From 7cb8c8d3f0c7e88828e466c7836fd6ee34fc9641 Mon Sep 17 00:00:00 2001
From: Martin Boehm <martin.boehm@1mbsoftware.net>
Date: Mon, 14 May 2018 15:49:08 +0200
Subject: [PATCH] Add option to disable txcache

---
 blockbook.go  |  4 +++-
 db/txcache.go | 40 ++++++++++++++++++++++++++--------------
 2 files changed, 29 insertions(+), 15 deletions(-)

diff --git a/blockbook.go b/blockbook.go
index 1aedb3c0..1de5c3cc 100644
--- a/blockbook.go
+++ b/blockbook.go
@@ -63,6 +63,8 @@ var (
 	explorerURL = flag.String("explorer", "", "address of blockchain explorer")
 
 	coin = flag.String("coin", "btc", "coin name")
+
+	noTxCache = flag.Bool("notxcache", false, "disable tx cache")
 )
 
 var (
@@ -156,7 +158,7 @@ func main() {
 		return
 	}
 
-	if txCache, err = db.NewTxCache(index, chain, metrics); err != nil {
+	if txCache, err = db.NewTxCache(index, chain, metrics, !*noTxCache); err != nil {
 		glog.Error("txCache ", err)
 		return
 	}
diff --git a/db/txcache.go b/db/txcache.go
index 3b339352..8c30b42a 100644
--- a/db/txcache.go
+++ b/db/txcache.go
@@ -12,29 +12,39 @@ type TxCache struct {
 	db      *RocksDB
 	chain   bchain.BlockChain
 	metrics *common.Metrics
+	enabled bool
 }
 
 // NewTxCache creates new TxCache interface and returns its handle
-func NewTxCache(db *RocksDB, chain bchain.BlockChain, metrics *common.Metrics) (*TxCache, error) {
+func NewTxCache(db *RocksDB, chain bchain.BlockChain, metrics *common.Metrics, enabled bool) (*TxCache, error) {
+	if !enabled {
+		glog.Info("txcache: disabled")
+	}
 	return &TxCache{
 		db:      db,
 		chain:   chain,
 		metrics: metrics,
+		enabled: enabled,
 	}, nil
 }
 
 // GetTransaction returns transaction either from RocksDB or if not present from blockchain
 // it the transaction is confirmed, it is stored in the RocksDB
 func (c *TxCache) GetTransaction(txid string, bestheight uint32) (*bchain.Tx, uint32, error) {
-	tx, h, err := c.db.GetTx(txid)
-	if err != nil {
-		return nil, 0, err
-	}
-	if tx != nil {
-		// number of confirmations is not stored in cache, they change all the time
-		tx.Confirmations = bestheight - h + 1
-		c.metrics.TxCacheEfficiency.With(common.Labels{"status": "hit"}).Inc()
-		return tx, h, nil
+	var tx *bchain.Tx
+	var h uint32
+	var err error
+	if c.enabled {
+		tx, h, err = c.db.GetTx(txid)
+		if err != nil {
+			return nil, 0, err
+		}
+		if tx != nil {
+			// number of confirmations is not stored in cache, they change all the time
+			tx.Confirmations = bestheight - h + 1
+			c.metrics.TxCacheEfficiency.With(common.Labels{"status": "hit"}).Inc()
+			return tx, h, nil
+		}
 	}
 	tx, err = c.chain.GetTransaction(txid)
 	if err != nil {
@@ -45,10 +55,12 @@ func (c *TxCache) GetTransaction(txid string, bestheight uint32) (*bchain.Tx, ui
 	if tx.Confirmations > 0 {
 		// the transaction in the currently best block has 1 confirmation
 		h = bestheight - tx.Confirmations + 1
-		err = c.db.PutTx(tx, h, tx.Blocktime)
-		// do not return caching error, only log it
-		if err != nil {
-			glog.Error("PutTx error ", err)
+		if c.enabled {
+			err = c.db.PutTx(tx, h, tx.Blocktime)
+			// do not return caching error, only log it
+			if err != nil {
+				glog.Error("PutTx error ", err)
+			}
 		}
 	} else {
 		h = 0