b6e9844eca
Summary: This is the basic framework for some new tests for `eden fsck` that work by unpacking one of the existing saved snapshot files, breaking it in various ways, and then running `eden fsck` to fix it. Using an existing snapshot file rather than creating a new mount point on the fly in the test has a few advantages: - This lets us confirm that newer versions of Eden can still correctly repair and mount old file formats, even if we update the mount point data formats in the future. - Unpacking a snapshot is much faster than starting Eden, creating an hg repository, cloning a new Eden checkout from the repo, and then unmounting the checkout. - The inode number allocations for the snapshot are fixed, which makes it easier for the test code to manipulate specific inode numbers and always know which path this refers to. If we created a mount point on the fly we can't guarantee ahead of time which inode numbers would map to each file, and we would need to do more work to look up this information after creating the checkout. These tests are pretty basic at the moment, but I plan to expand them as I check in more of the fsck logic to repair errors. Reviewed By: wez Differential Revision: D12955045 fbshipit-source-id: 5d5a96cec812f8e72caf93e57bf0f1311e28aab8 |
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|---|---|---|
| CMake | ||
| common | ||
| eden | ||
| .gitignore | ||
| CMakeLists.txt | ||
| CONTRIBUTING.md | ||
| getdeps.py | ||
| LICENSE | ||
| PATENTS | ||
| README.md | ||
EdenFS is a FUSE virtual filesystem for source control repositories.
EdenFS speeds up operations in large repositories by only populating working
directory files on demand, as they are accessed. This makes operations like
checkout much faster, in exchange for a small performance hit when first
accessing new files. This is quite beneficial in large repositories where
developers often only work with a small subset of the repository at a time.
EdenFS has similar performance advantages to using sparse checkouts, but a much better user experience. Unlike with sparse checkouts, EdenFS does not require manually curating the list of files to check out, and users can transparently access any file without needing to update the profile.
EdenFS also keeps track of which files have been modified, allowing very
efficient status queries that do not need to scan the working directory.
The filesystem monitoring tool Watchman
also integrates with EdenFS, allowing it to more efficiently track updates to
the filesystem.
Building EdenFS
EdenFS currently only builds on Linux. We have primarily tested building it on Ubuntu 18.04.
TL;DR
[eden]$ ./getdeps.py --system-deps
[eden]$ mkdir _build && cd _build
[eden/_build]$ cmake ..
[eden/_build]$ make
Dependencies
EdenFS depends on several other third-party projects. Some of these are commonly available as part of most Linux distributions, while others need to be downloaded and built from GitHub.
The getdeps.py script can be used to help download and build EdenFS's
dependencies.
Operating System Dependencies
Running getdeps.py with --system-deps will make it install third-party
dependencies available from your operating system's package management system.
Without this argument it assumes you already have correct OS dependencies
installed, and it only updates and builds dependencies that must be compiled
from source.
GitHub Dependencies
By default getdeps.py will check out third-party dependencies into the
eden/external/ directory, then build and install them into
eden/external/install/
If repositories for some of the dependencies are already present in
eden/external/ getdeps.py does not automatically fetch the latest upstream
changes from GitHub. You can explicitly run ./getdeps.py --update if you
want it to fetch the latest updates for each dependency and rebuild them from
scratch.