internal/ethapi: support block number or hash on state-related methods (

ethereum#19491)

This change adds support for EIP-1898.

core/blockchain.go

@@ -2139,6 +2139,11 @@ func (bc *BlockChain) HasHeader(hash common.Hash, number uint64) bool {
 	return bc.hc.HasHeader(hash, number)
 }
 
+// GetCanonicalHash returns the canonical hash for a given block number
+func (bc *BlockChain) GetCanonicalHash(number uint64) common.Hash {
+	return bc.hc.GetCanonicalHash(number)
+}
+
 // GetBlockHashesFromHash retrieves a number of block hashes starting at a given
 // hash, fetching towards the genesis block.
 func (bc *BlockChain) GetBlockHashesFromHash(hash common.Hash, max uint64) []common.Hash {

core/headerchain.go

@@ -448,6 +448,10 @@ func (hc *HeaderChain) GetHeaderByNumber(number uint64) *types.Header {
 	return hc.GetHeader(hash, number)
 }
 
+func (hc *HeaderChain) GetCanonicalHash(number uint64) common.Hash {
+	return rawdb.ReadCanonicalHash(hc.chainDb, number)
+}
+
 // CurrentHeader retrieves the current head header of the canonical chain. The
 // header is retrieved from the HeaderChain's internal cache.
 func (hc *HeaderChain) CurrentHeader() *types.Header {

eth/api_backend.go

@@ -72,6 +72,23 @@ func (b *EthAPIBackend) HeaderByNumber(ctx context.Context, number rpc.BlockNumb
 	return b.eth.blockchain.GetHeaderByNumber(uint64(number)), nil
 }
 
+func (b *EthAPIBackend) HeaderByNumberOrHash(ctx context.Context, blockNrOrHash rpc.BlockNumberOrHash) (*types.Header, error) {
+	if blockNr, ok := blockNrOrHash.Number(); ok {
+		return b.HeaderByNumber(ctx, blockNr)
+	}
+	if hash, ok := blockNrOrHash.Hash(); ok {
+		header := b.eth.blockchain.GetHeaderByHash(hash)
+		if header == nil {
+			return nil, errors.New("header for hash not found")
+		}
+		if blockNrOrHash.RequireCanonical && b.eth.blockchain.GetCanonicalHash(header.Number.Uint64()) != hash {
+			return nil, errors.New("hash is not currently canonical")
+		}
+		return header, nil
+	}
+	return nil, errors.New("invalid arguments; neither block nor hash specified")
+}
+
 func (b *EthAPIBackend) HeaderByHash(ctx context.Context, hash common.Hash) (*types.Header, error) {
 	return b.eth.blockchain.GetHeaderByHash(hash), nil
 }
@@ -93,6 +110,27 @@ func (b *EthAPIBackend) BlockByHash(ctx context.Context, hash common.Hash) (*typ
 	return b.eth.blockchain.GetBlockByHash(hash), nil
 }
 
+func (b *EthAPIBackend) BlockByNumberOrHash(ctx context.Context, blockNrOrHash rpc.BlockNumberOrHash) (*types.Block, error) {
+	if blockNr, ok := blockNrOrHash.Number(); ok {
+		return b.BlockByNumber(ctx, blockNr)
+	}
+	if hash, ok := blockNrOrHash.Hash(); ok {
+		header := b.eth.blockchain.GetHeaderByHash(hash)
+		if header == nil {
+			return nil, errors.New("header for hash not found")
+		}
+		if blockNrOrHash.RequireCanonical && b.eth.blockchain.GetCanonicalHash(header.Number.Uint64()) != hash {
+			return nil, errors.New("hash is not currently canonical")
+		}
+		block := b.eth.blockchain.GetBlock(hash, header.Number.Uint64())
+		if block == nil {
+			return nil, errors.New("header found, but block body is missing")
+		}
+		return block, nil
+	}
+	return nil, errors.New("invalid arguments; neither block nor hash specified")
+}
+
 func (b *EthAPIBackend) StateAndHeaderByNumber(ctx context.Context, number rpc.BlockNumber) (*state.StateDB, *types.Header, error) {
 	// Pending state is only known by the miner
 	if number == rpc.PendingBlockNumber {
@@ -111,6 +149,27 @@ func (b *EthAPIBackend) StateAndHeaderByNumber(ctx context.Context, number rpc.B
 	return stateDb, header, err
 }
 
+func (b *EthAPIBackend) StateAndHeaderByNumberOrHash(ctx context.Context, blockNrOrHash rpc.BlockNumberOrHash) (*state.StateDB, *types.Header, error) {
+	if blockNr, ok := blockNrOrHash.Number(); ok {
+		return b.StateAndHeaderByNumber(ctx, blockNr)
+	}
+	if hash, ok := blockNrOrHash.Hash(); ok {
+		header, err := b.HeaderByHash(ctx, hash)
+		if err != nil {
+			return nil, nil, err
+		}
+		if header == nil {
+			return nil, nil, errors.New("header for hash not found")
+		}
+		if blockNrOrHash.RequireCanonical && b.eth.blockchain.GetCanonicalHash(header.Number.Uint64()) != hash {
+			return nil, nil, errors.New("hash is not currently canonical")
+		}
+		stateDb, err := b.eth.BlockChain().StateAt(header.Root)
+		return stateDb, header, err
+	}
+	return nil, nil, errors.New("invalid arguments; neither block nor hash specified")
+}
+
 func (b *EthAPIBackend) GetReceipts(ctx context.Context, hash common.Hash) (types.Receipts, error) {
 	return b.eth.blockchain.GetReceiptsByHash(hash), nil
 }