core/state: access trie through Database interface, track errors (#14589)

With this commit, core/state's access to the underlying key/value database is
mediated through an interface. Database errors are tracked in StateDB and
returned by CommitTo or the new Error method.

Motivation for this change: We can remove the light client's duplicated copy of
core/state. The light client now supports node iteration, so tracing and storage
enumeration can work with the light client (not implemented in this commit).

1 files changed, 0 insertions, 275 deletions

diff --git a/light/state_object.go b/light/state_object.go
deleted file mode 100644
index a54ea1d9f..000000000
--- a/light/state_object.go
+++ /dev/null
@@ -1,275 +0,0 @@
-// Copyright 2015 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 light
-
-import (
-	"bytes"
-	"context"
-	"fmt"
-	"math/big"
-
-	"github.com/ethereum/go-ethereum/common"
-	"github.com/ethereum/go-ethereum/crypto"
-	"github.com/ethereum/go-ethereum/rlp"
-)
-
-var emptyCodeHash = crypto.Keccak256(nil)
-
-// Code represents a contract code in binary form
-type Code []byte
-
-// String returns a string representation of the code
-func (self Code) String() string {
-	return string(self) //strings.Join(Disassemble(self), " ")
-}
-
-// Storage is a memory map cache of a contract storage
-type Storage map[common.Hash]common.Hash
-
-// String returns a string representation of the storage cache
-func (self Storage) String() (str string) {
-	for key, value := range self {
-		str += fmt.Sprintf("%X : %X\n", key, value)
-	}
-
-	return
-}
-
-// Copy copies the contents of a storage cache
-func (self Storage) Copy() Storage {
-	cpy := make(Storage)
-	for key, value := range self {
-		cpy[key] = value
-	}
-
-	return cpy
-}
-
-// StateObject is a memory representation of an account or contract and its storage.
-// This version is ODR capable, caching only the already accessed part of the
-// storage, retrieving unknown parts on-demand from the ODR backend. Changes are
-// never stored in the local database, only in the memory objects.
-type StateObject struct {
-	odr  OdrBackend
-	trie *LightTrie
-
-	// Address belonging to this account
-	address common.Address
-	// The balance of the account
-	balance *big.Int
-	// The nonce of the account
-	nonce uint64
-	// The code hash if code is present (i.e. a contract)
-	codeHash []byte
-	// The code for this account
-	code Code
-	// Cached storage (flushed when updated)
-	storage Storage
-
-	// Mark for deletion
-	// When an object is marked for deletion it will be delete from the trie
-	// during the "update" phase of the state transition
-	remove  bool
-	deleted bool
-	dirty   bool
-}
-
-// NewStateObject creates a new StateObject of the specified account address
-func NewStateObject(address common.Address, odr OdrBackend) *StateObject {
-	object := &StateObject{
-		odr:      odr,
-		address:  address,
-		balance:  new(big.Int),
-		dirty:    true,
-		codeHash: emptyCodeHash,
-		storage:  make(Storage),
-	}
-	object.trie = NewLightTrie(&TrieID{}, odr, true)
-	return object
-}
-
-// MarkForDeletion marks an account to be removed
-func (self *StateObject) MarkForDeletion() {
-	self.remove = true
-	self.dirty = true
-}
-
-// getAddr gets the storage value at the given address from the trie
-func (c *StateObject) getAddr(ctx context.Context, addr common.Hash) (common.Hash, error) {
-	var ret []byte
-	val, err := c.trie.Get(ctx, addr[:])
-	if err != nil {
-		return common.Hash{}, err
-	}
-	rlp.DecodeBytes(val, &ret)
-	return common.BytesToHash(ret), nil
-}
-
-// Storage returns the storage cache object of the account
-func (self *StateObject) Storage() Storage {
-	return self.storage
-}
-
-// GetState returns the storage value at the given address from either the cache
-// or the trie
-func (self *StateObject) GetState(ctx context.Context, key common.Hash) (common.Hash, error) {
-	value, exists := self.storage[key]
-	if !exists {
-		var err error
-		value, err = self.getAddr(ctx, key)
-		if err != nil {
-			return common.Hash{}, err
-		}
-		if (value != common.Hash{}) {
-			self.storage[key] = value
-		}
-	}
-
-	return value, nil
-}
-
-// SetState sets the storage value at the given address
-func (self *StateObject) SetState(k, value common.Hash) {
-	self.storage[k] = value
-	self.dirty = true
-}
-
-// AddBalance adds the given amount to the account balance
-func (c *StateObject) AddBalance(amount *big.Int) {
-	c.SetBalance(new(big.Int).Add(c.balance, amount))
-}
-
-// SubBalance subtracts the given amount from the account balance
-func (c *StateObject) SubBalance(amount *big.Int) {
-	c.SetBalance(new(big.Int).Sub(c.balance, amount))
-}
-
-// SetBalance sets the account balance to the given amount
-func (c *StateObject) SetBalance(amount *big.Int) {
-	c.balance = amount
-	c.dirty = true
-}
-
-// ReturnGas returns the gas back to the origin. Used by the Virtual machine or Closures
-func (c *StateObject) ReturnGas(gas *big.Int) {}
-
-// Copy creates a copy of the state object
-func (self *StateObject) Copy() *StateObject {
-	stateObject := NewStateObject(self.Address(), self.odr)
-	stateObject.balance.Set(self.balance)
-	stateObject.codeHash = common.CopyBytes(self.codeHash)
-	stateObject.nonce = self.nonce
-	stateObject.trie = self.trie
-	stateObject.code = self.code
-	stateObject.storage = self.storage.Copy()
-	stateObject.remove = self.remove
-	stateObject.dirty = self.dirty
-	stateObject.deleted = self.deleted
-
-	return stateObject
-}
-
-//
-// Attribute accessors
-//
-
-// empty returns whether the account is considered empty.
-func (self *StateObject) empty() bool {
-	return self.nonce == 0 && self.balance.Sign() == 0 && bytes.Equal(self.codeHash, emptyCodeHash)
-}
-
-// Balance returns the account balance
-func (self *StateObject) Balance() *big.Int {
-	return self.balance
-}
-
-// Address returns the address of the contract/account
-func (self *StateObject) Address() common.Address {
-	return self.address
-}
-
-// Code returns the contract code
-func (self *StateObject) Code() []byte {
-	return self.code
-}
-
-// SetCode sets the contract code
-func (self *StateObject) SetCode(hash common.Hash, code []byte) {
-	self.code = code
-	self.codeHash = hash[:]
-	self.dirty = true
-}
-
-// SetNonce sets the account nonce
-func (self *StateObject) SetNonce(nonce uint64) {
-	self.nonce = nonce
-	self.dirty = true
-}
-
-// Nonce returns the account nonce
-func (self *StateObject) Nonce() uint64 {
-	return self.nonce
-}
-
-// ForEachStorage calls a callback function for every key/value pair found
-// in the local storage cache. Note that unlike core/state.StateObject,
-// light.StateObject only returns cached values and doesn't download the
-// entire storage tree.
-func (self *StateObject) ForEachStorage(cb func(key, value common.Hash) bool) {
-	for h, v := range self.storage {
-		cb(h, v)
-	}
-}
-
-// Never called, but must be present to allow StateObject to be used
-// as a vm.Account interface that also satisfies the vm.ContractRef
-// interface. Interfaces are awesome.
-func (self *StateObject) Value() *big.Int {
-	panic("Value on StateObject should never be called")
-}
-
-// Encoding
-
-type extStateObject struct {
-	Nonce    uint64
-	Balance  *big.Int
-	Root     common.Hash
-	CodeHash []byte
-}
-
-// DecodeObject decodes an RLP-encoded state object.
-func DecodeObject(ctx context.Context, stateID *TrieID, address common.Address, odr OdrBackend, data []byte) (*StateObject, error) {
-	var (
-		obj = &StateObject{address: address, odr: odr, storage: make(Storage)}
-		ext extStateObject
-		err error
-	)
-	if err = rlp.DecodeBytes(data, &ext); err != nil {
-		return nil, err
-	}
-	trieID := StorageTrieID(stateID, address, ext.Root)
-	obj.trie = NewLightTrie(trieID, odr, true)
-	if !bytes.Equal(ext.CodeHash, emptyCodeHash) {
-		if obj.code, err = retrieveContractCode(ctx, obj.odr, trieID, common.BytesToHash(ext.CodeHash)); err != nil {
-			return nil, fmt.Errorf("can't find code for hash %x: %v", ext.CodeHash, err)
-		}
-	}
-	obj.nonce = ext.Nonce
-	obj.balance = ext.Balance
-	obj.codeHash = ext.CodeHash
-	return obj, nil
-}