From 0c86f2467e795e620aaab6d1851fd7146556f2b8 Mon Sep 17 00:00:00 2001
From: Giulio rebuffo <giulio.rebuffo@gmail.com>
Date: Sat, 21 Dec 2024 00:49:28 +0100
Subject: [PATCH] E3: make state snapshots download optional (#13107)

---
 cmd/utils/flags.go                 |  7 +++++++
 eth/ethconfig/config.go            | 15 ++++++++-------
 turbo/snapshotsync/snapshotsync.go |  8 ++++++--
 3 files changed, 21 insertions(+), 9 deletions(-)

diff --git a/cmd/utils/flags.go b/cmd/utils/flags.go
index d1a9b1a882b..722ec2aad00 100644
--- a/cmd/utils/flags.go
+++ b/cmd/utils/flags.go
@@ -675,6 +675,11 @@ var (
 		Name:  ethconfig.FlagSnapStateStop,
 		Usage: "Workaround to stop producing new state files, if you meet some state-related critical bug. It will stop aggregate DB history in a state files. DB will grow and may slightly slow-down - and removing this flag in future will not fix this effect (db size will not greatly reduce).",
 	}
+	SnapSkipStateSnapshotDownloadFlag = cli.BoolFlag{
+		Name:  "snap.skip-state-snapshot-download",
+		Usage: "Skip state download and start from genesis block",
+		Value: false,
+	}
 	TorrentVerbosityFlag = cli.IntFlag{
 		Name:  "torrent.verbosity",
 		Value: 2,
@@ -749,6 +754,7 @@ var (
 		Usage: "Enable WRITE_MAP feature for fast database writes and fast commit times",
 		Value: true,
 	}
+
 	HealthCheckFlag = cli.BoolFlag{
 		Name:  "healthcheck",
 		Usage: "Enabling grpc health check",
@@ -1860,6 +1866,7 @@ func SetEthConfig(ctx *cli.Context, nodeConfig *nodecfg.Config, cfg *ethconfig.C
 	cfg.Snapshot.KeepBlocks = ctx.Bool(SnapKeepBlocksFlag.Name)
 	cfg.Snapshot.ProduceE2 = !ctx.Bool(SnapStopFlag.Name)
 	cfg.Snapshot.ProduceE3 = !ctx.Bool(SnapStateStopFlag.Name)
+	cfg.Snapshot.DisableDownloadE3 = ctx.Bool(SnapSkipStateSnapshotDownloadFlag.Name)
 	cfg.Snapshot.NoDownloader = ctx.Bool(NoDownloaderFlag.Name)
 	cfg.Snapshot.Verify = ctx.Bool(DownloaderVerifyFlag.Name)
 	cfg.Snapshot.DownloaderAddr = strings.TrimSpace(ctx.String(DownloaderAddrFlag.Name))
diff --git a/eth/ethconfig/config.go b/eth/ethconfig/config.go
index 8ea5f2bbab1..d8f9c9e9cc5 100644
--- a/eth/ethconfig/config.go
+++ b/eth/ethconfig/config.go
@@ -135,13 +135,14 @@ func init() {
 //go:generate gencodec -dir . -type Config -formats toml -out gen_config.go
 
 type BlocksFreezing struct {
-	KeepBlocks     bool // produce new snapshots of blocks but don't remove blocks from DB
-	ProduceE2      bool // produce new block files
-	ProduceE3      bool // produce new state files
-	NoDownloader   bool // possible to use snapshots without calling Downloader
-	Verify         bool // verify snapshots on startup
-	DownloaderAddr string
-	ChainName      string
+	KeepBlocks        bool // produce new snapshots of blocks but don't remove blocks from DB
+	ProduceE2         bool // produce new block files
+	ProduceE3         bool // produce new state files
+	NoDownloader      bool // possible to use snapshots without calling Downloader
+	Verify            bool // verify snapshots on startup
+	DisableDownloadE3 bool // disable download state snapshots
+	DownloaderAddr    string
+	ChainName         string
 }
 
 func (s BlocksFreezing) String() string {
diff --git a/turbo/snapshotsync/snapshotsync.go b/turbo/snapshotsync/snapshotsync.go
index 7bbfee50d17..9182cfb319a 100644
--- a/turbo/snapshotsync/snapshotsync.go
+++ b/turbo/snapshotsync/snapshotsync.go
@@ -158,7 +158,7 @@ func adjustBlockPrune(blocks, minBlocksToDownload uint64) uint64 {
 	return blocks - blocks%snaptype.Erigon2MergeLimit
 }
 
-func shouldUseStepsForPruning(name string) bool {
+func isStateSnapshot(name string) bool {
 	return strings.HasPrefix(name, "idx") || strings.HasPrefix(name, "history") || strings.HasPrefix(name, "accessor")
 }
 
@@ -182,7 +182,7 @@ func buildBlackListForPruning(pruneMode bool, stepPrune, minBlockToDownload, blo
 		}
 		var _, to uint64
 		var err error
-		if shouldUseStepsForPruning(name) {
+		if isStateSnapshot(name) {
 			// parse "from" (0) and "to" (64) from the name
 			// parse the snapshot "kind". e.g kind of 'idx/v1-accounts.0-64.ef' is "idx/v1-accounts"
 			rangeString := strings.Split(name, ".")[1]
@@ -337,6 +337,10 @@ func WaitForDownloader(ctx context.Context, logPrefix string, dirs datadir.Dirs,
 		if caplin == OnlyCaplin && !strings.Contains(p.Name, "beaconblocks") && !strings.Contains(p.Name, "blobsidecars") && !strings.Contains(p.Name, "caplin") {
 			continue
 		}
+
+		if isStateSnapshot(p.Name) && blockReader.FreezingCfg().DisableDownloadE3 {
+			continue
+		}
 		if !blobs && strings.Contains(p.Name, "blobsidecars") {
 			continue
 		}