Migrate editor to use remote backed buffer by kevinyang372 · Pull Request #10520 · warpdotdev/warp

kevinyang372 · 2026-05-08T21:16:32Z

Description

Wire editor to use remote backed buffer. A few noteable things:

LocalCodeEditor (I will change its name in a follow-up) now takes a FileLocation, which could be a local / remote file
Existing LocalCodeEditor concepts like conflict resolution banner is now hooked up with the remote logic

Also fixed a bug where server detected conflicts aren't being properly forwarded to the client

This also removes the remote file tree gating on not opening files

Testing

Tested locally

oz-for-oss · 2026-05-08T21:16:44Z

@kevinyang372

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kevinyang372 · 2026-05-08T21:16:47Z

Migrate editor to use remote backed buffer #10520 👈 (View in Graphite)
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oz-for-oss

Overview

This PR wires the code editor and file tree to open and save remote-backed buffers, adds conflict notifications, and extends buffer tracking for server-local buffers.

Concerns

Remote OpenBuffer responses can still replace the editable buffer unconditionally, which can drop user edits made before the initial load completes.
Local file-tree CodeSource state no longer persists its file path because the only location field is skipped by serde.
Remote save failure handling can clear the dirty state even when the save failed.
Discarding a remote conflict by closing and reopening the buffer does not guarantee a disk reload when another connection still has that server buffer open.

Found: 1 critical, 3 important, 0 suggestions

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oz-for-oss · 2026-05-08T21:28:53Z

+        // (which contains stale client edits). The subsequent OpenBuffer
+        // will create a fresh buffer and read from disk.
+        let path_for_close = path_str.clone();
+        client.close_buffer(path_for_close);


⚠️ [IMPORTANT] Discarding a remote conflict by sending CloseBuffer does not force a fresh disk read when another connection still has the same server buffer open; the server keeps the stale in-memory buffer and the subsequent OpenBuffer can return it again. Use an explicit reload/accept-server RPC or otherwise force the server to reopen from disk.

This is a very good call. Updated to have a force_reload flag for opening buffers

moirahuang

the delay is kinda long when overwriting, can we auto dismiss and then bring back the banner if it fails to save
https://github.com/user-attachments/assets/56e11d37-251f-4329-8c02-0692982b22e6
when we discard, we aren't correctly writing the first time. it only correctly writes the 2nd time
https://github.com/user-attachments/assets/221b8d00-f826-48da-8e03-ca39d395637e

moirahuang · 2026-05-08T23:38:03Z


        match item {
            FileTreeItem::File { metadata, .. } => {
-                // Remote file trees don't support opening files in the editor.


very niceeeee

moirahuang · 2026-05-08T23:41:56Z

+            let manager = RemoteServerManager::handle(ctx);
            manager.as_ref(ctx).client_for_host(&host_id).cloned()
        };
+        log::debug!(


nit: do we need the log debugs here and below?

I will keep this for now in case of future debugging

moirahuang · 2026-05-09T00:04:20Z

+                    return;
+                };
+                if let BufferSource::Remote { sync_clock, .. } = &mut state.source {
+                    *sync_clock = Some(SyncClock::from_wire(response.server_version, 0));


why do we save this version as 0 vs. the latest version?

moirahuang

higher level comment, i think there's some log::debugs that can be cleaned up

moirahuang · 2026-05-12T02:46:10Z

+                                .unwrap_or_else(|| path.clone());
                            self.watcher.update(ctx, |watcher, _ctx| {
-                                std::mem::drop(watcher.unregister_path(path.as_path()));
+                                std::mem::drop(watcher.unregister_path(&watch_path));


should we reference count here so if there's other paths to the parent directory we don't unconditionally drop?

moirahuang · 2026-05-12T02:56:00Z

+                    let new_server_version =
+                        if let BufferSource::ServerLocal { sync_clock, .. } = &mut state.source {
+                            let sv = sync_clock.bump_server();
+                            // Reset client version since the buffer is fresh from disk.


i see you added this comment but i'm sorry :woman-bowing: i still don't understand why it's reset vs. being the latest disk version

This is necessary. The client to server contract is a newly opened buffer starts with client version 0 (which makes sense because it's fresh). If we don't reset here, server and client will disagree about their tracked client version on the next sync

## Description Wire editor to use remote backed buffer. A few noteable things: 1. LocalCodeEditor (I will change its name in a follow-up) now takes a FileLocation, which could be a local / remote file 2. Existing LocalCodeEditor concepts like conflict resolution banner is now hooked up with the remote logic Also fixed a bug where server detected conflicts aren't being properly forwarded to the client This also removes the remote file tree gating on not opening files ## Testing Tested locally

cla-bot Bot added the cla-signed label May 8, 2026

oz-for-oss Bot reviewed May 8, 2026

View reviewed changes

kevinyang372 requested a review from moirahuang May 8, 2026 22:54

moirahuang reviewed May 9, 2026

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moirahuang reviewed May 12, 2026

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moirahuang approved these changes May 12, 2026

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kevinyang372 added 12 commits May 12, 2026 00:22

Migrate editor to use remote backed buffer

5dcf833

e2e

0373859

self-revie

4493fd7

self-review

157af26

nit

7dab93c

fix reload

721c7e4

nit

91ecde7

improve

e84c772

fix individual file watcher registration

5876622

fix

6995b13

cleanup log

b9e441d

comment

1b3f6b0

kevinyang372 force-pushed the kevin/migrate-editor-to-use-remote-buffer branch from 8787b06 to 1b3f6b0 Compare May 12, 2026 04:33

kevinyang372 enabled auto-merge (squash) May 12, 2026 04:34

comment

698518a

kevinyang372 merged commit c83e1ef into master May 12, 2026
25 of 26 checks passed

kevinyang372 deleted the kevin/migrate-editor-to-use-remote-buffer branch May 12, 2026 05:04

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kevinyang372 commented May 8, 2026 •

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oz-for-oss Bot commented May 8, 2026 •

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