From ef0ebde4f524987e35fd5f76411539152c66d09d Mon Sep 17 00:00:00 2001
From: Matthew Wampler-Doty <matthew.wampler.doty@gmail.com>
Date: Sat, 28 Feb 2015 14:58:37 -0500
Subject: [PATCH] Introducing ethash

---
 .gitignore                 |  1 +
 .travis.yml                |  1 +
 core/block_processor.go    |  5 ++--
 core/chain_makers.go       | 47 +++++++++++++++++++++++---------------
 core/chain_manager_test.go | 46 +++++++++++++++++++++++++------------
 core/transaction_pool.go   |  2 +-
 core/types/block.go        | 15 +++++++++++-
 miner/agent.go             |  4 ++--
 miner/worker.go            |  9 ++++++--
 pow/block.go               | 12 ++++++++--
 pow/dagger/dagger.go       |  4 ++--
 pow/dash/crypto.c          |  5 ----
 pow/dash/crypto.go         | 14 ------------
 pow/ezp/pow.go             |  8 +++----
 pow/pow.go                 |  2 +-
 15 files changed, 105 insertions(+), 70 deletions(-)
 delete mode 100644 pow/dash/crypto.c
 delete mode 100644 pow/dash/crypto.go

diff --git a/.gitignore b/.gitignore
index e2aa4de9569c..0cd8a23c45a4 100644
--- a/.gitignore
+++ b/.gitignore
@@ -6,6 +6,7 @@
 
 /tmp
 */**/*un~
+*/**/*.test
 *un~
 .DS_Store
 */**/.DS_Store
diff --git a/.travis.yml b/.travis.yml
index c4e39b05eaba..5901c9d93eee 100644
--- a/.travis.yml
+++ b/.travis.yml
@@ -5,6 +5,7 @@ before_install:
   - sudo add-apt-repository ppa:beineri/opt-qt541 -y
   - sudo apt-get update -qq
   - sudo apt-get install -yqq libgmp3-dev libreadline6-dev qt54quickcontrols qt54webengine
+  - go get github.com/ethereum/ethash/go-ethash
 install:
   # - go get code.google.com/p/go.tools/cmd/goimports
   # - go get github.com/golang/lint/golint
diff --git a/core/block_processor.go b/core/block_processor.go
index aef53c940417..e91c9c9f7d9a 100644
--- a/core/block_processor.go
+++ b/core/block_processor.go
@@ -7,12 +7,12 @@ import (
 	"sync"
 	"time"
 
+	"github.com/ethereum/ethash/go-ethash"
 	"github.com/ethereum/go-ethereum/core/types"
 	"github.com/ethereum/go-ethereum/ethutil"
 	"github.com/ethereum/go-ethereum/event"
 	"github.com/ethereum/go-ethereum/logger"
 	"github.com/ethereum/go-ethereum/pow"
-	"github.com/ethereum/go-ethereum/pow/ezp"
 	"github.com/ethereum/go-ethereum/state"
 	"gopkg.in/fatih/set.v0"
 )
@@ -50,7 +50,7 @@ func NewBlockProcessor(db ethutil.Database, txpool *TxPool, chainManager *ChainM
 	sm := &BlockProcessor{
 		db:       db,
 		mem:      make(map[string]*big.Int),
-		Pow:      ezp.New(),
+		Pow:      ethash.New(chainManager),
 		bc:       chainManager,
 		eventMux: eventMux,
 		txpool:   txpool,
@@ -255,6 +255,7 @@ func (sm *BlockProcessor) ValidateBlock(block, parent *types.Block) error {
 		return fmt.Errorf("GasLimit check failed for block %v, %v", block.Header().GasLimit, expl)
 	}
 
+	// There can be at most one uncle
 	if len(block.Uncles()) > 1 {
 		return ValidationError("Block can only contain one uncle (contained %v)", len(block.Uncles()))
 	}
diff --git a/core/chain_makers.go b/core/chain_makers.go
index eb43f8aa080e..2c36b892e544 100644
--- a/core/chain_makers.go
+++ b/core/chain_makers.go
@@ -13,21 +13,31 @@ import (
 // So we can generate blocks easily
 type FakePow struct{}
 
-func (f FakePow) Search(block pow.Block, stop <-chan struct{}) []byte { return nil }
-func (f FakePow) Verify(block pow.Block) bool                         { return true }
-func (f FakePow) GetHashrate() int64                                  { return 0 }
-func (f FakePow) Turbo(bool)                                          {}
+func (f FakePow) Search(block pow.Block, stop <-chan struct{}) ([]byte, []byte, []byte) {
+	return nil, nil, nil
+}
+func (f FakePow) Verify(block pow.Block) bool { return true }
+func (f FakePow) GetHashrate() int64          { return 0 }
+func (f FakePow) Turbo(bool)                  {}
+
+// So we can deterministically seed different blockchains
+var (
+	CanonicalSeed = 1
+	ForkSeed      = 2
+)
 
+// Utility functions for making chains on the fly
+// Exposed for sake of testing from other packages (eg. go-ethash)
 func NewBlockFromParent(addr []byte, parent *types.Block) *types.Block {
 	return newBlockFromParent(addr, parent)
 }
 
-func MakeBlock(bman *BlockProcessor, parent *types.Block, i int, db ethutil.Database) *types.Block {
-	return makeBlock(bman, parent, i, db)
+func MakeBlock(bman *BlockProcessor, parent *types.Block, i int, db ethutil.Database, seed int) *types.Block {
+	return makeBlock(bman, parent, i, db, seed)
 }
 
-func MakeChain(bman *BlockProcessor, parent *types.Block, max int, db ethutil.Database) types.Blocks {
-	return makeChain(bman, parent, max, db)
+func MakeChain(bman *BlockProcessor, parent *types.Block, max int, db ethutil.Database, seed int) types.Blocks {
+	return makeChain(bman, parent, max, db, seed)
 }
 
 func NewChainMan(block *types.Block, eventMux *event.TypeMux, db ethutil.Database) *ChainManager {
@@ -42,9 +52,9 @@ func NewCanonical(n int, db ethutil.Database) (*BlockProcessor, error) {
 	return newCanonical(n, db)
 }
 
+// block time is fixed at 10 seconds
 func newBlockFromParent(addr []byte, parent *types.Block) *types.Block {
 	block := types.NewBlock(parent.Hash(), addr, parent.Root(), ethutil.BigPow(2, 32), nil, "")
-
 	block.SetUncles(nil)
 	block.SetTransactions(nil)
 	block.SetReceipts(nil)
@@ -52,6 +62,7 @@ func newBlockFromParent(addr []byte, parent *types.Block) *types.Block {
 	header := block.Header()
 	header.Difficulty = CalcDifficulty(block, parent)
 	header.Number = new(big.Int).Add(parent.Header().Number, ethutil.Big1)
+	header.Time = parent.Header().Time + 10
 	header.GasLimit = CalcGasLimit(parent, block)
 
 	block.Td = parent.Td
@@ -60,8 +71,10 @@ func newBlockFromParent(addr []byte, parent *types.Block) *types.Block {
 }
 
 // Actually make a block by simulating what miner would do
-func makeBlock(bman *BlockProcessor, parent *types.Block, i int, db ethutil.Database) *types.Block {
+// we seed chains by the first byte of the coinbase
+func makeBlock(bman *BlockProcessor, parent *types.Block, i int, db ethutil.Database, seed int) *types.Block {
 	addr := ethutil.LeftPadBytes([]byte{byte(i)}, 20)
+	addr[0] = byte(seed)
 	block := newBlockFromParent(addr, parent)
 	state := state.New(block.Root(), db)
 	cbase := state.GetOrNewStateObject(addr)
@@ -74,11 +87,11 @@ func makeBlock(bman *BlockProcessor, parent *types.Block, i int, db ethutil.Data
 
 // Make a chain with real blocks
 // Runs ProcessWithParent to get proper state roots
-func makeChain(bman *BlockProcessor, parent *types.Block, max int, db ethutil.Database) types.Blocks {
+func makeChain(bman *BlockProcessor, parent *types.Block, max int, db ethutil.Database, seed int) types.Blocks {
 	bman.bc.currentBlock = parent
 	blocks := make(types.Blocks, max)
 	for i := 0; i < max; i++ {
-		block := makeBlock(bman, parent, i, db)
+		block := makeBlock(bman, parent, i, db, seed)
 		td, err := bman.processWithParent(block, parent)
 		if err != nil {
 			fmt.Println("process with parent failed", err)
@@ -87,9 +100,7 @@ func makeChain(bman *BlockProcessor, parent *types.Block, max int, db ethutil.Da
 		block.Td = td
 		blocks[i] = block
 		parent = block
-		fmt.Printf("New Block: %x\n", block.Hash())
 	}
-	fmt.Println("Done making chain")
 	return blocks
 }
 
@@ -113,7 +124,7 @@ func newBlockProcessor(db ethutil.Database, txpool *TxPool, cman *ChainManager,
 	return bman
 }
 
-// Make a new canonical chain by running InsertChain
+// Make a new, deterministic canonical chain by running InsertChain
 // on result of makeChain
 func newCanonical(n int, db ethutil.Database) (*BlockProcessor, error) {
 	eventMux := &event.TypeMux{}
@@ -125,7 +136,7 @@ func newCanonical(n int, db ethutil.Database) (*BlockProcessor, error) {
 	if n == 0 {
 		return bman, nil
 	}
-	lchain := makeChain(bman, parent, n, db)
-	bman.bc.InsertChain(lchain)
-	return bman, nil
+	lchain := makeChain(bman, parent, n, db, CanonicalSeed)
+	err := bman.bc.InsertChain(lchain)
+	return bman, err
 }
diff --git a/core/chain_manager_test.go b/core/chain_manager_test.go
index e6614212f2c7..b562b677d280 100644
--- a/core/chain_manager_test.go
+++ b/core/chain_manager_test.go
@@ -24,12 +24,6 @@ func init() {
 
 // Test fork of length N starting from block i
 func testFork(t *testing.T, bman *BlockProcessor, i, N int, f func(td1, td2 *big.Int)) {
-	fmt.Println("Testing Fork!")
-	var b *types.Block = nil
-	if i > 0 {
-		b = bman.bc.GetBlockByNumber(uint64(i))
-	}
-	_ = b
 	// switch databases to process the new chain
 	db, err := ethdb.NewMemDatabase()
 	if err != nil {
@@ -40,13 +34,25 @@ func testFork(t *testing.T, bman *BlockProcessor, i, N int, f func(td1, td2 *big
 	if err != nil {
 		t.Fatal("could not make new canonical in testFork", err)
 	}
+	// asert the bmans have the same block at i
+	bi1 := bman.bc.GetBlockByNumber(uint64(i)).Hash()
+	bi2 := bman2.bc.GetBlockByNumber(uint64(i)).Hash()
+	if bytes.Compare(bi1, bi2) != 0 {
+		t.Fatal("chains do not have the same hash at height", i)
+	}
+
 	bman2.bc.SetProcessor(bman2)
 
+	// extend the fork
 	parent := bman2.bc.CurrentBlock()
-	chainB := makeChain(bman2, parent, N, db)
-	bman2.bc.InsertChain(chainB)
+	chainB := makeChain(bman2, parent, N, db, ForkSeed)
+	err = bman2.bc.InsertChain(chainB)
+	if err != nil {
+		t.Fatal("Insert chain error for fork:", err)
+	}
 
 	tdpre := bman.bc.Td()
+	// Test the fork's blocks on the original chain
 	td, err := testChain(chainB, bman)
 	if err != nil {
 		t.Fatal("expected chainB not to give errors:", err)
@@ -55,6 +61,14 @@ func testFork(t *testing.T, bman *BlockProcessor, i, N int, f func(td1, td2 *big
 	f(tdpre, td)
 }
 
+func printChain(bc *ChainManager) {
+	for i := bc.CurrentBlock().Number().Uint64(); i > 0; i-- {
+		b := bc.GetBlockByNumber(uint64(i))
+		fmt.Printf("\t%x\n", b.Hash())
+	}
+}
+
+// process blocks against a chain
 func testChain(chainB types.Blocks, bman *BlockProcessor) (*big.Int, error) {
 	td := new(big.Int)
 	for _, block := range chainB {
@@ -102,12 +116,13 @@ func insertChain(done chan bool, chainMan *ChainManager, chain types.Blocks, t *
 }
 
 func TestExtendCanonical(t *testing.T) {
+	CanonicalLength := 5
 	db, err := ethdb.NewMemDatabase()
 	if err != nil {
 		t.Fatal("Failed to create db:", err)
 	}
 	// make first chain starting from genesis
-	bman, err := newCanonical(5, db)
+	bman, err := newCanonical(CanonicalLength, db)
 	if err != nil {
 		t.Fatal("Could not make new canonical chain:", err)
 	}
@@ -116,11 +131,11 @@ func TestExtendCanonical(t *testing.T) {
 			t.Error("expected chainB to have higher difficulty. Got", td2, "expected more than", td1)
 		}
 	}
-	// Start fork from current height (5)
-	testFork(t, bman, 5, 1, f)
-	testFork(t, bman, 5, 2, f)
-	testFork(t, bman, 5, 5, f)
-	testFork(t, bman, 5, 10, f)
+	// Start fork from current height (CanonicalLength)
+	testFork(t, bman, CanonicalLength, 1, f)
+	testFork(t, bman, CanonicalLength, 2, f)
+	testFork(t, bman, CanonicalLength, 5, f)
+	testFork(t, bman, CanonicalLength, 10, f)
 }
 
 func TestShorterFork(t *testing.T) {
@@ -189,6 +204,7 @@ func TestEqualFork(t *testing.T) {
 	}
 	// Sum of numbers must be equal to 10
 	// for this to be an equal fork
+	testFork(t, bman, 0, 10, f)
 	testFork(t, bman, 1, 9, f)
 	testFork(t, bman, 2, 8, f)
 	testFork(t, bman, 5, 5, f)
@@ -215,7 +231,7 @@ func TestBrokenChain(t *testing.T) {
 	}
 	bman2.bc.SetProcessor(bman2)
 	parent := bman2.bc.CurrentBlock()
-	chainB := makeChain(bman2, parent, 5, db2)
+	chainB := makeChain(bman2, parent, 5, db2, ForkSeed)
 	chainB = chainB[1:]
 	_, err = testChain(chainB, bman)
 	if err == nil {
diff --git a/core/transaction_pool.go b/core/transaction_pool.go
index 860f57dc3096..bd377f67900f 100644
--- a/core/transaction_pool.go
+++ b/core/transaction_pool.go
@@ -121,7 +121,7 @@ func (self *TxPool) add(tx *types.Transaction) error {
 	if len(tx.From()) > 0 {
 		from = ethutil.Bytes2Hex(tx.From()[:4])
 	} else {
-		from = "INVALID"
+		return errors.New(fmt.Sprintf("FROM ADDRESS MUST BE POSITIVE (was %v)", tx.From()))
 	}
 	txplogger.Debugf("(t) %x => %s (%v) %x\n", from, to, tx.Value, tx.Hash())
 
diff --git a/core/types/block.go b/core/types/block.go
index f637b5c3b8e4..a37038f73931 100644
--- a/core/types/block.go
+++ b/core/types/block.go
@@ -48,7 +48,20 @@ type Header struct {
 }
 
 func (self *Header) rlpData(withNonce bool) []interface{} {
-	fields := []interface{}{self.ParentHash, self.UncleHash, self.Coinbase, self.Root, self.TxHash, self.ReceiptHash, self.Bloom, self.Difficulty, self.Number, self.GasLimit, self.GasUsed, self.Time, self.Extra}
+	fields := []interface{}{
+		self.ParentHash,
+		self.UncleHash,
+		self.Coinbase,
+		self.Root,
+		self.TxHash,
+		self.ReceiptHash,
+		self.Bloom,
+		self.Difficulty,
+		self.Number,
+		self.GasLimit,
+		self.GasUsed,
+		self.Time,
+		self.Extra}
 	if withNonce {
 		fields = append(fields, self.Nonce, self.MixDigest, self.SeedHash)
 	}
diff --git a/miner/agent.go b/miner/agent.go
index 9046f5d5ab1c..5b2bfdb06ca9 100644
--- a/miner/agent.go
+++ b/miner/agent.go
@@ -69,8 +69,8 @@ done:
 
 func (self *CpuMiner) mine(block *types.Block) {
 	minerlogger.Infof("(re)started agent[%d]. mining...\n", self.index)
-	nonce := self.pow.Search(block, self.quitCurrentOp)
+	nonce, mixDigest, seedHash := self.pow.Search(block, self.quitCurrentOp)
 	if nonce != nil {
-		self.returnCh <- Work{block.Number().Uint64(), nonce}
+		self.returnCh <- Work{block.Number().Uint64(), nonce, mixDigest, seedHash}
 	}
 }
diff --git a/miner/worker.go b/miner/worker.go
index 4f0909302c55..201367fdf9fb 100644
--- a/miner/worker.go
+++ b/miner/worker.go
@@ -42,8 +42,10 @@ func env(block *types.Block, eth core.Backend) *environment {
 }
 
 type Work struct {
-	Number uint64
-	Nonce  []byte
+	Number    uint64
+	Nonce     []byte
+	MixDigest []byte
+	SeedHash  []byte
 }
 
 type Agent interface {
@@ -138,9 +140,12 @@ out:
 func (self *worker) wait() {
 	for {
 		for work := range self.recv {
+			// Someone Successfully Mined!
 			block := self.current.block
 			if block.Number().Uint64() == work.Number && block.Nonce() == nil {
 				self.current.block.Header().Nonce = work.Nonce
+				self.current.block.Header().MixDigest = work.MixDigest
+				self.current.block.Header().SeedHash = work.SeedHash
 
 				if err := self.chain.InsertChain(types.Blocks{self.current.block}); err == nil {
 					self.mux.Post(core.NewMinedBlockEvent{self.current.block})
diff --git a/pow/block.go b/pow/block.go
index 129f96fd3218..eb07bc86e7b7 100644
--- a/pow/block.go
+++ b/pow/block.go
@@ -1,12 +1,20 @@
 package pow
 
-import "math/big"
+import (
+	"github.com/ethereum/go-ethereum/core/types"
+	"math/big"
+)
 
 type Block interface {
 	Difficulty() *big.Int
 	HashNoNonce() []byte
 	Nonce() []byte
-	Number() *big.Int
 	MixDigest() []byte
 	SeedHash() []byte
+	NumberU64() uint64
+}
+
+type ChainManager interface {
+	GetBlockByNumber(uint64) *types.Block
+	CurrentBlock() *types.Block
 }
diff --git a/pow/dagger/dagger.go b/pow/dagger/dagger.go
index 310f8abdddfc..3da7683d564b 100644
--- a/pow/dagger/dagger.go
+++ b/pow/dagger/dagger.go
@@ -44,7 +44,7 @@ func (dag *Dagger) Find(obj *big.Int, resChan chan int64) {
 	resChan <- 0
 }
 
-func (dag *Dagger) Search(hash, diff *big.Int) *big.Int {
+func (dag *Dagger) Search(hash, diff *big.Int) ([]byte, []byte, []byte) {
 	// TODO fix multi threading. Somehow it results in the wrong nonce
 	amountOfRoutines := 1
 
@@ -69,7 +69,7 @@ func (dag *Dagger) Search(hash, diff *big.Int) *big.Int {
 		}
 	}
 
-	return big.NewInt(res)
+	return big.NewInt(res).Bytes(), nil, nil
 }
 
 func (dag *Dagger) Verify(hash, diff, nonce *big.Int) bool {
diff --git a/pow/dash/crypto.c b/pow/dash/crypto.c
deleted file mode 100644
index 9c5a62d16aaf..000000000000
--- a/pow/dash/crypto.c
+++ /dev/null
@@ -1,5 +0,0 @@
-extern char *Sha3(char *, int);
-char *sha3_cgo(char *data, int l)
-{
-	return Sha3(data, l);
-}
diff --git a/pow/dash/crypto.go b/pow/dash/crypto.go
deleted file mode 100644
index 0644a54ae5e6..000000000000
--- a/pow/dash/crypto.go
+++ /dev/null
@@ -1,14 +0,0 @@
-package dash
-
-/*
-char *sha3_cgo(char *, int); // Forward declaration
-*/
-import "C"
-import (
-	"github.com/ethereum/go-ethereum/crypto"
-)
-
-//export Sha3
-func Sha3(data []byte, l int) []byte {
-	return crypto.Sha3(data)
-}
diff --git a/pow/ezp/pow.go b/pow/ezp/pow.go
index 8808d7ce0902..49854c3d0276 100644
--- a/pow/ezp/pow.go
+++ b/pow/ezp/pow.go
@@ -32,7 +32,7 @@ func (pow *EasyPow) Turbo(on bool) {
 	pow.turbo = on
 }
 
-func (pow *EasyPow) Search(block pow.Block, stop <-chan struct{}) []byte {
+func (pow *EasyPow) Search(block pow.Block, stop <-chan struct{}) ([]byte, []byte, []byte) {
 	r := rand.New(rand.NewSource(time.Now().UnixNano()))
 	hash := block.HashNoNonce()
 	diff := block.Difficulty()
@@ -57,7 +57,7 @@ empty:
 	for {
 		select {
 		case <-stop:
-			return nil
+			return nil, nil, nil
 		default:
 			i++
 
@@ -67,7 +67,7 @@ empty:
 
 			sha := crypto.Sha3(big.NewInt(r.Int63()).Bytes())
 			if verify(hash, diff, sha) {
-				return sha
+				return sha, nil, nil
 			}
 		}
 
@@ -75,8 +75,6 @@ empty:
 			time.Sleep(20 * time.Microsecond)
 		}
 	}
-
-	return nil
 }
 
 func (pow *EasyPow) Verify(block pow.Block) bool {
diff --git a/pow/pow.go b/pow/pow.go
index c94ee40ba454..11aecbd6bc9d 100644
--- a/pow/pow.go
+++ b/pow/pow.go
@@ -1,7 +1,7 @@
 package pow
 
 type PoW interface {
-	Search(block Block, stop <-chan struct{}) []byte
+	Search(block Block, stop <-chan struct{}) ([]byte, []byte, []byte)
 	Verify(block Block) bool
 	GetHashrate() int64
 	Turbo(bool)