add fetch methods

internal/index/index.go

@@ -86,8 +86,15 @@ func (d *DB) GetAllSnapshots() (entries []*SnapshotEntry) {
 // GetBestSnapshots returns newest-to-oldest snapshots.
 // The `max` argument controls the max number of snapshots to return.
 // If max is negative, it returns all snapshots.
-func (d *DB) GetBestSnapshots(max int) (entries []*SnapshotEntry) {
-	res, err := d.DB.Txn(false).Get(tableSnapshotEntry, "slot")
+func (d *DB) GetBestSnapshotsByGroup(max int, group string) (entries []*SnapshotEntry) {
+	var res memdb.ResultIterator
+	var err error
+	if group != "" {
+		res, err = d.DB.Txn(false).Get(tableSnapshotEntry, "slot_by_group", group)
+	} else {
+		res, err = d.DB.Txn(false).Get(tableSnapshotEntry, "slot")
+	}
+
 	if err != nil {
 		panic("getting best snapshots failed: " + err.Error())
 	}
@@ -102,21 +109,16 @@ func (d *DB) GetBestSnapshots(max int) (entries []*SnapshotEntry) {
 }
 
 // Fetches the snapshots that are at a given slot.
-func (d *DB) GetSnapshotsAtSlot(slot uint64) (entries []*SnapshotEntry) {
-	res, err := d.DB.Txn(false).Get(tableSnapshotEntry, "base_slot", slot)
-	if err != nil {
-		panic("getting best snapshots failed: " + err.Error())
-	}
+func (d *DB) GetSnapshotsAtSlotByGroup(group string, slot uint64) (entries []*SnapshotEntry) {
+	var res memdb.ResultIterator
+	var err error
 
-	for entry := res.Next(); entry != nil; entry = res.Next() {
-		entries = append(entries, entry.(*SnapshotEntry))
+	if group != "" {
+		res, err = d.DB.Txn(false).Get(tableSnapshotEntry, "base_slot_by_group", slot, group)
+	} else {
+		res, err = d.DB.Txn(false).Get(tableSnapshotEntry, "base_slot", slot)
 	}
-	return
-}
 
-// Fetches the snapshots that are at a given slot.
-func (d *DB) GetSnapshotsAtSlotByGroup(group string, slot uint64) (entries []*SnapshotEntry) {
-	res, err := d.DB.Txn(false).Get(tableSnapshotEntry, "base_slot_by_group", group, slot)
 	if err != nil {
 		panic("getting best snapshots failed: " + err.Error())
 	}
@@ -127,6 +129,16 @@ func (d *DB) GetSnapshotsAtSlotByGroup(group string, slot uint64) (entries []*Sn
 	return
 }
 
+// Fetches the best snapshots
+func (d *DB) GetBestSnapshots(max int) (entries []*SnapshotEntry) {
+	return d.GetBestSnapshotsByGroup(max, "")
+}
+
+// Fetches the snapshots that are at a given slot.
+func (d *DB) GetSnapshotsAtSlot(slot uint64) (entries []*SnapshotEntry) {
+	return d.GetSnapshotsAtSlotByGroup("", slot)
+}
+
 // DeleteOldSnapshots delete snapshot entry older than the given timestamp.
 func (d *DB) DeleteOldSnapshots(minTime time.Time) (n int) {
 	txn := d.DB.Txn(true)

internal/index/index_test.go

@@ -140,4 +140,16 @@ func TestDB(t *testing.T) {
 			snapshotEntry3,
 		},
 		db.GetBestSnapshots(-1))
+
+    assert.Equal(t,
+		[]*SnapshotEntry{
+			snapshotEntry4,
+		},
+		db.GetBestSnapshotsByGroup(-1, "devnet"))
+
+	assert.Equal(t,
+		[]*SnapshotEntry{
+			snapshotEntry1,
+			snapshotEntry3
+		}, 	)
 }