bugfix and dashboard improvement

internal/storage/stats.go

@@ -0,0 +1,52 @@
+package storage
+
+import (
+	"context"
+	"fmt"
+	"time"
+)
+
+// CountRoots returns the number of metadata roots in the file index.
+//
+// SCARD, not SMEMBERS: GetAllHashIDs ships every member over the wire (~3MB
+// and rising on an 88k-record box) just so the caller can take len(). A
+// dashboard tile that polls needs the number, never the list.
+func (c *Client) CountRoots() (int64, error) {
+	c.mu.RLock()
+	defer c.mu.RUnlock()
+
+	if c.client == nil {
+		return 0, fmt.Errorf("not connected")
+	}
+
+	ctx, cancel := context.WithTimeout(context.Background(), 5*time.Second)
+	defer cancel()
+
+	n, err := c.client.SCard(ctx, c.buildIndexKey()).Result()
+	if err != nil {
+		return 0, fmt.Errorf("scard failed: %w", err)
+	}
+	return n, nil
+}
+
+// CountKeys returns DBSIZE — every key in the Redis database, not just the
+// ones meta-core owns. It is the denominator for "how much of Redis is
+// records": ~3.1M keys against ~89k roots means the flat per-field keys
+// (file:{root}/{field}) dominate, which is expected.
+func (c *Client) CountKeys() (int64, error) {
+	c.mu.RLock()
+	defer c.mu.RUnlock()
+
+	if c.client == nil {
+		return 0, fmt.Errorf("not connected")
+	}
+
+	ctx, cancel := context.WithTimeout(context.Background(), 5*time.Second)
+	defer cancel()
+
+	n, err := c.client.DBSize(ctx).Result()
+	if err != nil {
+		return 0, fmt.Errorf("dbsize failed: %w", err)
+	}
+	return n, nil
+}