Adding upstream version 0.28.1.

Signed-off-by: Daniel Baumann <daniel@debian.org>

tools/subscriptions/broker.go

@@ -0,0 +1,65 @@
+package subscriptions
+
+import (
+	"fmt"
+
+	"github.com/pocketbase/pocketbase/tools/list"
+	"github.com/pocketbase/pocketbase/tools/store"
+)
+
+// Broker defines a struct for managing subscriptions clients.
+type Broker struct {
+	store *store.Store[string, Client]
+}
+
+// NewBroker initializes and returns a new Broker instance.
+func NewBroker() *Broker {
+	return &Broker{
+		store: store.New[string, Client](nil),
+	}
+}
+
+// Clients returns a shallow copy of all registered clients indexed
+// with their connection id.
+func (b *Broker) Clients() map[string]Client {
+	return b.store.GetAll()
+}
+
+// ChunkedClients splits the current clients into a chunked slice.
+func (b *Broker) ChunkedClients(chunkSize int) [][]Client {
+	return list.ToChunks(b.store.Values(), chunkSize)
+}
+
+// TotalClients returns the total number of registered clients.
+func (b *Broker) TotalClients() int {
+	return b.store.Length()
+}
+
+// ClientById finds a registered client by its id.
+//
+// Returns non-nil error when client with clientId is not registered.
+func (b *Broker) ClientById(clientId string) (Client, error) {
+	client, ok := b.store.GetOk(clientId)
+	if !ok {
+		return nil, fmt.Errorf("no client associated with connection ID %q", clientId)
+	}
+
+	return client, nil
+}
+
+// Register adds a new client to the broker instance.
+func (b *Broker) Register(client Client) {
+	b.store.Set(client.Id(), client)
+}
+
+// Unregister removes a single client by its id and marks it as discarded.
+//
+// If client with clientId doesn't exist, this method does nothing.
+func (b *Broker) Unregister(clientId string) {
+	client := b.store.Get(clientId)
+	if client == nil {
+		return
+	}
+	client.Discard()
+	b.store.Remove(clientId)
+}