plugins: start work on plugin system

plugins/interface.go

@@ -0,0 +1,78 @@
+// Copyright 2024 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 plugins
+
+import (
+	"github.com/ethereum/go-ethereum/common"
+	"github.com/ethereum/go-ethereum/core/state/snapshot"
+	"github.com/ethereum/go-ethereum/core/types"
+	"github.com/holiman/uint256"
+)
+
+// Plugin is an interface that allows 3rd-party developers to build plugins
+// for go-ethereum which can be used to add additional functionality to geth
+// without modifying the chain logic.
+type Plugin interface {
+	// Setup is called on startup when the Plugin is initialized.
+	Setup(chain Chain)
+	// Close is called when the geth node is torn down.
+	Close()
+	// NewHead is called when a new head is set.
+	NewHead()
+}
+
+// The Chain interface allows for interacting with the chain from a plugin.
+type Chain interface {
+	// Head returns the number of the current head and finalized block.
+	Head() (uint64, uint64)
+	// Header returns a header in the canonical chain.
+	Header(number uint64) *types.Header
+	// Block returns a block in the canonical chain.
+	Block(number uint64) *types.Block
+	// Receipts returns the receipts of a block in the canonical chain.
+	Receipts(number uint64) types.Receipts
+	// State returns the state at a certain root.
+	State(root common.Hash) State
+}
+
+// The State interface allows for interacting with a specific state from a plugin.
+// Please note that State might hold internal references which interferes with garbage collection.
+// Make sure to not hold references to State for long.
+type State interface {
+	// Account retrieves an account from the state.
+	Account(addr common.Address) Account
+	// AccountIterator creates an iterator to iterate over accounts.
+	AccountIterator(seek common.Hash) snapshot.AccountIterator
+	// NewAccount interprets an rlp slim account as an Account.
+	NewAccount(addr common.Address, account []byte) Account
+}
+
+// The Account interface allows for interacting with a specific account from a plugin.
+// Please note that Account might hold internal references which interferes with garbage collection.
+// Make sure to not hold references to Account for long.
+type Account interface {
+	// Balance returns the balance of an account.
+	Balance() *uint256.Int
+	// Nonce returns the nonce of an account.
+	Nonce() uint64
+	// Code returns the code of an account.
+	Code() []byte
+	// Storage returns a storage slot.
+	Storage(slot common.Hash) common.Hash
+	// StorageIterator creates an iterator over the storage slots of an account.
+	StorageIterator(seek common.Hash) snapshot.StorageIterator
+}

plugins/internal/chain.go

@@ -0,0 +1,165 @@
+// Copyright 2024 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 internal
+
+import (
+	"github.com/ethereum/go-ethereum/common"
+	"github.com/ethereum/go-ethereum/core"
+	"github.com/ethereum/go-ethereum/core/state"
+	"github.com/ethereum/go-ethereum/core/state/snapshot"
+	"github.com/ethereum/go-ethereum/core/types"
+	"github.com/ethereum/go-ethereum/crypto"
+	"github.com/ethereum/go-ethereum/plugins"
+	"github.com/ethereum/go-ethereum/rlp"
+	"github.com/holiman/uint256"
+)
+
+var _ = plugins.Chain(Chain{})
+
+type Chain struct {
+	chain *core.BlockChain
+}
+
+func (c Chain) Head() (uint64, uint64) {
+	return c.chain.CurrentHeader().Number.Uint64(), c.chain.CurrentFinalBlock().Number.Uint64()
+}
+
+func (c Chain) Header(number uint64) *types.Header {
+	hash := c.chain.GetCanonicalHash(number)
+	return c.chain.GetHeaderByHash(hash)
+}
+
+func (c Chain) Block(number uint64) *types.Block {
+	hash := c.chain.GetCanonicalHash(number)
+	return c.chain.GetBlockByHash(hash)
+}
+
+func (c Chain) Receipts(number uint64) types.Receipts {
+	hash := c.chain.GetCanonicalHash(number)
+	return c.chain.GetReceiptsByHash(hash)
+}
+
+func (c Chain) State(root common.Hash) plugins.State {
+	reader, err := c.chain.StateCache().Reader(root)
+	if err != nil {
+		return nil
+	}
+
+	return State{
+		root:   root,
+		cache:  c.chain.StateCache(),
+		reader: reader,
+	}
+}
+
+type State struct {
+	root   common.Hash
+	cache  state.Database
+	reader state.Reader
+}
+
+func (s State) Account(addr common.Address) plugins.Account {
+	hash := crypto.Keccak256Hash(addr.Bytes())
+	reader, err := s.cache.Reader(s.root)
+	if err != nil {
+		return nil
+	}
+	account, err := reader.Account(addr)
+	if err != nil {
+		return nil
+	}
+	return Account{
+		root:    s.root,
+		hash:    hash,
+		account: account,
+		cache:   s.cache,
+	}
+}
+
+func (s State) AccountIterator(seek common.Hash) snapshot.AccountIterator {
+	if it, err := s.cache.Snapshot().AccountIterator(s.root, seek); err == nil {
+		return it
+	}
+	return nil
+}
+
+func (s State) NewAccount(addr common.Address, accRLP []byte) plugins.Account {
+	hash := crypto.Keccak256Hash(addr.Bytes())
+	var slim *types.SlimAccount
+	if err := rlp.DecodeBytes(accRLP, &slim); err != nil {
+		return nil
+	}
+	account := &types.StateAccount{
+		Nonce:    slim.Nonce,
+		Balance:  slim.Balance,
+		CodeHash: slim.CodeHash,
+		Root:     common.BytesToHash(slim.Root),
+	}
+	if len(account.CodeHash) == 0 {
+		account.CodeHash = types.EmptyCodeHash.Bytes()
+	}
+	if account.Root == (common.Hash{}) {
+		account.Root = types.EmptyRootHash
+	}
+	return Account{
+		root:    s.root,
+		hash:    hash,
+		account: account,
+		cache:   s.cache,
+	}
+}
+
+type Account struct {
+	addr    common.Address
+	root    common.Hash
+	hash    common.Hash
+	account *types.StateAccount
+	cache   state.Database
+}
+
+func (a Account) Balance() *uint256.Int {
+	return a.account.Balance
+}
+
+func (a Account) Nonce() uint64 {
+	return a.account.Nonce
+}
+
+func (a Account) Code() []byte {
+	if code, err := a.cache.ContractCode(a.addr, a.account.Root); err == nil {
+		return code
+	}
+	return nil
+}
+
+func (a Account) Storage(slot common.Hash) common.Hash {
+	reader, err := a.cache.Reader(a.root)
+	if err != nil {
+		return common.Hash{}
+	}
+	if storage, err := reader.Storage(a.addr, slot); err == nil {
+		return storage
+	}
+	return common.Hash{}
+}
+
+func (a Account) StorageIterator(seek common.Hash) snapshot.StorageIterator {
+	if it, err := a.cache.Snapshot().StorageIterator(a.root, a.hash, seek); err == nil {
+		return it
+	}
+	return nil
+}