P8(1): restore homepage overview curves on a memory-only sampling ring

Backend: new overviewMetrics store — a single-tier (2s x 360 = 12min)
in-memory ring fed by ServerService.RefreshStatus for exactly the eight
overview series (cpu/mem/swap/diskUsage/netUp/netDown/tcpCount/udpCount).
No persistence, no gob snapshot, no system-history page: the only surface
is GET /panel/api/server/history/:metric/:bucket restricted to those
keys, which seeds the frontend curves. ~46KB bounded by construction;
the ring starts empty on every panel start.

Frontend: restore useOverviewHistory + the VitalTile/ThroughputCard/
ConnectionsCard sparklines and the IndexPage wiring exactly as they
were before P7 removed them along with the history module.

internal/web/controller/server.go

@@ -4,6 +4,7 @@ import (
 	"fmt"
 	"net/http"
 	"regexp"
+	"slices"
 	"strconv"
 
 	"github.com/mhsanaei/3x-ui/v3/internal/database/model"
@@ -39,6 +40,7 @@ func NewServerController(g *gin.RouterGroup) *ServerController {
 // initRouter sets up the routes for server status, Xray management, and utility endpoints.
 func (a *ServerController) initRouter(g *gin.RouterGroup) {
 	g.GET("/status", a.status)
+	g.GET("/history/:metric/:bucket", a.getOverviewHistoryBucket)
 	g.GET("/getPanelUpdateInfo", a.getPanelUpdateInfo)
 	g.GET("/getUpdateStatus", a.getUpdateStatus)
 	g.GET("/getConfigJson", a.getConfigJson)
@@ -86,6 +88,25 @@ func (a *ServerController) startTask() {
 // status returns the current server status information.
 func (a *ServerController) status(c *gin.Context) { jsonObj(c, a.serverService.LastStatus(), nil) }
 
+// getOverviewHistoryBucket returns up to 60 buckets of one homepage
+// overview metric (see service.OverviewMetricKeys). It backs only the
+// index-page sparkline seed; the store behind it is the memory-only
+// overview ring — not the removed system-history API (no other metrics,
+// no persistence, nothing to browse beyond the overview window).
+func (a *ServerController) getOverviewHistoryBucket(c *gin.Context) {
+	metric := c.Param("metric")
+	if !slices.Contains(service.OverviewMetricKeys, metric) {
+		jsonMsg(c, "invalid metric", fmt.Errorf("unknown metric"))
+		return
+	}
+	bucket, err := strconv.Atoi(c.Param("bucket"))
+	if err != nil || bucket <= 0 || !service.IsAllowedHistoryBucket(bucket) {
+		jsonMsg(c, "invalid bucket", fmt.Errorf("unsupported bucket"))
+		return
+	}
+	jsonObj(c, a.serverService.AggregateOverviewMetric(metric, bucket, 60), nil)
+}
+
 func (a *ServerController) getFail2banStatus(c *gin.Context) {
 	jsonObj(c, a.serverService.GetFail2banStatus(), nil)
 }

internal/web/service/metric_history.go

@@ -87,8 +87,12 @@ type series struct {
 }
 
 func newSeries() *series {
-	s := &series{tiers: make([]*tierBuf, len(metricTiers))}
-	for i, spec := range metricTiers {
+	return newSeriesWithTiers(metricTiers)
+}
+
+func newSeriesWithTiers(specs []tierSpec) *series {
+	s := &series{tiers: make([]*tierBuf, len(specs))}
+	for i, spec := range specs {
 		s.tiers[i] = &tierBuf{resolution: spec.resolution, capacity: spec.capacity}
 	}
 	return s
@@ -112,14 +116,20 @@ func (s *series) pickTier(spanSeconds int64) *tierBuf {
 }
 
 // metricHistory is a thread-safe, in-memory store of tiered series keyed by
-// arbitrary strings. One singleton lives below: per-node metrics.
+// arbitrary strings. Two singletons live below: per-node metrics (full
+// rollup ladder) and the homepage overview series (one small fixed ring).
 type metricHistory struct {
 	mu     sync.Mutex
+	tiers  []tierSpec
 	series map[string]*series
 }
 
 func newMetricHistory() *metricHistory {
-	return &metricHistory{series: map[string]*series{}}
+	return newMetricHistoryWithTiers(metricTiers)
+}
+
+func newMetricHistoryWithTiers(tiers []tierSpec) *metricHistory {
+	return &metricHistory{tiers: tiers, series: map[string]*series{}}
 }
 
 // append stores a single sample for the given metric across all tiers.
@@ -128,7 +138,7 @@ func (h *metricHistory) append(metric string, t time.Time, v float64) {
 	defer h.mu.Unlock()
 	s := h.series[metric]
 	if s == nil {
-		s = newSeries()
+		s = newSeriesWithTiers(h.tiers)
 		h.series[metric] = s
 	}
 	s.add(t.Unix(), v)
@@ -208,12 +218,27 @@ func (h *metricHistory) aggregate(metric string, bucketSeconds int, maxPoints in
 	return out
 }
 
-// nodeMetrics is the remaining singleton: per-node CPU/Mem/net series fed by
-// NodeHeartbeatJob (via UpdateHeartbeat) and read by the node history panel.
-// The whole-host system series and the xray expvar series that used to live
-// here were removed with the system-history and xray-metrics features,
-// together with the gob persistence of the host series.
+// nodeMetrics holds per-node CPU/Mem/net series fed by NodeHeartbeatJob
+// (via UpdateHeartbeat) and read by the node history panel. The whole-host
+// system series and the xray expvar series that used to live here were
+// removed with the system-history and xray-metrics features, together with
+// the gob persistence of the host series.
 var nodeMetrics = newMetricHistory()
 
 // NodeMetricKeys lists the per-node metric names NodeHeartbeatJob writes.
 var NodeMetricKeys = []string{"cpu", "mem", "netUp", "netDown"}
+
+// overviewMetrics is the homepage overview store (P8): a deliberately small,
+// memory-only ring feeding the index-page sparkline seed — NOT a revival of
+// the removed system-history feature. One tier at the status cadence (2s)
+// holding 360 samples = a 12-minute window; eight series of 360 samples are
+// ~46 KB of payload, bounded by construction. Nothing is persisted: the
+// ring starts empty on every panel start and the overview curves simply
+// accumulate from there.
+var overviewMetrics = newMetricHistoryWithTiers([]tierSpec{{resolution: 2, capacity: 360}})
+
+// OverviewMetricKeys lists the host metric names ServerService writes on
+// every status sample for the homepage overview. It matches the frontend
+// useOverviewHistory SERIES_KEYS exactly; the controller validates incoming
+// history requests against this allow-list.
+var OverviewMetricKeys = []string{"cpu", "mem", "swap", "diskUsage", "netUp", "netDown", "tcpCount", "udpCount"}

internal/web/service/overview_history_test.go

@@ -0,0 +1,67 @@
+package service
+
+import (
+	"testing"
+	"time"
+)
+
+// The overview ring is a fresh store per test (the package singleton is fed
+// by RefreshStatus in production); these tests pin its contract: only the
+// overview keys are written by AppendOverviewSample, samples come back
+// through AggregateOverviewMetric, and the window is hard-bounded by the
+// single tier's capacity no matter how long the panel runs.
+
+func overviewTestStatus(cpu float64) *Status {
+	st := &Status{Cpu: cpu, TcpCount: 3, UdpCount: 2}
+	st.Mem.Current = 1
+	st.Mem.Total = 4
+	st.Swap.Current = 0
+	st.Swap.Total = 0
+	st.Disk.Current = 1
+	st.Disk.Total = 2
+	st.NetIO.Up = 100
+	st.NetIO.Down = 200
+	return st
+}
+
+func TestOverviewRingAppendAndAggregate(t *testing.T) {
+	s := &ServerService{}
+	base := time.Now().Add(-10 * time.Second).Truncate(2 * time.Second)
+	for i := range 5 {
+		s.AppendOverviewSample(base.Add(time.Duration(i*2)*time.Second), overviewTestStatus(float64(i)))
+	}
+	// overviewMetrics is the package singleton; the samples just appended
+	// must be visible through the aggregate the controller serves.
+	out := s.AggregateOverviewMetric("cpu", 2, 60)
+	if len(out) == 0 {
+		t.Fatal("AggregateOverviewMetric(cpu) returned no points after appends")
+	}
+	last := out[len(out)-1]
+	if got, _ := last["v"].(float64); got != 4 {
+		t.Fatalf("last cpu point = %v, want 4", last["v"])
+	}
+	for _, key := range OverviewMetricKeys {
+		if pts := s.AggregateOverviewMetric(key, 2, 60); len(pts) == 0 {
+			t.Fatalf("overview key %q has no points after AppendOverviewSample", key)
+		}
+	}
+}
+
+func TestOverviewRingIsBounded(t *testing.T) {
+	h := newMetricHistoryWithTiers([]tierSpec{{resolution: 2, capacity: 360}})
+	base := time.Unix(1_700_000_000, 0)
+	// Feed ten windows' worth of samples; the ring must not grow past its
+	// single tier capacity.
+	for i := range 3600 {
+		h.append("cpu", base.Add(time.Duration(i*2)*time.Second), float64(i))
+	}
+	// readSamples returns the closed buckets plus the still-open one, so the
+	// hard bound is capacity+1.
+	raw := h.series["cpu"].tiers[0].readSamples()
+	if len(raw) > 361 {
+		t.Fatalf("overview tier retained %d samples, want <= 361 (capacity + open bucket)", len(raw))
+	}
+	if len(raw) == 0 {
+		t.Fatal("overview tier retained no samples")
+	}
+}

internal/web/service/server.go

@@ -177,8 +177,8 @@ var allowedHistoryBuckets = map[int]bool{
 }
 
 // IsAllowedHistoryBucket reports whether a bucket-seconds value is in the
-// whitelist used by /server/history, /server/cpuHistory, /server/xrayMetricsHistory,
-// /server/xrayObservatoryHistory, and /nodes/history.
+// whitelist used by the time-series aggregation endpoints
+// (/server/history for the homepage overview, /nodes/history).
 func IsAllowedHistoryBucket(bucketSeconds int) bool {
 	return allowedHistoryBuckets[bucketSeconds]
 }
@@ -242,7 +242,7 @@ func (s *ServerService) isFail2banInstalled() bool {
 // Returns the new snapshot (may be nil if collection failed). Called by the
 // background ticker; the caller is responsible for any side effects
 // (websocket broadcast). The realtime status served to the UI comes from
-// this snapshot — the removed system-history series used to be fed here too.
+// this snapshot; the homepage overview ring is fed here too.
 func (s *ServerService) RefreshStatus() *Status {
 	next := s.GetStatus(s.LastStatus())
 	if next == nil {
@@ -251,9 +251,47 @@ func (s *ServerService) RefreshStatus() *Status {
 	s.lastStatusMu.Lock()
 	s.lastStatus = next
 	s.lastStatusMu.Unlock()
+	s.AppendOverviewSample(time.Now(), next)
 	return next
 }
 
+// AppendOverviewSample writes one tick of the homepage overview metrics —
+// CPU, memory/swap/disk percents, network throughput (bytes/s) and TCP/UDP
+// connection counts — into the memory-only overview ring. Called by
+// RefreshStatus on the @2s status cadence, so all series stay aligned.
+// Only the overview keys are kept; this is not the removed system-history
+// sampler (no extra series, no persistence).
+func (s *ServerService) AppendOverviewSample(t time.Time, status *Status) {
+	if status == nil {
+		return
+	}
+	overviewMetrics.append("cpu", t, status.Cpu)
+	if status.Mem.Total > 0 {
+		overviewMetrics.append("mem", t, float64(status.Mem.Current)*100.0/float64(status.Mem.Total))
+	}
+	if status.Swap.Total > 0 {
+		overviewMetrics.append("swap", t, float64(status.Swap.Current)*100.0/float64(status.Swap.Total))
+	} else {
+		overviewMetrics.append("swap", t, 0)
+	}
+	overviewMetrics.append("netUp", t, float64(status.NetIO.Up))
+	overviewMetrics.append("netDown", t, float64(status.NetIO.Down))
+	if status.Disk.Total > 0 {
+		overviewMetrics.append("diskUsage", t, float64(status.Disk.Current)*100.0/float64(status.Disk.Total))
+	}
+	overviewMetrics.append("tcpCount", t, float64(status.TcpCount))
+	overviewMetrics.append("udpCount", t, float64(status.UdpCount))
+}
+
+// AggregateOverviewMetric returns up to maxPoints averaged buckets of size
+// bucketSeconds for one overview metric (see OverviewMetricKeys). Output
+// points have keys {"t": unixSec, "v": value}. It backs the seed fetch of
+// the homepage overview curves; the ring behind it is memory-only, so
+// shortly after a panel restart it legitimately returns few or no points.
+func (s *ServerService) AggregateOverviewMetric(metric string, bucketSeconds int, maxPoints int) []map[string]any {
+	return overviewMetrics.aggregate(metric, bucketSeconds, maxPoints)
+}
+
 func getPublicIP(url string) string {
 	client := &http.Client{
 		Timeout: 3 * time.Second,