This PR changes how base texts are managed by the `buffer_diff` crate, to enable keeping two diff entities alive that share the same base text buffer entity. Previously, each diff owned its own base text buffer and edited it when calling `BufferDiff::set_snapshot`, so the only way to reuse the same base text between two diffs was to have two independent buffers for it, which is pretty inefficient. After this PR, each diff still has a base text buffer, but `set_snapshot` doesn't edit it. Instead, that responsibility moves into the caller. For updating the base text buffer, this PR also introduces a new pair of APIs, `Buffer::snapshot_with_edits` and `Buffer::fast_forward`, which allow us to move the parsing of the new base text into the background and then install the new syntax tree synchronously on the foreground. The git store uses the low-level APIs `set_snapshot` and `fast_forward` directly, and manages the head text and index text buffers itself (garbage-collecting them when they're no longer needed); this enables adding an `open_staged_diff` API which returns a diff between the managed index buffer and the managed head buffer (the latter is also used for the uncommitted diff's base text). Other downstreams don't need to reuse a base text buffer, and those have been migrated to use the high-level `set_base_text` API, which now calls `set_snapshot` and `fast_forward` internally, with a guard to prevent concurrent updates. Another change worthy of note is that we now always diff the old base text with the new base text to create `snapshot_with_edits`. There are also some incidental bug fixes: - Fixed an issue where a dangling weak unstaged diff could stick around in the git store forever - Restored the `IndexMatchesHead` optimization that had become inoperative in the remote case - Fixed a crash in the multibuffer due to the handling of `BufferDiffEvent::LanguageChanged`, which could cause the multibuffer to have transforms that were inconsistent with the diff base text. Self-Review Checklist: - [x] I've reviewed my own diff for quality, security, and reliability - [x] Unsafe blocks (if any) have justifying comments - [x] The content is consistent with the [UI/UX checklist](https://github.com/zed-industries/zed/blob/main/CONTRIBUTING.md#uiux-checklist) - [x] Tests cover the new/changed behavior - [x] Performance impact has been considered and is acceptable Closes ZED-81P Release Notes: - Fixed a rare crash that could occur while using the uncommitted diff. --------- Co-authored-by: Ben Kunkle <ben@zed.dev> Co-authored-by: Anthony Eid <hello@anthonyeid.me>
Zed Server
This crate is what we run at https://collab.zed.dev.
It contains our back-end logic for collaboration, to which we connect from the Zed client via a websocket after authenticating via https://zed.dev, which is a separate repo running on Vercel.
Local Development
Database setup
Before you can run the collab server locally, you'll need to set up a zed Postgres database. Follow the steps sequentially:
- Ensure you have postgres installed. If not, install with
brew install postgresql@15. - Follow the steps on Brew's formula and verify your
$PATHcontains/opt/homebrew/opt/postgresql@15/bin. - If you hadn't done it before, create the
postgresuser withcreateuser -s postgres. - You are now ready to run the
bootstrapscript:
script/bootstrap
This script will set up the zed Postgres database, and populate it with some users. It requires internet access, because it fetches some users from the GitHub API.
The script will create several admin users, who you'll sign in as by default when developing locally. The GitHub logins for the default users are specified in the seed.default.json file.
To use a different set of admin users, create crates/collab/seed.json.
{
"admins": ["yourgithubhere"],
"channels": ["zed"]
}
Testing collaborative features locally
In one terminal, run Zed's collaboration server and the livekit dev server:
foreman start
In a second terminal, run two or more instances of Zed.
script/zed-local -2
This script starts one to four instances of Zed, depending on the -2, -3 or -4 flags. Each instance will be connected to the local collab server, signed in as a different user from seed.json or seed.default.json.
Deployment
We run two instances of collab:
- Staging (https://staging-collab.zed.dev)
- Production (https://collab.zed.dev)
Both of these run on the Kubernetes cluster hosted in Digital Ocean.
Deployment is triggered by pushing to the collab-staging (or collab-production) tag in GitHub. The best way to do this is:
./script/deploy-collab staging./script/deploy-collab production
You can tell what is currently deployed with ./script/what-is-deployed.