From a38d4fa46c078fe519c114799a3d8621f795a0d7 Mon Sep 17 00:00:00 2001
From: "Jason E. Aten" <jason.aten@molecula.com>
Date: Fri, 6 Nov 2020 15:30:10 +0000
Subject: [PATCH] apply --fsync flag to all tx backend

 - rename from --rbf-fsync to --fsync, as it
   now effects bolt, lmdb too.
---
 bolt.go        | 10 ++++++++--
 lmdb.go        | 22 ++++++++++------------
 rbf/cfg/cfg.go |  4 +++-
 3 files changed, 21 insertions(+), 15 deletions(-)

diff --git a/bolt.go b/bolt.go
index 9772957ab..7980bb3a7 100644
--- a/bolt.go
+++ b/bolt.go
@@ -164,8 +164,14 @@ func (r *boltRegistrar) OpenDBWrapper(path0 string, doAllocZero bool, rbfcfg *rb
 	// re-sync during recovery.
 	// NoFreelistSync bool
 
-	//db.NoSync = true
-	//db.NoFreelistSync = true
+	if rbfcfg != nil && !rbfcfg.FsyncEnabled {
+		db.NoSync = true
+		db.NoFreelistSync = true
+	} else {
+		// default to using fsync on bolt.
+		db.NoSync = false
+		db.NoFreelistSync = false
+	}
 
 	err = db.Update(func(tx *bolt.Tx) (err error) {
 		_, err = tx.CreateBucketIfNotExists(bucketCT)
diff --git a/lmdb.go b/lmdb.go
index 4973b2287..28075de2d 100644
--- a/lmdb.go
+++ b/lmdb.go
@@ -183,13 +183,6 @@ func (r *lmdbRegistrar) OpenDBWrapper(path0 string, doAllocZero bool, rbfcfg *rb
 	// flags = flags | lmdb.WriteMap | lmdb.NoMetaSync | lmdb.NoSync // about the same speed
 	// flags = flags | lmdb.NoMetaSync | lmdb.NoSync // slows things down
 
-	// TODO(jea): we got an odd segfault in the roaring/ pkg when we went to read-only mmap
-	// with the row-cache off; probably means we were trying to write to mmap-ed
-	// memory. Investigate at some point. reference: 2a77b25d ja/write_map_prevents_segfault
-	//
-	// Update: added COW to roaring/roaring.go:3282  func (c *Container) arrayRemove(),
-	// seems to fix the issue.
-	//
 	//flags = flags | lmdb.WriteMap // seems faster than without: or maybe not. not sure.
 	// kRemove  N=  710401   avg/op:      7.714µs   sd:      27.83µs  total: 5.480656859s
 	//    kAdd  N=  722835   avg/op:      9.096µs   sd:    105.787µs  total: 6.575497725s
@@ -202,12 +195,17 @@ func (r *lmdbRegistrar) OpenDBWrapper(path0 string, doAllocZero bool, rbfcfg *rb
 		// On my darwin/OSX laptop with 16GB ram, for instance, we
 		// can have difficulty obtaining this, resulting in
 		//   panic: mdb_env_open: no space left on device
-		lmdb.WriteMap | // Use a writable memory map.
+		lmdb.WriteMap // Use a writable memory map.
 
-		// default ACI (not Durable) transactions; 300% faster write speed results.
-		lmdb.NoMetaSync | // Don't fsync metapage after commit.
-		lmdb.NoSync | // Don't fsync after commit.
-		lmdb.MapAsync // Flush asynchronously when using the WriteMap flag.
+	if rbfcfg == nil || !rbfcfg.FsyncEnabled {
+		// default for lmdb: fsync off.
+		// unsafe, but get upper bound on performance.
+		flags = flags |
+			// default ACI (not Durable) transactions; 300% faster write speed results.
+			lmdb.NoMetaSync | // Don't fsync metapage after commit.
+			lmdb.NoSync | // Don't fsync after commit.
+			lmdb.MapAsync // Flush asynchronously when using the WriteMap flag.
+	}
 
 	if !DirExists(path) {
 		panicOn(os.MkdirAll(path, 0755))
diff --git a/rbf/cfg/cfg.go b/rbf/cfg/cfg.go
index f13e14f4f..733b945ce 100644
--- a/rbf/cfg/cfg.go
+++ b/rbf/cfg/cfg.go
@@ -58,5 +58,7 @@ func (cfg *Config) DefineFlags(flags *pflag.FlagSet) {
 	flags.DurationVar(&cfg.CheckpointEveryDur, "rbf-checkpoint-dur", default0.CheckpointEveryDur,
 		"RBF checkpoint on the next write that occurs this long or more after the previous write. 0 means checkpoint after every write.")
 	flags.Int64Var(&cfg.MaxSize, "rbf-max-db-size", default0.MaxSize, "RBF maximum size in bytes of a database file (distinct from a WAL file)")
-	flags.BoolVar(&cfg.FsyncEnabled, "rbf-fsync", default0.FsyncEnabled, "RBF: enable fsync fully safe flush-to-disk at each checkpoint")
+
+	// renamed from --rbf-fsync to just --fsync because now it applies to all Tx backends.
+	flags.BoolVar(&cfg.FsyncEnabled, "fsync", default0.FsyncEnabled, "enable fsync fully safe flush-to-disk")
 }