go-ethereum/block_manager.go

509 lines
12 KiB
Go

package main
import (
"bytes"
"errors"
"fmt"
"github.com/ethereum/ethutil-go"
"github.com/obscuren/secp256k1-go"
"log"
"math"
"math/big"
)
type BlockChain struct {
// Last block
LastBlock *ethutil.Block
// The famous, the fabulous Mister GENESIIIIIIS (block)
genesisBlock *ethutil.Block
// Last known total difficulty
TD *big.Int
}
func NewBlockChain() *BlockChain {
bc := &BlockChain{}
bc.genesisBlock = ethutil.NewBlock(ethutil.Encode(ethutil.Genesis))
// Set the last know difficulty (might be 0x0 as initial value, Genesis)
bc.TD = ethutil.BigD(ethutil.Config.Db.LastKnownTD())
// TODO get last block from the database
bc.LastBlock = bc.genesisBlock
return bc
}
func (bc *BlockChain) HasBlock(hash string) bool {
data, _ := ethutil.Config.Db.Get([]byte(hash))
return len(data) != 0
}
func (bc *BlockChain) GenesisBlock() *ethutil.Block {
return bc.genesisBlock
}
type BlockManager struct {
// The block chain :)
bc *BlockChain
// Last known block number
LastBlockNumber *big.Int
// Stack for processing contracts
stack *Stack
// non-persistent key/value memory storage
mem map[string]string
}
func NewBlockManager() *BlockManager {
bm := &BlockManager{
bc: NewBlockChain(),
stack: NewStack(),
mem: make(map[string]string),
}
// Set the last known block number based on the blockchains last
// block
bm.LastBlockNumber = bm.BlockInfo(bm.bc.LastBlock).Number
return bm
}
// Process a block.
func (bm *BlockManager) ProcessBlock(block *ethutil.Block) error {
// Block validation
if err := bm.ValidateBlock(block); err != nil {
return err
}
// I'm not sure, but I don't know if there should be thrown
// any errors at this time.
if err := bm.AccumelateRewards(block); err != nil {
return err
}
// Get the tx count. Used to create enough channels to 'join' the go routines
txCount := len(block.Transactions())
// Locking channel. When it has been fully buffered this method will return
lockChan := make(chan bool, txCount)
// Process each transaction/contract
for _, tx := range block.Transactions() {
// If there's no recipient, it's a contract
if tx.IsContract() {
go bm.ProcessContract(tx, block, lockChan)
} else {
// "finish" tx which isn't a contract
lockChan <- true
}
}
// Wait for all Tx to finish processing
for i := 0; i < txCount; i++ {
<-lockChan
}
// Calculate the new total difficulty and sync back to the db
if bm.CalculateTD(block) {
ethutil.Config.Db.Put(block.Hash(), block.RlpEncode())
bm.bc.LastBlock = block
}
return nil
}
// Unexported method for writing extra non-essential block info to the db
func (bm *BlockManager) writeBlockInfo(block *ethutil.Block) {
bi := ethutil.BlockInfo{Number: bm.LastBlockNumber.Add(bm.LastBlockNumber, big.NewInt(1))}
// For now we use the block hash with the words "info" appended as key
ethutil.Config.Db.Put(append(block.Hash(), []byte("Info")...), bi.RlpEncode())
}
func (bm *BlockManager) BlockInfo(block *ethutil.Block) ethutil.BlockInfo {
bi := ethutil.BlockInfo{}
data, _ := ethutil.Config.Db.Get(append(block.Hash(), []byte("Info")...))
bi.RlpDecode(data)
return bi
}
func (bm *BlockManager) CalculateTD(block *ethutil.Block) bool {
uncleDiff := new(big.Int)
for _, uncle := range block.Uncles {
uncleDiff = uncleDiff.Add(uncleDiff, uncle.Difficulty)
}
// TD(genesis_block) = 0 and TD(B) = TD(B.parent) + sum(u.difficulty for u in B.uncles) + B.difficulty
td := new(big.Int)
td = td.Add(bm.bc.TD, uncleDiff)
td = td.Add(td, block.Difficulty)
// The new TD will only be accepted if the new difficulty is
// is greater than the previous.
if td.Cmp(bm.bc.TD) > 0 {
bm.bc.LastBlock = block
// Set the new total difficulty back to the block chain
bm.bc.TD = td
if Debug {
log.Println("TD(block) =", td)
}
return true
}
return false
}
// Validates the current block. Returns an error if the block was invalid,
// an uncle or anything that isn't on the current block chain.
// Validation validates easy over difficult (dagger takes longer time = difficult)
func (bm *BlockManager) ValidateBlock(block *ethutil.Block) error {
// TODO
// 2. Check if the difficulty is correct
// Check if we have the parent hash, if it isn't known we discard it
// Reasons might be catching up or simply an invalid block
if bm.bc.LastBlock != nil && block.PrevHash == "" &&
!bm.bc.HasBlock(block.PrevHash) {
return errors.New("Block's parent unknown")
}
// Check each uncle's previous hash. In order for it to be valid
// is if it has the same block hash as the current
for _, uncle := range block.Uncles {
if uncle.PrevHash != block.PrevHash {
if Debug {
log.Printf("Uncle prvhash mismatch %x %x\n", block.PrevHash, uncle.PrevHash)
}
return errors.New("Mismatching Prvhash from uncle")
}
}
// Verify the nonce of the block. Return an error if it's not valid
if bm.bc.LastBlock != nil && block.PrevHash == "" &&
!DaggerVerify(ethutil.BigD(block.Hash()), block.Difficulty, block.Nonce) {
return errors.New("Block's nonce is invalid")
}
log.Println("Block validation PASSED")
return nil
}
func (bm *BlockManager) AccumelateRewards(block *ethutil.Block) error {
// Get the coinbase rlp data
d := block.State().Get(block.Coinbase)
ether := ethutil.NewEtherFromData([]byte(d))
// Reward amount of ether to the coinbase address
ether.AddFee(ethutil.CalculateBlockReward(block, len(block.Uncles)))
block.State().Update(block.Coinbase, string(ether.RlpEncode()))
// TODO Reward each uncle
return nil
}
func (bm *BlockManager) ProcessContract(tx *ethutil.Transaction, block *ethutil.Block, lockChan chan bool) {
// Recovering function in case the VM had any errors
defer func() {
if r := recover(); r != nil {
fmt.Println("Recovered from VM execution with err =", r)
// Let the channel know where done even though it failed (so the execution may resume normally)
lockChan <- true
}
}()
// Process contract
bm.ProcContract(tx, block, func(opType OpType) bool {
// TODO turn on once big ints are in place
//if !block.PayFee(tx.Hash(), StepFee.Uint64()) {
// return false
//}
return true // Continue
})
// Broadcast we're done
lockChan <- true
}
// Contract evaluation is done here.
func (bm *BlockManager) ProcContract(tx *ethutil.Transaction, block *ethutil.Block, cb TxCallback) {
// Instruction pointer
pc := 0
blockInfo := bm.BlockInfo(block)
contract := block.GetContract(tx.Hash())
if contract == nil {
fmt.Println("Contract not found")
return
}
Pow256 := ethutil.BigPow(2, 256)
//fmt.Printf("# op arg\n")
out:
for {
// The base big int for all calculations. Use this for any results.
base := new(big.Int)
// XXX Should Instr return big int slice instead of string slice?
// Get the next instruction from the contract
//op, _, _ := Instr(contract.state.Get(string(Encode(uint32(pc)))))
nb := ethutil.NumberToBytes(uint64(pc), 32)
o, _, _ := ethutil.Instr(contract.State().Get(string(nb)))
op := OpCode(o)
if !cb(0) {
break
}
if Debug {
//fmt.Printf("%-3d %-4s\n", pc, op.String())
}
switch op {
case oSTOP:
break out
case oADD:
x, y := bm.stack.Popn()
// (x + y) % 2 ** 256
base.Add(x, y)
base.Mod(base, Pow256)
// Pop result back on the stack
bm.stack.Push(base.String())
case oSUB:
x, y := bm.stack.Popn()
// (x - y) % 2 ** 256
base.Sub(x, y)
base.Mod(base, Pow256)
// Pop result back on the stack
bm.stack.Push(base.String())
case oMUL:
x, y := bm.stack.Popn()
// (x * y) % 2 ** 256
base.Mul(x, y)
base.Mod(base, Pow256)
// Pop result back on the stack
bm.stack.Push(base.String())
case oDIV:
x, y := bm.stack.Popn()
// floor(x / y)
base.Div(x, y)
// Pop result back on the stack
bm.stack.Push(base.String())
case oSDIV:
x, y := bm.stack.Popn()
// n > 2**255
if x.Cmp(Pow256) > 0 {
x.Sub(Pow256, x)
}
if y.Cmp(Pow256) > 0 {
y.Sub(Pow256, y)
}
z := new(big.Int)
z.Div(x, y)
if z.Cmp(Pow256) > 0 {
z.Sub(Pow256, z)
}
// Push result on to the stack
bm.stack.Push(z.String())
case oMOD:
x, y := bm.stack.Popn()
base.Mod(x, y)
bm.stack.Push(base.String())
case oSMOD:
x, y := bm.stack.Popn()
// n > 2**255
if x.Cmp(Pow256) > 0 {
x.Sub(Pow256, x)
}
if y.Cmp(Pow256) > 0 {
y.Sub(Pow256, y)
}
z := new(big.Int)
z.Mod(x, y)
if z.Cmp(Pow256) > 0 {
z.Sub(Pow256, z)
}
// Push result on to the stack
bm.stack.Push(z.String())
case oEXP:
x, y := bm.stack.Popn()
base.Exp(x, y, Pow256)
bm.stack.Push(base.String())
case oNEG:
base.Sub(Pow256, ethutil.Big(bm.stack.Pop()))
bm.stack.Push(base.String())
case oLT:
x, y := bm.stack.Popn()
// x < y
if x.Cmp(y) < 0 {
bm.stack.Push("1")
} else {
bm.stack.Push("0")
}
case oLE:
x, y := bm.stack.Popn()
// x <= y
if x.Cmp(y) < 1 {
bm.stack.Push("1")
} else {
bm.stack.Push("0")
}
case oGT:
x, y := bm.stack.Popn()
// x > y
if x.Cmp(y) > 0 {
bm.stack.Push("1")
} else {
bm.stack.Push("0")
}
case oGE:
x, y := bm.stack.Popn()
// x >= y
if x.Cmp(y) > -1 {
bm.stack.Push("1")
} else {
bm.stack.Push("0")
}
case oNOT:
x, y := bm.stack.Popn()
// x != y
if x.Cmp(y) != 0 {
bm.stack.Push("1")
} else {
bm.stack.Push("0")
}
// Please note that the following code contains some
// ugly string casting. This will have to change to big
// ints. TODO :)
case oMYADDRESS:
bm.stack.Push(string(tx.Hash()))
case oTXSENDER:
bm.stack.Push(string(tx.Sender()))
case oTXVALUE:
bm.stack.Push(tx.Value.String())
case oTXDATAN:
bm.stack.Push(big.NewInt(int64(len(tx.Data))).String())
case oTXDATA:
v := ethutil.Big(bm.stack.Pop())
// v >= len(data)
if v.Cmp(big.NewInt(int64(len(tx.Data)))) >= 0 {
//I know this will change. It makes no
//sense. Read comment above
bm.stack.Push(ethutil.Big("0").String())
} else {
bm.stack.Push(ethutil.Big(tx.Data[v.Uint64()]).String())
}
case oBLK_PREVHASH:
bm.stack.Push(string(block.PrevHash))
case oBLK_COINBASE:
bm.stack.Push(block.Coinbase)
case oBLK_TIMESTAMP:
bm.stack.Push(big.NewInt(block.Time).String())
case oBLK_NUMBER:
bm.stack.Push(blockInfo.Number.String())
case oBLK_DIFFICULTY:
bm.stack.Push(block.Difficulty.String())
case oBASEFEE:
// e = 10^21
e := big.NewInt(0).Exp(big.NewInt(10), big.NewInt(21), big.NewInt(0))
d := new(big.Rat)
d.SetInt(block.Difficulty)
c := new(big.Rat)
c.SetFloat64(0.5)
// d = diff / 0.5
d.Quo(d, c)
// base = floor(d)
base.Div(d.Num(), d.Denom())
x := new(big.Int)
x.Div(e, base)
// x = floor(10^21 / floor(diff^0.5))
bm.stack.Push(x.String())
case oSHA256, oRIPEMD160:
// This is probably save
// ceil(pop / 32)
length := int(math.Ceil(float64(ethutil.Big(bm.stack.Pop()).Uint64()) / 32.0))
// New buffer which will contain the concatenated popped items
data := new(bytes.Buffer)
for i := 0; i < length; i++ {
// Encode the number to bytes and have it 32bytes long
num := ethutil.NumberToBytes(ethutil.Big(bm.stack.Pop()).Bytes(), 256)
data.WriteString(string(num))
}
if op == oSHA256 {
bm.stack.Push(base.SetBytes(ethutil.Sha256Bin(data.Bytes())).String())
} else {
bm.stack.Push(base.SetBytes(ethutil.Ripemd160(data.Bytes())).String())
}
case oECMUL:
y := bm.stack.Pop()
x := bm.stack.Pop()
//n := bm.stack.Pop()
//if ethutil.Big(x).Cmp(ethutil.Big(y)) {
data := new(bytes.Buffer)
data.WriteString(x)
data.WriteString(y)
if secp256k1.VerifyPubkeyValidity(data.Bytes()) == 1 {
// TODO
} else {
// Invalid, push infinity
bm.stack.Push("0")
bm.stack.Push("0")
}
//} else {
// // Invalid, push infinity
// bm.stack.Push("0")
// bm.stack.Push("0")
//}
case oECADD:
case oECSIGN:
case oECRECOVER:
case oECVALID:
case oSHA3:
case oPUSH:
// Get the next entry and pushes the value on the stack
pc++
bm.stack.Push(contract.State().Get(string(ethutil.NumberToBytes(uint64(pc), 32))))
case oPOP:
// Pop current value of the stack
bm.stack.Pop()
case oDUP:
case oSWAP:
case oMLOAD:
case oMSTORE:
case oSLOAD:
case oSSTORE:
case oJMP:
case oJMPI:
case oIND:
case oEXTRO:
case oBALANCE:
case oMKTX:
case oSUICIDE:
/*
case oLOAD:
// Load instruction X on the stack
i, _ := strconv.Atoi(bm.stack.Pop())
bm.stack.Push(contract.State().Get(string(ethutil.NumberToBytes(uint64(i), 32))))
*/
}
pc++
}
bm.stack.Print()
}