TODO:
- [x] merge main
- [x] nonshrinking `set_excerpts_for_path`
- [x] Test-drive potential problem areas in the app
- [x] prepare cloud side
- [x] test collaboration
- [ ] docstrings
- [ ] ???
## Context
### Background
Currently, a multibuffer consists of an arbitrary list of
anchor-delimited excerpts from individual buffers. Excerpt ranges for a
fixed buffer are permitted to overlap, and can appear in any order in
the multibuffer, possibly separated by excerpts from other buffers.
However, in practice all code that constructs multibuffers does so using
the APIs defined in the `path_key` submodule of the `multi_buffer` crate
(`set_excerpts_for_path` etc.) If you only use these APIs, the resulting
multibuffer will maintain the following invariants:
- All excerpts for the same buffer appear contiguously in the
multibuffer
- Excerpts for the same buffer cannot overlap
- Excerpts for the same buffer appear in order
- The placement of the excerpts for a specific buffer in the multibuffer
are determined by the `PathKey` passed to `set_excerpts_for_path`. There
is exactly one `PathKey` per buffer in the multibuffer
### Purpose of this PR
This PR changes the multibuffer so that the invariants maintained by the
`path_key` APIs *always* hold. It's no longer possible to construct a
multibuffer with overlapping excerpts, etc. The APIs that permitted
this, like `insert_excerpts_with_ids_after`, have been removed in favor
of the `path_key` suite.
The main upshot of this is that given a `text::Anchor` and a
multibuffer, it's possible to efficiently figure out the unique excerpt
that includes that anchor, if any:
```
impl MultiBufferSnapshot {
fn buffer_anchor_to_anchor(&self, anchor: text::Anchor) -> Option<multi_buffer::Anchor>;
}
```
And in the other direction, given a `multi_buffer::Anchor`, we can look
at its `text::Anchor` to locate the excerpt that contains it. That means
we don't need an `ExcerptId` to create or resolve
`multi_buffer::Anchor`, and in fact we can delete `ExcerptId` entirely,
so that excerpts no longer have any identity outside their
`Range<text::Anchor>`.
There are a large number of changes to `editor` and other downstream
crates as a result of removing `ExcerptId` and multibuffer APIs that
assumed it.
### Other changes
There are some other improvements that are not immediate consequences of
that big change, but helped make it smoother. Notably:
- The `buffer_id` field of `text::Anchor` is no longer optional.
`text::Anchor::{MIN, MAX}` have been removed in favor of
`min_for_buffer`, etc.
- `multi_buffer::Anchor` is now a three-variant enum (inlined slightly):
```
enum Anchor {
Min,
Excerpt {
text_anchor: text::Anchor,
path_key_index: PathKeyIndex,
diff_base_anchor: Option<text::Anchor>,
},
Max,
}
```
That means it's no longer possible to unconditionally access the
`text_anchor` field, which is good because most of the places that were
doing that were buggy for min/max! Instead, we have a new API that
correctly resolves min/max to the start of the first excerpt or the end
of the last excerpt:
```
impl MultiBufferSnapshot {
fn anchor_to_buffer_anchor(&self, anchor: multi_buffer::Anchor) -> Option<text::Anchor>;
}
```
- `MultiBufferExcerpt` has been removed in favor of a new
`map_excerpt_ranges` API directly on `MultiBufferSnapshot`.
## Self-Review Checklist
<!-- Check before requesting review: -->
- [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
Release Notes:
- N/A
---------
Co-authored-by: Conrad Irwin <conrad.irwin@gmail.com>
Co-authored-by: Piotr Osiewicz <24362066+osiewicz@users.noreply.github.com>
Co-authored-by: Jakub Konka <kubkon@jakubkonka.com>
Co-authored-by: Conrad <conrad@zed.dev>
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.