Verify historical slots per archived point (#6159)

* Add check for slots point
* Test
* Gaz

beacon-chain/db/kv/BUILD.bazel

@@ -66,6 +66,7 @@ go_test(
         "attestations_test.go",
         "backup_test.go",
         "blocks_test.go",
+        "check_historical_test_test.go",
         "checkpoint_test.go",
         "deposit_contract_test.go",
         "encoding_test.go",

beacon-chain/db/kv/check_historical_state.go

@@ -2,14 +2,18 @@ package kv
 
 import (
 	"context"
+	"fmt"
 
 	"github.com/pkg/errors"
+	"github.com/prysmaticlabs/prysm/shared/bytesutil"
 	"github.com/prysmaticlabs/prysm/shared/featureconfig"
+	"github.com/prysmaticlabs/prysm/shared/params"
 	log "github.com/sirupsen/logrus"
 	bolt "go.etcd.io/bbolt"
 )
 
 var historicalStateDeletedKey = []byte("historical-states-deleted")
+var archivedSlotsPerPointKey = []byte("slots-per-archived-point")
 
 // HistoricalStatesDeleted verifies historical states exist in DB.
 func (kv *Store) HistoricalStatesDeleted(ctx context.Context) error {
@@ -20,6 +24,10 @@ func (kv *Store) HistoricalStatesDeleted(ctx context.Context) error {
 		})
 	}
 
+	if err := kv.verifySlotsPerArchivePoint(); err != nil {
+		return err
+	}
+
 	var historicalStateDeleted bool
 	if err := kv.db.View(func(tx *bolt.Tx) error {
 		bkt := tx.Bucket(newStateServiceCompatibleBucket)
@@ -42,3 +50,24 @@ func (kv *Store) HistoricalStatesDeleted(ctx context.Context) error {
 		return bkt.Put(historicalStateDeletedKey, []byte{0x00})
 	})
 }
+
+// This verifies the slots per archived point has not been altered since it's used.
+// The node does not allow slots per archived point to alter once it's in operation.
+func (kv *Store) verifySlotsPerArchivePoint() error {
+	return kv.db.Update(func(tx *bolt.Tx) error {
+		bkt := tx.Bucket(newStateServiceCompatibleBucket)
+		v := bkt.Get(archivedSlotsPerPointKey)
+		if v == nil {
+			if err := bkt.Put(archivedSlotsPerPointKey, bytesutil.Bytes8(params.BeaconConfig().SlotsPerArchivedPoint)); err != nil {
+				return err
+			}
+		} else {
+			slotsPerPoint := bytesutil.FromBytes8(v)
+			if slotsPerPoint != params.BeaconConfig().SlotsPerArchivedPoint {
+				return fmt.Errorf("could not update --slots-per-archive-point after it has been set. Please continue to use %d, or resync from genesis using %d",
+					slotsPerPoint, params.BeaconConfig().SlotsPerArchivedPoint)
+			}
+		}
+		return nil
+	})
+}

beacon-chain/db/kv/check_historical_test_test.go

@@ -0,0 +1,33 @@
+package kv
+
+import (
+	"strings"
+	"testing"
+
+	"github.com/prysmaticlabs/prysm/shared/params"
+)
+
+func TestVerifySlotsPerArchivePoint(t *testing.T) {
+	db := setupDB(t)
+
+	// This should set default to 2048.
+	if err := db.verifySlotsPerArchivePoint(); err != nil {
+		t.Fatal(err)
+	}
+
+	// This should not fail with default 2048.
+	if err := db.verifySlotsPerArchivePoint(); err != nil {
+		t.Fatal(err)
+	}
+
+	params.SetupTestConfigCleanup(t)
+	config := params.BeaconConfig()
+	config.SlotsPerArchivedPoint = 256
+	params.OverrideBeaconConfig(config)
+
+	// This should fail.
+	msg := "could not update --slots-per-archive-point after it has been set"
+	if err := db.verifySlotsPerArchivePoint(); err == nil || !strings.Contains(err.Error(), msg) {
+		t.Error("Did not get wanted error")
+	}
+}