From bf912d4eaa945187332b35a897345fd4bfc264dc Mon Sep 17 00:00:00 2001
From: "alex.sharov" <AskAlexSharov@gmail.com>
Date: Wed, 7 Dec 2022 10:31:14 +0700
Subject: [PATCH] save

---
 common/dbg/experiments.go | 16 ++++++++++++++++
 kv/mdbx/kv_mdbx.go        |  3 +++
 2 files changed, 19 insertions(+)

diff --git a/common/dbg/experiments.go b/common/dbg/experiments.go
index 4bbd97b13..c911115a8 100644
--- a/common/dbg/experiments.go
+++ b/common/dbg/experiments.go
@@ -58,6 +58,22 @@ func WriteMap() bool {
 	return writeMap
 }
 
+var (
+	noSync     bool
+	noSyncOnce sync.Once
+)
+
+func NoSync() bool {
+	noSyncOnce.Do(func() {
+		v, _ := os.LookupEnv("NO_SYNC")
+		if v == "true" {
+			noSync = true
+			log.Info("[Experiment]", "NO_SYNC", noSync)
+		}
+	})
+	return noSync
+}
+
 var (
 	mergeTr     int
 	mergeTrOnce sync.Once
diff --git a/kv/mdbx/kv_mdbx.go b/kv/mdbx/kv_mdbx.go
index a093437c3..9aa368314 100644
--- a/kv/mdbx/kv_mdbx.go
+++ b/kv/mdbx/kv_mdbx.go
@@ -177,6 +177,9 @@ func (opts MdbxOpts) Open() (kv.RwDB, error) {
 	if dbg.WriteMap() {
 		opts = opts.WriteMap() //nolint
 	}
+	if dbg.NoSync() {
+		opts = opts.Flags(func(u uint) uint { return u | mdbx.SafeNoSync }) //nolint
+	}
 	if dbg.MergeTr() > 0 {
 		opts = opts.WriteMergeThreshold(uint64(dbg.MergeTr() * 8192)) //nolint
 	}