From 223a61da9dc59f7edb12b59bf1e336f383466b19 Mon Sep 17 00:00:00 2001
From: gagliardetto <gagliardetto@users.noreply.github.com>
Date: Mon, 25 Sep 2023 13:18:31 +0200
Subject: [PATCH] Check if can recover slot when it's the first not found slot
 (upper bound)

---
 pkg/blockstore/schedule.go | 24 ++++++++++++++++++++----
 1 file changed, 20 insertions(+), 4 deletions(-)

diff --git a/pkg/blockstore/schedule.go b/pkg/blockstore/schedule.go
index 0573c61..7acbadf 100644
--- a/pkg/blockstore/schedule.go
+++ b/pkg/blockstore/schedule.go
@@ -481,11 +481,11 @@ func (schedule *TraversalSchedule) init(
 					wanted,
 				)
 				{
-					_, err := handle.DB.GetSlotMeta(wanted)
-					if err == nil {
-						logInfof("even though we couldn't find the slot root, we found the meta for slot %d", wanted)
+					ok, err := canRecoverSlot(handle, wanted)
+					if ok {
+						logInfof("even though we couldn't find the slot root, the slot %d is recoverable", wanted)
 					} else {
-						logInfof("we couldn't find the slot root, and we couldn't find the meta for slot %d either", wanted)
+						logInfof("we couldn't find the slot root, and the slot %d is not recoverable: %s", wanted, err)
 					}
 				}
 				break slotLoop
@@ -658,6 +658,22 @@ func (schedule *TraversalSchedule) init(
 	return nil
 }
 
+func canRecoverSlot(db *WalkHandle, slot uint64) (bool, error) {
+	// can get meta, and can get entries
+	meta, err := db.DB.GetSlotMeta(slot)
+	if err != nil {
+		return false, fmt.Errorf("db %q: failed to get meta for slot %d: %s", db.DB.DB.Name(), slot, err)
+	}
+	if meta == nil {
+		return false, fmt.Errorf("db %q: meta for slot %d is nil", db.DB.DB.Name(), slot)
+	}
+	_, err = db.DB.GetEntries(meta, db.shredRevision)
+	if err != nil {
+		return false, fmt.Errorf("db %q: failed to get entries for slot %d: %s", db.DB.DB.Name(), slot, err)
+	}
+	return true, nil
+}
+
 func reverse[T any](x []T) {
 	for i := len(x)/2 - 1; i >= 0; i-- {
 		opp := len(x) - 1 - i