From 3ad4335accd08f2160aac489e4e16dceaae695be Mon Sep 17 00:00:00 2001
From: Martin Holst Swende <martin@swende.se>
Date: Mon, 2 Dec 2019 09:31:07 +0100
Subject: [PATCH] core/state/snapshot: node behavioural difference on bloom
content
---
core/state/snapshot/difflayer.go | 19 ++++++++++++++++---
core/state/snapshot/difflayer_test.go | 9 ++++++---
2 files changed, 22 insertions(+), 6 deletions(-)
diff --git a/core/state/snapshot/difflayer.go b/core/state/snapshot/difflayer.go
index cf8c47c3e..634118a10 100644
--- a/core/state/snapshot/difflayer.go
+++ b/core/state/snapshot/difflayer.go
@@ -20,6 +20,7 @@ import (
"encoding/binary"
"fmt"
"math"
+ "math/rand"
"sort"
"sync"
"time"
@@ -63,8 +64,20 @@ var (
// bloom filter to keep its size to a minimum (given it's size and maximum
// entry count).
bloomFuncs = math.Round((bloomSize / float64(aggregatorItemLimit)) * math.Log(2))
+
+ // bloomHashesOffset is a runtime constant which determines which part of the
+ // the account/storage hash the hasher functions looks at, to determine the
+ // bloom key for an account/slot. This is randomized at init(), so that the
+ // global population of nodes do not all display the exact same behaviour with
+ // regards to bloom content
+ bloomHasherOffset = 0
)
+func init() {
+ // Init bloomHasherOffset in the range [0:24] (requires 8 bytes)
+ bloomHasherOffset = rand.Intn(25)
+}
+
// diffLayer represents a collection of modifications made to a state snapshot
// after running a block on top. It contains one sorted list for the account trie
// and one-one list for each storage tries.
@@ -100,7 +113,7 @@ func (h accountBloomHasher) Reset() { panic("not impl
func (h accountBloomHasher) BlockSize() int { panic("not implemented") }
func (h accountBloomHasher) Size() int { return 8 }
func (h accountBloomHasher) Sum64() uint64 {
- return binary.BigEndian.Uint64(h[:8])
+ return binary.BigEndian.Uint64(h[bloomHasherOffset : bloomHasherOffset+8])
}
// storageBloomHasher is a wrapper around a [2]common.Hash to satisfy the interface
@@ -114,7 +127,8 @@ func (h storageBloomHasher) Reset() { panic("not impl
func (h storageBloomHasher) BlockSize() int { panic("not implemented") }
func (h storageBloomHasher) Size() int { return 8 }
func (h storageBloomHasher) Sum64() uint64 {
- return binary.BigEndian.Uint64(h[0][:8]) ^ binary.BigEndian.Uint64(h[1][:8])
+ return binary.BigEndian.Uint64(h[0][bloomHasherOffset:bloomHasherOffset+8]) ^
+ binary.BigEndian.Uint64(h[1][bloomHasherOffset:bloomHasherOffset+8])
}
// newDiffLayer creates a new diff on top of an existing snapshot, whether that's a low
@@ -205,7 +219,6 @@ func (dl *diffLayer) rebloom(origin *diskLayer) {
k := float64(dl.diffed.K())
n := float64(dl.diffed.N())
m := float64(dl.diffed.M())
-
snapshotBloomErrorGauge.Update(math.Pow(1.0-math.Exp((-k)*(n+0.5)/(m-1)), k))
}
diff --git a/core/state/snapshot/difflayer_test.go b/core/state/snapshot/difflayer_test.go
index 84220e359..7d7b21eb0 100644
--- a/core/state/snapshot/difflayer_test.go
+++ b/core/state/snapshot/difflayer_test.go
@@ -24,6 +24,7 @@ import (
"github.com/VictoriaMetrics/fastcache"
"github.com/ethereum/go-ethereum/common"
+ "github.com/ethereum/go-ethereum/crypto"
"github.com/ethereum/go-ethereum/ethdb/memorydb"
"github.com/ethereum/go-ethereum/rlp"
)
@@ -216,7 +217,7 @@ func BenchmarkSearch(b *testing.B) {
layer = fill(layer)
}
- key := common.Hash{}
+ key := crypto.Keccak256Hash([]byte{0x13, 0x38})
b.ResetTimer()
for i := 0; i < b.N; i++ {
layer.AccountRLP(key)
@@ -229,10 +230,12 @@ func BenchmarkSearch(b *testing.B) {
// BenchmarkSearchSlot-6 100000 14554 ns/op
// BenchmarkSearchSlot-6 100000 22254 ns/op (when checking parent root using mutex)
// BenchmarkSearchSlot-6 100000 14551 ns/op (when checking parent number using atomic)
+// With bloom filter:
+// BenchmarkSearchSlot-6 3467835 351 ns/op
func BenchmarkSearchSlot(b *testing.B) {
// First, we set up 128 diff layers, with 1K items each
- accountKey := common.Hash{}
- storageKey := common.HexToHash("0x1337")
+ accountKey := crypto.Keccak256Hash([]byte{0x13, 0x37})
+ storageKey := crypto.Keccak256Hash([]byte{0x13, 0x37})
accountRLP := randomAccount()
fill := func(parent snapshot) *diffLayer {
accounts := make(map[common.Hash][]byte)
--
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