweb/nifty-links] tg: use `exit` to abort the recursive update altogether.
172 [t/gitweb/nifty-links] $ ..resolve..
173 [t/gitweb/nifty-links] $ git commit
174 [t/gitweb/nifty-links] $ tg update
175 [t/gitweb/nifty-links] tg: Updating t/gitweb/nifty-links against new base...
177 [t/gitweb/nifty-links] tg: Please resolve the merge and commit.
178 [t/gitweb/nifty-links] tg: You can abort this operation using `git reset --hard`.
179 [t/gitweb/nifty-links] tg: You are in a subshell. After you either commit or abort
180 [t/gitweb/nifty-links] tg: your merge, use `exit` to proceed with the recursive update.
181 [t/gitweb/nifty-links] $ ..resolve..
182 [t/gitweb/nifty-links] $ git commit
183 [t/gitweb/nifty-links] $ exit
184 tg: Updating base with t/gitweb/nifty-links changes...
185 tg: Updating t/whatever against new base...
187 ## Clone a TopGit-controlled repository
190 $ tg remote --populate origin
195 ## Add a TopGit remote to a repository and push to it
196 $ git remote add foo URL
198 $ tg push -r foo t/whatever
199 # Note that magit still uses git push, which is wrong as of TopGit 0.8
201 ## Update from a non-default TopGit remote
210 The 'tg' tool of TopGit has several subcommands:
214 Our sophisticated integrated help facility. Doesn't do
219 Create a new TopGit-controlled topic branch of a given name
220 (required argument) and switch to it. If no dependencies
221 are specified (by extra arguments passed after the first one),
222 the current branch is assumed to be the only dependency.
224 After `tg create`, you should insert the patch description
225 to the '.topmsg' file, which will already contain some
226 prefilled bits. You can set topgit.to, topgit.cc and topgit.bcc
227 configuration variables in order to have `tg create`
228 add these headers with given default values to '.topmsg'.
230 The main task of `tg create` is to set up the topic branch
231 base from the dependencies. This may fail due to merge conflicts.
232 In that case, after you commit the conflicts resolution,
233 you should call `tg create` again (without any arguments);
234 it will detect that you are on a topic branch base ref and
235 resume the topic branch creation operation.
237 In an alternative use case, if '-r BRANCH' is given instead
238 of dependency list, the topic branch is created based on
239 the given remote branch.
243 Remove a TopGit-controlled topic branch of given name
244 (required argument). Normally, this command will remove
245 only empty branch (base == head) without dependencies; use '-f'
246 to remove non-empty branch or branch that is dependent upon.
248 The '-f' option is also useful to force removal of a branch's base, if
249 you used 'git branch -D B' to remove the branch B, and then certain
250 TopGit commands complain, because the base of branch B is still there.
252 Currently, this command will _NOT_ remove the branch from
253 the dependency list in other branches. You need to take
254 care of this _manually_. This is even more complicated
255 in combination with '-f', in that case you need to manually
256 unmerge the removed branch's changes from the branches
259 TODO: '-a' to delete all empty branches, depfix, revert
263 Change dependencies of a TopGit-controlled topic branch.
264 This should have several subcommands, but only 'add' is
267 The 'add' subcommand takes an argument of a topic branch
268 to be added, adds it to '.topdeps', performs a commit and
269 then updates your topic branch accordingly. If you want to
270 do other things related to the dependency addition, like
271 adjusting '.topmsg', prepare them in the index before
272 calling 'tg depend add'.
274 TODO: Subcommand for removing dependencies, obviously
278 List files changed by the current or specified topic branch.
281 -i list files based on index instead of branch
282 -w list files based on working tree instead of branch
286 Show a summary information about the current or specified
291 Generate a patch from the current or specified topic branch.
292 This means that the diff between the topic branch base and
293 head (latest commit) is shown, appended to the description
294 found in the .topmsg file.
296 The patch is by default simply dumped to stdout. In the future,
297 tg patch will be able to automatically send the patches by mail
298 or save them to files. (TODO)
301 -i base patch generation on index instead of branch
302 -w base patch generation on working tree instead of branch
306 Send a patch from the current or specified topic branch as
309 Takes the patch given on the command line and emails it out.
310 Destination addresses such as To, Cc and Bcc are taken from the
313 Since it actually boils down to `git send-email` please refer to
314 its documentation for details on how to setup email for git.
315 You can pass arbitrary options to this command through the
316 '-s' parameter, but you must double-quote everything.
317 The '-r' parameter with msgid can be used to generate in-reply-to
318 and reference headers to an earlier mail.
320 Note: be careful when using this command. It easily sends out several
321 mails. You might want to run
323 git config sendemail.confirm always
325 to let `git send-email` ask for confirmation before sending any mail.
328 -i base patch generation on index instead of branch
329 -w base patch generation on working tree instead of branch
331 TODO: 'tg mail patchfile' to mail an already exported patch
332 TODO: mailing patch series
333 TODO: specifying additional options and addresses on command
338 Register given remote as TopGit-controlled. This will create
339 the namespace for the remote branch bases and teach 'git fetch'
340 to operate on them. However, from TopGit 0.8 onwards you need to
341 use 'tg push', or 'git push --mirror', for pushing TopGit-controlled
344 'tg remote' takes a optional remote name argument, and optional
345 '--populate' switch - use that for your origin-style remote,
346 it will seed the local topic branch system based on the
347 remote topic branches. '--populate' will also make 'tg remote'
348 automatically fetch the remote and 'tg update' to look at
349 branches of this remote for updates by default.
353 Show overview of all TopGit-tracked topic branches and their
354 up-to-date status ('>' marks the current topic branch,
355 '0' marks that it introduces no own changes,
356 'l'/'r' marks that it is local-only or has remote mate,
357 'L'/'R' marks that it is ahead/out-of-date wrt. its remote mate,
358 'D' marks that it is out-of-date wrt. its dependencies,
359 '!' marks that it has missing dependencies (even recursively),
360 'B' marks that it is out-of-date wrt. its base).
362 This can take long time to accurately determine all the relevant
363 information about each branch; you can pass '-t' to get just
364 terse list of topic branch names quickly. Alternately, you can
365 pass '--graphviz' to get a dot-suitable output to draw a dependency
366 graph between the topic branches.
368 You can also use the --sort option to sort the branches using
369 a topological sort. This is especially useful if each
370 TopGit-tracked topic branch depends on a single parent branch,
371 since it will then print the branches in the dependency
372 order. In more complex scenarios, a text graph view would be
373 much more useful, but that is not yet implemented.
375 The --deps option outputs dependency informations between
376 branches in a machine-readable format. Feed this to "tsort"
377 to get the output from --sort.
380 -i Use TopGit meta data from the index instead of branch
381 -w Use TopGit meta data from the working tree instead of branch
383 TODO: Speed up by an order of magnitude
384 TODO: Text graph view
388 Export a tidied-up history of the current topic branch
389 and its dependencies, suitable for feeding upstream.
390 Each topic branch corresponds to a single commit or patch
391 in the cleaned up history (corresponding basically exactly
392 to `tg patch` output for the topic branch).
394 The command has three possible outputs now - either a Git branch with
395 the collapsed history, a Git branch with a linearized history, or a
396 quilt series in new directory.
398 In case of producing collapsed history in new branch,
399 you can use this collapsed structure either for providing
400 a pull source for upstream, or further linearization e.g.
401 for creation of a quilt series using git log:
403 git log --pretty=email -p --topo-order origin..exported
405 To better understand the function of `tg export`,
406 consider this dependency structure of topic branches:
408 origin/master - t/foo/blue - t/foo/red - master
409 `- t/bar/good <,----------'
410 `- t/baz ------------'
412 (Where each of the branches may have hefty history.) Then
414 master$ tg export for-linus
416 will create this commit structure on branch for-linus:
418 origin/master - t/foo/blue -. merge - t/foo/red -.. merge - master
419 `- t/bar/good <,-------------------'/
420 `- t/baz ---------------------'
422 In case of using the linearize mode:
424 master$ tg export --linearize for-linus
426 you get a linear history respecting the dependencies of your patches in
427 a new branch for-linus. The result should be more or less the same as
428 using quilt mode and reimporting it into a Git branch. (More or less
429 because the topologic order can usually be extended in more than one
430 way into a complete ordering and the two methods may choose different
431 one's.) The result might be more appropriate for merging upstream as
432 it contains fewer merges.
434 Note that you might get conflicts during linearization because the
435 patches are reordered to get a linear history.
437 In case of the quilt mode,
439 master$ tg export --quilt for-linus
441 would create this directory for-linus:
443 for-linus/t/foo/blue.diff
444 for-linus/t/foo/red.diff
445 for-linus/t/bar/good.diff
453 The command works on the current topic branch
454 and can be called either without a parameter
455 (in that case, '--collapse' is assumed)
456 and with one mandatory argument: the name of the branch
457 where the exported result shall be stored.
458 The branch will be silently overwritten if it exists already!
459 Use git reflog to recover in case of mistake.
461 Alternatively, call it with the '--quilt' parameter
462 and an argument specifying the directory
463 where the quilt series should be saved.
465 With '--quilt', you can also pass '-b' parameter followed by
466 a comma-separated explicit list of branches to export. This
467 mode of operation is currently not supported with collapse.
469 In '--quilt' mode the patches are named like the originating topgit
470 branch. So usually they end up in subdirectories of the output
471 directory. With option '--flatten' the names are mangled such that
472 they end up directly in the output dir (i.e. slashed are substituted by
473 underscores). With '--numbered' (which implies '--flatten') the patch
474 names get a number as prefix to allow getting the order without
475 consulting the series file, which eases sending out the patches.
477 Usage: tg export ([(--collapse | --linearize)] BRANCH | --quilt DIR)
479 TODO: Make stripping of non-essential headers configurable
480 TODO: Make stripping of [PATCH] and other prefixes configurable
481 TODO: --mbox option for other mode of operation
482 TODO: -a option to export all branches
483 TODO: For quilt exporting, export the linearized history created in a
484 temporary branch---this would allow producing conflict-less
489 Import commits within the given revision range into TopGit,
490 creating one topic branch per commit, the dependencies forming
491 a linear sequence starting on your current branch (or a branch
492 specified by the '-d' parameter).
494 The branch names are auto-guessed from the commit messages
495 and prefixed by t/ by default; use '-p PREFIX' to specify
496 an alternative prefix (even an empty one).
498 Alternatively, you can use the '-s NAME' parameter to specify
499 the name of target branch; the command will then take one more
500 argument describing a single commit to import.
504 Update the current, specified or all topic branches wrt. changes
505 in the branches they depends on and remote branches.
506 This is performed in two phases - first,
507 changes within the dependencies are merged to the base,
508 then the base is merged into the topic branch.
509 The output will guide you in case of conflicts.
511 When -a is specifed, updates all topic branches matched by
512 PATTERNs (see git-for-all-refs(1) for details) or all if
515 After the update if single topic branch was specified, it is left
516 as current; if -a was specified, returns to branch which was
517 current at the beginning.
519 In case your dependencies are not up-to-date, tg update
520 will first recurse into them and update these.
522 If a remote branch update brings dependencies on branches
523 not yet instantiated locally, you can either bring in all
524 the new branches from the remote using 'tg remote --populate'
525 or only pick out the missing ones using 'tg create -r'
526 ('tg summary' will point out branches with incomplete
527 dependencies by showing an '!' near to them).
529 TODO: tg update -a -c to autoremove (clean) up-to-date branches
533 pushes a TopGit-controlled topic branch to a remote
534 repository. By default the remote gets all dependencies
535 (both tgish and non-tgish) and bases pushed to.
539 Prints the base commit of the current topic branch. Silently
540 exits with exit code 1 if you are not working on a TopGit
545 Prints the git log of the named topgit branch.
547 Note: if you have merged changes from a different repository, this
548 command might not list all interesting commits.
552 Outputs the direct dependencies for the current or named patch.
555 -i show dependencies based on index instead of branch
556 -w show dependencies based on working tree instead of branch
560 Outputs all patches which directly depend on the current or
564 -i show dependencies based on index instead of branch
565 -w show dependencies based on working tree instead of branch
572 TopGit stores all the topic branches in the regular refs/heads/
573 namespace, (we recommend to mark them with the 't/' prefix).
574 Except that, TopGit also maintains a set of auxiliary refs in
575 refs/top-*. Currently, only refs/top-bases/ is used, containing
576 the current _base_ of the given topic branch - this is basically
577 a merge of all the branches the topic branch depends on; it is
578 updated during `tg update` and then merged to the topic branch,
579 and it is the base of a patch generated from the topic branch by
582 All the metadata is tracked within the source tree and history
583 of the topic branch itself, in .top* files; these files are kept
584 isolated within the topic branches during TopGit-controlled merges
585 and are of course omitted during `tg patch`. The state of these
586 files in base commits is undefined; look at them only in the topic
587 branches themselves. Currently, two files are defined:
589 .topmsg: Contains the description of the topic branch
590 in a mail-like format, plus the author information,
591 whatever Cc headers you choose or the post-three-dashes message.
592 When mailing out your patch, basically only few extra headers
593 mail headers are inserted and the patch itself is appended.
594 Thus, as your patches evolve, you can record nuances like whether
595 the particular patch should have To-list/Cc-maintainer or vice
596 versa and similar nuances, if your project is into that.
597 From is prefilled from your current GIT_AUTHOR_IDENT, other headers
598 can be prefilled from various optional topgit.* config options.
600 .topdeps: Contains the one-per-line list of branches
601 your patch depends on, pre-seeded with `tg create`. (Continuously
602 updated) merge of these branches will be the "base" of your topic
603 branch. DO NOT EDIT THIS FILE MANUALLY!!! If you do so, you need
604 to know exactly what are you doing, since this file must stay in
605 sync with the Git history information, otherwise very bad things
608 TopGit also automagically installs a bunch of custom commit-related
609 hooks that will verify if you are committing the .top* files in sane
610 state. It will add the hooks to separate files within the hooks/
611 subdirectory and merely insert calls of them to the appropriate hooks
612 and make them executable (but make sure the original hooks code
613 is not called if the hook was not executable beforehand).
615 Another automagically installed piece is .git/info/attributes specifier
616 for an 'ours' merge strategy for the files .topmsg and .topdeps, and
617 the (intuitive) 'ours' merge strategy definition in .git/config.
623 There are two remaining issues with accessing topic branches in remote
626 (i) Referring to remote topic branches from your local repository
627 (ii) Developing some of the remote topic branches locally
629 There are two somewhat contradictory design considerations here:
631 (a) Hacking on multiple independent TopGit remotes in a single
633 (b) Having a self-contained topic system in local refs space
635 To us, (a) does not appear to be very convincing, while (b) is quite desirable
636 for 'git-log topic' etc. working, and increased conceptual simplicity.
638 Thus, we choose to instantiate all the topic branches of given remote locally;
639 this is performed by 'tg remote --populate'.
640 'tg update' will also check if a branch can be updated from its corresponding
641 remote branch. The logic is somewhat involved if we should DTRT.
642 First, we update the base, handling the remote branch as if it was the first
643 dependency; thus, conflict resolutions made in the remote branch will be
644 carried over to our local base automagically. Then, the base is merged into
645 remote branch and the result is merged to local branch - again, to carry over
646 remote conflict resolutions. In the future, this order might be adjustable
647 per-update in case local changes are diverging more than the remote ones.
649 All commands by default refer to the remote that 'tg remote --populate'
650 was called on the last time ('topgit.remote' configuration variable). You can
651 manually run any command with a different base remote by passing '-r REMOTE'
652 _before_ the subcommand name.
658 The following references are useful to understand the development of topgit and
662 http://lists-archives.org/git/688698-add-list-and-rm-sub-commands-to-tg-depend.html