refactor stubs

op-program/client/l1/cache.go

@@ -16,20 +16,17 @@ type CachingOracle struct {
 	blocks *simplelru.LRU[common.Hash, eth.BlockInfo]
 	txs    *simplelru.LRU[common.Hash, types.Transactions]
 	rcpts  *simplelru.LRU[common.Hash, types.Receipts]
-	outputs *simplelru.LRU[common.Hash, eth.Output]
 }
 
 func NewCachingOracle(oracle Oracle) *CachingOracle {
 	blockLRU, _ := simplelru.NewLRU[common.Hash, eth.BlockInfo](cacheSize, nil)
 	txsLRU, _ := simplelru.NewLRU[common.Hash, types.Transactions](cacheSize, nil)
 	rcptsLRU, _ := simplelru.NewLRU[common.Hash, types.Receipts](cacheSize, nil)
-	outputsLRU, _ := simplelru.NewLRU[common.Hash, eth.Output](cacheSize, nil)
 	return &CachingOracle{
 		oracle: oracle,
 		blocks: blockLRU,
 		txs:    txsLRU,
 		rcpts:  rcptsLRU,
-		outputs: outputsLRU,
 	}
 }
 
@@ -64,13 +61,3 @@ func (o *CachingOracle) ReceiptsByBlockHash(blockHash common.Hash) (eth.BlockInf
 	o.rcpts.Add(blockHash, rcpts)
 	return block, rcpts
 }
-
-func (o *CachingOracle) L2OutputByRoot(l2OutputRoot common.Hash) eth.Output {
-	output, ok := o.outputs.Get(l2OutputRoot)
-	if ok {
-		return output
-	}
-	output = o.oracle.L2OutputByRoot(l2OutputRoot)
-	o.outputs.Add(l2OutputRoot, output)
-	return output
-}

op-program/client/l1/cache_test.go

@@ -7,7 +7,6 @@ import (
 	"github.com/ethereum-optimism/optimism/op-node/eth"
 	"github.com/ethereum-optimism/optimism/op-node/testutils"
 	"github.com/ethereum-optimism/optimism/op-program/client/l1/test"
-	"github.com/ethereum/go-ethereum/common"
 	"github.com/stretchr/testify/require"
 )
 
@@ -72,29 +71,3 @@ func TestCachingOracle_ReceiptsByBlockHash(t *testing.T) {
 	require.Equal(t, eth.BlockToInfo(block), actualBlock)
 	require.EqualValues(t, rcpts, actualRcpts)
 }
-
-func TestCachingOracle_L2OutputByRoot(t *testing.T) {
-	rng := rand.New(rand.NewSource(1))
-	stub := test.NewStubOracle(t)
-	oracle := NewCachingOracle(stub)
-	block, _ := testutils.RandomBlock(rng, 3)
-
-	var storageRoot [32]byte
-	rng.Read(storageRoot[:])
-	l2Output := &eth.OutputV0{
-		StateRoot:                eth.Bytes32(block.Root()),
-		MessagePasserStorageRoot: storageRoot,
-		BlockHash:                block.Hash(),
-	}
-	l2OutputRoot := common.Hash(eth.OutputRoot(l2Output))
-
-	// Initial call retrieves from the stub
-	stub.L2Outputs[l2OutputRoot] = l2Output
-	result := oracle.L2OutputByRoot(l2OutputRoot)
-	require.Equal(t, l2Output.Marshal(), result)
-
-	// Later calls should retrieve from cache
-	delete(stub.L2Outputs, l2OutputRoot)
-	result = oracle.L2OutputByRoot(l2OutputRoot)
-	require.Equal(t, l2Output.Marshal(), result)
-}

op-program/client/l1/client.go

@@ -80,7 +80,3 @@ func (o *OracleL1Client) InfoAndTxsByHash(ctx context.Context, hash common.Hash)
 	info, txs := o.oracle.TransactionsByBlockHash(hash)
 	return info, txs, nil
 }
-
-func (o *OracleL1Client) L2OutputByRoot(ctx context.Context, root common.Hash) (eth.Output, error) {
-	return o.oracle.L2OutputByRoot(root), nil
-}

op-program/client/l1/hints.go

@@ -10,7 +10,6 @@ const (
 	HintL1BlockHeader  = "l1-block-header"
 	HintL1Transactions = "l1-transactions"
 	HintL1Receipts     = "l1-receipts"
-	HintL2Output       = "l1-l2-output"
 )
 
 type BlockHeaderHint common.Hash
@@ -36,11 +35,3 @@ var _ preimage.Hint = ReceiptsHint{}
 func (l ReceiptsHint) Hint() string {
 	return HintL1Receipts + " " + (common.Hash)(l).String()
 }
-
-type L2OutputHint common.Hash
-
-var _ preimage.Hint = L2OutputHint{}
-
-func (l L2OutputHint) Hint() string {
-	return HintL2Output + " " + (common.Hash)(l).String()
-}

op-program/client/l1/oracle.go

@@ -21,9 +21,6 @@ type Oracle interface {
 
 	// ReceiptsByBlockHash retrieves the receipts from the block with the given hash.
 	ReceiptsByBlockHash(blockHash common.Hash) (eth.BlockInfo, types.Receipts)
-
-	// L2OutputByRoot retrieves the L2 output for the given L2 output root.
-	L2OutputByRoot(l2OutputRoot common.Hash) eth.Output
 }
 
 // PreimageOracle implements Oracle using by interfacing with the pure preimage.Oracle
@@ -89,13 +86,3 @@ func (p *PreimageOracle) ReceiptsByBlockHash(blockHash common.Hash) (eth.BlockIn
 
 	return info, receipts
 }
-
-func (p *PreimageOracle) L2OutputByRoot(l2OutputRoot common.Hash) eth.Output {
-	p.hint.Hint(L2OutputHint(l2OutputRoot))
-	data := p.oracle.Get(preimage.Keccak256Key(l2OutputRoot))
-	output, err := eth.UnmarshalOutput(data)
-	if err != nil {
-		panic(fmt.Errorf("invalidd L2 output data for root %s: %w", l2OutputRoot, err))
-	}
-	return output
-}

op-program/client/l1/test/stub_oracle.go

@@ -19,9 +19,6 @@ type StubOracle struct {
 
 	// Rcpts maps Block hash to receipts
 	Rcpts map[common.Hash]types.Receipts
-
-	// L2Outputs maps L2 output roots to L2 outputs
-	L2Outputs map[common.Hash]eth.Output
 }
 
 func NewStubOracle(t *testing.T) *StubOracle {
@@ -30,7 +27,6 @@ func NewStubOracle(t *testing.T) *StubOracle {
 		Blocks: make(map[common.Hash]eth.BlockInfo),
 		Txs:    make(map[common.Hash]types.Transactions),
 		Rcpts:  make(map[common.Hash]types.Receipts),
-		L2Outputs: make(map[common.Hash]eth.Output),
 	}
 }
 func (o StubOracle) HeaderByBlockHash(blockHash common.Hash) eth.BlockInfo {
@@ -56,11 +52,3 @@ func (o StubOracle) ReceiptsByBlockHash(blockHash common.Hash) (eth.BlockInfo, t
 	}
 	return o.HeaderByBlockHash(blockHash), rcpts
 }
-
-func (o StubOracle) L2OutputByRoot(l2OutputRoot common.Hash) eth.Output {
-	output, ok := o.L2Outputs[l2OutputRoot]
-	if !ok {
-		o.t.Fatalf("unknown output %s", l2OutputRoot)
-	}
-	return output
-}

op-program/client/l2/cache.go

 package l2
 
 import (
+	"github.com/ethereum-optimism/optimism/op-node/eth"
 	"github.com/ethereum/go-ethereum/common"
 	"github.com/ethereum/go-ethereum/core/types"
 	"github.com/hashicorp/golang-lru/v2/simplelru"
@@ -17,17 +18,20 @@ type CachingOracle struct {
 	blocks  *simplelru.LRU[common.Hash, *types.Block]
 	nodes   *simplelru.LRU[common.Hash, []byte]
 	codes   *simplelru.LRU[common.Hash, []byte]
+	outputs *simplelru.LRU[common.Hash, eth.Output]
 }
 
 func NewCachingOracle(oracle Oracle) *CachingOracle {
 	blockLRU, _ := simplelru.NewLRU[common.Hash, *types.Block](blockCacheSize, nil)
 	nodeLRU, _ := simplelru.NewLRU[common.Hash, []byte](nodeCacheSize, nil)
 	codeLRU, _ := simplelru.NewLRU[common.Hash, []byte](codeCacheSize, nil)
+	outputLRU, _ := simplelru.NewLRU[common.Hash, eth.Output](codeCacheSize, nil)
 	return &CachingOracle{
 		oracle:  oracle,
 		blocks:  blockLRU,
 		nodes:   nodeLRU,
 		codes:   codeLRU,
+		outputs: outputLRU,
 	}
 }
 
@@ -60,3 +64,13 @@ func (o *CachingOracle) BlockByHash(blockHash common.Hash) *types.Block {
 	o.blocks.Add(blockHash, block)
 	return block
 }
+
+func (o *CachingOracle) L2OutputByRoot(root common.Hash) eth.Output {
+	output, ok := o.outputs.Get(root)
+	if ok {
+		return output
+	}
+	output = o.oracle.L2OutputByRoot(root)
+	o.outputs.Add(root, output)
+	return output
+}

op-program/client/l2/engine_backend.go

@@ -4,6 +4,7 @@ import (
 	"fmt"
 	"math/big"
 
+	"github.com/ethereum-optimism/optimism/op-node/eth"
 	"github.com/ethereum-optimism/optimism/op-program/client/l2/engineapi"
 	"github.com/ethereum/go-ethereum/common"
 	"github.com/ethereum/go-ethereum/consensus"
@@ -39,8 +40,13 @@ type OracleBackedL2Chain struct {
 
 var _ engineapi.EngineBackend = (*OracleBackedL2Chain)(nil)
 
-func NewOracleBackedL2Chain(logger log.Logger, oracle Oracle, chainCfg *params.ChainConfig, l2Head common.Hash) (*OracleBackedL2Chain, error) {
-	head := oracle.BlockByHash(l2Head)
+func NewOracleBackedL2Chain(logger log.Logger, oracle Oracle, chainCfg *params.ChainConfig, l2OutputRoot common.Hash) (*OracleBackedL2Chain, error) {
+	output := oracle.L2OutputByRoot(l2OutputRoot)
+	outputV0, ok := output.(*eth.OutputV0)
+	if !ok {
+		return nil, fmt.Errorf("unsupported L2 output version: %d", output.Version())
+	}
+	head := oracle.BlockByHash(outputV0.BlockHash)
 	logger.Info("Loaded L2 head", "hash", head.Hash(), "number", head.Number())
 	return &OracleBackedL2Chain{
 		log:      logger,

op-program/client/l2/hints.go

@@ -11,6 +11,7 @@ const (
 	HintL2Transactions = "l2-transactions"
 	HintL2Code         = "l2-code"
 	HintL2StateNode    = "l2-state-node"
+	HintL2Output       = "l2-output"
 )
 
 type BlockHeaderHint common.Hash
@@ -44,3 +45,11 @@ var _ preimage.Hint = StateNodeHint{}
 func (l StateNodeHint) Hint() string {
 	return HintL2StateNode + " " + (common.Hash)(l).String()
 }
+
+type L2OutputHint common.Hash
+
+var _ preimage.Hint = L2OutputHint{}
+
+func (l L2OutputHint) Hint() string {
+	return HintL2Output + " " + (common.Hash)(l).String()
+}

op-program/client/l2/oracle.go

@@ -32,6 +32,8 @@ type Oracle interface {
 
 	// BlockByHash retrieves the block with the given hash.
 	BlockByHash(blockHash common.Hash) *types.Block
+
+	L2OutputByRoot(root common.Hash) eth.Output
 }
 
 // PreimageOracle implements Oracle using by interfacing with the pure preimage.Oracle
@@ -85,3 +87,13 @@ func (p *PreimageOracle) CodeByHash(codeHash common.Hash) []byte {
 	p.hint.Hint(CodeHint(codeHash))
 	return p.oracle.Get(preimage.Keccak256Key(codeHash))
 }
+
+func (p *PreimageOracle) L2OutputByRoot(l2OutputRoot common.Hash) eth.Output {
+	p.hint.Hint(L2OutputHint(l2OutputRoot))
+	data := p.oracle.Get(preimage.Keccak256Key(l2OutputRoot))
+	output, err := eth.UnmarshalOutput(data)
+	if err != nil {
+		panic(fmt.Errorf("invalid L2 output data for root %s: %w", l2OutputRoot, err))
+	}
+	return output
+}

op-program/client/l2/test/stub_oracle.go

@@ -3,6 +3,7 @@ package test
 import (
 	"testing"
 
+	"github.com/ethereum-optimism/optimism/op-node/eth"
 	"github.com/ethereum/go-ethereum/common"
 	"github.com/ethereum/go-ethereum/core/rawdb"
 	"github.com/ethereum/go-ethereum/core/types"
@@ -18,6 +19,7 @@ type stateOracle interface {
 type StubBlockOracle struct {
 	t         *testing.T
 	Blocks    map[common.Hash]*types.Block
+	L2Outputs map[common.Hash]eth.Output
 	stateOracle
 }
 
@@ -50,6 +52,14 @@ func (o StubBlockOracle) BlockByHash(blockHash common.Hash) *types.Block {
 	return block
 }
 
+func (o StubBlockOracle) L2OutputByRoot(root common.Hash) eth.Output {
+	output, ok := o.L2Outputs[root]
+	if !ok {
+		o.t.Fatalf("requested unknown output root %s", root)
+	}
+	return output
+}
+
 // KvStateOracle loads data from a source ethdb.KeyValueStore
 type KvStateOracle struct {
 	t      *testing.T

op-program/client/program.go

@@ -64,16 +64,7 @@ func RunProgram(logger log.Logger, preimageOracle io.ReadWriter, preimageHinter
 // runDerivation executes the L2 state transition, given a minimal interface to retrieve data.
 func runDerivation(logger log.Logger, cfg *rollup.Config, l2Cfg *params.ChainConfig, l1Head common.Hash, l2OutputRoot common.Hash, l2Claim common.Hash, l2ClaimBlockNum uint64, l1Oracle l1.Oracle, l2Oracle l2.Oracle) error {
 	l1Source := l1.NewOracleL1Client(logger, l1Oracle, l1Head)
-	output, err := l1Source.L2OutputByRoot(context.Background(), l2OutputRoot)
-	if err != nil {
-		return fmt.Errorf("failed to find L2 output for %s: %w", l2OutputRoot, err)
-	}
-	outputV0, ok := output.(*eth.OutputV0)
-	if !ok {
-		return fmt.Errorf("unsupported L2 output version: %d", output.Version())
-	}
-	l2Head := outputV0.BlockHash
-	engineBackend, err := l2.NewOracleBackedL2Chain(logger, l2Oracle, l2Cfg, l2Head)
+	engineBackend, err := l2.NewOracleBackedL2Chain(logger, l2Oracle, l2Cfg, l2OutputRoot)
 	if err != nil {
 		return fmt.Errorf("failed to create oracle-backed L2 chain: %w", err)
 	}

op-program/host/prefetcher/prefetcher.go

@@ -99,12 +99,6 @@ func (p *Prefetcher) prefetch(ctx context.Context, hint string) error {
 			return fmt.Errorf("failed to fetch L1 block %s receipts: %w", hash, err)
 		}
 		return p.storeReceipts(receipts)
-	case l1.HintL2Output:
-		output, err := p.l2Fetcher.L2OutputByRoot(ctx, hash)
-		if err != nil {
-			return fmt.Errorf("failed to fetch L2 output root %s: %w", hash, err)
-		}
-		return p.kvStore.Put(preimage.Keccak256Key(hash).PreimageKey(), output.Marshal())
 	case l2.HintL2BlockHeader:
 		header, txs, err := p.l2Fetcher.InfoAndTxsByHash(ctx, hash)
 		if err != nil {
@@ -131,6 +125,12 @@ func (p *Prefetcher) prefetch(ctx context.Context, hint string) error {
 			return fmt.Errorf("failed to fetch L2 contract code %s: %w", hash, err)
 		}
 		return p.kvStore.Put(preimage.Keccak256Key(hash).PreimageKey(), code)
+	case l2.HintL2Output:
+		output, err := p.l2Fetcher.L2OutputByRoot(ctx, hash)
+		if err != nil {
+			return fmt.Errorf("failed to fetch L2 output root %s: %w", hash, err)
+		}
+		return p.kvStore.Put(preimage.Keccak256Key(hash).PreimageKey(), output.Marshal())
 	}
 	return fmt.Errorf("unknown hint type: %v", hintType)
 }