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The idea of Scalar (https://github.com/microsoft/scalar), and before that, of VFS for Git, has always been to prove that Git _can_ scale, and to upstream whatever strategies have been demonstrated to help. With this patch, we start the journey from that C# project to move what is left to Git's own `contrib/` directory, reimplementing it in pure C, with the intention to facilitate integrating the functionality into core Git all while maintaining backwards-compatibility for existing Scalar users (which will be much easier when both live in the same worktree). It has always been the plan to contribute all of the proven strategies back to core Git. For example, while the virtual filesystem provided by VFS for Git helped the team developing the Windows operating system to move onto Git, while trying to upstream it we realized that it cannot be done: getting the virtual filesystem to work (which we only managed to implement fully on Windows, but not on, say, macOS or Linux), and the required server-side support for the GVFS protocol, made this not quite feasible. The Scalar project learned from that and tackled the problem with different tactics: instead of pretending to Git that the working directory is fully populated, it _specifically_ teaches Git about partial clone (which is based on VFS for Git's cache server), about sparse checkout (which VFS for Git tried to do transparently, in the file system layer), and regularly runs maintenance tasks to keep the repository in a healthy state. With partial clone, sparse checkout and `git maintenance` having been upstreamed, there is little left that `scalar.exe` does which `git.exe` cannot do. One such thing is that `scalar clone <url>` will automatically set up a partial, sparse clone, and configure known-helpful settings from the start. So let's bring this convenience into Git's tree. The idea here is that you can (optionally) build Scalar via make -C contrib/scalar/ This will build the `scalar` executable and put it into the contrib/scalar/ subdirectory. The slightly awkward addition of the `contrib/scalar/*` bits to the top-level `Makefile` are actually really required: we want to link to `libgit.a`, which means that we will need to use the very same `CFLAGS` and `LDFLAGS` as the rest of Git. An early development version of this patch tried to replicate all the conditional code in `contrib/scalar/Makefile` (e.g. `NO_POLL`) just like `contrib/svn-fe/Makefile` used to do before it was retired. It turned out to be quite the whack-a-mole game: the SHA-1-related flags, the flags enabling/disabling `compat/poll/`, `compat/regex/`, `compat/win32mmap.c` & friends depending on the current platform... To put it mildly: it was a major mess. Instead, this patch makes minimal changes to the top-level `Makefile` so that the bits in `contrib/scalar/` can be compiled and linked, and adds a `contrib/scalar/Makefile` that uses the top-level `Makefile` in a most minimal way to do the actual compiling. Note: With this commit, we only establish the infrastructure, no Scalar functionality is implemented yet; We will do that incrementally over the next few commits. Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de> Signed-off-by: Junio C Hamano <gitster@pobox.com> |
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| buildsystems | ||
| coccinelle | ||
| completion | ||
| contacts | ||
| credential | ||
| diff-highlight | ||
| emacs | ||
| examples | ||
| fast-import | ||
| git-jump | ||
| git-shell-commands | ||
| hg-to-git | ||
| hooks | ||
| long-running-filter | ||
| mw-to-git | ||
| persistent-https | ||
| remote-helpers | ||
| scalar | ||
| stats | ||
| subtree | ||
| thunderbird-patch-inline | ||
| update-unicode | ||
| vscode | ||
| workdir | ||
| coverage-diff.sh | ||
| git-resurrect.sh | ||
| README | ||
| remotes2config.sh | ||
| rerere-train.sh | ||
Contributed Software Although these pieces are available as part of the official git source tree, they are in somewhat different status. The intention is to keep interesting tools around git here, maybe even experimental ones, to give users an easier access to them, and to give tools wider exposure, so that they can be improved faster. I am not expecting to touch these myself that much. As far as my day-to-day operation is concerned, these subdirectories are owned by their respective primary authors. I am willing to help if users of these components and the contrib/ subtree "owners" have technical/design issues to resolve, but the initiative to fix and/or enhance things _must_ be on the side of the subtree owners. IOW, I won't be actively looking for bugs and rooms for enhancements in them as the git maintainer -- I may only do so just as one of the users when I want to scratch my own itch. If you have patches to things in contrib/ area, the patch should be first sent to the primary author, and then the primary author should ack and forward it to me (git pull request is nicer). This is the same way as how I have been treating gitk, and to a lesser degree various foreign SCM interfaces, so you know the drill. I expect that things that start their life in the contrib/ area to graduate out of contrib/ once they mature, either by becoming projects on their own, or moving to the toplevel directory. On the other hand, I expect I'll be proposing removal of disused and inactive ones from time to time. If you have new things to add to this area, please first propose it on the git mailing list, and after a list discussion proves there are some general interests (it does not have to be a list-wide consensus for a tool targeted to a relatively narrow audience -- for example I do not work with projects whose upstream is svn, so I have no use for git-svn myself, but it is of general interest for people who need to interoperate with SVN repositories in a way git-svn works better than git-svnimport), submit a patch to create a subdirectory of contrib/ and put your stuff there. -jc