Skip to content

Commit 4a81210

Browse files
derrickstoleedscho
derrickstolee
authored and
dscho
committed
scalar: add docs from microsoft/scalar
These docs have been altered to fit the version implemented in C within microsoft/git. This means in particular that the advanced.md file no longer applied at all. Some other areas were removed or significantly edited. Signed-off-by: Derrick Stolee <[email protected]>
1 parent 469b549 commit 4a81210

File tree

5 files changed

+280
-0
lines changed

5 files changed

+280
-0
lines changed

‎contrib/scalar/docs/faq.md

Lines changed: 51 additions & 0 deletions
Original file line numberDiff line numberDiff line change
@@ -0,0 +1,51 @@
1+
Frequently Asked Questions
2+
==========================
3+
4+
Using Scalar
5+
------------
6+
7+
### I don't want a sparse clone, I want every file after I clone!
8+
9+
Run `scalar clone --full-clone <url>` to initialize your repo to include
10+
every file. You can switch to a sparse-checkout later by running
11+
`git sparse-checkout init --cone`.
12+
13+
### I already cloned without `--full-clone`. How do I get everything?
14+
15+
Run `git sparse-checkout disable`.
16+
17+
Scalar Design Decisions
18+
-----------------------
19+
20+
There may be many design decisions within Scalar that are confusing at first
21+
glance. Some of them may cause friction when you use Scalar with your existing
22+
repos and existing habits.
23+
24+
> Scalar has the most benefit when users design repositories
25+
> with efficient patterns.
26+
27+
For example: Scalar uses the sparse-checkout feature to limit the size of the
28+
working directory within a large monorepo. It is designed to work efficiently
29+
with monorepos that are highly componentized, allowing most developers to
30+
need many fewer files in their daily work.
31+
32+
### Why does `scalar clone` create a `<repo>/src` folder?
33+
34+
Scalar uses a file system watcher to keep track of changes under this `src` folder.
35+
Any activity in this folder is assumed to be important to Git operations. By
36+
creating the `src` folder, we are making it easy for your build system to
37+
create output folders outside the `src` directory. We commonly see systems
38+
create folders for build outputs and package downloads. Scalar itself creates
39+
these folders during its builds.
40+
41+
Your build system may create build artifacts such as `.obj` or `.lib` files
42+
next to your source code. These are commonly "hidden" from Git using
43+
`.gitignore` files. Having such artifacts in your source tree creates
44+
additional work for Git because it needs to look at these files and match them
45+
against the `.gitignore` patterns.
46+
47+
By following the `src` pattern Scalar tries to establish and placing your build
48+
intermediates and outputs parallel with the `src` folder and not inside it,
49+
you can help optimize Git command performance for developers in the repository
50+
by limiting the number of files Git needs to consider for many common
51+
operations.

‎contrib/scalar/docs/getting-started.md

Lines changed: 93 additions & 0 deletions
Original file line numberDiff line numberDiff line change
@@ -0,0 +1,93 @@
1+
Getting Started
2+
===============
3+
4+
Registering existing Git repos
5+
------------------------------
6+
7+
To add a repository to the list of registered repos, run `scalar register [<path>]`.
8+
If `<path>` is not provided, then the "current repository" is discovered from
9+
the working directory by scanning the parent paths for a path containing a `.git`
10+
folder, possibly inside a `src` folder.
11+
12+
To see which repositories are currently tracked by the service, run
13+
`scalar list`.
14+
15+
Run `scalar unregister [<path>]` to remove the repo from this list.
16+
17+
Creating a new Scalar clone
18+
---------------------------------------------------
19+
20+
The `clone` verb creates a local enlistment of a remote repository using the
21+
partial clone feature available e.g. on GitHub.
22+
23+
24+
```
25+
scalar clone [options] <url> [<dir>]
26+
```
27+
28+
Create a local copy of the repository at `<url>`. If specified, create the `<dir>`
29+
directory and place the repository there. Otherwise, the last section of the `<url>`
30+
will be used for `<dir>`.
31+
32+
At the end, the repo is located at `<dir>/src`. By default, the sparse-checkout
33+
feature is enabled and the only files present are those in the root of your
34+
Git repository. Use `git sparse-checkout set` to expand the set of directories
35+
you want to see, or `git sparse-checkout disable` to expand to all files. You
36+
can explore the subdirectories outside your sparse-checkout specification using
37+
`git ls-tree HEAD`.
38+
39+
### Sparse Repo Mode
40+
41+
By default, Scalar reduces your working directory to only the files at the
42+
root of the repository. You need to add the folders you care about to build up
43+
to your working set.
44+
45+
* `scalar clone <url>`
46+
* Please choose the **Clone with HTTPS** option in the `Clone Repository` dialog in Azure Repos, not **Clone with SSH**.
47+
* `cd <root>\src`
48+
* At this point, your `src` directory only contains files that appear in your root
49+
tree. No folders are populated.
50+
* Set the directory list for your sparse-checkout using:
51+
1. `git sparse-checkout set <dir1> <dir2> ...`
52+
2. `git sparse-checkout set --stdin < dir-list.txt`
53+
* Run git commands as you normally would.
54+
* To fully populate your working directory, run `git sparse-checkout disable`.
55+
56+
If instead you want to start with all files on-disk, you can clone with the
57+
`--full-clone` option. To enable sparse-checkout after the fact, run
58+
`git sparse-checkout init --cone`. This will initialize your sparse-checkout
59+
patterns to only match the files at root.
60+
61+
If you are unfamiliar with what directories are available in the repository,
62+
then you can run `git ls-tree -d --name-only HEAD` to discover the directories
63+
at root, or `git ls-tree -d --name-only HEAD <path>` to discover the directories
64+
in `<path>`.
65+
66+
### Options
67+
68+
These options allow a user to customize their initial enlistment.
69+
70+
* `--full-clone`: If specified, do not initialize the sparse-checkout feature.
71+
All files will be present in your `src` directory. This uses a Git partial
72+
clone: blobs are downloaded on demand.
73+
74+
* `--branch=<ref>`: Specify the branch to checkout after clone.
75+
76+
### Advanced Options
77+
78+
The options below are not intended for use by a typical user. These are
79+
usually used by build machines to create a temporary enlistment that
80+
operates on a single commit.
81+
82+
* `--single-branch`: Use this option to only download metadata for the branch
83+
that will be checked out. This is helpful for build machines that target
84+
a remote with many branches. Any `git fetch` commands after the clone will
85+
still ask for all branches.
86+
87+
Removing a Scalar Clone
88+
-----------------------
89+
90+
Since the `scalar clone` command sets up a file-system watcher (when available),
91+
that watcher could prevent deleting the enlistment. Run `scalar delete <path>`
92+
from outside of your enlistment to unregister the enlistment from the filesystem
93+
watcher and delete the enlistment at `<path>`.

‎contrib/scalar/docs/index.md

Lines changed: 50 additions & 0 deletions
Original file line numberDiff line numberDiff line change
@@ -0,0 +1,50 @@
1+
Scalar: Enabling Git at Scale
2+
=============================
3+
4+
Scalar is a tool that helps Git scale to some of the largest Git repositories.
5+
It achieves this by enabling some advanced Git features, such as:
6+
7+
* *Partial clone:* reduces time to get a working repository by not
8+
downloading all Git objects right away.
9+
10+
* *Background prefetch:* downloads Git object data from all remotes every
11+
hour, reducing the amount of time for foreground `git fetch` calls.
12+
13+
* *Sparse-checkout:* limits the size of your working directory.
14+
15+
* *File system monitor:* tracks the recently modified files and eliminates
16+
the need for Git to scan the entire worktree.
17+
18+
* *Commit-graph:* accelerates commit walks and reachability calculations,
19+
speeding up commands like `git log`.
20+
21+
* *Multi-pack-index:* enables fast object lookups across many pack-files.
22+
23+
* *Incremental repack:* Repacks the packed Git data into fewer pack-file
24+
without disrupting concurrent commands by using the multi-pack-index.
25+
26+
By running `scalar register` in any Git repo, Scalar will automatically enable
27+
these features for that repo (except partial clone) and start running suggested
28+
maintenance in the background using
29+
[the `git maintenance` feature](https://git-scm.com/docs/git-maintenance).
30+
31+
Repos cloned with the `scalar clone` command use partial clone to significantly
32+
reduce the amount of data required to get started using a repository. By
33+
delaying all blob downloads until they are required, Scalar allows you to work
34+
with very large repositories quickly.
35+
36+
Documentation
37+
-------------
38+
39+
* [Getting Started](getting-started.md): Get started with Scalar.
40+
Includes `scalar register`, `scalar unregister`, `scalar clone`, and
41+
`scalar delete`.
42+
43+
* [Troubleshooting](troubleshooting.md):
44+
Collect diagnostic information or update custom settings. Includes
45+
`scalar diagnose`.
46+
47+
* [The Philosophy of Scalar](philosophy.md): Why does Scalar work the way
48+
it does, and how do we make decisions about its future?
49+
50+
* [Frequently Asked Questions](faq.md)

‎contrib/scalar/docs/philosophy.md

Lines changed: 66 additions & 0 deletions
Original file line numberDiff line numberDiff line change
@@ -0,0 +1,66 @@
1+
The Philosophy of Scalar
2+
========================
3+
4+
The team building Scalar has **opinions** about Git performance. Scalar
5+
takes out the guesswork by automatically configuring your Git repositories
6+
to take advantage of the latest and greatest features. It is difficult to
7+
say that these are the absolute best settings for every repository, but
8+
these settings do work for some of the largest repositories in the world.
9+
10+
Scalar intends to do very little more than the standard Git client. We
11+
actively implement new features into Git instead of Scalar, then update
12+
Scalar only to configure those new settings. In particular, we ported
13+
features like background maintenance to Git to make Scalar simpler and
14+
make Git more powerful.
15+
16+
Services such as GitHub support partial clone , a standard adopted by the Git
17+
project to download only part of the Git objects when cloning, and fetching
18+
further objects on demand. If your hosting service supports partial clone, then
19+
we absolutely recommend it as a way to greatly speed up your clone and fetch
20+
times and to reduce how much disk space your Git repository requires. Scalar
21+
will help with this!
22+
23+
Most of the value of Scalar can be found in the core Git client. However, most
24+
of the advanced features that really optimize Git's performance are off by
25+
default for compatibility reasons. To really take advantage of Git's latest and
26+
greatest features, you either need to study the [`git config`
27+
documentation](https://git-scm.com/docs/git-config) and regularly read [the Git
28+
release notes](https://github.com/git/git/tree/master/Documentation/RelNotes).
29+
Even if you do all that work and customize your Git settings on your machines,
30+
you likely will want to share those settings with other team members. Or, you
31+
can just use Scalar!
32+
33+
Using `scalar register` on an existing Git repository will give you these
34+
benefits:
35+
36+
* Additional compression of your `.git/index` file.
37+
* Hourly background `git fetch` operations, keeping you in-sync with your
38+
remotes.
39+
* Advanced data structures, such as the `commit-graph` and `multi-pack-index`
40+
are updated automatically in the background.
41+
* If using macOS or Windows, then Scalar configures Git's builtin File System
42+
Monitor, providing faster commands such as `git status` or `git add`.
43+
44+
Additionally, if you use `scalar clone` to create a new repository, then
45+
you will automatically get these benefits:
46+
47+
* Use Git's partial clone feature to only download the files you need for
48+
your current checkout.
49+
* Use Git's [sparse-checkout feature][sparse-checkout] to minimize the
50+
number of files required in your working directory.
51+
[Read more about sparse-checkout here.][sparse-checkout-blog]
52+
* Create the Git repository inside `<repo-name>/src` to make it easy to
53+
place build artifacts outside of the Git repository, such as in
54+
`<repo-name>/bin` or `<repo-name>/packages`.
55+
56+
We also admit that these **opinions** can always be improved! If you have
57+
an idea of how to improve our setup, consider
58+
[creating an issue](https://github.com/microsoft/scalar/issues/new) or
59+
contributing a pull request! Some [existing](https://github.com/microsoft/scalar/issues/382)
60+
[issues](https://github.com/microsoft/scalar/issues/388) have already
61+
improved our configuration settings and roadmap!
62+
63+
[gvfs-protocol]: https://github.com/microsoft/VFSForGit/blob/HEAD/Protocol.md
64+
[microsoft-git]: https://github.com/microsoft/git
65+
[sparse-checkout]: https://git-scm.com/docs/git-sparse-checkout
66+
[sparse-checkout-blog]: https://github.blog/2020-01-17-bring-your-monorepo-down-to-size-with-sparse-checkout/

‎contrib/scalar/docs/troubleshooting.md

Lines changed: 20 additions & 0 deletions
Original file line numberDiff line numberDiff line change
@@ -0,0 +1,20 @@
1+
Troubleshooting
2+
===============
3+
4+
Diagnosing Issues
5+
-----------------
6+
7+
The `scalar diagnose` command collects logs and config details for the current
8+
repository. The resulting zip file helps root-cause issues.
9+
10+
When run inside your repository, creates a zip file containing several important
11+
files for that repository. This includes:
12+
13+
* Configuration files from your `.git` folder, such as the `config` file,
14+
`index`, `hooks`, and `refs`.
15+
16+
* A summary of your Git object database, including the number of loose objects
17+
and the names and sizes of pack-files.
18+
19+
As the `diagnose` command completes, it provides the path of the resulting
20+
zip file. This zip can be attached to bug reports to make the analysis easier.

0 commit comments

Comments
 (0)