Make snowman use snowflake directly instead of snowball (#3403)

Signed-off-by: Yacov Manevich <[email protected]>

chains/manager.go

@@ -28,6 +28,7 @@ import (
 	"github.com/ava-labs/avalanchego/network"
 	"github.com/ava-labs/avalanchego/network/p2p"
 	"github.com/ava-labs/avalanchego/snow"
+	"github.com/ava-labs/avalanchego/snow/consensus/snowball"
 	"github.com/ava-labs/avalanchego/snow/engine/avalanche/bootstrap/queue"
 	"github.com/ava-labs/avalanchego/snow/engine/avalanche/state"
 	"github.com/ava-labs/avalanchego/snow/engine/avalanche/vertex"
@@ -917,7 +918,7 @@ func (m *manager) createAvalancheChain(
 		return nil, fmt.Errorf("couldn't initialize snow base message handler: %w", err)
 	}
 
-	var snowmanConsensus smcon.Consensus = &smcon.Topological{}
+	var snowmanConsensus smcon.Consensus = &smcon.Topological{Factory: snowball.SnowflakeFactory}
 	if m.TracingEnabled {
 		snowmanConsensus = smcon.Trace(snowmanConsensus, m.Tracer)
 	}
@@ -1310,7 +1311,7 @@ func (m *manager) createSnowmanChain(
 		return nil, fmt.Errorf("couldn't initialize snow base message handler: %w", err)
 	}
 
-	var consensus smcon.Consensus = &smcon.Topological{}
+	var consensus smcon.Consensus = &smcon.Topological{Factory: snowball.SnowflakeFactory}
 	if m.TracingEnabled {
 		consensus = smcon.Trace(consensus, m.Tracer)
 	}

snow/consensus/snowball/tree.go

@@ -360,7 +360,7 @@ func (u *unaryNode) Add(newChoice ids.ID) node {
 	newChild := &unaryNode{
 		tree:          u.tree,
 		preference:    newChoice,
-		decidedPrefix: index + 1,   // The new child assumes this branch has decided in it's favor
+		decidedPrefix: index + 1,   // The new child assumes this branch has decided in its favor
 		commonPrefix:  ids.NumBits, // The new child has no conflicts under this branch
 		snow:          newChildSnow,
 	}

snow/consensus/snowman/consensus_test.go

@@ -691,7 +691,7 @@ func RecordPollTransitivelyResetConfidenceTest(t *testing.T, factory Factory) {
 	votesFor3 := bag.Of(block3.ID())
 	require.NoError(sm.RecordPoll(context.Background(), votesFor3))
 	require.Equal(2, sm.NumProcessing())
-	require.Equal(block2.ID(), sm.Preference())
+	require.Equal(block3.ID(), sm.Preference())
 
 	require.NoError(sm.RecordPoll(context.Background(), votesFor3))
 	require.Zero(sm.NumProcessing())

snow/consensus/snowman/mixed_test.go

@@ -0,0 +1,55 @@
+// Copyright (C) 2019-2024, Ava Labs, Inc. All rights reserved.
+// See the file LICENSE for licensing terms.
+
+package snowman
+
+import (
+	"fmt"
+	"testing"
+
+	"github.com/stretchr/testify/require"
+	"gonum.org/v1/gonum/mathext/prng"
+
+	"github.com/ava-labs/avalanchego/snow/consensus/snowball"
+)
+
+func TestConvergenceSnowFlakeSnowBall(t *testing.T) {
+	require := require.New(t)
+
+	params := snowball.Parameters{
+		K:                     20,
+		AlphaPreference:       11,
+		AlphaConfidence:       11,
+		Beta:                  20,
+		ConcurrentRepolls:     1,
+		OptimalProcessing:     1,
+		MaxOutstandingItems:   1,
+		MaxItemProcessingTime: 1,
+	}
+
+	for peerCount := 20; peerCount < 2000; peerCount *= 10 {
+		numNodes := peerCount
+
+		t.Run(fmt.Sprintf("%d nodes", numNodes), func(t *testing.T) {
+			n := NewNetwork(params, 10, prng.NewMT19937())
+			for i := 0; i < numNodes; i++ {
+				var sbFactory snowball.Factory
+				if i%2 == 0 {
+					sbFactory = snowball.SnowflakeFactory
+				} else {
+					sbFactory = snowball.SnowballFactory
+				}
+
+				factory := TopologicalFactory{factory: sbFactory}
+				sm := factory.New()
+				require.NoError(n.AddNode(t, sm))
+			}
+
+			for !n.Finalized() {
+				require.NoError(n.Round())
+			}
+
+			require.True(n.Agreement())
+		})
+	}
+}

snow/consensus/snowman/snowman_block.go

@@ -36,7 +36,7 @@ func (n *snowmanBlock) AddChild(child Block) {
 	// if the snowball instance is nil, this is the first child. So the instance
 	// should be initialized.
 	if n.sb == nil {
-		n.sb = snowball.NewTree(snowball.SnowballFactory, n.t.params, childID)
+		n.sb = snowball.NewTree(n.t.Factory, n.t.params, childID)
 		n.children = make(map[ids.ID]Block)
 	} else {
 		n.sb.Add(childID)

snow/consensus/snowman/topological.go

@@ -29,16 +29,20 @@ var (
 )
 
 // TopologicalFactory implements Factory by returning a topological struct
-type TopologicalFactory struct{}
+type TopologicalFactory struct {
+	factory snowball.Factory
+}
 
-func (TopologicalFactory) New() Consensus {
-	return &Topological{}
+func (tf TopologicalFactory) New() Consensus {
+	return &Topological{Factory: tf.factory}
 }
 
 // Topological implements the Snowman interface by using a tree tracking the
 // strongly preferred branch. This tree structure amortizes network polls to
 // vote on more than just the next block.
 type Topological struct {
+	Factory snowball.Factory
+
 	metrics *metrics
 
 	// pollNumber is the number of times RecordPolls has been called

snow/consensus/snowman/topological_test.go

@@ -3,8 +3,12 @@
 
 package snowman
 
-import "testing"
+import (
+	"testing"
+
+	"github.com/ava-labs/avalanchego/snow/consensus/snowball"
+)
 
 func TestTopological(t *testing.T) {
-	runConsensusTests(t, TopologicalFactory{})
+	runConsensusTests(t, TopologicalFactory{factory: snowball.SnowflakeFactory})
 }

snow/engine/snowman/config_test.go

@@ -34,6 +34,6 @@ func DefaultConfig(t testing.TB) Config {
 			MaxOutstandingItems:   1,
 			MaxItemProcessingTime: 1,
 		},
-		Consensus: &snowman.Topological{},
+		Consensus: &snowman.Topological{Factory: snowball.SnowflakeFactory},
 	}
 }

snow/engine/snowman/engine_test.go

@@ -3026,7 +3026,7 @@ func TestGetProcessingAncestor(t *testing.T) {
 				ctx = snowtest.ConsensusContext(
 					snowtest.Context(t, snowtest.PChainID),
 				)
-				consensus = &snowman.Topological{}
+				consensus = &snowman.Topological{Factory: snowball.SnowflakeFactory}
 			)
 			require.NoError(consensus.Initialize(
 				ctx,
@@ -3100,7 +3100,7 @@ func TestShouldIssueBlock(t *testing.T) {
 
 	require.NoError(t, blocks[0].Accept(context.Background()))
 
-	c := &snowman.Topological{}
+	c := &snowman.Topological{Factory: snowball.SnowflakeFactory}
 	require.NoError(t, c.Initialize(
 		ctx,
 		snowball.DefaultParameters,

vms/platformvm/vm_test.go

@@ -1380,7 +1380,7 @@ func TestBootstrapPartiallyAccepted(t *testing.T) {
 			MaxOutstandingItems:   1,
 			MaxItemProcessingTime: 1,
 		},
-		Consensus: &smcon.Topological{},
+		Consensus: &smcon.Topological{Factory: snowball.SnowflakeFactory},
 	}
 	engine, err := smeng.New(engineConfig)
 	require.NoError(err)