begin eth api recapitulation

pkg/super_node/eth/api.go

@@ -0,0 +1,81 @@
+package eth
+
+import (
+	"context"
+
+	"github.com/ethereum/go-ethereum/core/types"
+
+	"github.com/ethereum/go-ethereum/common/hexutil"
+	"github.com/ethereum/go-ethereum/rpc"
+)
+
+// APIName is the namespace used for the state diffing service API
+const APIName = "eth"
+
+// APIVersion is the version of the state diffing service API
+const APIVersion = "0.0.1"
+
+type PublicEthAPI struct {
+	b Backend
+}
+
+// NewPublicEthAPI creates a new PublicEthAPI with the provided underlying Backend
+func NewPublicEthAPI(b Backend) *PublicEthAPI {
+	return &PublicEthAPI{
+		b: b,
+	}
+}
+
+/*
+to start, need
+eth_blockNumber
+eth_getLogs
+eth_getHeaderByNumber
+*/
+
+// BlockNumber returns the block number of the chain head.
+func (pea *PublicEthAPI) BlockNumber() hexutil.Uint64 {
+	number, _ := pea.b.retriever.RetrieveLastBlockNumber()
+	return hexutil.Uint64(number)
+}
+
+// GetHeaderByNumber returns the requested canonical block header.
+// * When blockNr is -1 the chain head is returned.
+func (pea *PublicEthAPI) GetHeaderByNumber(ctx context.Context, number rpc.BlockNumber) (map[string]interface{}, error) {
+	header, err := pea.b.HeaderByNumber(ctx, number)
+	if header != nil && err == nil {
+		return pea.rpcMarshalHeader(header), err
+	}
+	return nil, err
+}
+
+// rpcMarshalHeader uses the generalized output filler, then adds the total difficulty field, which requires
+// a `PublicBlockchainAPI`.
+func (pea *PublicEthAPI) rpcMarshalHeader(header *types.Header) map[string]interface{} {
+	fields := RPCMarshalHeader(header)
+	fields["totalDifficulty"] = (*hexutil.Big)(pea.b.GetTd(header.Hash()))
+	return fields
+}
+
+// RPCMarshalHeader converts the given header to the RPC output .
+func RPCMarshalHeader(head *types.Header) map[string]interface{} {
+	return map[string]interface{}{
+		"number":           (*hexutil.Big)(head.Number),
+		"hash":             head.Hash(),
+		"parentHash":       head.ParentHash,
+		"nonce":            head.Nonce,
+		"mixHash":          head.MixDigest,
+		"sha3Uncles":       head.UncleHash,
+		"logsBloom":        head.Bloom,
+		"stateRoot":        head.Root,
+		"miner":            head.Coinbase,
+		"difficulty":       (*hexutil.Big)(head.Difficulty),
+		"extraData":        hexutil.Bytes(head.Extra),
+		"size":             hexutil.Uint64(head.Size()),
+		"gasLimit":         hexutil.Uint64(head.GasLimit),
+		"gasUsed":          hexutil.Uint64(head.GasUsed),
+		"timestamp":        hexutil.Uint64(head.Time),
+		"transactionsRoot": head.TxHash,
+		"receiptsRoot":     head.ReceiptHash,
+	}
+}

pkg/super_node/eth/backend.go

@@ -0,0 +1,88 @@
+package eth
+
+import (
+	"context"
+	"errors"
+	"fmt"
+	"math/big"
+
+	"github.com/vulcanize/vulcanizedb/pkg/datastore/postgres"
+
+	"github.com/ethereum/go-ethereum/common"
+	"github.com/ethereum/go-ethereum/core/types"
+	"github.com/ethereum/go-ethereum/rlp"
+	"github.com/ethereum/go-ethereum/rpc"
+	"github.com/hashicorp/golang-lru"
+
+	"github.com/vulcanize/vulcanizedb/pkg/ipfs"
+	"github.com/vulcanize/vulcanizedb/pkg/super_node"
+)
+
+var (
+	errPendingBlockNumber = errors.New("pending block number not supported")
+)
+
+type Backend struct {
+	retriever super_node.CIDRetriever
+	fetcher   ipfs.IPLDFetcher
+	db        *postgres.DB
+
+	headerCache *lru.Cache // Cache for the most recent block headers
+	tdCache     *lru.Cache // Cache for the most recent block total difficulties
+	numberCache *lru.Cache // Cache for the most recent block numbers
+}
+
+func NewEthBackend(r super_node.CIDRetriever, f ipfs.IPLDFetcher) *Backend {
+	return &Backend{
+		retriever: r,
+		fetcher:   f,
+		db:        r.Database(),
+	}
+}
+
+func (b *Backend) HeaderByNumber(ctx context.Context, blockNumber rpc.BlockNumber) (*types.Header, error) {
+	number := blockNumber.Int64()
+	var err error
+	if blockNumber == rpc.LatestBlockNumber {
+		number, err = b.retriever.RetrieveLastBlockNumber()
+		if err != nil {
+			return nil, err
+		}
+	}
+	if blockNumber == rpc.PendingBlockNumber {
+		return nil, errPendingBlockNumber
+	}
+	// Retrieve the CIDs for headers at this height
+	tx, err := b.db.Beginx()
+	if err != nil {
+		return nil, err
+	}
+	headerCids, err := b.retriever.RetrieveHeaderCIDs(tx, number)
+	if err != nil {
+		return nil, err
+	}
+	if err := tx.Commit(); err != nil {
+		return nil, err
+	}
+	// If there are none, throw an error
+	if len(headerCids) < 1 {
+		return nil, fmt.Errorf("header at block %d is not available", number)
+	}
+	// Fetch the header IPLDs for those CIDs
+	headerIPLDs, err := b.fetcher.FetchHeaders(headerCids)
+	if err != nil {
+		return nil, err
+	}
+	// Decode the first header at this block height and return it
+	// We throw an error in FetchHeaders() if the number of headers does not match the number of CIDs and we already
+	// confirmed the number of CIDs is greater than 0 so there is no need to bound check the slice before accessing
+	header := new(types.Header)
+	if err := rlp.DecodeBytes(headerIPLDs[0].RawData(), header); err != nil {
+		return nil, err
+	}
+	return header, nil
+}
+
+func (b *Backend) GetTd(blockHash common.Hash) *big.Int {
+	panic("implement me")
+}