Add ethclient

7 files changed, 976 insertions, 0 deletions

diff --git a/coreth.go b/coreth.go
index d1fd29f..01bc9af 100644
--- a/coreth.go
+++ b/coreth.go
@@ -19,6 +19,7 @@ import (
 	"github.com/ethereum/go-ethereum/ethdb"
 	"github.com/ethereum/go-ethereum/event"
 	"github.com/ethereum/go-ethereum/trie"
+
 	//"github.com/ethereum/go-ethereum/event"
 	"github.com/ethereum/go-ethereum/log"
 	"github.com/mattn/go-isatty"
diff --git a/ethclient/ethclient.go b/ethclient/ethclient.go
new file mode 100644
index 0000000..f7e56da
--- /dev/null
+++ b/ethclient/ethclient.go
@@ -0,0 +1,575 @@
+// Copyright 2016 The go-ethereum Authors
+// This file is part of the go-ethereum library.
+//
+// The go-ethereum library is free software: you can redistribute it and/or modify
+// it under the terms of the GNU Lesser General Public License as published by
+// the Free Software Foundation, either version 3 of the License, or
+// (at your option) any later version.
+//
+// The go-ethereum library is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+// GNU Lesser General Public License for more details.
+//
+// You should have received a copy of the GNU Lesser General Public License
+// along with the go-ethereum library. If not, see <http://www.gnu.org/licenses/>.
+
+// Package ethclient provides a client for the Ethereum RPC API.
+package ethclient
+
+import (
+	"context"
+	"encoding/json"
+	"errors"
+	"fmt"
+	"math/big"
+
+	"github.com/ava-labs/coreth"
+	"github.com/ava-labs/coreth/core/types"
+	"github.com/ava-labs/coreth/rpc"
+	"github.com/ava-labs/gecko/ids"
+	"github.com/ethereum/go-ethereum/common"
+	"github.com/ethereum/go-ethereum/common/hexutil"
+	"github.com/ethereum/go-ethereum/rlp"
+)
+
+// Client defines typed wrappers for the Ethereum RPC API.
+type Client struct {
+	c *rpc.Client
+}
+
+// Dial connects a client to the given URL.
+func Dial(rawurl string) (*Client, error) {
+	return DialContext(context.Background(), rawurl)
+}
+
+func DialContext(ctx context.Context, rawurl string) (*Client, error) {
+	c, err := rpc.DialContext(ctx, rawurl)
+	if err != nil {
+		return nil, err
+	}
+	return NewClient(c), nil
+}
+
+// NewClient creates a client that uses the given RPC client.
+func NewClient(c *rpc.Client) *Client {
+	return &Client{c}
+}
+
+func (ec *Client) Close() {
+	ec.c.Close()
+}
+
+// Blockchain Access
+
+// ChainId retrieves the current chain ID for transaction replay protection.
+func (ec *Client) ChainID(ctx context.Context) (*big.Int, error) {
+	var result hexutil.Big
+	err := ec.c.CallContext(ctx, &result, "eth_chainId")
+	if err != nil {
+		return nil, err
+	}
+	return (*big.Int)(&result), err
+}
+
+// BlockByHash returns the given full block.
+//
+// Note that loading full blocks requires two requests. Use HeaderByHash
+// if you don't need all transactions or uncle headers.
+func (ec *Client) BlockByHash(ctx context.Context, hash common.Hash) (*types.Block, error) {
+	return ec.getBlock(ctx, "eth_getBlockByHash", hash, true)
+}
+
+// BlockByNumber returns a block from the current canonical chain. If number is nil, the
+// latest known block is returned.
+//
+// Note that loading full blocks requires two requests. Use HeaderByNumber
+// if you don't need all transactions or uncle headers.
+func (ec *Client) BlockByNumber(ctx context.Context, number *big.Int) (*types.Block, error) {
+	return ec.getBlock(ctx, "eth_getBlockByNumber", toBlockNumArg(number), true)
+}
+
+// BlockNumber returns the most recent block number
+func (ec *Client) BlockNumber(ctx context.Context) (uint64, error) {
+	var result hexutil.Uint64
+	err := ec.c.CallContext(ctx, &result, "eth_blockNumber")
+	return uint64(result), err
+}
+
+type rpcBlock struct {
+	Hash         common.Hash      `json:"hash"`
+	Transactions []rpcTransaction `json:"transactions"`
+	UncleHashes  []common.Hash    `json:"uncles"`
+	Version      uint32           `json:"version"`
+	ExtraData    *[]byte          `json:"blockExtraData"`
+}
+
+func (ec *Client) getBlock(ctx context.Context, method string, args ...interface{}) (*types.Block, error) {
+	var raw json.RawMessage
+	err := ec.c.CallContext(ctx, &raw, method, args...)
+	if err != nil {
+		return nil, err
+	} else if len(raw) == 0 {
+		return nil, coreth.NotFound
+	}
+	// Decode header and transactions.
+	var head *types.Header
+	var body rpcBlock
+	if err := json.Unmarshal(raw, &head); err != nil {
+		return nil, err
+	}
+	if err := json.Unmarshal(raw, &body); err != nil {
+		return nil, err
+	}
+	// Quick-verify transaction and uncle lists. This mostly helps with debugging the server.
+	if head.UncleHash == types.EmptyUncleHash && len(body.UncleHashes) > 0 {
+		return nil, fmt.Errorf("server returned non-empty uncle list but block header indicates no uncles")
+	}
+	if head.UncleHash != types.EmptyUncleHash && len(body.UncleHashes) == 0 {
+		return nil, fmt.Errorf("server returned empty uncle list but block header indicates uncles")
+	}
+	if head.TxHash == types.EmptyRootHash && len(body.Transactions) > 0 {
+		return nil, fmt.Errorf("server returned non-empty transaction list but block header indicates no transactions")
+	}
+	if head.TxHash != types.EmptyRootHash && len(body.Transactions) == 0 {
+		return nil, fmt.Errorf("server returned empty transaction list but block header indicates transactions")
+	}
+	// Load uncles because they are not included in the block response.
+	var uncles []*types.Header
+	if len(body.UncleHashes) > 0 {
+		uncles = make([]*types.Header, len(body.UncleHashes))
+		reqs := make([]rpc.BatchElem, len(body.UncleHashes))
+		for i := range reqs {
+			reqs[i] = rpc.BatchElem{
+				Method: "eth_getUncleByBlockHashAndIndex",
+				Args:   []interface{}{body.Hash, hexutil.EncodeUint64(uint64(i))},
+				Result: &uncles[i],
+			}
+		}
+		if err := ec.c.BatchCallContext(ctx, reqs); err != nil {
+			return nil, err
+		}
+		for i := range reqs {
+			if reqs[i].Error != nil {
+				return nil, reqs[i].Error
+			}
+			if uncles[i] == nil {
+				return nil, fmt.Errorf("got null header for uncle %d of block %x", i, body.Hash[:])
+			}
+		}
+	}
+	// Fill the sender cache of transactions in the block.
+	txs := make([]*types.Transaction, len(body.Transactions))
+	for i, tx := range body.Transactions {
+		if tx.From != nil {
+			setSenderFromServer(tx.tx, *tx.From, body.Hash)
+		}
+		txs[i] = tx.tx
+	}
+	return types.NewBlockWithHeader(head).WithBody(txs, uncles, body.Version, body.ExtraData), nil
+}
+
+// HeaderByHash returns the block header with the given hash.
+func (ec *Client) HeaderByHash(ctx context.Context, hash common.Hash) (*types.Header, error) {
+	var head *types.Header
+	err := ec.c.CallContext(ctx, &head, "eth_getBlockByHash", hash, false)
+	if err == nil && head == nil {
+		err = coreth.NotFound
+	}
+	return head, err
+}
+
+// HeaderByNumber returns a block header from the current canonical chain. If number is
+// nil, the latest known header is returned.
+func (ec *Client) HeaderByNumber(ctx context.Context, number *big.Int) (*types.Header, error) {
+	var head *types.Header
+	err := ec.c.CallContext(ctx, &head, "eth_getBlockByNumber", toBlockNumArg(number), false)
+	if err == nil && head == nil {
+		err = coreth.NotFound
+	}
+	return head, err
+}
+
+type rpcTransaction struct {
+	tx *types.Transaction
+	txExtraInfo
+}
+
+type txExtraInfo struct {
+	BlockNumber *string         `json:"blockNumber,omitempty"`
+	BlockHash   *common.Hash    `json:"blockHash,omitempty"`
+	From        *common.Address `json:"from,omitempty"`
+}
+
+func (tx *rpcTransaction) UnmarshalJSON(msg []byte) error {
+	if err := json.Unmarshal(msg, &tx.tx); err != nil {
+		return err
+	}
+	return json.Unmarshal(msg, &tx.txExtraInfo)
+}
+
+// TransactionByHash returns the transaction with the given hash.
+func (ec *Client) TransactionByHash(ctx context.Context, hash common.Hash) (tx *types.Transaction, isPending bool, err error) {
+	var json *rpcTransaction
+	err = ec.c.CallContext(ctx, &json, "eth_getTransactionByHash", hash)
+	if err != nil {
+		return nil, false, err
+	} else if json == nil {
+		return nil, false, coreth.NotFound
+	} else if _, r, _ := json.tx.RawSignatureValues(); r == nil {
+		return nil, false, fmt.Errorf("server returned transaction without signature")
+	}
+	if json.From != nil && json.BlockHash != nil {
+		setSenderFromServer(json.tx, *json.From, *json.BlockHash)
+	}
+	return json.tx, json.BlockNumber == nil, nil
+}
+
+// TransactionSender returns the sender address of the given transaction. The transaction
+// must be known to the remote node and included in the blockchain at the given block and
+// index. The sender is the one derived by the protocol at the time of inclusion.
+//
+// There is a fast-path for transactions retrieved by TransactionByHash and
+// TransactionInBlock. Getting their sender address can be done without an RPC interaction.
+func (ec *Client) TransactionSender(ctx context.Context, tx *types.Transaction, block common.Hash, index uint) (common.Address, error) {
+	// Try to load the address from the cache.
+	sender, err := types.Sender(&senderFromServer{blockhash: block}, tx)
+	if err == nil {
+		return sender, nil
+	}
+	var meta struct {
+		Hash common.Hash
+		From common.Address
+	}
+	if err = ec.c.CallContext(ctx, &meta, "eth_getTransactionByBlockHashAndIndex", block, hexutil.Uint64(index)); err != nil {
+		return common.Address{}, err
+	}
+	if meta.Hash == (common.Hash{}) || meta.Hash != tx.Hash() {
+		return common.Address{}, errors.New("wrong inclusion block/index")
+	}
+	return meta.From, nil
+}
+
+// TransactionCount returns the total number of transactions in the given block.
+func (ec *Client) TransactionCount(ctx context.Context, blockHash common.Hash) (uint, error) {
+	var num hexutil.Uint
+	err := ec.c.CallContext(ctx, &num, "eth_getBlockTransactionCountByHash", blockHash)
+	return uint(num), err
+}
+
+// TransactionInBlock returns a single transaction at index in the given block.
+func (ec *Client) TransactionInBlock(ctx context.Context, blockHash common.Hash, index uint) (*types.Transaction, error) {
+	var json *rpcTransaction
+	err := ec.c.CallContext(ctx, &json, "eth_getTransactionByBlockHashAndIndex", blockHash, hexutil.Uint64(index))
+	if err != nil {
+		return nil, err
+	}
+	if json == nil {
+		return nil, coreth.NotFound
+	} else if _, r, _ := json.tx.RawSignatureValues(); r == nil {
+		return nil, fmt.Errorf("server returned transaction without signature")
+	}
+	if json.From != nil && json.BlockHash != nil {
+		setSenderFromServer(json.tx, *json.From, *json.BlockHash)
+	}
+	return json.tx, err
+}
+
+// TransactionReceipt returns the receipt of a transaction by transaction hash.
+// Note that the receipt is not available for pending transactions.
+func (ec *Client) TransactionReceipt(ctx context.Context, txHash common.Hash) (*types.Receipt, error) {
+	var r *types.Receipt
+	err := ec.c.CallContext(ctx, &r, "eth_getTransactionReceipt", txHash)
+	if err == nil {
+		if r == nil {
+			return nil, coreth.NotFound
+		}
+	}
+	return r, err
+}
+
+func toBlockNumArg(number *big.Int) string {
+	// The Ethereum implementation uses a different mapping from
+	// negative numbers to special strings (latest, pending) then is
+	// used on its server side. See rpc/types.go for the comparison.
+	// if number == nil {
+	// 	return "latest"
+	// }
+	// pending := big.NewInt(-1)
+	// if number.Cmp(pending) == 0 {
+	// 	return "pending"
+	// }
+
+	// In Coreth, latest, pending, and accepted are all treated the same
+	// therefore, if [number] is nil or a negative number in [-3, -1]
+	// we want the latest accepted block
+	if number == nil {
+		return "latest"
+	}
+	low := big.NewInt(-3)
+	high := big.NewInt(-1)
+	if number.Cmp(low) >= 0 && number.Cmp(high) <= 0 {
+		return "latest"
+	}
+	return hexutil.EncodeBig(number)
+}
+
+type rpcProgress struct {
+	StartingBlock hexutil.Uint64
+	CurrentBlock  hexutil.Uint64
+	HighestBlock  hexutil.Uint64
+	PulledStates  hexutil.Uint64
+	KnownStates   hexutil.Uint64
+}
+
+// SyncProgress retrieves the current progress of the sync algorithm. If there's
+// no sync currently running, it returns nil.
+func (ec *Client) SyncProgress(ctx context.Context) (*coreth.SyncProgress, error) {
+	var raw json.RawMessage
+	if err := ec.c.CallContext(ctx, &raw, "eth_syncing"); err != nil {
+		return nil, err
+	}
+	// Handle the possible response types
+	var syncing bool
+	if err := json.Unmarshal(raw, &syncing); err == nil {
+		return nil, nil // Not syncing (always false)
+	}
+	var progress *rpcProgress
+	if err := json.Unmarshal(raw, &progress); err != nil {
+		return nil, err
+	}
+	return &coreth.SyncProgress{
+		StartingBlock: uint64(progress.StartingBlock),
+		CurrentBlock:  uint64(progress.CurrentBlock),
+		HighestBlock:  uint64(progress.HighestBlock),
+		PulledStates:  uint64(progress.PulledStates),
+		KnownStates:   uint64(progress.KnownStates),
+	}, nil
+}
+
+// SubscribeNewHead subscribes to notifications about the current blockchain head
+// on the given channel.
+func (ec *Client) SubscribeNewHead(ctx context.Context, ch chan<- *types.Header) (coreth.Subscription, error) {
+	return ec.c.EthSubscribe(ctx, ch, "newHeads")
+}
+
+// State Access
+
+// NetworkID returns the network ID (also known as the chain ID) for this chain.
+func (ec *Client) NetworkID(ctx context.Context) (*big.Int, error) {
+	version := new(big.Int)
+	var ver string
+	if err := ec.c.CallContext(ctx, &ver, "net_version"); err != nil {
+		return nil, err
+	}
+	if _, ok := version.SetString(ver, 10); !ok {
+		return nil, fmt.Errorf("invalid net_version result %q", ver)
+	}
+	return version, nil
+}
+
+// BalanceAt returns the wei balance of the given account.
+// The block number can be nil, in which case the balance is taken from the latest known block.
+func (ec *Client) BalanceAt(ctx context.Context, account common.Address, blockNumber *big.Int) (*big.Int, error) {
+	var result hexutil.Big
+	err := ec.c.CallContext(ctx, &result, "eth_getBalance", account, toBlockNumArg(blockNumber))
+	return (*big.Int)(&result), err
+}
+
+// AssetBalanceAt returns the [assetID] balance of the given account
+// The block number can be nil, in which case the balance is taken from the latest known block.
+func (ec *Client) AssetBalanceAt(ctx context.Context, account common.Address, assetID ids.ID, blockNumber *big.Int) (*big.Int, error) {
+	var result hexutil.Big
+	err := ec.c.CallContext(ctx, &result, "eth_getBalance", account, toBlockNumArg(blockNumber), assetID)
+	return (*big.Int)(&result), err
+}
+
+// StorageAt returns the value of key in the contract storage of the given account.
+// The block number can be nil, in which case the value is taken from the latest known block.
+func (ec *Client) StorageAt(ctx context.Context, account common.Address, key common.Hash, blockNumber *big.Int) ([]byte, error) {
+	var result hexutil.Bytes
+	err := ec.c.CallContext(ctx, &result, "eth_getStorageAt", account, key, toBlockNumArg(blockNumber))
+	return result, err
+}
+
+// CodeAt returns the contract code of the given account.
+// The block number can be nil, in which case the code is taken from the latest known block.
+func (ec *Client) CodeAt(ctx context.Context, account common.Address, blockNumber *big.Int) ([]byte, error) {
+	var result hexutil.Bytes
+	err := ec.c.CallContext(ctx, &result, "eth_getCode", account, toBlockNumArg(blockNumber))
+	return result, err
+}
+
+// NonceAt returns the account nonce of the given account.
+// The block number can be nil, in which case the nonce is taken from the latest known block.
+func (ec *Client) NonceAt(ctx context.Context, account common.Address, blockNumber *big.Int) (uint64, error) {
+	var result hexutil.Uint64
+	err := ec.c.CallContext(ctx, &result, "eth_getTransactionCount", account, toBlockNumArg(blockNumber))
+	return uint64(result), err
+}
+
+// Filters
+
+// FilterLogs executes a filter query.
+func (ec *Client) FilterLogs(ctx context.Context, q coreth.FilterQuery) ([]types.Log, error) {
+	var result []types.Log
+	arg, err := toFilterArg(q)
+	if err != nil {
+		return nil, err
+	}
+	err = ec.c.CallContext(ctx, &result, "eth_getLogs", arg)
+	return result, err
+}
+
+// SubscribeFilterLogs subscribes to the results of a streaming filter query.
+func (ec *Client) SubscribeFilterLogs(ctx context.Context, q coreth.FilterQuery, ch chan<- types.Log) (coreth.Subscription, error) {
+	arg, err := toFilterArg(q)
+	if err != nil {
+		return nil, err
+	}
+	return ec.c.EthSubscribe(ctx, ch, "logs", arg)
+}
+
+func toFilterArg(q coreth.FilterQuery) (interface{}, error) {
+	arg := map[string]interface{}{
+		"address": q.Addresses,
+		"topics":  q.Topics,
+	}
+	if q.BlockHash != nil {
+		arg["blockHash"] = *q.BlockHash
+		if q.FromBlock != nil || q.ToBlock != nil {
+			return nil, fmt.Errorf("cannot specify both BlockHash and FromBlock/ToBlock")
+		}
+	} else {
+		if q.FromBlock == nil {
+			arg["fromBlock"] = "0x0"
+		} else {
+			arg["fromBlock"] = toBlockNumArg(q.FromBlock)
+		}
+		arg["toBlock"] = toBlockNumArg(q.ToBlock)
+	}
+	return arg, nil
+}
+
+// Pending State is irrelevant in Coreth
+
+// // PendingBalanceAt returns the wei balance of the given account in the pending state.
+// func (ec *Client) PendingBalanceAt(ctx context.Context, account common.Address) (*big.Int, error) {
+// 	var result hexutil.Big
+// 	err := ec.c.CallContext(ctx, &result, "eth_getBalance", account, "pending")
+// 	return (*big.Int)(&result), err
+// }
+
+// // PendingStorageAt returns the value of key in the contract storage of the given account in the pending state.
+// func (ec *Client) PendingStorageAt(ctx context.Context, account common.Address, key common.Hash) ([]byte, error) {
+// 	var result hexutil.Bytes
+// 	err := ec.c.CallContext(ctx, &result, "eth_getStorageAt", account, key, "pending")
+// 	return result, err
+// }
+
+// // PendingCodeAt returns the contract code of the given account in the pending state.
+// func (ec *Client) PendingCodeAt(ctx context.Context, account common.Address) ([]byte, error) {
+// 	var result hexutil.Bytes
+// 	err := ec.c.CallContext(ctx, &result, "eth_getCode", account, "pending")
+// 	return result, err
+// }
+
+// // PendingNonceAt returns the account nonce of the given account in the pending state.
+// // This is the nonce that should be used for the next transaction.
+// func (ec *Client) PendingNonceAt(ctx context.Context, account common.Address) (uint64, error) {
+// 	var result hexutil.Uint64
+// 	err := ec.c.CallContext(ctx, &result, "eth_getTransactionCount", account, "pending")
+// 	return uint64(result), err
+// }
+
+// // PendingTransactionCount returns the total number of transactions in the pending state.
+// func (ec *Client) PendingTransactionCount(ctx context.Context) (uint, error) {
+// 	var num hexutil.Uint
+// 	err := ec.c.CallContext(ctx, &num, "eth_getBlockTransactionCountByNumber", "pending")
+// 	return uint(num), err
+// }
+
+// TODO: SubscribePendingTransactions (needs server side)
+
+// Contract Calling
+
+// CallContract executes a message call transaction, which is directly executed in the VM
+// of the node, but never mined into the blockchain.
+//
+// blockNumber selects the block height at which the call runs. It can be nil, in which
+// case the code is taken from the latest known block. Note that state from very old
+// blocks might not be available.
+func (ec *Client) CallContract(ctx context.Context, msg coreth.CallMsg, blockNumber *big.Int) ([]byte, error) {
+	var hex hexutil.Bytes
+	err := ec.c.CallContext(ctx, &hex, "eth_call", toCallArg(msg), toBlockNumArg(blockNumber))
+	if err != nil {
+		return nil, err
+	}
+	return hex, nil
+}
+
+// // PendingCallContract executes a message call transaction using the EVM.
+// // The state seen by the contract call is the pending state.
+// func (ec *Client) PendingCallContract(ctx context.Context, msg coreth.CallMsg) ([]byte, error) {
+// 	var hex hexutil.Bytes
+// 	err := ec.c.CallContext(ctx, &hex, "eth_call", toCallArg(msg), "pending")
+// 	if err != nil {
+// 		return nil, err
+// 	}
+// 	return hex, nil
+// }
+
+// SuggestGasPrice retrieves the currently suggested gas price to allow a timely
+// execution of a transaction.
+func (ec *Client) SuggestGasPrice(ctx context.Context) (*big.Int, error) {
+	var hex hexutil.Big
+	if err := ec.c.CallContext(ctx, &hex, "eth_gasPrice"); err != nil {
+		return nil, err
+	}
+	return (*big.Int)(&hex), nil
+}
+
+// EstimateGas tries to estimate the gas needed to execute a specific transaction based on
+// the current pending state of the backend blockchain. There is no guarantee that this is
+// the true gas limit requirement as other transactions may be added or removed by miners,
+// but it should provide a basis for setting a reasonable default.
+func (ec *Client) EstimateGas(ctx context.Context, msg coreth.CallMsg) (uint64, error) {
+	var hex hexutil.Uint64
+	err := ec.c.CallContext(ctx, &hex, "eth_estimateGas", toCallArg(msg))
+	if err != nil {
+		return 0, err
+	}
+	return uint64(hex), nil
+}
+
+// SendTransaction injects a signed transaction into the pending pool for execution.
+//
+// If the transaction was a contract creation use the TransactionReceipt method to get the
+// contract address after the transaction has been mined.
+func (ec *Client) SendTransaction(ctx context.Context, tx *types.Transaction) error {
+	data, err := rlp.EncodeToBytes(tx)
+	if err != nil {
+		return err
+	}
+	return ec.c.CallContext(ctx, nil, "eth_sendRawTransaction", hexutil.Encode(data))
+}
+
+func toCallArg(msg coreth.CallMsg) interface{} {
+	arg := map[string]interface{}{
+		"from": msg.From,
+		"to":   msg.To,
+	}
+	if len(msg.Data) > 0 {
+		arg["data"] = hexutil.Bytes(msg.Data)
+	}
+	if msg.Value != nil {
+		arg["value"] = (*hexutil.Big)(msg.Value)
+	}
+	if msg.Gas != 0 {
+		arg["gas"] = hexutil.Uint64(msg.Gas)
+	}
+	if msg.GasPrice != nil {
+		arg["gasPrice"] = (*hexutil.Big)(msg.GasPrice)
+	}
+	return arg
+}
diff --git a/ethclient/signer.go b/ethclient/signer.go
new file mode 100644
index 0000000..4a9f645
--- /dev/null
+++ b/ethclient/signer.go
@@ -0,0 +1,59 @@
+// Copyright 2017 The go-ethereum Authors
+// This file is part of the go-ethereum library.
+//
+// The go-ethereum library is free software: you can redistribute it and/or modify
+// it under the terms of the GNU Lesser General Public License as published by
+// the Free Software Foundation, either version 3 of the License, or
+// (at your option) any later version.
+//
+// The go-ethereum library is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+// GNU Lesser General Public License for more details.
+//
+// You should have received a copy of the GNU Lesser General Public License
+// along with the go-ethereum library. If not, see <http://www.gnu.org/licenses/>.
+
+package ethclient
+
+import (
+	"errors"
+	"math/big"
+
+	"github.com/ava-labs/coreth/core/types"
+	"github.com/ethereum/go-ethereum/common"
+)
+
+// senderFromServer is a types.Signer that remembers the sender address returned by the RPC
+// server. It is stored in the transaction's sender address cache to avoid an additional
+// request in TransactionSender.
+type senderFromServer struct {
+	addr      common.Address
+	blockhash common.Hash
+}
+
+var errNotCached = errors.New("sender not cached")
+
+func setSenderFromServer(tx *types.Transaction, addr common.Address, block common.Hash) {
+	// Use types.Sender for side-effect to store our signer into the cache.
+	types.Sender(&senderFromServer{addr, block}, tx)
+}
+
+func (s *senderFromServer) Equal(other types.Signer) bool {
+	os, ok := other.(*senderFromServer)
+	return ok && os.blockhash == s.blockhash
+}
+
+func (s *senderFromServer) Sender(tx *types.Transaction) (common.Address, error) {
+	if s.blockhash == (common.Hash{}) {
+		return common.Address{}, errNotCached
+	}
+	return s.addr, nil
+}
+
+func (s *senderFromServer) Hash(tx *types.Transaction) common.Hash {
+	panic("can't sign with senderFromServer")
+}
+func (s *senderFromServer) SignatureValues(tx *types.Transaction, sig []byte) (R, S, V *big.Int, err error) {
+	panic("can't sign with senderFromServer")
+}
diff --git a/go.mod b/go.mod
index e9e7a78..d270331 100644
--- a/go.mod
+++ b/go.mod
@@ -4,7 +4,9 @@ go 1.14
 
 require (
 	github.com/VictoriaMetrics/fastcache v1.5.7
+	github.com/ava-labs/avalanche-testing v0.9.6
 	github.com/ava-labs/avalanchego v1.0.4-update-id-2
+	github.com/ava-labs/gecko v0.6.1-rc.1
 	github.com/davecgh/go-spew v1.1.1
 	github.com/deckarep/golang-set v1.7.1
 	github.com/edsrzf/mmap-go v1.0.0
@@ -23,6 +25,7 @@ require (
 	github.com/pborman/uuid v1.2.0
 	github.com/prometheus/tsdb v0.10.0
 	github.com/rjeczalik/notify v0.9.2
+	github.com/sirupsen/logrus v1.6.0
 	github.com/status-im/keycard-go v0.0.0-20200402102358-957c09536969
 	github.com/steakknife/bloomfilter v0.0.0-20180922174646-6819c0d2a570
 	github.com/tyler-smith/go-bip39 v1.0.2
diff --git a/go.sum b/go.sum
index 428792c..b5b3349 100644
--- a/go.sum
+++ b/go.sum
@@ -16,6 +16,7 @@ github.com/AppsFlyer/go-sundheit v0.2.0/go.mod h1:rCRkVTMQo7/krF7xQ9X0XEF1an68vi
 github.com/Azure/azure-pipeline-go v0.2.1/go.mod h1:UGSo8XybXnIGZ3epmeBw7Jdz+HiUVpqIlpz/HKHylF4=
 github.com/Azure/azure-pipeline-go v0.2.2/go.mod h1:4rQ/NZncSvGqNkkOsNpOU1tgoNuIlp9AfUH5G1tvCHc=
 github.com/Azure/azure-storage-blob-go v0.7.0/go.mod h1:f9YQKtsG1nMisotuTPpO0tjNuEjKRYAcJU8/ydDI++4=
+github.com/Azure/go-ansiterm v0.0.0-20170929234023-d6e3b3328b78/go.mod h1:LmzpDX56iTiv29bbRTIsUNlaFfuhWRQBWjQdVyAevI8=
 github.com/Azure/go-autorest/autorest v0.9.0/go.mod h1:xyHB1BMZT0cuDHU7I0+g046+BFDTQ8rEZB0s4Yfa6bI=
 github.com/Azure/go-autorest/autorest/adal v0.5.0/go.mod h1:8Z9fGy2MpX0PvDjB1pEgQTmVqjGhiHBW7RJJEciWzS0=
 github.com/Azure/go-autorest/autorest/adal v0.8.0/go.mod h1:Z6vX6WXXuyieHAXwMj0S6HY6e6wcHn37qQMBQlvY3lc=
@@ -28,8 +29,11 @@ github.com/Azure/go-autorest/logger v0.1.0/go.mod h1:oExouG+K6PryycPJfVSxi/koC6L
 github.com/Azure/go-autorest/tracing v0.5.0/go.mod h1:r/s2XiOKccPW3HrqB+W0TQzfbtp2fGCgRFtBroKn4Dk=
 github.com/BurntSushi/toml v0.3.1/go.mod h1:xHWCNGjB5oqiDr8zfno3MHue2Ht5sIBksp03qcyfWMU=
 github.com/BurntSushi/xgb v0.0.0-20160522181843-27f122750802/go.mod h1:IVnqGOEym/WlBOVXweHU+Q+/VP0lqqI8lqeDx9IjBqo=
+github.com/Microsoft/go-winio v0.4.11/go.mod h1:VhR8bwka0BXejwEJY73c50VrPtXAaKcyvVC4A4RozmA=
 github.com/Microsoft/go-winio v0.4.14/go.mod h1:qXqCSQ3Xa7+6tgxaGTIe4Kpcdsi+P8jBhyzoq1bpyYA=
 github.com/OneOfOne/xxhash v1.2.2/go.mod h1:HSdplMjZKSmBqAxg5vPj2TmRDmfkzw+cTzAElWljhcU=
+github.com/Shopify/sarama v1.26.1/go.mod h1:NbSGBSSndYaIhRcBtY9V0U7AyH+x71bG668AuWys/yU=
+github.com/Shopify/toxiproxy v2.1.4+incompatible/go.mod h1:OXgGpZ6Cli1/URJOF1DMxUHB2q5Ap20/P/eIdh4G0pI=
 github.com/StackExchange/wmi v0.0.0-20180116203802-5d049714c4a6/go.mod h1:3eOhrUMpNV+6aFIbp5/iudMxNCF27Vw2OZgy4xEx0Fg=
 github.com/VictoriaMetrics/fastcache v1.5.7 h1:4y6y0G8PRzszQUYIQHHssv/jgPHAb5qQuuDNdCbyAgw=
 github.com/VictoriaMetrics/fastcache v1.5.7/go.mod h1:ptDBkNMQI4RtmVo8VS/XwRY6RoTu1dAWCbrk+6WsEM8=
@@ -39,13 +43,30 @@ github.com/alecthomas/template v0.0.0-20190718012654-fb15b899a751/go.mod h1:LOuy
 github.com/alecthomas/units v0.0.0-20151022065526-2efee857e7cf/go.mod h1:ybxpYRFXyAe+OPACYpWeL0wqObRcbAqCMya13uyzqw0=
 github.com/alecthomas/units v0.0.0-20190717042225-c3de453c63f4/go.mod h1:ybxpYRFXyAe+OPACYpWeL0wqObRcbAqCMya13uyzqw0=
 github.com/allegro/bigcache v1.2.1-0.20190218064605-e24eb225f156/go.mod h1:Cb/ax3seSYIx7SuZdm2G2xzfwmv3TPSk2ucNfQESPXM=
+github.com/allegro/bigcache v1.2.1/go.mod h1:Cb/ax3seSYIx7SuZdm2G2xzfwmv3TPSk2ucNfQESPXM=
+github.com/aristanetworks/fsnotify v1.4.2/go.mod h1:D/rtu7LpjYM8tRJphJ0hUBYpjai8SfX+aSNsWDTq/Ks=
+github.com/aristanetworks/glog v0.0.0-20191112221043-67e8567f59f3/go.mod h1:KASm+qXFKs/xjSoWn30NrWBBvdTTQq+UjkhjEJHfSFA=
 github.com/aristanetworks/goarista v0.0.0-20170210015632-ea17b1a17847 h1:rtI0fD4oG/8eVokGVPYJEW1F88p1ZNgXiEIs9thEE4A=
 github.com/aristanetworks/goarista v0.0.0-20170210015632-ea17b1a17847/go.mod h1:D/tb0zPVXnP7fmsLZjtdUhSsumbK/ij54UXjjVgMGxQ=
+github.com/aristanetworks/goarista v0.0.0-20200812190859-4cb0e71f3c0e h1:tkEt0le4Lv5+VmcxZPIVSrP8LVPLhndIm/BOP7iPh/w=
+github.com/aristanetworks/goarista v0.0.0-20200812190859-4cb0e71f3c0e/go.mod h1:QZe5Yh80Hp1b6JxQdpfSEEe8X7hTyTEZSosSrFf/oJE=
+github.com/aristanetworks/splunk-hec-go v0.3.3/go.mod h1:1VHO9r17b0K7WmOlLb9nTk/2YanvOEnLMUgsFrxBROc=
 github.com/armon/circbuf v0.0.0-20150827004946-bbbad097214e/go.mod h1:3U/XgcO3hCbHZ8TKRvWD2dDTCfh9M9ya+I9JpbB7O8o=
 github.com/armon/go-metrics v0.0.0-20180917152333-f0300d1749da/go.mod h1:Q73ZrmVTwzkszR9V5SSuryQ31EELlFMUz1kKyl939pY=
 github.com/armon/go-radix v0.0.0-20180808171621-7fddfc383310/go.mod h1:ufUuZ+zHj4x4TnLV4JWEpy2hxWSpsRywHrMgIH9cCH8=
+github.com/ava-labs/avalanche-go v0.8.0-beta/go.mod h1:quYojL1hu0ue2glUT1ng28kADs9R94zGdEvfW0/HRg8=
+github.com/ava-labs/avalanche-testing v0.9.6 h1:ibIxQ8J1Gf0TARjlq95ZykMRacSEzV4uS+4ERY3gWc0=
+github.com/ava-labs/avalanche-testing v0.9.6/go.mod h1:ehGdLaAuMnY4Kvwy/t/T+1FhDhScOid3F66a1g8gFvo=
+github.com/ava-labs/avalanchego v0.8.3/go.mod h1:6zPzQv7m6vSvdKAwH+lLTga0IMd/0+HLMT5OULrpFcU=
+github.com/ava-labs/avalanchego v1.0.0/go.mod h1:0N34atGvJCfJaIjFkHBDG5QzqlSJlsC07/d9irZfA7Y=
 github.com/ava-labs/avalanchego v1.0.4-update-id-2 h1:C4Ss43XgWw1NdCm74mHiQbgsP02+I6QvTCfvIEgmkM0=
 github.com/ava-labs/avalanchego v1.0.4-update-id-2/go.mod h1:4GfedhY9S6k/SOUeMzDh6cuLoPAtnkFsL4R89xg5wf0=
+github.com/ava-labs/coreth v0.2.14-rc.1/go.mod h1:Zhb60GFIB7G5AnUCks0Jo4Rezx/EovL8o+z51aBF1A8=
+github.com/ava-labs/coreth v0.2.15-rc.4/go.mod h1:+sK2XGKCNA48uzeHWe4iBzmiOBYmYvnnzLtOkQeQfkk=
+github.com/ava-labs/coreth v0.3.4/go.mod h1:d5h8SoFyMOoFqg2gHzYgftZlKgZ1MHKKydjyq2hoABk=
+github.com/ava-labs/gecko v0.6.1-rc.1 h1:BhWmoDGA0Obs5ZbEdpNqw/3rx9ZMPmjcZu1oD+yySLY=
+github.com/ava-labs/gecko v0.6.1-rc.1/go.mod h1:TT6uA1BETZpVMR0xiFtE8I5Mv4DULlS+lAL3xuYKnpA=
+github.com/ava-labs/go-ethereum v1.9.3/go.mod h1:a+agc6fXfZFsPZCylA3ry4Y8CLCqLKg3Rc23NXZ9aw8=
 github.com/aws/aws-sdk-go v1.25.48/go.mod h1:KmX6BPdI08NWTb3/sm4ZGu5ShLoqVDhKgpiN924inxo=
 github.com/beorn7/perks v0.0.0-20180321164747-3a771d992973/go.mod h1:Dwedo/Wpr24TaqPxmxbtue+5NUziq4I4S80YR8gNf3Q=
 github.com/beorn7/perks v1.0.0/go.mod h1:KWe93zE9D1o94FZ5RNwFwVgaQK1VOXiVxmqh+CedLV8=
@@ -66,6 +87,7 @@ github.com/btcsuite/websocket v0.0.0-20150119174127-31079b680792/go.mod h1:ghJtE
 github.com/btcsuite/winsvc v1.0.0/go.mod h1:jsenWakMcC0zFBFurPLEAyrnc/teJEM1O46fmI40EZs=
 github.com/census-instrumentation/opencensus-proto v0.2.1/go.mod h1:f6KPmirojxKA12rnyqOA5BBL4O983OfeGPqjHWSTneU=
 github.com/cespare/cp v0.1.0/go.mod h1:SOGHArjBr4JWaSDEVpWpo/hNg6RoKrls6Oh40hiwW+s=
+github.com/cespare/cp v1.1.1/go.mod h1:SOGHArjBr4JWaSDEVpWpo/hNg6RoKrls6Oh40hiwW+s=
 github.com/cespare/xxhash v1.1.0 h1:a6HrQnmkObjyL+Gs60czilIUGqrzKutQD6XZog3p+ko=
 github.com/cespare/xxhash v1.1.0/go.mod h1:XrSqR1VqqWfGrhpAt58auRo0WTKS1nRRg3ghfAqPWnc=
 github.com/cespare/xxhash/v2 v2.1.1 h1:6MnRN8NT7+YBpUIWxHtefFZOKTAPgGjpQSxqLNn0+qY=
@@ -73,12 +95,15 @@ github.com/cespare/xxhash/v2 v2.1.1/go.mod h1:VGX0DQ3Q6kWi7AoAeZDth3/j3BFtOZR5XL
 github.com/client9/misspell v0.3.4/go.mod h1:qj6jICC3Q7zFZvVWo7KLAzC3yx5G7kyvSDkc90ppPyw=
 github.com/cloudflare/cloudflare-go v0.10.2-0.20190916151808-a80f83b9add9/go.mod h1:1MxXX1Ux4x6mqPmjkUgTP1CdXIBXKX7T+Jk9Gxrmx+U=
 github.com/cncf/udpa/go v0.0.0-20191209042840-269d4d468f6f/go.mod h1:M8M6+tZqaGXZJjfX53e64911xZQV5JYwmTeXPW+k8Sc=
+github.com/containerd/containerd v1.3.4/go.mod h1:bC6axHOhabU15QhwfG7w5PipXdVtMXFTttgp+kVtyUA=
 github.com/coreos/bbolt v1.3.2/go.mod h1:iRUV2dpdMOn7Bo10OQBFzIJO9kkE559Wcmn+qkEiiKk=
 github.com/coreos/etcd v3.3.13+incompatible/go.mod h1:uF7uidLiAD3TWHmW31ZFd/JWoc32PjwdhPthX9715RE=
 github.com/coreos/go-semver v0.3.0/go.mod h1:nnelYz7RCh+5ahJtPPxZlU+153eP4D4r3EedlOD2RNk=
 github.com/coreos/go-systemd v0.0.0-20190321100706-95778dfbb74e/go.mod h1:F5haX7vjVVG0kc13fIWeqUViNPyEJxv/OmvnBo0Yme4=
 github.com/coreos/pkg v0.0.0-20180928190104-399ea9e2e55f/go.mod h1:E3G3o1h8I7cfcXa63jLwjI0eiQQMgzzUDFVpN/nH/eA=
 github.com/cpuguy83/go-md2man/v2 v2.0.0-20190314233015-f79a8a8ca69d/go.mod h1:maD7wRr/U5Z6m/iR4s+kqSMx2CaBsrgA7czyZG/E6dU=
+github.com/creack/pty v1.1.7/go.mod h1:lj5s0c3V2DBrqTV7llrYr5NG6My20zk30Fl46Y7DoTY=
+github.com/creack/pty v1.1.9/go.mod h1:oKZEueFk5CKHvIhNR5MUki03XCEU+Q6VDXinZuGJ33E=
 github.com/davecgh/go-spew v0.0.0-20171005155431-ecdeabc65495/go.mod h1:J7Y8YcW2NihsgmVo/mv3lAwl/skON4iLHjSsI+c5H38=
 github.com/davecgh/go-spew v1.1.0/go.mod h1:J7Y8YcW2NihsgmVo/mv3lAwl/skON4iLHjSsI+c5H38=
 github.com/davecgh/go-spew v1.1.1 h1:vj9j/u1bqnvCEfJOwUhtlOARqs3+rkHYY13jYWTU97c=
@@ -94,11 +119,19 @@ github.com/dgrijalva/jwt-go v3.2.0+incompatible h1:7qlOGliEKZXTDg6OTjfoBKDXWrumC
 github.com/dgrijalva/jwt-go v3.2.0+incompatible/go.mod h1:E3ru+11k8xSBh+hMPgOLZmtrrCbhqsmaPHjLKYnJCaQ=
 github.com/dgryski/go-sip13 v0.0.0-20181026042036-e10d5fee7954/go.mod h1:vAd38F8PWV+bWy6jNmig1y/TA+kYO4g3RSRF0IAv0no=
 github.com/dlclark/regexp2 v1.2.0/go.mod h1:2pZnwuY/m+8K6iRw6wQdMtk+rH5tNGR1i55kozfMjCc=
+github.com/docker/distribution v2.7.1+incompatible/go.mod h1:J2gT2udsDAN96Uj4KfcMRqY0/ypR+oyYUYmja8H+y+w=
 github.com/docker/docker v1.4.2-0.20180625184442-8e610b2b55bf/go.mod h1:eEKB0N0r5NX/I1kEveEz05bcu8tLC/8azJZsviup8Sk=
+github.com/docker/docker v17.12.0-ce-rc1.0.20200514193020-5da88705cccc+incompatible/go.mod h1:eEKB0N0r5NX/I1kEveEz05bcu8tLC/8azJZsviup8Sk=
+github.com/docker/go-connections v0.4.0/go.mod h1:Gbd7IOopHjR8Iph03tsViu4nIes5XhDvyHbTtUxmeec=
+github.com/docker/go-units v0.4.0/go.mod h1:fgPhTUdO+D/Jk86RDLlptpiXQzgHJF7gydDDbaIK4Dk=
 github.com/dop251/goja v0.0.0-20200721192441-a695b0cdd498/go.mod h1:Mw6PkjjMXWbTj+nnj4s3QPXq1jaT0s5pC0iFD4+BOAA=
+github.com/eapache/go-resiliency v1.2.0/go.mod h1:kFI+JgMyC7bLPUVY133qvEBtVayf5mFgVsvEsIPBvNs=
+github.com/eapache/go-xerial-snappy v0.0.0-20180814174437-776d5712da21/go.mod h1:+020luEh2TKB4/GOp8oxxtq0Daoen/Cii55CzbTV6DU=
+github.com/eapache/queue v1.1.0/go.mod h1:6eCeP0CKFpHLu8blIFXhExK/dRa7WDZfr6jVFPTqq+I=
 github.com/edsrzf/mmap-go v0.0.0-20160512033002-935e0e8a636c/go.mod h1:YO35OhQPt3KJa3ryjFM5Bs14WD66h8eGKpfaBNrHW5M=
 github.com/edsrzf/mmap-go v1.0.0 h1:CEBF7HpRnUCSJgGUb5h1Gm7e3VkmVDrR8lvWVLtrOFw=
 github.com/edsrzf/mmap-go v1.0.0/go.mod h1:YO35OhQPt3KJa3ryjFM5Bs14WD66h8eGKpfaBNrHW5M=
+github.com/elastic/gosigar v0.11.0/go.mod h1:cdorVVzy1fhmEqmtgqkoE3bYtCfSCkVyjTyCIo22xvs=
 github.com/envoyproxy/go-control-plane v0.9.0/go.mod h1:YTl/9mNaCwkRvm6d1a2C3ymFceY/DCBVvsKhRF0iEA4=
 github.com/envoyproxy/go-control-plane v0.9.1-0.20191026205805-5f8ba28d4473/go.mod h1:YTl/9mNaCwkRvm6d1a2C3ymFceY/DCBVvsKhRF0iEA4=
 github.com/envoyproxy/go-control-plane v0.9.4/go.mod h1:6rpuAdCZL397s3pYoYcLgu1mIlRU8Am5FuJP05cCM98=
@@ -112,11 +145,14 @@ github.com/fjl/memsize v0.0.0-20180418122429-ca190fb6ffbc/go.mod h1:VvhXpOYNQvB+
 github.com/fjl/memsize v0.0.0-20190710130421-bcb5799ab5e5 h1:FtmdgXiUlNeRsoNMFlKLDt+S+6hbjVMEW6RGQ7aUf7c=
 github.com/fjl/memsize v0.0.0-20190710130421-bcb5799ab5e5/go.mod h1:VvhXpOYNQvB+uIk2RvXzuaQtkQJzzIx6lSBe1xv7hi0=
 github.com/fortytw2/leaktest v1.3.0/go.mod h1:jDsjWgpAGjm2CA7WthBh/CdZYEPF31XHquHwclZch5g=
+github.com/frankban/quicktest v1.7.2/go.mod h1:jaStnuzAqU1AJdCO0l53JDCJrVDKcS03DbaAcR7Ks/o=
 github.com/fsnotify/fsnotify v1.4.7/go.mod h1:jwhsz4b93w/PPRr/qN1Yymfu8t87LnFCMoQvtojpjFo=
 github.com/fsnotify/fsnotify v1.4.9/go.mod h1:znqG4EE+3YCdAaPaxE2ZRY/06pZUdp0tY4IgpuI1SZQ=
+github.com/garyburd/redigo v1.6.0/go.mod h1:NR3MbYisc3/PwhQ00EMzDiPmrwpPxAn5GI05/YaO1SY=
 github.com/gballet/go-libpcsclite v0.0.0-20190607065134-2772fd86a8ff/go.mod h1:x7DCsMOv1taUwEWCzT4cmDeAkigA5/QCwUodaVOe8Ww=
 github.com/gballet/go-libpcsclite v0.0.0-20191108122812-4678299bea08 h1:f6D9Hr8xV8uYKlyuj8XIruxlh9WjVjdh1gIicAS7ays=
 github.com/gballet/go-libpcsclite v0.0.0-20191108122812-4678299bea08/go.mod h1:x7DCsMOv1taUwEWCzT4cmDeAkigA5/QCwUodaVOe8Ww=
+github.com/gdamore/optopia v0.2.0/go.mod h1:YKYEwo5C1Pa617H7NlPcmQXl+vG6YnSSNB44n8dNL0Q=
 github.com/ghodss/yaml v1.0.0/go.mod h1:4dBDuWmgqj2HViK6kFavaiC9ZROes6MMH2rRYeMEF04=
 github.com/go-gl/glfw v0.0.0-20190409004039-e6da0acd62b1/go.mod h1:vR7hzQXu2zJy9AVAgeJqvqgH9Q5CA+iKCZ2gyEVpxRU=
 github.com/go-kit/kit v0.8.0/go.mod h1:xBxKIO96dXMWWy0MnWVtmwkA9/13aqxPnvrjFYMA2as=
@@ -129,6 +165,8 @@ github.com/go-stack/stack v1.8.0 h1:5SgMzNM5HxrEjV0ww2lTmX6E2Izsfxas4+YHWRs3Lsk=
 github.com/go-stack/stack v1.8.0/go.mod h1:v0f6uXyyMGvRgIKkXu+yp6POWl0qKG85gN/melR3HDY=
 github.com/gogo/protobuf v1.1.1/go.mod h1:r8qH/GZQm5c6nD/R0oafs1akxWv10x8SbQlK7atdtwQ=
 github.com/gogo/protobuf v1.2.1/go.mod h1:hp+jE20tsWTFYpLwKvXlhS1hjn+gTNwPg2I6zVXpSg4=
+github.com/gogo/protobuf v1.3.1/go.mod h1:SlYgWuQ5SjCEi6WLHjHCa1yvBfUnHcTbrrZtXPKa29o=
+github.com/golang-collections/collections v0.0.0-20130729185459-604e922904d3/go.mod h1:nPpo7qLxd6XL3hWJG/O60sR8ZKfMCiIoNap5GvD12KU=
 github.com/golang/glog v0.0.0-20160126235308-23def4e6c14b/go.mod h1:SBH7ygxi8pfUlaOkMMuAQtPIUF8ecWP5IEl/CR7VP2Q=
 github.com/golang/groupcache v0.0.0-20190129154