Merge pull request #2 from ava-labs/plugin

Added the EVM as a plugin

8 files changed, 902 insertions, 0 deletions

diff --git a/plugin/evm/block.go b/plugin/evm/block.go
new file mode 100644
index 0000000..ec47490
--- /dev/null
+++ b/plugin/evm/block.go
@@ -0,0 +1,75 @@
+// (c) 2019-2020, Ava Labs, Inc. All rights reserved.
+// See the file LICENSE for licensing terms.
+
+package evm
+
+import (
+	"fmt"
+
+	"github.com/ava-labs/go-ethereum/core/types"
+	"github.com/ava-labs/go-ethereum/rlp"
+
+	"github.com/ava-labs/gecko/ids"
+	"github.com/ava-labs/gecko/snow/choices"
+	"github.com/ava-labs/gecko/snow/consensus/snowman"
+)
+
+// Block implements the snowman.Block interface
+type Block struct {
+	id       ids.ID
+	ethBlock *types.Block
+	vm       *VM
+}
+
+// ID implements the snowman.Block interface
+func (b *Block) ID() ids.ID { return b.id }
+
+// Accept implements the snowman.Block interface
+func (b *Block) Accept() {
+	b.vm.ctx.Log.Verbo("Block %s is accepted", b.ID())
+	b.vm.updateStatus(b.ID(), choices.Accepted)
+}
+
+// Reject implements the snowman.Block interface
+func (b *Block) Reject() {
+	b.vm.ctx.Log.Verbo("Block %s is rejected", b.ID())
+	b.vm.updateStatus(b.ID(), choices.Rejected)
+}
+
+// Status implements the snowman.Block interface
+func (b *Block) Status() choices.Status {
+	status := b.vm.getCachedStatus(b.ID())
+	if status == choices.Unknown && b.ethBlock != nil {
+		return choices.Processing
+	}
+	return status
+}
+
+// Parent implements the snowman.Block interface
+func (b *Block) Parent() snowman.Block {
+	parentID := ids.NewID(b.ethBlock.ParentHash())
+	block := &Block{
+		id:       parentID,
+		ethBlock: b.vm.getCachedBlock(parentID),
+		vm:       b.vm,
+	}
+	b.vm.ctx.Log.Verbo("Parent(%s) has status: %s", block.ID(), block.Status())
+	return block
+}
+
+// Verify implements the snowman.Block interface
+func (b *Block) Verify() error {
+	_, err := b.vm.chain.InsertChain([]*types.Block{b.ethBlock})
+	return err
+}
+
+// Bytes implements the snowman.Block interface
+func (b *Block) Bytes() []byte {
+	res, err := rlp.EncodeToBytes(b.ethBlock)
+	if err != nil {
+		panic(err)
+	}
+	return res
+}
+
+func (b *Block) String() string { return fmt.Sprintf("EVM block, ID = %s", b.ID()) }
diff --git a/plugin/evm/database.go b/plugin/evm/database.go
new file mode 100644
index 0000000..de592e1
--- /dev/null
+++ b/plugin/evm/database.go
@@ -0,0 +1,66 @@
+// (c) 2019-2020, Ava Labs, Inc. All rights reserved.
+// See the file LICENSE for licensing terms.
+
+package evm
+
+import (
+	"errors"
+
+	"github.com/ava-labs/go-ethereum/ethdb"
+
+	"github.com/ava-labs/gecko/database"
+)
+
+var (
+	errOpNotSupported = errors.New("this operation is not supported")
+)
+
+// Database implements ethdb.Database
+type Database struct{ database.Database }
+
+// HasAncient returns an error as we don't have a backing chain freezer.
+func (db Database) HasAncient(kind string, number uint64) (bool, error) {
+	return false, errOpNotSupported
+}
+
+// Ancient returns an error as we don't have a backing chain freezer.
+func (db Database) Ancient(kind string, number uint64) ([]byte, error) { return nil, errOpNotSupported }
+
+// Ancients returns an error as we don't have a backing chain freezer.
+func (db Database) Ancients() (uint64, error) { return 0, errOpNotSupported }
+
+// AncientSize returns an error as we don't have a backing chain freezer.
+func (db Database) AncientSize(kind string) (uint64, error) { return 0, errOpNotSupported }
+
+// AppendAncient returns an error as we don't have a backing chain freezer.
+func (db Database) AppendAncient(number uint64, hash, header, body, receipts, td []byte) error {
+	return errOpNotSupported
+}
+
+// TruncateAncients returns an error as we don't have a backing chain freezer.
+func (db Database) TruncateAncients(items uint64) error { return errOpNotSupported }
+
+// Sync returns an error as we don't have a backing chain freezer.
+func (db Database) Sync() error { return errOpNotSupported }
+
+// NewBatch implements ethdb.Database
+func (db Database) NewBatch() ethdb.Batch { return Batch{db.Database.NewBatch()} }
+
+// NewIterator implements ethdb.Database
+func (db Database) NewIterator() ethdb.Iterator { return db.Database.NewIterator() }
+
+// NewIteratorWithPrefix implements ethdb.Database
+func (db Database) NewIteratorWithPrefix(prefix []byte) ethdb.Iterator {
+	return db.NewIteratorWithPrefix(prefix)
+}
+
+// NewIteratorWithStart implements ethdb.Database
+func (db Database) NewIteratorWithStart(start []byte) ethdb.Iterator {
+	return db.NewIteratorWithStart(start)
+}
+
+// Batch implements ethdb.Batch
+type Batch struct{ database.Batch }
+
+// Replay implements ethdb.Batch
+func (batch Batch) Replay(w ethdb.KeyValueWriter) error { return batch.Batch.Replay(w) }
diff --git a/plugin/evm/factory.go b/plugin/evm/factory.go
new file mode 100644
index 0000000..a4c0eca
--- /dev/null
+++ b/plugin/evm/factory.go
@@ -0,0 +1,19 @@
+// (c) 2019-2020, Ava Labs, Inc. All rights reserved.
+// See the file LICENSE for licensing terms.
+
+package evm
+
+import (
+	"github.com/ava-labs/gecko/ids"
+)
+
+// ID this VM should be referenced by
+var (
+	ID = ids.NewID([32]byte{'e', 'v', 'm'})
+)
+
+// Factory ...
+type Factory struct{}
+
+// New ...
+func (f *Factory) New() interface{} { return &VM{} }
diff --git a/plugin/evm/service.go b/plugin/evm/service.go
new file mode 100644
index 0000000..70135cc
--- /dev/null
+++ b/plugin/evm/service.go
@@ -0,0 +1,122 @@
+// (c) 2019-2020, Ava Labs, Inc. All rights reserved.
+// See the file LICENSE for licensing terms.
+
+package evm
+
+import (
+	"context"
+	"crypto/rand"
+	"fmt"
+	"math/big"
+
+	"github.com/ava-labs/coreth"
+
+	"github.com/ava-labs/go-ethereum/common"
+	"github.com/ava-labs/go-ethereum/common/hexutil"
+	"github.com/ava-labs/go-ethereum/core/types"
+	"github.com/ava-labs/go-ethereum/crypto"
+)
+
+const (
+	version = "Athereum 1.0"
+)
+
+// test constants
+const (
+	GenesisTestAddr = "0x751a0b96e1042bee789452ecb20253fba40dbe85"
+	GenesisTestKey  = "0xabd71b35d559563fea757f0f5edbde286fb8c043105b15abb7cd57189306d7d1"
+)
+
+// DebugAPI introduces helper functions for debuging
+type DebugAPI struct{ vm *VM }
+
+// SnowmanAPI introduces snowman specific functionality to the evm
+type SnowmanAPI struct{ vm *VM }
+
+// NetAPI offers network related API methods
+type NetAPI struct{ vm *VM }
+
+// NewNetAPI creates a new net API instance.
+func NewNetAPI(vm *VM) *NetAPI { return &NetAPI{vm} }
+
+// Listening returns an indication if the node is listening for network connections.
+func (s *NetAPI) Listening() bool { return true } // always listening
+
+// PeerCount returns the number of connected peers
+func (s *NetAPI) PeerCount() hexutil.Uint { return hexutil.Uint(0) } // TODO: report number of connected peers
+
+// Version returns the current ethereum protocol version.
+func (s *NetAPI) Version() string { return fmt.Sprintf("%d", s.vm.networkID) }
+
+// Web3API offers helper API methods
+type Web3API struct{}
+
+// ClientVersion returns the version of the vm running
+func (s *Web3API) ClientVersion() string { return version }
+
+// Sha3 returns the bytes returned by hashing [input] with Keccak256
+func (s *Web3API) Sha3(input hexutil.Bytes) hexutil.Bytes { return crypto.Keccak256(input) }
+
+// GetAcceptedFrontReply defines the reply that will be sent from the
+// GetAcceptedFront API call
+type GetAcceptedFrontReply struct {
+	Hash   common.Hash `json:"hash"`
+	Number *big.Int    `json:"number"`
+}
+
+// GetAcceptedFront returns the last accepted block's hash and height
+func (api *SnowmanAPI) GetAcceptedFront(ctx context.Context) (*GetAcceptedFrontReply, error) {
+	blk := api.vm.getLastAccepted().ethBlock
+	return &GetAcceptedFrontReply{
+		Hash:   blk.Hash(),
+		Number: blk.Number(),
+	}, nil
+}
+
+// GetGenesisBalance returns the current funds in the genesis
+func (api *DebugAPI) GetGenesisBalance(ctx context.Context) (*hexutil.Big, error) {
+	lastAccepted := api.vm.getLastAccepted()
+	api.vm.ctx.Log.Verbo("Currently accepted block front: %s", lastAccepted.ethBlock.Hash().Hex())
+	state, err := api.vm.chain.BlockState(lastAccepted.ethBlock)
+	if err != nil {
+		return nil, err
+	}
+	return (*hexutil.Big)(state.GetBalance(common.HexToAddress(GenesisTestAddr))), nil
+}
+
+// SpendGenesis funds
+func (api *DebugAPI) SpendGenesis(ctx context.Context, nonce uint64) error {
+	api.vm.ctx.Log.Info("Spending the genesis")
+
+	value := big.NewInt(1000000000000)
+	gasLimit := 21000
+	gasPrice := big.NewInt(1000000000)
+
+	genPrivateKey, err := crypto.HexToECDSA(GenesisTestKey[2:])
+	if err != nil {
+		return err
+	}
+	bob, err := coreth.NewKey(rand.Reader)
+	if err != nil {
+		return err
+	}
+
+	tx := types.NewTransaction(nonce, bob.Address, value, uint64(gasLimit), gasPrice, nil)
+	signedTx, err := types.SignTx(tx, types.NewEIP155Signer(api.vm.chainID), genPrivateKey)
+	if err != nil {
+		return err
+	}
+
+	if err := api.vm.issueRemoteTxs([]*types.Transaction{signedTx}); err != nil {
+		return err
+	}
+
+	return nil
+}
+
+// IssueBlock to the chain
+func (api *DebugAPI) IssueBlock(ctx context.Context) error {
+	api.vm.ctx.Log.Info("Issuing a new block")
+
+	return api.vm.tryBlockGen()
+}
diff --git a/plugin/evm/static_service.go b/plugin/evm/static_service.go
new file mode 100644
index 0000000..d3870ca
--- /dev/null
+++ b/plugin/evm/static_service.go
@@ -0,0 +1,22 @@
+// (c) 2019-2020, Ava Labs, Inc. All rights reserved.
+// See the file LICENSE for licensing terms.
+
+package evm
+
+import (
+	"context"
+	"encoding/json"
+
+	"github.com/ava-labs/coreth/core"
+	"github.com/ava-labs/gecko/utils/formatting"
+)
+
+// StaticService defines the static API services exposed by the evm
+type StaticService struct{}
+
+// BuildGenesis returns the UTXOs such that at least one address in [args.Addresses] is
+// referenced in the UTXO.
+func (*StaticService) BuildGenesis(_ context.Context, args *core.Genesis) (formatting.CB58, error) {
+	bytes, err := json.Marshal(args)
+	return formatting.CB58{Bytes: bytes}, err
+}
diff --git a/plugin/evm/static_service_test.go b/plugin/evm/static_service_test.go
new file mode 100644
index 0000000..c492798
--- /dev/null
+++ b/plugin/evm/static_service_test.go
@@ -0,0 +1,64 @@
+// (c) 2019-2020, Ava Labs, Inc. All rights reserved.
+// See the file LICENSE for licensing terms.
+
+package evm
+
+import (
+	"math/big"
+	"testing"
+
+	"github.com/ava-labs/go-ethereum/common"
+	"github.com/ava-labs/go-ethereum/params"
+
+	"github.com/ava-labs/coreth/core"
+)
+
+func TestBuildGenesis(t *testing.T) {
+	expected := "3wP629bGfSGj9trh1UNBp5qGRGCcma5d8ezLeSmd9hnUJjSMUJesHHoxbZNcVUC9CjH7PEGNA96htNTd1saZCMt1Mf1dZFG7JDhcYNok6RS4TZufejXdxbVVgquohSa7nCCcrXpiVeiRFwzLJAxyQbXzYRhaCRtcDDfCcqfaVdtkFsPbNeQ49pDTbEC5hVkmfopeQ2Zz8tAG5QXKBdbYBCukR3xNHJ4xDxeixmEwPr1odb42yQRYrL7xREKNn2LFoFwAWUjBTsCkf5GPNgY2GvvN9o8wFWXTroW5fp754DhpdxHYxkMTfuE9DGyNWHTyrEbrUHutUdsfitcSHVj5ctFtkN2wGCs3cyv1eRRNvFFMggWTbarjne6AYaeCrJ631qAu3CbrUtrTH5N2E6G2yQKX4sT4Sk3qWPJdsGXuT95iKKcgNn1u5QRHHw9DXXuGPpJjkcKQRGUCuqpXy61iF5RNPEwAwKDa8f2Y25WMmNgWynUuLj8iSAyePj7USPWk54QFUr86ApVzqAdzzdD1qSVScpmudGnGbz9UNXdzHqSot6XLrNTYsgkabiu6TGntFm7qywbCRmtNdBuT9aznGQdUVimjt5QzUz68HXhUxBzTkrz7yXfVGV5JcWxVHQXYS4oc41U5yu83mH3A7WBrZLVq6UyNrvQVbim5nDxeKKbALPxwzVwywjgY5cp39AvzGnY8CX2AtuBNnKmZaAvG8JWAkx3yxjnJrwWhLgpDQYcCvRp2jg1EPBqN8FKJxSPE6eedjDHDJfB57mNzyEtmg22BPnem3eLdiovX8awkhBUHdE7uPrapNSVprnS85u1saW2Kwza3FsS2jAM3LckGW8KdtfPTpHBTRKAUo49zZLuPsyGL5WduedGyAdaM3a2KPoyXuz4UbexTVUWFNypFvvgyoDS8FMxDCNoMMaD7y4yVnoDpSpVFEVZD6EuSGHe9U8Ew57xLPbjhepDx6"
+
+	balance, success := new(big.Int).SetString("33b2e3c9fd0804000000000", 16)
+	if !success {
+		t.Fatal("Failed to initialize balance")
+	}
+
+	args := core.Genesis{
+		Config: &params.ChainConfig{
+			ChainID:             big.NewInt(43110),
+			HomesteadBlock:      big.NewInt(0),
+			DAOForkBlock:        big.NewInt(0),
+			DAOForkSupport:      true,
+			EIP150Block:         big.NewInt(0),
+			EIP150Hash:          common.HexToHash("0x2086799aeebeae135c246c65021c82b4e15a2c451340993aacfd2751886514f0"),
+			EIP155Block:         big.NewInt(0),
+			EIP158Block:         big.NewInt(0),
+			ByzantiumBlock:      big.NewInt(0),
+			ConstantinopleBlock: big.NewInt(0),
+			PetersburgBlock:     big.NewInt(0),
+		},
+		Nonce:      0,
+		Timestamp:  0,
+		ExtraData:  []byte{},
+		GasLimit:   100000000,
+		Difficulty: big.NewInt(0),
+		Mixhash:    common.HexToHash("0x0000000000000000000000000000000000000000000000000000000000000000"),
+		Coinbase:   common.HexToAddress("0x0000000000000000000000000000000000000000"),
+		Alloc: core.GenesisAlloc{
+			common.HexToAddress("751a0b96e1042bee789452ecb20253fba40dbe85"): core.GenesisAccount{
+				Balance: balance,
+			},
+		},
+		Number:     0,
+		GasUsed:    0,
+		ParentHash: common.HexToHash("0x0000000000000000000000000000000000000000000000000000000000000000"),
+	}
+
+	ss := StaticService{}
+	result, err := ss.BuildGenesis(nil, &args)
+	if err != nil {
+		t.Fatal(err)
+	}
+
+	if result.String() != expected {
+		t.Fatalf("StaticService.BuildGenesis:\nReturned: %s\nExpected: %s", result, expected)
+	}
+}
diff --git a/plugin/evm/vm.go b/plugin/evm/vm.go
new file mode 100644
index 0000000..a9011ea
--- /dev/null
+++ b/plugin/evm/vm.go
@@ -0,0 +1,502 @@
+// (c) 2019-2020, Ava Labs, Inc. All rights reserved.
+// See the file LICENSE for licensing terms.
+
+package evm
+
+import (
+	"crypto/rand"
+	"encoding/json"
+	"errors"
+	"fmt"
+	"math/big"
+	"sync"
+	"sync/atomic"
+	"time"
+
+	"github.com/ava-labs/coreth"
+	"github.com/ava-labs/coreth/core"
+	"github.com/ava-labs/coreth/eth"
+	"github.com/ava-labs/coreth/node"
+
+	"github.com/ava-labs/go-ethereum/common"
+	"github.com/ava-labs/go-ethereum/core/types"
+	"github.com/ava-labs/go-ethereum/rlp"
+	"github.com/ava-labs/go-ethereum/rpc"
+
+	"github.com/ava-labs/gecko/cache"
+	"github.com/ava-labs/gecko/database"
+	"github.com/ava-labs/gecko/ids"
+	"github.com/ava-labs/gecko/snow"
+	"github.com/ava-labs/gecko/snow/choices"
+	"github.com/ava-labs/gecko/snow/consensus/snowman"
+	"github.com/ava-labs/gecko/utils/timer"
+
+	commonEng "github.com/ava-labs/gecko/snow/engine/common"
+)
+
+const (
+	lastAcceptedKey = "snowman_lastAccepted"
+)
+
+const (
+	minBlockTime = 250 * time.Millisecond
+	maxBlockTime = 1000 * time.Millisecond
+	batchSize    = 250
+)
+
+const (
+	bdTimerStateMin = iota
+	bdTimerStateMax
+	bdTimerStateLong
+)
+
+var (
+	errEmptyBlock     = errors.New("empty block")
+	errCreateBlock    = errors.New("couldn't create block")
+	errUnknownBlock   = errors.New("unknown block")
+	errBlockFrequency = errors.New("too frequent block issuance")
+	errUnsupportedFXs = errors.New("unsupported feature extensions")
+)
+
+func maxDuration(x, y time.Duration) time.Duration {
+	if x > y {
+		return x
+	}
+	return y
+}
+
+// VM implements the snowman.ChainVM interface
+type VM struct {
+	ctx *snow.Context
+
+	chainID           *big.Int
+	networkID         uint64
+	chain             *coreth.ETHChain
+	chaindb           Database
+	newBlockChan      chan *Block
+	networkChan       chan<- commonEng.Message
+	newTxPoolHeadChan chan core.NewTxPoolHeadEvent
+
+	txPoolStabilizedHead common.Hash
+	txPoolStabilizedOk   chan struct{}
+	txPoolStabilizedLock sync.Mutex
+
+	metalock                     sync.Mutex
+	blockCache, blockStatusCache cache.LRU
+	lastAccepted                 *Block
+	writingMetadata              uint32
+
+	bdlock          sync.Mutex
+	blockDelayTimer *timer.Timer
+	bdTimerState    int8
+	bdGenWaitFlag   bool
+	bdGenFlag       bool
+
+	genlock      sync.Mutex
+	txSubmitChan <-chan struct{}
+}
+
+/*
+ ******************************************************************************
+ ********************************* Snowman API ********************************
+ ******************************************************************************
+ */
+
+// Initialize implements the snowman.ChainVM interface
+func (vm *VM) Initialize(
+	ctx *snow.Context,
+	db database.Database,
+	b []byte,
+	toEngine chan<- commonEng.Message,
+	fxs []*commonEng.Fx,
+) error {
+	if len(fxs) > 0 {
+		return errUnsupportedFXs
+	}
+
+	vm.ctx = ctx
+	vm.chaindb = Database{db}
+	g := new(core.Genesis)
+	err := json.Unmarshal(b, g)
+	if err != nil {
+		return err
+	}
+
+	vm.chainID = g.Config.ChainID
+
+	config := eth.DefaultConfig
+	config.ManualCanonical = true
+	config.Genesis = g
+	config.Miner.ManualMining = true
+	config.Miner.DisableUncle = true
+	if err := config.SetGCMode("archive"); err != nil {
+		panic(err)
+	}
+	nodecfg := node.Config{NoUSB: true}
+	chain := coreth.NewETHChain(&config, &nodecfg, nil, vm.chaindb)
+	vm.chain = chain
+	vm.networkID = config.NetworkId
+	chain.SetOnHeaderNew(func(header *types.Header) {
+		hid := make([]byte, 32)
+		_, err := rand.Read(hid)
+		if err != nil {
+			panic("cannot generate hid")
+		}
+		header.Extra = append(header.Extra, hid...)
+	})
+	chain.SetOnSeal(func(block *types.Block) error {
+		if len(block.Transactions()) == 0 {
+			// this could happen due to the async logic of geth tx pool
+			vm.newBlockChan <- nil
+			return errEmptyBlock
+		}
+		return nil
+	})
+	chain.SetOnSealFinish(func(block *types.Block) error {
+		vm.ctx.Log.Verbo("EVM sealed a block")
+
+		blk := &Block{
+			id:       ids.NewID(block.Hash()),
+			ethBlock: block,
+			vm:       vm,
+		}
+		vm.newBlockChan <- blk
+		vm.updateStatus(ids.NewID(block.Hash()), choices.Processing)
+		vm.txPoolStabilizedLock.Lock()
+		vm.txPoolStabilizedHead = block.Hash()
+		vm.txPoolStabilizedLock.Unlock()
+		return nil
+	})
+	chain.SetOnQueryAcceptedBlock(func() *types.Block {
+		return vm.getLastAccepted().ethBlock
+	})
+	vm.blockCache = cache.LRU{Size: 2048}
+	vm.blockStatusCache = cache.LRU{Size: 1024}
+	vm.newBlockChan = make(chan *Block)
+	vm.networkChan = toEngine
+	vm.blockDelayTimer = timer.NewTimer(func() {
+		vm.bdlock.Lock()
+		switch vm.bdTimerState {
+		case bdTimerStateMin:
+			vm.bdTimerState = bdTimerStateMax
+			vm.blockDelayTimer.SetTimeoutIn(maxDuration(maxBlockTime-minBlockTime, 0))
+		case bdTimerStateMax:
+			vm.bdTimerState = bdTimerStateLong
+		}
+		tryAgain := vm.bdGenWaitFlag
+		vm.bdlock.Unlock()
+		if tryAgain {
+			vm.tryBlockGen()
+		}
+	})
+	go ctx.Log.RecoverAndPanic(vm.blockDelayTimer.Dispatch)
+
+	vm.bdTimerState = bdTimerStateLong
+	vm.bdGenWaitFlag = true
+	vm.newTxPoolHeadChan = make(chan core.NewTxPoolHeadEvent, 1)
+	vm.txPoolStabilizedOk = make(chan struct{}, 1)
+	chain.GetTxPool().SubscribeNewHeadEvent(vm.newTxPoolHeadChan)
+	// TODO: shutdown this go routine
+	go ctx.Log.RecoverAndPanic(func() {
+		for {
+			select {
+			case h := <-vm.newTxPoolHeadChan:
+				vm.txPoolStabilizedLock.Lock()
+				if vm.txPoolStabilizedHead == h.Block.Hash() {
+					vm.txPoolStabilizedOk <- struct{}{}
+					vm.txPoolStabilizedHead = common.Hash{}
+				}
+				vm.txPoolStabilizedLock.Unlock()
+			}
+		}
+	})
+	chain.Start()
+
+	var lastAccepted *types.Block
+	if b, err := vm.chaindb.Get([]byte(lastAcceptedKey)); err == nil {
+		var hash common.Hash
+		if err = rlp.DecodeBytes(b, &hash); err == nil {
+			if block := chain.GetBlockByHash(hash); block == nil {
+				vm.ctx.Log.Debug("lastAccepted block not found in chaindb")
+			} else {
+				lastAccepted = block
+			}
+		}
+	}
+	if lastAccepted == nil {
+		vm.ctx.Log.Debug("lastAccepted is unavailable, setting to the genesis block")
+		lastAccepted = chain.GetGenesisBlock()
+	}
+	vm.lastAccepted = &Block{
+		id:       ids.NewID(lastAccepted.Hash()),
+		ethBlock: lastAccepted,
+		vm:       vm,
+	}
+	vm.ctx.Log.Info(fmt.Sprintf("lastAccepted = %s", vm.lastAccepted.ethBlock.Hash().Hex()))
+
+	// TODO: shutdown this go routine
+	go vm.ctx.Log.RecoverAndPanic(func() {
+		vm.txSubmitChan = vm.chain.GetTxSubmitCh()
+		for {
+			select {
+			case <-vm.txSubmitChan:
+				vm.ctx.Log.Verbo("New tx detected, trying to generate a block")
+				vm.tryBlockGen()
+			case <-time.After(5 * time.Second):
+				vm.tryBlockGen()
+			}
+		}
+	})
+
+	return nil
+}
+
+// Shutdown implements the snowman.ChainVM interface
+func (vm *VM) Shutdown() {
+	if vm.ctx == nil {
+		return
+	}
+
+	vm.writeBackMetadata()
+	vm.chain.Stop()
+}
+
+// BuildBlock implements the snowman.ChainVM interface
+func (vm *VM) BuildBlock() (snowman.Block, error) {
+	vm.chain.GenBlock()
+	block := <-vm.newBlockChan
+	if block == nil {
+		return nil, errCreateBlock
+	}
+	// reset the min block time timer
+	vm.bdlock.Lock()
+	vm.bdTimerState = bdTimerStateMin
+	vm.bdGenWaitFlag = false
+	vm.bdGenFlag = false
+	vm.blockDelayTimer.SetTimeoutIn(minBlockTime)
+	vm.bdlock.Unlock()
+
+	vm.ctx.Log.Debug("built block 0x%x", block.ID().Bytes())
+	// make sure Tx Pool is updated
+	<-vm.txPoolStabilizedOk
+	return block, nil
+}
+
+// ParseBlock implements the snowman.ChainVM interface
+func (vm *VM) ParseBlock(b []byte) (snowman.Block, error) {
+	vm.metalock.Lock()
+	defer vm.metalock.Unlock()
+
+	ethBlock := new(types.Block)
+	if err := rlp.DecodeBytes(b, ethBlock); err != nil {
+		return nil, err
+	}
+	block := &Block{
+		id:       ids.NewID(ethBlock.Hash()),
+		ethBlock: ethBlock,
+		vm:       vm,
+	}
+	vm.blockCache.Put(block.ID(), block)
+	return block, nil
+}
+
+// GetBlock implements the snowman.ChainVM interface
+func (vm *VM) GetBlock(id ids.ID) (snowman.Block, error) {
+	vm.metalock.Lock()
+	defer vm.metalock.Unlock()
+
+	block := vm.getBlock(id)
+	if block == nil {
+		return nil, errUnknownBlock
+	}
+	return block, nil
+}
+
+// SetPreference sets what the current tail of the chain is
+func (vm *VM) SetPreference(blkID ids.ID) {
+	err := vm.chain.SetTail(blkID.Key())
+	vm.ctx.Log.AssertNoError(err)
+}
+
+// LastAccepted returns the ID of the block that was last accepted
+func (vm *VM) LastAccepted() ids.ID {
+	vm.metalock.Lock()
+	defer vm.metalock.Unlock()
+
+	return vm.lastAccepted.ID()
+}
+
+// CreateHandlers makes new http handlers that can handle API calls
+func (vm *VM) CreateHandlers() map[string]*commonEng.HTTPHandler {
+	handler := vm.chain.NewRPCHandler()
+	vm.chain.AttachEthService(handler, []string{"eth", "personal", "txpool"})
+	handler.RegisterName("net", &NetAPI{vm})
+	handler.RegisterName("snowman", &SnowmanAPI{vm})
+	handler.RegisterName("web3", &Web3API{})
+	handler.RegisterName("debug", &DebugAPI{vm})
+
+	return map[string]*commonEng.HTTPHandler{
+		"/rpc": &commonEng.HTTPHandler{LockOptions: commonEng.NoLock, Handler: handler},
+		"/ws":  &commonEng.HTTPHandler{LockOptions: commonEng.NoLock, Handler: handler.WebsocketHandler([]string{"*"})},
+	}
+}
+
+// CreateStaticHandlers makes new http handlers that can handle API calls
+func (vm *VM) CreateStaticHandlers() map[string]*commonEng.HTTPHandler {
+	handler := rpc.NewServer()
+	handler.RegisterName("static", &StaticService{})
+	return map[string]*commonEng.HTTPHandler{
+		"/rpc": &commonEng.HTTPHandler{LockOptions: commonEng.NoLock, Handler: handler},
+		"/ws":  &commonEng.HTTPHandler{LockOptions: commonEng.NoLock, Handler: handler.WebsocketHandler([]string{"*"})},
+	}
+}
+
+/*
+ ******************************************************************************
+ *********************************** Helpers **********************************
+ ******************************************************************************
+ */
+
+func (vm *VM) updateStatus(blockID ids.ID, status choices.Status) {
+	vm.metalock.Lock()
+	defer vm.metalock.Unlock()
+
+	if status == choices.Accepted {
+		vm.lastAccepted = vm.getBlock(blockID)
+		// TODO: improve this naive implementation
+		if atomic.SwapUint32(&vm.writingMetadata, 1) == 0 {
+			go vm.ctx.Log.RecoverAndPanic(vm.writeBackMetadata)
+		}
+	}
+	vm.blockStatusCache.Put(blockID, status)
+}
+
+func (vm *VM) getCachedBlock(blockID ids.ID) *types.Block {
+	return vm.chain.GetBlockByHash(blockID.Key())
+}
+
+func (vm *VM) tryBlockGen() error {
+	vm.bdlock.Lock()
+	defer vm.bdlock.Unlock()
+	if vm.bdGenFlag {
+		// skip if one call already generates a block in this round
+		return nil
+	}
+	vm.bdGenWaitFlag = true
+
+	vm.genlock.Lock()
+	defer vm.genlock.Unlock()
+	// get pending size
+	size, err := vm.chain.PendingSize()
+	if err != nil {
+		return err
+	}
+	if size == 0 {
+		return nil
+	}
+
+	switch vm.bdTimerState {
+	case bdTimerStateMin:
+		return nil
+	case bdTimerStateMax:
+		if size < batchSize {
+			return nil
+		}
+	case bdTimerStateLong:
+		// timeout; go ahead and generate a new block anyway
+	}
+	select {
+	case vm.networkChan <- commonEng.PendingTxs:
+		// successfully push out the notification; this round ends
+		vm.bdGenFlag = true
+	default:
+		return errBlockFrequency
+	}
+	return nil
+}
+
+func (vm *VM) getCachedStatus(blockID ids.ID) choices.Status {
+	vm.metalock.Lock()
+	defer vm.metalock.Unlock()
+	status := choices.Processing
+
+	if statusIntf, ok := vm.blockStatusCache.Get(blockID); ok {
+		status = statusIntf.(choices.Status)
+	} else {
+		blk := vm.chain.GetBlockByHash(blockID.Key())
+		if blk == nil {
+			return choices.Unknown
+		}
+		acceptedBlk := vm.lastAccepted.ethBlock
+
+		// TODO: There must be a better way of doing this.
+		// Traverse up the chain from the lower block until the indices match
+		highBlock := blk
+		lowBlock := acceptedBlk
+		if highBlock.Number().Cmp(lowBlock.Number()) < 0 {
+			highBlock, lowBlock = lowBlock, highBlock
+		}
+		for highBlock.Number().Cmp(lowBlock.Number()) > 0 {
+			highBlock = vm.chain.GetBlockByHash(highBlock.ParentHash())
+		}
+
+		if highBlock.Hash() == lowBlock.Hash() { // on the same branch
+			if blk.Number().Cmp(acceptedBlk.Number()) <= 0 {
+				status = choices.Accepted
+			}
+		} else { // on different branches
+			status = choices.Rejected
+		}
+	}
+
+	vm.blockStatusCache.Put(blockID, status)
+	return status
+}
+
+func (vm *VM) getBlock(id ids.ID) *Block {
+	if blockIntf, ok := vm.blockCache.Get(id); ok {
+		return blockIntf.(*Block)
+	}
+	ethBlock := vm.getCachedBlock(id)
+	if ethBlock == nil {
+		return nil
+	}
+	block := &Block{
+		id:       ids.NewID(ethBlock.Hash()),
+		ethBlock: ethBlock,
+		vm:       vm,
+	}
+	vm.blockCache.Put(id, block)
+	return block
+}
+
+func (vm *VM) issueRemoteTxs(txs []*types.Transaction) error {
+	errs := vm.chain.AddRemoteTxs(txs)
+	for _, err := range errs {
+		if err != nil {
+			return err
+		}
+	}
+	return vm.tryBlockGen()
+}
+
+func (vm *VM) writeBackMetadata() {
+	vm.metalock.Lock()
+	defer vm.metalock.Unlock()
+
+	b, err := rlp.EncodeToBytes(vm.lastAccepted.ethBlock.Hash())
+	if err != nil {
+		vm.ctx.Log.Error("snowman-eth: error while writing back metadata")
+		return
+	}
+	vm.ctx.Log.Debug("writing back metadata")
+	vm.chaindb.Put([]byte(lastAcceptedKey), b)
+	atomic.StoreUint32(&vm.writingMetadata, 0)
+}
+
+func (vm *VM) getLastAccepted() *Block {
+	vm.metalock.Lock()
+	defer vm.metalock.Unlock()
+
+	return vm.lastAccepted
+}
diff --git a/plugin/evm/vm_genesis_parse_test.go b/plugin/evm/vm_genesis_parse_test.go
new file mode 100644
index 0000000..9a113fb
--- /dev/null
+++ b/plugin/evm/vm_genesis_parse_test.go
@@ -0,0 +1,32 @@
+// (c) 2019-2020, Ava Labs, Inc. All rights reserved.
+// See the file LICENSE for licensing terms.
+
+package evm
+
+import (
+	"encoding/json"
+	"testing"
+
+	"github.com/ava-labs/coreth/core"
+)
+
+func TestParseGenesis(t *testing.T) {
+	genesis := []byte(`{"config":{"chainId":43110,"homesteadBlock":0,"daoForkBlock":0,"daoForkSupport":true,"eip150Block":0,"eip150Hash":"0x2086799aeebeae135c246c65021c82b4e15a2c451340993aacfd2751886514f0","eip155Block":0,"eip158Block":0,"byzantiumBlock":0,"constantinopleBlock":0,"petersburgBlock":0},"nonce":"0x0","timestamp":"0x0","extraData":"0x00","gasLimit":"0x5f5e100","difficulty":"0x0","mixHash":"0x0000000000000000000000000000000000000000000000000000000000000000","coinbase":"0x0000000000000000000000000000000000000000","alloc":{"751a0b96e1042bee789452ecb20253fba40dbe85":{"balance":"0x33b2e3c9fd0804000000000"}},"number":"0x0","gasUsed":"0x0","parentHash":"0x0000000000000000000000000000000000000000000000000000000000000000"}`)
+
+	genesisBlock := new(core.Genesis)
+	err := json.Unmarshal(genesis, genesisBlock)
+	if err != nil {
+		t.Fatal(err)
+	}
+
+	marshalledBytes, err := json.Marshal(genesisBlock)
+	if err != nil {
+		t.Fatal(err)
+	}
+
+	secondGenesisBlock := new(core.Genesis)
+	err = json.Unmarshal(marshalledBytes, secondGenesisBlock)
+	if err != nil {
+		t.Fatal(err)
+	}
+}