Core/v2

core/mock/state.go

@@ -2,6 +2,7 @@ package mock
 
 import (
 	"context"
+	"encoding/binary"
 	"fmt"
 	"math/big"
 	"sort"
@@ -36,7 +37,8 @@ type PrivateOperatorState struct {
 }
 
 func MakeOperatorId(id int) core.OperatorID {
-	data := [32]byte{uint8(id)}
+	var data [32]byte
+	binary.LittleEndian.PutUint64(data[:8], uint64(id))
 	return data
 }
 

core/v2/assignment.go

@@ -0,0 +1,123 @@
+package corev2
+
+import (
+	"fmt"
+	"math/big"
+	"sort"
+
+	"github.com/Layr-Labs/eigenda/core"
+)
+
+func GetAssignments(state *core.OperatorState, blobVersion byte, quorum uint8) (map[core.OperatorID]Assignment, error) {
+
+	params, ok := ParametersMap[blobVersion]
+	if !ok {
+		return nil, fmt.Errorf("blob version %d not found", blobVersion)
+	}
+
+	ops, ok := state.Operators[quorum]
+	if !ok {
+		return nil, fmt.Errorf("no operators found for quorum %d", quorum)
+	}
+
+	if len(ops) > int(params.MaxNumOperators()) {
+		return nil, fmt.Errorf("too many operators for blob version %d", blobVersion)
+	}
+
+	n := big.NewInt(int64(len(ops)))
+	m := big.NewInt(int64(params.NumChunks))
+
+	type assignment struct {
+		id     core.OperatorID
+		index  uint32
+		chunks uint32
+		stake  *big.Int
+	}
+
+	chunkAssignments := make([]assignment, 0, len(ops))
+	for ID, r := range state.Operators[quorum] {
+
+		num := new(big.Int).Mul(r.Stake, new(big.Int).Sub(m, n))
+		denom := state.Totals[quorum].Stake
+
+		chunks := RoundUpDivideBig(num, denom)
+
+		chunkAssignments = append(chunkAssignments, assignment{id: ID, index: uint32(r.Index), chunks: uint32(chunks.Uint64()), stake: r.Stake})
+	}
+
+	// Sort chunk decreasing by stake or operator ID in case of a tie
+	sort.Slice(chunkAssignments, func(i, j int) bool {
+		if chunkAssignments[i].stake.Cmp(chunkAssignments[j].stake) == 0 {
+			return chunkAssignments[i].index < chunkAssignments[j].index
+		}
+		return chunkAssignments[i].stake.Cmp(chunkAssignments[j].stake) == 1
+	})
+
+	mp := 0
+	for _, a := range chunkAssignments {
+		mp += int(a.chunks)
+	}
+
+	delta := int(params.NumChunks) - mp
+	if delta < 0 {
+		return nil, fmt.Errorf("total chunks %d exceeds maximum %d", mp, params.NumChunks)
+	}
+
+	assignments := make(map[core.OperatorID]Assignment, len(chunkAssignments))
+	index := uint32(0)
+	for i, a := range chunkAssignments {
+		if i < delta {
+			a.chunks++
+		}
+
+		assignment := Assignment{
+			StartIndex: index,
+			NumChunks:  a.chunks,
+		}
+
+		assignments[a.id] = assignment
+		index += a.chunks
+	}
+
+	return assignments, nil
+
+}
+
+func GetAssignment(state *core.OperatorState, blobVersion byte, quorum core.QuorumID, id core.OperatorID) (Assignment, error) {
+
+	assignments, err := GetAssignments(state, blobVersion, quorum)
+	if err != nil {
+		return Assignment{}, err
+	}
+
+	assignment, ok := assignments[id]
+	if !ok {
+		return Assignment{}, ErrNotFound
+	}
+
+	return assignment, nil
+}
+
+func GetChunkLength(blobVersion byte, blobLength uint32) (uint32, error) {
+
+	if blobLength == 0 {
+		return 0, fmt.Errorf("blob length must be greater than 0")
+	}
+
+	// Check that the blob length is a power of 2
+	if blobLength&(blobLength-1) != 0 {
+		return 0, fmt.Errorf("blob length %d is not a power of 2", blobLength)
+	}
+
+	if _, ok := ParametersMap[blobVersion]; !ok {
+		return 0, fmt.Errorf("blob version %d not found", blobVersion)
+	}
+
+	chunkLength := blobLength * ParametersMap[blobVersion].CodingRate / ParametersMap[blobVersion].NumChunks
+	if chunkLength == 0 {
+		chunkLength = 1
+	}
+
+	return chunkLength, nil
+
+}

core/v2/assignment_test.go

@@ -0,0 +1,220 @@
+package corev2_test
+
+import (
+	"context"
+	"math/rand"
+	"testing"
+
+	"github.com/Layr-Labs/eigenda/core"
+	"github.com/Layr-Labs/eigenda/core/mock"
+	corev2 "github.com/Layr-Labs/eigenda/core/v2"
+	"github.com/stretchr/testify/assert"
+)
+
+const (
+	maxNumOperators = 3537
+)
+
+func TestOperatorAssignmentsV2(t *testing.T) {
+
+	state := dat.GetTotalOperatorState(context.Background(), 0)
+	operatorState := state.OperatorState
+
+	blobVersion := byte(0)
+
+	assignments, err := corev2.GetAssignments(operatorState, blobVersion, 0)
+	assert.NoError(t, err)
+	expectedAssignments := map[core.OperatorID]corev2.Assignment{
+		mock.MakeOperatorId(0): {
+			StartIndex: 7802,
+			NumChunks:  390,
+		},
+		mock.MakeOperatorId(1): {
+			StartIndex: 7022,
+			NumChunks:  780,
+		},
+		mock.MakeOperatorId(2): {
+			StartIndex: 5852,
+			NumChunks:  1170,
+		},
+		mock.MakeOperatorId(3): {
+			StartIndex: 4291,
+			NumChunks:  1561,
+		},
+		mock.MakeOperatorId(4): {
+			StartIndex: 2340,
+			NumChunks:  1951,
+		},
+		mock.MakeOperatorId(5): {
+			StartIndex: 0,
+			NumChunks:  2340,
+		},
+	}
+
+	for operatorID, assignment := range assignments {
+
+		assert.Equal(t, assignment, expectedAssignments[operatorID])
+
+		assignment, err := corev2.GetAssignment(operatorState, blobVersion, 0, operatorID)
+		assert.NoError(t, err)
+
+		assert.Equal(t, assignment, expectedAssignments[operatorID])
+
+	}
+
+}
+
+func TestMaxNumOperators(t *testing.T) {
+
+	assert.Equal(t, corev2.ParametersMap[0].MaxNumOperators(), uint32(maxNumOperators))
+
+}
+
+func TestAssignmentWithTooManyOperators(t *testing.T) {
+
+	numOperators := maxNumOperators + 1
+
+	stakes := map[core.QuorumID]map[core.OperatorID]int{
+		0: {},
+	}
+	for i := 0; i < numOperators; i++ {
+		stakes[0][mock.MakeOperatorId(i)] = rand.Intn(100) + 1
+	}
+
+	dat, err := mock.NewChainDataMock(stakes)
+	if err != nil {
+		t.Fatal(err)
+	}
+
+	state := dat.GetTotalOperatorState(context.Background(), 0)
+
+	assert.Equal(t, len(state.Operators[0]), numOperators)
+
+	blobVersion := byte(0)
+
+	_, err = corev2.GetAssignments(state.OperatorState, blobVersion, 0)
+	assert.Error(t, err)
+
+}
+
+func FuzzOperatorAssignmentsV2(f *testing.F) {
+
+	// Add distributions to fuzz
+
+	for i := 1; i < 100; i++ {
+		f.Add(i)
+	}
+
+	for i := 0; i < 100; i++ {
+		f.Add(rand.Intn(2048) + 100)
+	}
+
+	for i := 0; i < 5; i++ {
+		f.Add(maxNumOperators)
+	}
+
+	f.Fuzz(func(t *testing.T, numOperators int) {
+
+		// Generate a random slice of integers of length n
+
+		stakes := map[core.QuorumID]map[core.OperatorID]int{
+			0: {},
+		}
+		for i := 0; i < numOperators; i++ {
+			stakes[0][mock.MakeOperatorId(i)] = rand.Intn(100) + 1
+		}
+
+		dat, err := mock.NewChainDataMock(stakes)
+		if err != nil {
+			t.Fatal(err)
+		}
+
+		state := dat.GetTotalOperatorState(context.Background(), 0)
+
+		blobVersion := byte(0)
+
+		assignments, err := corev2.GetAssignments(state.OperatorState, blobVersion, 0)
+		assert.NoError(t, err)
+
+		// Check that the total number of chunks is correct
+		totalChunks := uint32(0)
+		for _, assignment := range assignments {
+			totalChunks += assignment.NumChunks
+		}
+		assert.Equal(t, totalChunks, corev2.ParametersMap[blobVersion].NumChunks)
+
+		// Check that each operator's assignment satisfies the security requirement
+		for operatorID, assignment := range assignments {
+
+			totalStake := uint32(state.Totals[0].Stake.Uint64())
+			myStake := uint32(state.Operators[0][operatorID].Stake.Uint64())
+
+			LHS := assignment.NumChunks * totalStake * corev2.ParametersMap[blobVersion].CodingRate * uint32(corev2.ParametersMap[blobVersion].ReconstructionThreshold*100)
+			RHS := 100 * myStake * corev2.ParametersMap[blobVersion].NumChunks
+
+			assert.GreaterOrEqual(t, LHS, RHS)
+
+		}
+
+	})
+
+}
+
+func TestChunkLength(t *testing.T) {
+
+	blobVersion := byte(0)
+
+	pairs := []struct {
+		blobLength  uint32
+		chunkLength uint32
+	}{
+		{512, 1},
+		{1024, 1},
+		{2048, 2},
+		{4096, 4},
+		{8192, 8},
+	}
+
+	for _, pair := range pairs {
+
+		chunkLength, err := corev2.GetChunkLength(blobVersion, pair.blobLength)
+
+		assert.NoError(t, err)
+
+		assert.Equal(t, pair.chunkLength, chunkLength)
+	}
+
+}
+
+func TestInvalidChunkLength(t *testing.T) {
+
+	blobVersion := byte(0)
+
+	invalidLengths := []uint32{
+		0,
+		3,
+		5,
+		6,
+		7,
+		9,
+		10,
+		11,
+		12,
+		13,
+		14,
+		15,
+		31,
+		63,
+		127,
+		255,
+		511,
+		1023,
+	}
+
+	for _, length := range invalidLengths {
+
+		_, err := corev2.GetChunkLength(blobVersion, length)
+		assert.Error(t, err)
+	}
+
+}