Scalar

What is Scalar?

Scalar is a C# application that manages large Git repositories. It adds abilities like on-demand object retrieval, background maintenance tasks, and automatically sets Git config values and hooks that enable performance enhancements. Scalar also assists in setting up sparse enlistments.

Table of Contents

• Building Scalar on Windows
• Building Scalar on Mac
• Trying Scalar
• License

Installing on macOS

To install Scalar on macOS, download the .zip from the releases page. Extract the Scalar.Distribution folder, cd into it, and run ./InstallScalar.sh in a Terminal window. The script may prompt for your password as it installs the following components:

• Git (with custom patches)
• Git Credential Manager Core
• Scalar

Quick Start

If you want to get a feel for an initial workflow with a test project, here are some commands that clone our test repo and initialize some of the sparse content.

(Run these commands in Mac OSX Terminal or in Git Bash on Windows.)

$ scalar clone https://dev.azure.com/gvfs/ci/_git/ForTests
Clone parameters:
  Repo URL:     https://dev.azure.com/gvfs/ci/_git/ForTests
  Branch:       Default
  Cache Server: Default
  Local Cache:  C:\.scalarCache
  Destination:  C:\_git\ForTests
  FullClone:     False
Authenticating...Succeeded
Querying remote for config...Succeeded
Using cache server: None (https://dev.azure.com/gvfs/ci/_git/ForTests)
Cloning...Succeeded
Fetching commits and trees from origin (no cache server)...Succeeded
Configuring Watchman...Succeeded.
Validating repo...Succeeded
Mounting...Succeeded
Registering for automount...Succeeded

$ cd ForTests/src
$ ls
AuthoringTests.md  GvFlt_EULA.md  GVFS.sln  License.md  nuget.config  Protocol.md  Readme.md  Settings.StyleCop

$ scalar sparse --add="GVFS/GVFS.Common;GVFS/GVFS.UnitTests;GitHooksLoader"
Authenticating...Succeeded
Querying remote for config...Succeeded
Configured cache server: None (https://dev.azure.com/gvfs/ci/_git/ForTests)
Fetching blobs from origin (no cache server)...Succeeded

Stats:
  Matched blobs:    168
  Already cached:   168
  Downloaded:       0

$ ls
AuthoringTests.md  GitHooksLoader/  GvFlt_EULA.md  GVFS/  GVFS.sln  License.md  nuget.config  Protocol.md  Readme.md  Settings.StyleCop

$ ls GVFS
GVFS.Common/  GVFS.UnitTests/  LibGit2Sharp.NativeBinaries.props  ProjectedFSLib.NativeBinaries.props

$ scalar sparse --add="GVFS/GVFS"
Authenticating...Succeeded
Querying remote for config...Succeeded
Configured cache server: None (https://dev.azure.com/gvfs/ci/_git/ForTests)
Fetching blobs from origin (no cache server)...Succeeded

Stats:
  Matched blobs:    48
  Already cached:   48
  Downloaded:       0

$ ls GVFS
GVFS/  GVFS.Common/  GVFS.UnitTests/  LibGit2Sharp.NativeBinaries.props  ProjectedFSLib.NativeBinaries.props

$ scalar status
Enlistment root: C:\_git\ForTests
Repo URL: https://dev.azure.com/gvfs/ci/_git/ForTests
Cache Server: None (https://dev.azure.com/gvfs/ci/_git/ForTests)
Local Cache: C:\.scalarCache
Mount status: Ready
Background operations: 0
Disk layout version: 0.0

$ scalar unmount
Unmounting...Succeeded
Unregistering automount...Succeeded

$ scalar status
Unable to connect to Scalar.  Try running 'scalar mount'

Building Scalar on Windows

If you'd like to build your own Scalar Windows installer:

• Install Visual Studio 2017 Community Edition or higher (https://www.visualstudio.com/downloads/).
  • Include the following workloads:
    • .NET desktop development
    • Desktop development with C++
    • .NET Core cross-platform development
  • Include the following additional components:
    • .NET Core runtime
    • Windows 10 SDK (10.0.10586.0)
• Install the .NET Core 2.1 SDK (https://www.microsoft.com/net/download/dotnet-core/2.1)
• Create a folder to clone into, e.g. C:\Repos\Scalar
• Clone this repo into the src subfolder, e.g. C:\Repos\Scalar\src
• Run \src\Scripts\BuildScalarForWindows.bat
• You can also build in Visual Studio by opening src\Scalar.sln (do not upgrade any projects) and building. However, the very first build will fail, and the second and subsequent builds will succeed. This is because the build requires a prebuild code generation step. For details, see the build script in the previous step.

You can also use Visual Studio 2019. There are a couple of options for getting all the dependencies.

• You can install Visual Studio 2017 side by side with Visual Studio 2019, and make sure that you have all the dependencies from Visual Studio 2017 installed
• Alternatively, if you only want to have Visual Studio 2019 installed, install the following extra dependency:
  • MSVC v141 VS 2017 C++ build tools via the optional components in the Visual Studio 2019 installer.

Visual Studio 2019 will automatically prompt you to install these dependencies when you open the solution.

The installer can now be found at <repo root>\Scalar\BuildOutput\Scalar.Installer.Windows\bin\x64\[Debug|Release]\SetupScalar.<version>.exe

Building Scalar on Mac

Note that Scalar on Mac is under active development.

• Ensure you have Xcode installed, have accepted the terms of use, and have launched Xcode at least once.

• Install Visual Studio for Mac . (This will also install the dotnet CLI).

• If you still do not have the dotnet cli >= v2.1.300 installed [manually install it]. You can check what version you have with dotnet --version.(https://www.microsoft.com/net/download/dotnet-core/2.1)

• Create a Scalar directory and Clone Scalar into a directory called src inside it:

  mkdir Scalar
  cd Scalar
  git clone https://github.com/microsoft/scalar.git src
  

• Run the build and installation scripts:

  cd src/Scripts/Mac
  ./BuildScalarForMac.sh
  ./CreateScalarDistribution.sh
  ../../../BuildOutput/Scalar.Distribution/InstallScalar.sh
  

  Troubleshooting if this fails

  If you get

  xcodebuild: error: SDK "macosx10.13" cannot be located.
  

  You may have the "Xcode Command Line Tools" installed (helpfully by Mac OS) instead of full Xcode. Make sure

  xcode-select -p
  

  shows /Applications/Xcode.app/Contents/Developer. If it does not, install Xcode and then launch it (you can close it afterwards.)

Trying Scalar

Scalar will work with any Git service that supports the GVFS protocol. For example, you can clone a repo that is hosted in Azure DevOps.

Sparse Repo Mode

By default, Scalar reduces your working directory to the bare minimum. You need to add the folders you care about to build up to your working set.

• scalar clone <URL of repo you just created>
  • Please choose the Clone with HTTPS option in the Clone Repository dialog in Azure Repos, not Clone with SSH.
• cd <root>\src
• At this point, your src directory only contains files that appear in your root tree. No folders are populated.
• Add folders to your sparse-checkout using:
  1. scalar sparse --add="folder1;folder2;..."
  2. scalar sparse --add-stdin <folder-list.txt
• After running scalar sparse, you will have the requested folders populated.
• Run git commands as you normally would.
• scalar unmount when done.

Full Repo Mode

You can also clone a repo and checkout the full working directory.

• scalar clone --full-clone <URL of repo you just created>
  • Please choose the Clone with HTTPS option in the Clone Repository dialog in Azure Repos, not Clone with SSH.
• cd <root>\src
• Run git commands as you normally would
• scalar unmount when done

License

The Scalar source code in this repo is available under the MIT license. See License.md.