From 3906d7e51f79e7c1f19e2f603884ed5fe9ae33b5 Mon Sep 17 00:00:00 2001
From: Alex Sharov <AskAlexSharov@gmail.com>
Date: Tue, 26 Apr 2022 12:04:38 +0700
Subject: [PATCH] Snapshots: allow stage_headers --unwind behind available
 snapshots (#3971)

* save

* save

* save
---
 cmd/integration/commands/stages.go    |  2 +-
 core/rawdb/accessors_chain.go         | 18 +++---------------
 turbo/snapshotsync/block_snapshots.go |  2 +-
 3 files changed, 5 insertions(+), 17 deletions(-)

diff --git a/cmd/integration/commands/stages.go b/cmd/integration/commands/stages.go
index 1285c242854..9155d5e8892 100644
--- a/cmd/integration/commands/stages.go
+++ b/cmd/integration/commands/stages.go
@@ -477,7 +477,7 @@ func stageHeaders(db kv.RwDB, ctx context.Context) error {
 				return err
 			}
 			if err = tx.Put(kv.HeadHeaderKey, []byte(kv.HeadHeaderKey), hash[:]); err != nil {
-				log.Error("ReadHeadHeaderHash failed", "err", err)
+				return err
 			}
 			log.Info("Progress", "headers", progress)
 			return nil
diff --git a/core/rawdb/accessors_chain.go b/core/rawdb/accessors_chain.go
index 4c6a1e646ce..eaab7fc45c8 100644
--- a/core/rawdb/accessors_chain.go
+++ b/core/rawdb/accessors_chain.go
@@ -498,18 +498,6 @@ func RawTransactionsRange(db kv.Getter, from, to uint64) (res [][]byte, err erro
 
 // ResetSequence - allow set arbitrary value to sequence (for example to decrement it to exact value)
 func ResetSequence(tx kv.RwTx, bucket string, newValue uint64) error {
-	c, err := tx.Cursor(bucket)
-	if err != nil {
-		return err
-	}
-	k, _, err := c.Last()
-	if err != nil {
-		return err
-	}
-	if k != nil && binary.BigEndian.Uint64(k) >= newValue {
-		panic(fmt.Sprintf("must not happen. ResetSequence: %s, %d < lastInDB: %d\n", bucket, newValue, binary.BigEndian.Uint64(k)))
-	}
-
 	newVBytes := make([]byte, 8)
 	binary.BigEndian.PutUint64(newVBytes, newValue)
 	if err := tx.Put(kv.Sequence, []byte(bucket), newVBytes); err != nil {
@@ -1111,13 +1099,13 @@ func DeleteAncientBlocks(db kv.RwTx, blockTo uint64, blocksDeleteLimit int) erro
 	}
 	defer c.Close()
 
-	var stopAtBlock uint64
+	var stopAtBlock, firstNonGenesisInDB uint64
 	{
 		k, _, err := c.First()
 		if err != nil {
 			return err
 		}
-		firstNonGenesisInDB := binary.BigEndian.Uint64(k)
+		firstNonGenesisInDB = binary.BigEndian.Uint64(k)
 		if firstNonGenesisInDB == 0 { // keep genesis in DB
 			k, _, err := c.Next()
 			if err != nil {
@@ -1133,7 +1121,7 @@ func DeleteAncientBlocks(db kv.RwTx, blockTo uint64, blocksDeleteLimit int) erro
 		}
 
 		n := binary.BigEndian.Uint64(k)
-		if n >= stopAtBlock {
+		if n >= stopAtBlock { // [from, to)
 			break
 		}
 
diff --git a/turbo/snapshotsync/block_snapshots.go b/turbo/snapshotsync/block_snapshots.go
index 96f66b30c87..9123648e454 100644
--- a/turbo/snapshotsync/block_snapshots.go
+++ b/turbo/snapshotsync/block_snapshots.go
@@ -1265,7 +1265,7 @@ func DumpTxs(ctx context.Context, db kv.RoDB, segmentFile, tmpDir string, blockF
 	var lastBody types.BodyForStorage
 	if err := kv.BigChunks(db, kv.HeaderCanonical, from, func(tx kv.Tx, k, v []byte) (bool, error) {
 		blockNum := binary.BigEndian.Uint64(k)
-		if blockNum >= blockTo {
+		if blockNum >= blockTo { // [from, to)
 			return false, nil
 		}