From 06f3c3498116e188b4a233a9486ad5c7746ef925 Mon Sep 17 00:00:00 2001
From: Roman Khimov <roman@nspcc.ru>
Date: Wed, 9 Sep 2020 15:32:31 +0300
Subject: [PATCH] mempool: replace timeStamp with blockStamp

Time is not really relevant for us here and we don't use this timestamp in any
way. Yet it occupies 24 bytes and we do two clock_gettime calls to get it.

Replace it with blockStamp which is going to be used in the future for
transaction retransmissions.

It allows to improve single-node TPS by another 3%.
---
 pkg/core/blockchainer.go             | 1 -
 pkg/core/mempool/feer.go             | 1 +
 pkg/core/mempool/mem_pool.go         | 5 ++---
 pkg/core/mempool/mem_pool_test.go    | 4 ++++
 pkg/rpc/server/server_helper_test.go | 4 ++++
 5 files changed, 11 insertions(+), 4 deletions(-)

diff --git a/pkg/core/blockchainer.go b/pkg/core/blockchainer.go
index 6ead1cd03..76c032c61 100644
--- a/pkg/core/blockchainer.go
+++ b/pkg/core/blockchainer.go
@@ -19,7 +19,6 @@ type Blockchainer interface {
 	AddHeaders(...*block.Header) error
 	AddBlock(*block.Block) error
 	AddStateRoot(r *state.MPTRoot) error
-	BlockHeight() uint32
 	CalculateClaimable(value util.Fixed8, startHeight, endHeight uint32) (util.Fixed8, util.Fixed8, error)
 	Close()
 	HeaderHeight() uint32
diff --git a/pkg/core/mempool/feer.go b/pkg/core/mempool/feer.go
index 89b63dab5..f425ddd2a 100644
--- a/pkg/core/mempool/feer.go
+++ b/pkg/core/mempool/feer.go
@@ -7,6 +7,7 @@ import (
 
 // Feer is an interface that abstract the implementation of the fee calculation.
 type Feer interface {
+	BlockHeight() uint32
 	NetworkFee(t *transaction.Transaction) util.Fixed8
 	IsLowPriority(util.Fixed8) bool
 	FeePerByte(t *transaction.Transaction) util.Fixed8
diff --git a/pkg/core/mempool/mem_pool.go b/pkg/core/mempool/mem_pool.go
index 7dc38e2d4..8f1895132 100644
--- a/pkg/core/mempool/mem_pool.go
+++ b/pkg/core/mempool/mem_pool.go
@@ -4,7 +4,6 @@ import (
 	"errors"
 	"sort"
 	"sync"
-	"time"
 
 	"github.com/nspcc-dev/neo-go/pkg/core/transaction"
 	"github.com/nspcc-dev/neo-go/pkg/util"
@@ -26,7 +25,7 @@ var (
 // item represents a transaction in the the Memory pool.
 type item struct {
 	txn        *transaction.Transaction
-	timeStamp  time.Time
+	blockStamp uint32
 	perByteFee util.Fixed8
 	netFee     util.Fixed8
 	isLowPrio  bool
@@ -162,7 +161,7 @@ func dropInputFromSortedSlice(slice *[]*transaction.Input, input *transaction.In
 func (mp *Pool) Add(t *transaction.Transaction, fee Feer) error {
 	var pItem = &item{
 		txn:        t,
-		timeStamp:  time.Now().UTC(),
+		blockStamp: fee.BlockHeight(),
 		perByteFee: fee.FeePerByte(t),
 		netFee:     fee.NetworkFee(t),
 	}
diff --git a/pkg/core/mempool/mem_pool_test.go b/pkg/core/mempool/mem_pool_test.go
index 5cfcf7b70..2d4059281 100644
--- a/pkg/core/mempool/mem_pool_test.go
+++ b/pkg/core/mempool/mem_pool_test.go
@@ -18,6 +18,10 @@ type FeerStub struct {
 	perByteFee  util.Fixed8
 }
 
+func (fs *FeerStub) BlockHeight() uint32 {
+	return 0
+}
+
 func (fs *FeerStub) NetworkFee(*transaction.Transaction) util.Fixed8 {
 	return fs.netFee
 }
diff --git a/pkg/rpc/server/server_helper_test.go b/pkg/rpc/server/server_helper_test.go
index 61bcc2e0d..9a84e44ce 100644
--- a/pkg/rpc/server/server_helper_test.go
+++ b/pkg/rpc/server/server_helper_test.go
@@ -85,6 +85,10 @@ func initServerWithInMemoryChain(t *testing.T) (*core.Blockchain, *Server, *http
 
 type FeerStub struct{}
 
+func (fs *FeerStub) BlockHeight() uint32 {
+	return 0
+}
+
 func (fs *FeerStub) NetworkFee(*transaction.Transaction) util.Fixed8 {
 	return 0
 }