Initial plugin implementation

* refactor packages, flags, subscriptions
* DRY refactor builder tests
* use mockgen to generate mocks
* update README
* MODE=statediff no longer needed for unit tests
* simplify func names, clean up metrics
* move write params to service field
* sql indexer: confirm quit after ipld cache reset
  prevents negative waitgroup panic
* don't let TotalDifficulty become nil
* use forked plugeth, plugeth-utils for now

adapt/state.go

@@ -0,0 +1,74 @@
+package adapt
+
+import (
+	"github.com/ethereum/go-ethereum/common"
+	"github.com/ethereum/go-ethereum/core/state"
+	"github.com/ethereum/go-ethereum/trie"
+
+	plugeth "github.com/openrelayxyz/plugeth-utils/core"
+)
+
+// StateView exposes a minimal interface for state access for diff building
+type StateView interface {
+	OpenTrie(root common.Hash) (StateTrie, error)
+	ContractCode(codeHash common.Hash) ([]byte, error)
+}
+
+// StateTrie is an interface exposing only the necessary methods from state.Trie
+type StateTrie interface {
+	GetKey([]byte) []byte
+	NodeIterator([]byte) trie.NodeIterator
+}
+
+// adapts a state.Database to StateView - used in tests
+type stateDatabaseView struct {
+	db state.Database
+}
+
+var _ StateView = stateDatabaseView{}
+
+func GethStateView(db state.Database) StateView {
+	return stateDatabaseView{db}
+}
+
+func (a stateDatabaseView) OpenTrie(root common.Hash) (StateTrie, error) {
+	return a.db.OpenTrie(common.Hash(root))
+}
+
+func (a stateDatabaseView) ContractCode(hash common.Hash) ([]byte, error) {
+	return a.db.ContractCode(common.Hash{}, hash)
+}
+
+// adapts geth Trie to plugeth
+type adaptTrie struct {
+	plugeth.Trie
+}
+
+func NewStateTrie(t plugeth.Trie) StateTrie { return adaptTrie{t} }
+
+func (a adaptTrie) NodeIterator(start []byte) trie.NodeIterator {
+	return NodeIterator(a.Trie.NodeIterator(start))
+}
+
+func NodeIterator(it plugeth.NodeIterator) trie.NodeIterator {
+	return adaptIter{it}
+}
+
+type adaptIter struct {
+	plugeth.NodeIterator
+}
+
+func (it adaptIter) Hash() common.Hash {
+	return common.Hash(it.NodeIterator.Hash())
+}
+
+func (it adaptIter) Parent() common.Hash {
+	return common.Hash(it.NodeIterator.Parent())
+}
+
+func (it adaptIter) AddResolver(resolver trie.NodeResolver) {
+	r := func(owner plugeth.Hash, path []byte, hash plugeth.Hash) []byte {
+		return resolver(common.Hash(owner), path, common.Hash(hash))
+	}
+	it.NodeIterator.AddResolver(r)
+}

adapt/util.go

@@ -0,0 +1,38 @@
+package adapt
+
+import (
+	"github.com/ethereum/go-ethereum/common"
+	"github.com/ethereum/go-ethereum/core/types"
+	"github.com/ethereum/go-ethereum/params"
+
+	plugeth "github.com/openrelayxyz/plugeth-utils/core"
+	plugeth_params "github.com/openrelayxyz/plugeth-utils/restricted/params"
+)
+
+func StateAccount(a *plugeth.StateAccount) *types.StateAccount {
+	return &types.StateAccount{
+		Nonce:    a.Nonce,
+		Balance:  a.Balance,
+		Root:     common.Hash(a.Root),
+		CodeHash: a.CodeHash,
+	}
+}
+
+func ChainConfig(cc *plugeth_params.ChainConfig) *params.ChainConfig {
+	return &params.ChainConfig{
+		ChainID:             cc.ChainID,
+		HomesteadBlock:      cc.HomesteadBlock,
+		DAOForkBlock:        cc.DAOForkBlock,
+		DAOForkSupport:      cc.DAOForkSupport,
+		EIP150Block:         cc.EIP150Block,
+		EIP155Block:         cc.EIP155Block,
+		EIP158Block:         cc.EIP158Block,
+		ByzantiumBlock:      cc.ByzantiumBlock,
+		ConstantinopleBlock: cc.ConstantinopleBlock,
+		PetersburgBlock:     cc.PetersburgBlock,
+		IstanbulBlock:       cc.IstanbulBlock,
+		MuirGlacierBlock:    cc.MuirGlacierBlock,
+		BerlinBlock:         cc.BerlinBlock,
+		LondonBlock:         cc.LondonBlock,
+	}
+}