Merge pull request #8530 from ethereum-optimism/refcell/local-context-loading

feat(op-challenger): Alphabet Trace Provider Local Context Loading

op-challenger/game/fault/contracts/faultdisputegame.go

@@ -58,7 +58,7 @@ func (f *FaultDisputeGameContract) addLocalDataTx(data *types.PreimageOracleData
 	call := f.contract.Call(
 		methodAddLocalData,
 		data.GetIdent(),
-		data.LocalContext,
+		types.NoLocalContext,
 		new(big.Int).SetUint64(uint64(data.OracleOffset)),
 	)
 	return call.ToTxCandidate()

op-challenger/game/fault/contracts/faultdisputegame_test.go

@@ -60,7 +60,6 @@ func TestFaultDisputeGame_UpdateOracleTx(t *testing.T) {
 		stubRpc, game := setupFaultDisputeGameTest(t)
 		data := &faultTypes.PreimageOracleData{
 			IsLocal:      true,
-			LocalContext: common.Hash{0x02},
 			OracleKey:    common.Hash{0xbc}.Bytes(),
 			OracleData:   []byte{1, 2, 3, 4, 5, 6, 7},
 			OracleOffset: 16,
@@ -68,7 +67,7 @@ func TestFaultDisputeGame_UpdateOracleTx(t *testing.T) {
 		claimIdx := uint64(6)
 		stubRpc.SetResponse(fdgAddr, methodAddLocalData, batching.BlockLatest, []interface{}{
 			data.GetIdent(),
-			data.LocalContext,
+			faultTypes.NoLocalContext,
 			new(big.Int).SetUint64(uint64(data.OracleOffset)),
 		}, nil)
 		tx, err := game.UpdateOracleTx(context.Background(), claimIdx, data)

op-challenger/game/fault/contracts/outputbisectiongame_test.go

@@ -55,7 +55,6 @@ func TestOutputBisectionGame_UpdateOracleTx(t *testing.T) {
 		stubRpc, game := setupOutputBisectionGameTest(t)
 		data := &faultTypes.PreimageOracleData{
 			IsLocal:      true,
-			LocalContext: common.Hash{0x02},
 			OracleKey:    common.Hash{0xbc}.Bytes(),
 			OracleData:   []byte{1, 2, 3, 4, 5, 6, 7},
 			OracleOffset: 16,

op-challenger/game/fault/responder/responder_test.go

@@ -179,8 +179,7 @@ func TestPerformAction(t *testing.T) {
 			PreState:  []byte{1, 2, 3},
 			ProofData: []byte{4, 5, 6},
 			OracleData: &types.PreimageOracleData{
-				IsLocal:      true,
-				LocalContext: common.Hash{0x06},
+				IsLocal: true,
 			},
 		}
 		err := responder.PerformAction(context.Background(), action)

op-challenger/game/fault/test/alphabet.go

@@ -33,6 +33,6 @@ func (a *alphabetWithProofProvider) GetStepData(ctx context.Context, i types.Pos
 		return nil, nil, nil, err
 	}
 	traceIndex := i.TraceIndex(int(a.depth)).Uint64()
-	data := types.NewPreimageOracleData(types.NoLocalContext, []byte{byte(traceIndex)}, []byte{byte(traceIndex - 1)}, uint32(traceIndex-1))
+	data := types.NewPreimageOracleData([]byte{byte(traceIndex)}, []byte{byte(traceIndex - 1)}, uint32(traceIndex-1))
 	return preimage, []byte{byte(traceIndex - 1)}, data, nil
 }

op-challenger/game/fault/trace/alphabet/provider.go

@@ -7,12 +7,19 @@ import (
 	"math/big"
 	"strings"
 
+	preimage "github.com/ethereum-optimism/optimism/op-preimage"
+
 	"github.com/ethereum-optimism/optimism/cannon/mipsevm"
 	"github.com/ethereum-optimism/optimism/op-challenger/game/fault/types"
+
 	"github.com/ethereum/go-ethereum/common"
 	"github.com/ethereum/go-ethereum/crypto"
 )
 
+const (
+	L2ClaimBlockNumberLocalIndex = 4
+)
+
 var (
 	ErrIndexTooLarge = errors.New("index is larger than the maximum index")
 )
@@ -50,7 +57,9 @@ func (ap *AlphabetTraceProvider) GetStepData(ctx context.Context, i types.Positi
 	if traceIndex.Cmp(big.NewInt(int64(len(ap.state)))) >= 0 {
 		return ap.GetStepData(ctx, types.NewPosition(int(ap.depth), big.NewInt(int64(len(ap.state)))))
 	}
-	return BuildAlphabetPreimage(traceIndex, ap.state[traceIndex.Uint64()]), []byte{}, nil, nil
+	key := preimage.LocalIndexKey(L2ClaimBlockNumberLocalIndex).PreimageKey()
+	preimageData := types.NewPreimageOracleData(key[:], nil, 0)
+	return BuildAlphabetPreimage(traceIndex, ap.state[traceIndex.Uint64()]), []byte{}, preimageData, nil
 }
 
 // Get returns the claim value at the given index in the trace.

op-challenger/game/fault/trace/alphabet/provider_test.go

@@ -5,7 +5,10 @@ import (
 	"math/big"
 	"testing"
 
+	preimage "github.com/ethereum-optimism/optimism/op-preimage"
+
 	"github.com/ethereum-optimism/optimism/op-challenger/game/fault/types"
+
 	"github.com/ethereum/go-ethereum/common"
 	"github.com/stretchr/testify/require"
 )
@@ -58,7 +61,9 @@ func TestGetStepData_Succeeds(t *testing.T) {
 	require.NoError(t, err)
 	require.Equal(t, expected, retrieved)
 	require.Empty(t, proof)
-	require.Nil(t, data)
+	key := preimage.LocalIndexKey(L2ClaimBlockNumberLocalIndex).PreimageKey()
+	expectedLocalContextData := types.NewPreimageOracleData(key[:], nil, 0)
+	require.Equal(t, expectedLocalContextData, data)
 }
 
 // TestGetPreimage_TooLargeIndex_Fails tests the GetPreimage

op-challenger/game/fault/trace/cannon/provider.go

@@ -105,7 +105,7 @@ func (p *CannonTraceProvider) GetStepData(ctx context.Context, pos types.Positio
 	}
 	var oracleData *types.PreimageOracleData
 	if len(proof.OracleKey) > 0 {
-		oracleData = types.NewPreimageOracleData(p.localContext, proof.OracleKey, proof.OracleValue, proof.OracleOffset)
+		oracleData = types.NewPreimageOracleData(proof.OracleKey, proof.OracleValue, proof.OracleOffset)
 	}
 	return value, data, oracleData, nil
 }

op-challenger/game/fault/trace/cannon/provider_test.go

@@ -124,7 +124,7 @@ func TestGetStepData(t *testing.T) {
 
 		require.EqualValues(t, generator.proof.StateData, preimage)
 		require.EqualValues(t, generator.proof.ProofData, proof)
-		expectedData := types.NewPreimageOracleData(common.Hash{}, generator.proof.OracleKey, generator.proof.OracleValue, generator.proof.OracleOffset)
+		expectedData := types.NewPreimageOracleData(generator.proof.OracleKey, generator.proof.OracleValue, generator.proof.OracleOffset)
 		require.EqualValues(t, expectedData, data)
 	})
 

op-challenger/game/fault/types/types.go

@@ -20,7 +20,6 @@ var (
 // to load into the onchain oracle.
 type PreimageOracleData struct {
 	IsLocal      bool
-	LocalContext common.Hash
 	OracleKey    []byte
 	OracleData   []byte
 	OracleOffset uint32
@@ -37,10 +36,9 @@ func (p *PreimageOracleData) GetPreimageWithoutSize() []byte {
 }
 
 // NewPreimageOracleData creates a new [PreimageOracleData] instance.
-func NewPreimageOracleData(lctx common.Hash, key []byte, data []byte, offset uint32) *PreimageOracleData {
+func NewPreimageOracleData(key []byte, data []byte, offset uint32) *PreimageOracleData {
 	return &PreimageOracleData{
 		IsLocal:      len(key) > 0 && key[0] == byte(1),
-		LocalContext: lctx,
 		OracleKey:    key,
 		OracleData:   data,
 		OracleOffset: offset,

op-challenger/game/fault/types/types_test.go

@@ -4,24 +4,21 @@ import (
 	"math/big"
 	"testing"
 
-	"github.com/ethereum/go-ethereum/common"
 	"github.com/stretchr/testify/require"
 )
 
 func TestNewPreimageOracleData(t *testing.T) {
 	t.Run("LocalData", func(t *testing.T) {
-		data := NewPreimageOracleData(common.Hash{0x01}, []byte{1, 2, 3}, []byte{4, 5, 6}, 7)
+		data := NewPreimageOracleData([]byte{1, 2, 3}, []byte{4, 5, 6}, 7)
 		require.True(t, data.IsLocal)
-		require.Equal(t, common.Hash{0x01}, data.LocalContext)
 		require.Equal(t, []byte{1, 2, 3}, data.OracleKey)
 		require.Equal(t, []byte{4, 5, 6}, data.OracleData)
 		require.Equal(t, uint32(7), data.OracleOffset)
 	})
 
 	t.Run("GlobalData", func(t *testing.T) {
-		data := NewPreimageOracleData(common.Hash{0x01}, []byte{0, 2, 3}, []byte{4, 5, 6}, 7)
+		data := NewPreimageOracleData([]byte{0, 2, 3}, []byte{4, 5, 6}, 7)
 		require.False(t, data.IsLocal)
-		require.Equal(t, common.Hash{0x01}, data.LocalContext)
 		require.Equal(t, []byte{0, 2, 3}, data.OracleKey)
 		require.Equal(t, []byte{4, 5, 6}, data.OracleData)
 		require.Equal(t, uint32(7), data.OracleOffset)