From 6702c79216b7c472624be6ba34303ad19d5426d7 Mon Sep 17 00:00:00 2001
From: Elle Mouton <elle.mouton@gmail.com>
Date: Thu, 18 Mar 2021 13:40:53 +0200
Subject: [PATCH] multi: add block cache size config

This commit adds block cache size to the main lnd config along with the
chainreg config.
---
 chainreg/chainregistry.go | 3 +++
 config.go                 | 7 +++++++
 lnd.go                    | 1 +
 sample-lnd.conf           | 6 ++++++
 4 files changed, 17 insertions(+)

diff --git a/chainreg/chainregistry.go b/chainreg/chainregistry.go
index aec44b88..ff500820 100644
--- a/chainreg/chainregistry.go
+++ b/chainreg/chainregistry.go
@@ -73,6 +73,9 @@ type Config struct {
 	// RemoteChanDB is a pointer to the remote backing channel database.
 	RemoteChanDB *channeldb.DB
 
+	// BlockCacheSize is the size (in bytes) of blocks kept in memory.
+	BlockCacheSize uint64
+
 	// PrivateWalletPw is the private wallet password to the underlying
 	// btcwallet instance.
 	PrivateWalletPw []byte
diff --git a/config.go b/config.go
index 2052acda..67abc61d 100644
--- a/config.go
+++ b/config.go
@@ -101,6 +101,10 @@ const (
 	// initiated the channel closure.
 	defaultCoopCloseTargetConfs = 6
 
+	// defaultBlockCacheSize is the size (in bytes) of blocks that will be
+	// keep in memory if no size is specified.
+	defaultBlockCacheSize uint64 = 20 * 1024 * 1024 // 20 MB
+
 	// defaultHostSampleInterval is the default amount of time that the
 	// HostAnnouncer will wait between DNS resolutions to check if the
 	// backing IP of a host has changed.
@@ -273,6 +277,8 @@ type Config struct {
 	LtcdMode      *lncfg.Btcd     `group:"ltcd" namespace:"ltcd"`
 	LitecoindMode *lncfg.Bitcoind `group:"litecoind" namespace:"litecoind"`
 
+	BlockCacheSize uint64 `long:"blockcachesize" description:"The maximum capacity of the block cache"`
+
 	Autopilot *lncfg.AutoPilot `group:"Autopilot" namespace:"autopilot"`
 
 	Tor *lncfg.Tor `group:"Tor" namespace:"tor"`
@@ -434,6 +440,7 @@ func DefaultConfig() Config {
 			UserAgentName:    neutrino.UserAgentName,
 			UserAgentVersion: neutrino.UserAgentVersion,
 		},
+		BlockCacheSize:     defaultBlockCacheSize,
 		UnsafeDisconnect:   true,
 		MaxPendingChannels: lncfg.DefaultMaxPendingChannels,
 		NoSeedBackup:       defaultNoSeedBackup,
diff --git a/lnd.go b/lnd.go
index b82d2f7c..8e05ee5d 100644
--- a/lnd.go
+++ b/lnd.go
@@ -546,6 +546,7 @@ func Main(cfg *Config, lisCfg ListenerCfg, interceptor signal.Interceptor) error
 		Dialer: func(addr string) (net.Conn, error) {
 			return cfg.net.Dial("tcp", addr, cfg.ConnectionTimeout)
 		},
+		BlockCacheSize: cfg.BlockCacheSize,
 	}
 
 	activeChainControl, cleanup, err := chainreg.NewChainControl(chainControlCfg)
diff --git a/sample-lnd.conf b/sample-lnd.conf
index 4659c1ce..06158331 100644
--- a/sample-lnd.conf
+++ b/sample-lnd.conf
@@ -224,6 +224,12 @@
 ; The target location of the channel backup file.
 ; backupfilepath=~/.lnd/data/chain/bitcoin/simnet/channel.backup
 
+; The maximum capacity of the block cache in bytes. Increasing this will result
+; in more blocks being kept in memory but will increase performance when the
+; same block is required multiple times.
+; The example value below is 40 MB (1024 * 1024 * 40)
+; blockcachesize=41943040
+
 ; Optional URL for external fee estimation. If no URL is specified, the method
 ; for fee estimation will depend on the chosen backend and network. Must be set
 ; for neutrino on mainnet.