From c406c8a66a43bce977f20c00809b8fa0986781e3 Mon Sep 17 00:00:00 2001
From: eastorski <nikita.ostroukhov@phystech.edu>
Date: Tue, 17 Dec 2024 16:03:18 +0000
Subject: [PATCH] Fixed snapshot read from disk

---
 turbo/snapshotsync/snapshots.go | 40 +++++++++------------------------
 1 file changed, 11 insertions(+), 29 deletions(-)

diff --git a/turbo/snapshotsync/snapshots.go b/turbo/snapshotsync/snapshots.go
index c46d4a5ff02..6ecdc947dcf 100644
--- a/turbo/snapshotsync/snapshots.go
+++ b/turbo/snapshotsync/snapshots.go
@@ -35,7 +35,6 @@ import (
 	"github.com/erigontech/erigon-lib/common/background"
 	"github.com/erigontech/erigon-lib/common/datadir"
 	"github.com/erigontech/erigon-lib/common/dbg"
-	dir2 "github.com/erigontech/erigon-lib/common/dir"
 	"github.com/erigontech/erigon-lib/diagnostics"
 	"github.com/erigontech/erigon-lib/downloader/snaptype"
 	"github.com/erigontech/erigon-lib/log/v3"
@@ -56,6 +55,10 @@ type SortedRange interface {
 
 // NoOverlaps - keep largest ranges and avoid overlap
 func NoOverlaps[T SortedRange](in []T) (res []T) {
+	if len(in) == 1 {
+		return in
+	}
+
 	for i := 0; i < len(in); i++ {
 		r := in[i]
 		iFrom, iTo := r.GetRange()
@@ -83,6 +86,10 @@ func NoGaps[T SortedRange](in []T) (out []T, missingRanges []Range) {
 	if len(in) == 0 {
 		return nil, nil
 	}
+	if len(in) == 1 {
+		return in, nil
+	}
+
 	prevTo, _ := in[0].GetRange()
 	for _, f := range in {
 		from, to := f.GetRange()
@@ -980,10 +987,6 @@ func (s *RoSnapshots) InitSegments(fileNames []string) error {
 }
 
 func TypedSegments(dir string, minBlock uint64, types []snaptype.Type, allowGaps bool) (res []snaptype.FileInfo, missingSnapshots []Range, err error) {
-	segmentsTypeCheck := func(dir string, in []snaptype.FileInfo) (res []snaptype.FileInfo) {
-		return typeOfSegmentsMustExist(dir, in, types)
-	}
-
 	list, err := snaptype.Segments(dir)
 
 	if err != nil {
@@ -1002,10 +1005,11 @@ func TypedSegments(dir string, minBlock uint64, types []snaptype.Type, allowGaps
 			}
 
 			if allowGaps {
-				l = NoOverlaps(segmentsTypeCheck(dir, l))
+				l = NoOverlaps(l)
 			} else {
-				l, m = NoGaps(NoOverlaps(segmentsTypeCheck(dir, l)))
+				l, m = NoGaps(NoOverlaps(l))
 			}
+
 			if len(m) > 0 {
 				lst := m[len(m)-1]
 				log.Debug("[snapshots] see gap", "type", segType, "from", lst.from)
@@ -1619,28 +1623,6 @@ func sendDiagnostics(startIndexingTime time.Time, indexPercent map[string]int, a
 	})
 }
 
-func typeOfSegmentsMustExist(dir string, in []snaptype.FileInfo, types []snaptype.Type) (res []snaptype.FileInfo) {
-MainLoop:
-	for _, f := range in {
-		if f.From == f.To {
-			continue
-		}
-		for _, t := range types {
-			p := filepath.Join(dir, snaptype.SegmentFileName(f.Version, f.From, f.To, t.Enum()))
-			exists, err := dir2.FileExist(p)
-			if err != nil {
-				log.Debug("[snapshots] FileExist error", "err", err, "path", p)
-				continue MainLoop
-			}
-			if !exists {
-				continue MainLoop
-			}
-			res = append(res, f)
-		}
-	}
-	return res
-}
-
 func removeOldFiles(toDel []string, snapDir string) {
 	for _, f := range toDel {
 		_ = os.Remove(f)