From 6131a53eb49ed943a16a8f1ce0cc77e2bfc3e7b2 Mon Sep 17 00:00:00 2001
From: Oliver Gugger <gugger@gmail.com>
Date: Mon, 9 Nov 2020 10:21:23 +0100
Subject: [PATCH] lncfg+channeldb: add autocompact flags to BoltConfig

---
 channeldb/kvdb/config.go | 29 +++++++++++++++++++++--------
 lncfg/db.go              |  4 +++-
 sample-lnd.conf          | 12 ++++++++++++
 3 files changed, 36 insertions(+), 9 deletions(-)

diff --git a/channeldb/kvdb/config.go b/channeldb/kvdb/config.go
index 179fde78..ccd1c1d7 100644
--- a/channeldb/kvdb/config.go
+++ b/channeldb/kvdb/config.go
@@ -1,18 +1,31 @@
 package kvdb
 
-// BoltBackendName is the name of the backend that should be passed into
-// kvdb.Create to initialize a new instance of kvdb.Backend backed by a live
-// instance of bbolt.
-const BoltBackendName = "bdb"
+import "time"
 
-// EtcdBackendName is the name of the backend that should be passed into
-// kvdb.Create to initialize a new instance of kvdb.Backend backed by a live
-// instance of etcd.
-const EtcdBackendName = "etcd"
+const (
+	// BoltBackendName is the name of the backend that should be passed into
+	// kvdb.Create to initialize a new instance of kvdb.Backend backed by a
+	// live instance of bbolt.
+	BoltBackendName = "bdb"
+
+	// EtcdBackendName is the name of the backend that should be passed into
+	// kvdb.Create to initialize a new instance of kvdb.Backend backed by a
+	// live instance of etcd.
+	EtcdBackendName = "etcd"
+
+	// DefaultBoltAutoCompactMinAge is the default minimum time that must
+	// have passed since a bolt database file was last compacted for the
+	// compaction to be considered again.
+	DefaultBoltAutoCompactMinAge = time.Hour * 24 * 7
+)
 
 // BoltConfig holds bolt configuration.
 type BoltConfig struct {
 	SyncFreelist bool `long:"nofreelistsync" description:"Whether the databases used within lnd should sync their freelist to disk. This is disabled by default resulting in improved memory performance during operation, but with an increase in startup time."`
+
+	AutoCompact bool `long:"auto-compact" description:"Whether the databases used within lnd should automatically be compacted on every startup (and if the database has the configured minimum age). This is disabled by default because it requires additional disk space to be available during the compaction that is freed afterwards. In general compaction leads to smaller database files."`
+
+	AutoCompactMinAge time.Duration `long:"auto-compact-min-age" description:"How long ago the last compaction of a database file must be for it to be considered for auto compaction again. Can be set to 0 to compact on every startup."`
 }
 
 // EtcdConfig holds etcd configuration.
diff --git a/lncfg/db.go b/lncfg/db.go
index cb6bcb24..3b37ba39 100644
--- a/lncfg/db.go
+++ b/lncfg/db.go
@@ -26,7 +26,9 @@ type DB struct {
 func DefaultDB() *DB {
 	return &DB{
 		Backend: BoltBackend,
-		Bolt:    &kvdb.BoltConfig{},
+		Bolt: &kvdb.BoltConfig{
+			AutoCompactMinAge: kvdb.DefaultBoltAutoCompactMinAge,
+		},
 	}
 }
 
diff --git a/sample-lnd.conf b/sample-lnd.conf
index f2bc5486..0a6ea722 100644
--- a/sample-lnd.conf
+++ b/sample-lnd.conf
@@ -928,3 +928,15 @@ litecoin.node=ltcd
 [bolt]
 ; If true, prevents the database from syncing its freelist to disk. 
 ; db.bolt.nofreelistsync=1
+
+; Whether the databases used within lnd should automatically be compacted on
+; every startup (and if the database has the configured minimum age). This is
+; disabled by default because it requires additional disk space to be available
+; during the compaction that is freed afterwards. In general compaction leads to
+; smaller database files.
+; db.bolt.auto-compact=true
+
+; How long ago the last compaction of a database file must be for it to be
+; considered for auto compaction again. Can be set to 0 to compact on every
+; startup. (default: 168h)
+; db.bolt.auto-compact-min-age=0