Initial version

DataTransfer.Client/Components/ServerLoad.razor

@@ -0,0 +1,38 @@
+@implements IDisposable
+@inject ServerStatusMonitor Monitor
+
+@if (Monitor.Current is { } status)
+{
+    <span class="server-load @LoadClass(status)" title="@Describe(status)" data-testid="server-load">
+        <span class="server-load-dot" aria-hidden="true"></span>
+        <span class="server-load-count">@status.ActiveConnections/@status.MaxConnections</span>
+        <span class="server-load-label">connections</span>
+        @if (status.QueuedClients > 0)
+        {
+            <span class="server-load-queue">· @status.QueuedClients queued</span>
+        }
+    </span>
+}
+
+@code {
+
+    protected override void OnInitialized()
+    {
+        Monitor.Changed += OnMonitorChanged;
+        Monitor.EnsureStarted();
+    }
+
+    public void Dispose() => Monitor.Changed -= OnMonitorChanged;
+
+    private void OnMonitorChanged() => _ = InvokeAsync(StateHasChanged);
+
+    private static string LoadClass(ServerStatus status) =>
+        status.ActiveConnections >= status.MaxConnections ? "is-full"
+        : status.ActiveConnections * 5 >= status.MaxConnections * 4 ? "is-high"
+        : "is-ok";
+
+    private static string Describe(ServerStatus status) =>
+        $"{status.ActiveConnections} of {status.MaxConnections} connections in use"
+        + (status.QueuedClients > 0 ? $", {status.QueuedClients} waiting in the queue" : null);
+
+}