Files
gitea/services/pubsub/memory.go
mohammad rahimi 13d0f24423 feat: Replace SSE with WebSocket for UI notifications (#36965)
* Closes #36942
* Fixes #19265 

Replaces the SSE-based push channel (`/user/events`) with a WebSocket
endpoint (`/-/ws`).

### What changes

- **New `/-/ws` endpoint** (authenticated). One WebSocket per origin,
shared across tabs via a single `SharedWorker`.
- **Pubsub broker** (`services/pubsub`) for fan-out by topic, behind a
`Broker` interface. `MemoryBroker` is the default (single process); a
Redis backend is available for multi-process setups, configured via
`[websocket].PUBSUB_TYPE` / `PUBSUB_CONN_STR`. The internal Gitea queue
was not usable here because it has FIFO/single-consumer semantics.
- **Push-only event production.** Events are emitted by write-triggered
notifiers — `NotificationCountChange`, `PublishStopwatchesForUser`, and
the logout publisher — wired into the existing `notify.Notifier`
interface. No server-side pollers.
- **Typed pub/sub on the client.** `web_src/js/modules/worker.ts` is a
singleton transport; features subscribe per event type via
`onUserEvent('notification-count', cb)` instead of branching on
`event.data.type`.
- **Wire contract** (`UserEventType` union) is shared between the worker
and consumers via `web_src/js/types.ts`, kept in sync with
`services/websocket/events.go`.
- **Client-side periodic polling fallback** kicks in only when the
WebSocket cannot be established (e.g. proxy blocks WS, browser lacks
module-SharedWorker support).

### What's removed

- `modules/eventsource` (SSE manager, run loop, messenger).
- `/user/events` route and `tests/integration/eventsource_test.go`.
- All server-side polling for stopwatches and notification counts.

### Stopwatch multi-tab fix

The navbar stopwatch icon was previously rendered conditionally on `{{if
$activeStopwatch}}`, so tabs loaded before the timer started had no DOM
element to update. The icon and popup are now always rendered (toggled
with `tw-hidden`), and the start/stop/cancel handlers POST silently so
all open tabs reflect the change in real time.

### Deployment note

WebSocket needs the upgrade headers to pass through a reverse proxy,
e.g. for nginx:

```nginx
proxy_set_header Upgrade $http_upgrade;
proxy_set_header Connection "upgrade";
```

Without them the WebSocket cannot be established, and after 3
consecutive failed opens the shared worker signals `push-unavailable`:
the notification count and stopwatch fall back to periodic polling on
the existing `[ui.notification]` timeouts. Real-time push is lost, the
features keep working. The reverse-proxy docs need the same note (see
the `docs-update-needed` label).

---------

Co-authored-by: silverwind <me@silverwind.io>
Co-authored-by: wxiaoguang <wxiaoguang@gmail.com>
Co-authored-by: Epid <rexmrj@gmail.com>
2026-07-27 07:46:00 +00:00

72 lines
1.5 KiB
Go

// Copyright 2026 The Gitea Authors. All rights reserved.
// SPDX-License-Identifier: MIT
package pubsub
import (
"sync"
"gitea.dev/modules/log"
"gitea.dev/modules/util"
)
// MemoryBroker fans out within a single process. Suitable for single-instance
// deployments; multi-process deployments need a backend that crosses processes.
type MemoryBroker struct {
mu sync.RWMutex
subs map[string][]chan []byte
}
var _ Broker = (*MemoryBroker)(nil)
func NewMemoryBroker() *MemoryBroker {
return &MemoryBroker{
subs: make(map[string][]chan []byte),
}
}
func (b *MemoryBroker) Subscribe(topic string) (<-chan []byte, func()) {
ch := make(chan []byte, subChanBuffer)
b.mu.Lock()
b.subs[topic] = append(b.subs[topic], ch)
b.mu.Unlock()
var once sync.Once
cancel := func() {
once.Do(func() {
b.mu.Lock()
defer b.mu.Unlock()
subs := util.SliceRemoveAll(b.subs[topic], ch)
if len(subs) == 0 {
delete(b.subs, topic)
} else {
b.subs[topic] = subs
}
close(ch)
})
}
return ch, cancel
}
func (b *MemoryBroker) HasTopicSubscribers(topic string) bool {
b.mu.RLock()
defer b.mu.RUnlock()
return len(b.subs[topic]) > 0
}
// Non-blocking: slow subscribers drop. RLock held across fan-out to block
// cancel() from closing a channel between slice read and send.
func (b *MemoryBroker) Publish(topic string, msg []byte) {
b.mu.RLock()
defer b.mu.RUnlock()
for _, ch := range b.subs[topic] {
select {
case ch <- msg:
default:
log.Trace("pubsub: dropping message on topic %q — subscriber channel full", topic)
}
}
}