path: root/core/state/statedb.go

// Copyright 2014 The go-ethereum Authors
// This file is part of go-ethereum.
//
// go-ethereum 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.
//
// go-ethereum 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 go-ethereum.  If not, see <http://www.gnu.org/licenses/>.

// Package state provides a caching layer atop the Ethereum state trie.
package state

import (
    "bytes"
    "math/big"

    "github.com/ethereum/go-ethereum/common"
    "github.com/ethereum/go-ethereum/logger"
    "github.com/ethereum/go-ethereum/logger/glog"
    "github.com/ethereum/go-ethereum/trie"
)

// StateDBs within the ethereum protocol are used to store anything
// within the merkle trie. StateDBs take care of caching and storing
// nested states. It's the general query interface to retrieve:
// * Contracts
// * Accounts
type StateDB struct {
    db   common.Database
    trie *trie.SecureTrie
    root common.Hash

    stateObjects map[string]*StateObject

    refund *big.Int

    thash, bhash common.Hash
    txIndex      int
    logs         map[common.Hash]Logs
}

// Create a new state from a given trie
func New(root common.Hash, db common.Database) *StateDB {
    trie := trie.NewSecure(root[:], db)
    return &StateDB{root: root, db: db, trie: trie, stateObjects: make(map[string]*StateObject), refund: new(big.Int), logs: make(map[common.Hash]Logs)}
}

func (self *StateDB) PrintRoot() {
    self.trie.Trie.PrintRoot()
}

func (self *StateDB) StartRecord(thash, bhash common.Hash, ti int) {
    self.thash = thash
    self.bhash = bhash
    self.txIndex = ti
}

func (self *StateDB) AddLog(log *Log) {
    log.TxHash = self.thash
    log.BlockHash = self.bhash
    log.TxIndex = uint(self.txIndex)
    self.logs[self.thash] = append(self.logs[self.thash], log)
}

func (self *StateDB) GetLogs(hash common.Hash) Logs {
    return self.logs[hash]
}

func (self *StateDB) Logs() Logs {
    var logs Logs
    for _, lgs := range self.logs {
        logs = append(logs, lgs...)
    }
    return logs
}

func (self *StateDB) Refund(gas *big.Int) {
    self.refund.Add(self.refund, gas)
}

/*
 * GETTERS
 */

func (self *StateDB) HasAccount(addr common.Address) bool {
    return self.GetStateObject(addr) != nil
}

// Retrieve the balance from the given address or 0 if object not found
func (self *StateDB) GetBalance(addr common.Address) *big.Int {
    stateObject := self.GetStateObject(addr)
    if stateObject != nil {
        return stateObject.balance
    }

    return common.Big0
}

func (self *StateDB) GetNonce(addr common.Address) uint64 {
    stateObject := self.GetStateObject(addr)
    if stateObject != nil {
        return stateObject.nonce
    }

    return 0
}

func (self *StateDB) GetCode(addr common.Address) []byte {
    stateObject := self.GetStateObject(addr)
    if stateObject != nil {
        return stateObject.code
    }

    return nil
}

func (self *StateDB) GetState(a common.Address, b common.Hash) common.Hash {
    stateObject := self.GetStateObject(a)
    if stateObject != nil {
        return stateObject.GetState(b)
    }

    return common.Hash{}
}

func (self *StateDB) IsDeleted(addr common.Address) bool {
    stateObject := self.GetStateObject(addr)
    if stateObject != nil {
        return stateObject.remove
    }
    return false
}

/*
 * SETTERS
 */

func (self *StateDB) AddBalance(addr common.Address, amount *big.Int) {
    stateObject := self.GetOrNewStateObject(addr)
    if stateObject != nil {
        stateObject.AddBalance(amount)
    }
}

func (self *StateDB) SetNonce(addr common.Address, nonce uint64) {
    stateObject := self.GetOrNewStateObject(addr)
    if stateObject != nil {
        stateObject.SetNonce(nonce)
    }
}

func (self *StateDB) SetCode(addr common.Address, code []byte) {
    stateObject := self.GetOrNewStateObject(addr)
    if stateObject != nil {
        stateObject.SetCode(code)
    }
}

func (self *StateDB) SetState(addr common.Address, key common.Hash, value common.Hash) {
    stateObject := self.GetOrNewStateObject(addr)
    if stateObject != nil {
        stateObject.SetState(key, value)
    }
}

func (self *StateDB) Delete(addr common.Address) bool {
    stateObject := self.GetStateObject(addr)
    if stateObject != nil {
        stateObject.MarkForDeletion()
        stateObject.balance = new(big.Int)

        return true
    }

    return false
}

//
// Setting, updating & deleting state object methods
//

// Update the given state object and apply it to state trie
func (self *StateDB) UpdateStateObject(stateObject *StateObject) {
    //addr := stateObject.Address()

    if len(stateObject.CodeHash()) > 0 {
        self.db.Put(stateObject.CodeHash(), stateObject.code)
    }

    addr := stateObject.Address()
    self.trie.Update(addr[:], stateObject.RlpEncode())
}

// Delete the given state object and delete it from the state trie
func (self *StateDB) DeleteStateObject(stateObject *StateObject) {
    addr := stateObject.Address()
    self.trie.Delete(addr[:])

    //delete(self.stateObjects, addr.Str())
}

// Retrieve a state object given my the address. Nil if not found
func (self *StateDB) GetStateObject(addr common.Address) *StateObject {
    //addr = common.Address(addr)

    stateObject := self.stateObjects[addr.Str()]
    if stateObject != nil {
        return stateObject
    }

    data := self.trie.Get(addr[:])
    if len(data) == 0 {
        return nil
    }

    stateObject = NewStateObjectFromBytes(addr, []byte(data), self.db)
    self.SetStateObject(stateObject)

    return stateObject
}

func (self *StateDB) SetStateObject(object *StateObject) {
    self.stateObjects[object.Address().Str()] = object
}

// Retrieve a state object or create a new state object if nil
func (self *StateDB) GetOrNewStateObject(addr common.Address) *StateObject {
    stateObject := self.GetStateObject(addr)
    if stateObject == nil {
        stateObject = self.CreateAccount(addr)
    }

    return stateObject
}

// NewStateObject create a state object whether it exist in the trie or not
func (self *StateDB) newStateObject(addr common.Address) *StateObject {
    if glog.V(logger.Core) {
        glog.Infof("(+) %x\n", addr)
    }

    stateObject := NewStateObject(addr, self.db)
    self.stateObjects[addr.Str()] = stateObject

    return stateObject
}

// Creates creates a new state object and takes ownership. This is different from "NewStateObject"
func (self *StateDB) CreateAccount(addr common.Address) *StateObject {
    // Get previous (if any)
    so := self.GetStateObject(addr)
    // Create a new one
    newSo := self.newStateObject(addr)

    // If it existed set the balance to the new account
    if so != nil {
        newSo.balance = so.balance
    }

    return newSo
}

//
// Setting, copying of the state methods
//

func (s *StateDB) Cmp(other *StateDB) bool {
    return bytes.Equal(s.trie.Root(), other.trie.Root())
}

func (self *StateDB) Copy() *StateDB {
    state := New(common.Hash{}, self.db)
    state.trie = self.trie
    for k, stateObject := range self.stateObjects {
        state.stateObjects[k] = stateObject.Copy()
    }

    state.refund.Set(self.refund)

    for hash, logs := range self.logs {
        state.logs[hash] = make(Logs, len(logs))
        copy(state.logs[hash], logs)
    }

    return state
}

func (self *StateDB) Set(state *StateDB) {
    self.trie = state.trie
    self.stateObjects = state.stateObjects

    self.refund = state.refund
    self.logs = state.logs
}

func (s *StateDB) Root() common.Hash {
    return common.BytesToHash(s.trie.Root())
}

func (s *StateDB) Trie() *trie.SecureTrie {
    return s.trie
}

// Resets the trie and all siblings
func (s *StateDB) Reset() {
    s.trie.Reset()

    // Reset all nested states
    for _, stateObject := range s.stateObjects {
        stateObject.Reset()
    }

    s.Empty()
}

// Syncs the trie and all siblings
func (s *StateDB) Sync() {
    // Sync all nested states
    for _, stateObject := range s.stateObjects {
        stateObject.trie.Commit()
    }

    s.trie.Commit()

    s.Empty()
}

func (self *StateDB) Empty() {
    self.stateObjects = make(map[string]*StateObject)
    self.refund = new(big.Int)
}

func (self *StateDB) Refunds() *big.Int {
    return self.refund
}

// SyncIntermediate updates the intermediate state and all mid steps
func (self *StateDB) SyncIntermediate() {
    self.refund = new(big.Int)

    for _, stateObject := range self.stateObjects {
        if stateObject.dirty {
            if stateObject.remove {
                self.DeleteStateObject(stateObject)
            } else {
                stateObject.Update()

                self.UpdateStateObject(stateObject)
            }
            stateObject.dirty = false
        }
    }
}

// SyncObjects syncs the changed objects to the trie
func (self *StateDB) SyncObjects() {
    self.trie = trie.NewSecure(self.root[:], self.db)

    self.refund = new(big.Int)

    for _, stateObject := range self.stateObjects {
        if stateObject.remove {
            self.DeleteStateObject(stateObject)
        } else {
            stateObject.Update()

            self.UpdateStateObject(stateObject)
        }
        stateObject.dirty = false
    }
}

// Debug stuff
func (self *StateDB) CreateOutputForDiff() {
    for _, stateObject := range self.stateObjects {
        stateObject.CreateOutputForDiff()
    }
}