Refactor blockchain.Pending to return a reference

blockchain/blockchain.go

@@ -45,7 +45,7 @@ type Reader interface {
 
 	EventFilter(from *felt.Felt, keys [][]felt.Felt) (EventFilterer, error)
 
-	Pending() (Pending, error)
+	Pending() (*Pending, error)
 
 	Network() *utils.Network
 }
@@ -269,7 +269,7 @@ func (b *Blockchain) TransactionByHash(hash *felt.Felt) (core.Transaction, error
 
 		// not found in the canonical blocks, try pending
 		if errors.Is(err, db.ErrKeyNotFound) {
-			var pending Pending
+			var pending *Pending
 			pending, err = pendingBlock(txn)
 			if err != nil {
 				return err
@@ -302,7 +302,7 @@ func (b *Blockchain) Receipt(hash *felt.Felt) (*core.TransactionReceipt, *felt.F
 
 		// not found in the canonical blocks, try pending
 		if errors.Is(err, db.ErrKeyNotFound) {
-			var pending Pending
+			var pending *Pending
 			pending, err = pendingBlock(txn)
 			if err != nil {
 				if !errors.Is(err, ErrPendingBlockNotFound) {
@@ -1009,32 +1009,30 @@ func (b *Blockchain) StorePending(pending *Pending) error {
 	})
 }
 
-// Todo:
-// 2. Consider returning reference to Pending instead of Pending
-func pendingBlock(txn db.Transaction) (Pending, error) {
+func pendingBlock(txn db.Transaction) (*Pending, error) {
 	pending := cachedPending.Load()
 	if pending == nil {
-		return Pending{}, ErrPendingBlockNotFound
+		return nil, ErrPendingBlockNotFound
 	}
 
 	expectedParentHash := &felt.Zero
 	if head, err := headsHeader(txn); err == nil {
 		expectedParentHash = head.Hash
 	}
 	if pending.Block.ParentHash.Equal(expectedParentHash) {
-		return *pending, nil
+		return pending, nil
 	}
 
 	// Since the pending block in the cache is outdated remove it
 	cachedPending.Store(nil)
 
-	return Pending{}, ErrPendingBlockNotFound
+	return nil, ErrPendingBlockNotFound
 }
 
 // Pending returns the pending block from the database
-func (b *Blockchain) Pending() (Pending, error) {
+func (b *Blockchain) Pending() (*Pending, error) {
 	b.listener.OnRead("Pending")
-	var pending Pending
+	var pending *Pending
 	return pending, b.database.View(func(txn db.Transaction) error {
 		var err error
 		pending, err = pendingBlock(txn)
@@ -1055,9 +1053,5 @@ func (b *Blockchain) PendingState() (core.StateReader, StateCloser, error) {
 		return nil, nil, utils.RunAndWrapOnError(txn.Discard, err)
 	}
 
-	return NewPendingState(
-		pending.StateUpdate.StateDiff,
-		pending.NewClasses,
-		core.NewState(txn),
-	), txn.Discard, nil
+	return NewPendingState(pending.StateUpdate.StateDiff, pending.NewClasses, core.NewState(txn)), txn.Discard, nil
 }

blockchain/blockchain_test.go

@@ -706,11 +706,11 @@ func TestPending(t *testing.T) {
 	})
 
 	t.Run("store genesis as pending", func(t *testing.T) {
-		pendingGenesis := blockchain.Pending{
+		pendingGenesis := &blockchain.Pending{
 			Block:       b,
 			StateUpdate: su,
 		}
-		require.NoError(t, chain.StorePending(&pendingGenesis))
+		require.NoError(t, chain.StorePending(pendingGenesis))
 
 		gotPending, pErr := chain.Pending()
 		require.NoError(t, pErr)
@@ -739,11 +739,11 @@ func TestPending(t *testing.T) {
 		su, err = gw.StateUpdate(context.Background(), 1)
 		require.NoError(t, err)
 
-		expectedPending := blockchain.Pending{
+		expectedPending := &blockchain.Pending{
 			Block:       b,
 			StateUpdate: su,
 		}
-		require.NoError(t, chain.StorePending(&expectedPending))
+		require.NoError(t, chain.StorePending(expectedPending))
 
 		gotPending, pErr := chain.Pending()
 		require.NoError(t, pErr)

rpc/block_test.go

@@ -215,7 +215,7 @@ func TestBlockTransactionCount(t *testing.T) {
 	t.Run("blockID - pending", func(t *testing.T) {
 		latestBlock.Hash = nil
 		latestBlock.GlobalStateRoot = nil
-		mockReader.EXPECT().Pending().Return(blockchain.Pending{
+		mockReader.EXPECT().Pending().Return(&blockchain.Pending{
 			Block: latestBlock,
 		}, nil)
 
@@ -333,7 +333,7 @@ func TestBlockWithTxHashes(t *testing.T) {
 	t.Run("blockID - pending", func(t *testing.T) {
 		latestBlock.Hash = nil
 		latestBlock.GlobalStateRoot = nil
-		mockReader.EXPECT().Pending().Return(blockchain.Pending{
+		mockReader.EXPECT().Pending().Return(&blockchain.Pending{
 			Block: latestBlock,
 		}, nil)
 		mockReader.EXPECT().L1Head().Return(nil, db.ErrKeyNotFound)
@@ -470,7 +470,7 @@ func TestBlockWithTxs(t *testing.T) {
 	t.Run("blockID - pending", func(t *testing.T) {
 		latestBlock.Hash = nil
 		latestBlock.GlobalStateRoot = nil
-		mockReader.EXPECT().Pending().Return(blockchain.Pending{
+		mockReader.EXPECT().Pending().Return(&blockchain.Pending{
 			Block: latestBlock,
 		}, nil).Times(2)
 		mockReader.EXPECT().L1Head().Return(nil, db.ErrKeyNotFound).Times(2)

rpc/helpers.go

@@ -38,9 +38,11 @@ func (h *Handler) blockByID(id *BlockID) (*core.Block, *jsonrpc.Error) {
 	case id.Hash != nil:
 		block, err = h.bcReader.BlockByHash(id.Hash)
 	case id.Pending:
-		var pending blockchain.Pending
+		var pending *blockchain.Pending
 		pending, err = h.bcReader.Pending()
-		block = pending.Block
+		if err == nil {
+			block = pending.Block
+		}
 	default:
 		block, err = h.bcReader.BlockByNumber(id.Number)
 	}
@@ -66,9 +68,9 @@ func (h *Handler) blockHeaderByID(id *BlockID) (*core.Header, *jsonrpc.Error) {
 	case id.Hash != nil:
 		header, err = h.bcReader.BlockHeaderByHash(id.Hash)
 	case id.Pending:
-		var pending blockchain.Pending
+		var pending *blockchain.Pending
 		pending, err = h.bcReader.Pending()
-		if pending.Block != nil {
+		if err == nil {
 			header = pending.Block.Header
 		}
 	default:

rpc/state_update.go

@@ -75,7 +75,7 @@ func (h *Handler) StateUpdate(id BlockID) (*StateUpdate, *jsonrpc.Error) {
 			update, err = h.bcReader.StateUpdateByNumber(height)
 		}
 	} else if id.Pending {
-		var pending blockchain.Pending
+		var pending *blockchain.Pending
 		pending, err = h.bcReader.Pending()
 		if err == nil {
 			update = pending.StateUpdate

rpc/state_update_test.go

@@ -139,7 +139,7 @@ func TestStateUpdate(t *testing.T) {
 	t.Run("pending", func(t *testing.T) {
 		update21656.BlockHash = nil
 		update21656.NewRoot = nil
-		mockReader.EXPECT().Pending().Return(blockchain.Pending{
+		mockReader.EXPECT().Pending().Return(&blockchain.Pending{
 			StateUpdate: update21656,
 		}, nil)
 

rpc/transaction_test.go

@@ -470,7 +470,7 @@ func TestTransactionByBlockIdAndIndex(t *testing.T) {
 
 		latestBlock.Hash = nil
 		latestBlock.GlobalStateRoot = nil
-		mockReader.EXPECT().Pending().Return(blockchain.Pending{
+		mockReader.EXPECT().Pending().Return(&blockchain.Pending{
 			Block: latestBlock,
 		}, nil)
 		mockReader.EXPECT().TransactionByHash(latestBlock.Transactions[index].Hash()).DoAndReturn(