1 files changed, 296 insertions, 0 deletions
diff --git a/Godeps/_workspace/src/github.com/ethereum/ethash/ethash.go b/Godeps/_workspace/src/github.com/ethereum/ethash/ethash.go
new file mode 100644
index 000000000..32d3f0264
--- /dev/null
+++ b/Godeps/_workspace/src/github.com/ethereum/ethash/ethash.go
@@ -0,0 +1,296 @@
+package ethash
+
+/*
+#cgo CFLAGS: -std=gnu99 -Wall
+#include "libethash/ethash.h"
+#include "libethash/util.c"
+#include "libethash/internal.c"
+#include "libethash/sha3.c"
+*/
+import "C"
+
+import (
+	"bytes"
+	"encoding/binary"
+	"log"
+	"math/big"
+	"math/rand"
+	"sync"
+	"time"
+	"unsafe"
+
+	"github.com/ethereum/go-ethereum/logger"
+	"github.com/ethereum/go-ethereum/pow"
+)
+
+var powlogger = logger.NewLogger("POW")
+
+type DAG struct {
+	SeedBlockNum uint64
+	dag          unsafe.Pointer // full GB of memory for dag
+}
+
+type ParamsAndCache struct {
+	params       *C.ethash_params
+	cache        *C.ethash_cache
+	SeedBlockNum uint64
+}
+
+type Ethash struct {
+	turbo          bool
+	HashRate       int64
+	chainManager   pow.ChainManager
+	dag            *DAG
+	paramsAndCache *ParamsAndCache
+	nextdag        unsafe.Pointer
+	ret            *C.ethash_return_value
+	dagMutex       *sync.Mutex
+	cacheMutex     *sync.Mutex
+}
+
+func parseNonce(nonce []byte) (uint64, error) {
+	nonceBuf := bytes.NewBuffer(nonce)
+	nonceInt, err := binary.ReadUvarint(nonceBuf)
+	if err != nil {
+		return 0, err
+	}
+	return nonceInt, nil
+}
+
+const epochLength uint64 = 30000
+
+func getSeedBlockNum(blockNum uint64) uint64 {
+	var seedBlockNum uint64 = 0
+	if blockNum >= 2*epochLength {
+		seedBlockNum = ((blockNum / epochLength) - 1) * epochLength
+	}
+	return seedBlockNum
+}
+
+func makeParamsAndCache(chainManager pow.ChainManager, blockNum uint64) *ParamsAndCache {
+	seedBlockNum := getSeedBlockNum(blockNum)
+	paramsAndCache := &ParamsAndCache{
+		params:       new(C.ethash_params),
+		cache:        new(C.ethash_cache),
+		SeedBlockNum: seedBlockNum,
+	}
+	C.ethash_params_init(paramsAndCache.params, C.uint32_t(seedBlockNum))
+	paramsAndCache.cache.mem = C.malloc(paramsAndCache.params.cache_size)
+	seedHash := chainManager.GetBlockByNumber(seedBlockNum).Header().Hash()
+	log.Println("Params", paramsAndCache.params)
+
+	log.Println("Making Cache")
+	start := time.Now()
+	C.ethash_mkcache(paramsAndCache.cache, paramsAndCache.params, (*C.uint8_t)((unsafe.Pointer)(&seedHash[0])))
+	log.Println("Took:", time.Since(start))
+	return paramsAndCache
+}
+
+func (pow *Ethash) updateCache() {
+	pow.cacheMutex.Lock()
+	seedNum := getSeedBlockNum(pow.chainManager.CurrentBlock().NumberU64())
+	if pow.paramsAndCache.SeedBlockNum != seedNum {
+		pow.paramsAndCache = makeParamsAndCache(pow.chainManager, pow.chainManager.CurrentBlock().NumberU64())
+	}
+	pow.cacheMutex.Unlock()
+}
+
+func makeDAG(p *ParamsAndCache) *DAG {
+	d := &DAG{
+		dag:          C.malloc(p.params.full_size),
+		SeedBlockNum: p.SeedBlockNum,
+	}
+	C.ethash_compute_full_data(d.dag, p.params, p.cache)
+	return d
+}
+
+func (pow *Ethash) updateDAG() {
+	pow.cacheMutex.Lock()
+	pow.dagMutex.Lock()
+
+	seedNum := getSeedBlockNum(pow.chainManager.CurrentBlock().NumberU64())
+	if pow.dag == nil || pow.dag.SeedBlockNum != seedNum {
+		pow.dag = nil
+		log.Println("Making Dag")
+		start := time.Now()
+		pow.dag = makeDAG(pow.paramsAndCache)
+		log.Println("Took:", time.Since(start))
+	}
+
+	pow.dagMutex.Unlock()
+	pow.cacheMutex.Unlock()
+}
+
+func New(chainManager pow.ChainManager) *Ethash {
+	return &Ethash{
+		turbo:          false,
+		paramsAndCache: makeParamsAndCache(chainManager, chainManager.CurrentBlock().NumberU64()),
+		chainManager:   chainManager,
+		dag:            nil,
+		ret:            new(C.ethash_return_value),
+		cacheMutex:     new(sync.Mutex),
+		dagMutex:       new(sync.Mutex),
+	}
+}
+
+func (pow *Ethash) DAGSize() uint64 {
+	return uint64(pow.paramsAndCache.params.full_size)
+}
+
+func (pow *Ethash) CacheSize() uint64 {
+	return uint64(pow.paramsAndCache.params.cache_size)
+}
+
+func (pow *Ethash) GetSeedHash(blockNum uint64) []byte {
+	return pow.chainManager.GetBlockByNumber(getSeedBlockNum(blockNum)).Header().Hash()
+}
+
+func (pow *Ethash) Stop() {
+	pow.cacheMutex.Lock()
+	pow.dagMutex.Lock()
+	if pow.paramsAndCache.cache != nil {
+		C.free(pow.paramsAndCache.cache.mem)
+	}
+	if pow.dag != nil {
+		C.free(pow.dag.dag)
+	}
+	pow.dagMutex.Unlock()
+	pow.cacheMutex.Unlock()
+}
+
+func (pow *Ethash) Search(block pow.Block, stop <-chan struct{}) ([]byte, []byte, []byte) {
+	pow.updateDAG()
+
+	// Not very elegant, multiple mining instances are not supported
+	pow.dagMutex.Lock()
+	pow.cacheMutex.Lock()
+	defer pow.cacheMutex.Unlock()
+	defer pow.dagMutex.Unlock()
+
+	r := rand.New(rand.NewSource(time.Now().UnixNano()))
+	miningHash := block.HashNoNonce()
+	diff := block.Difficulty()
+	log.Println("difficulty", diff)
+	i := int64(0)
+	start := time.Now().UnixNano()
+	t := time.Now()
+
+	nonce := uint64(r.Int63())
+
+	for {
+		select {
+		case <-stop:
+			powlogger.Infoln("Breaking from mining")
+			pow.HashRate = 0
+			pow.dagMutex.Unlock()
+			return nil, nil, nil
+		default:
+			i++
+
+			if time.Since(t) > (1 * time.Second) {
+				elapsed := time.Now().UnixNano() - start
+				hashes := ((float64(1e9) / float64(elapsed)) * float64(i)) / 1000
+				pow.HashRate = int64(hashes)
+				powlogger.Infoln("Hashing @", pow.HashRate, "khash")
+
+				t = time.Now()
+			}
+
+			cMiningHash := (*C.uint8_t)(unsafe.Pointer(&miningHash))
+			cnonce := C.uint64_t(nonce)
+			log.Printf("seed hash, nonce: %x %x\n", miningHash, nonce)
+			// pow.hash is the output/return of ethash_full
+			C.ethash_full(pow.ret, pow.dag.dag, pow.paramsAndCache.params, cMiningHash, cnonce)
+			res := C.ethash_check_difficulty((*C.uint8_t)(&pow.ret.result[0]), (*C.uint8_t)(unsafe.Pointer(&diff.Bytes()[0])))
+			if res == 1 {
+				mixDigest := C.GoBytes(unsafe.Pointer(&pow.ret.mix_hash[0]), 32)
+				// We don't really nead 32 bytes here
+				buf := make([]byte, 32)
+				binary.PutUvarint(buf, nonce)
+				return buf, mixDigest, pow.GetSeedHash(block.NumberU64())
+			}
+			nonce += 1
+		}
+
+		if !pow.turbo {
+			time.Sleep(20 * time.Microsecond)
+		}
+	}
+}
+
+func (pow *Ethash) Verify(block pow.Block) bool {
+	// Make sure the SeedHash is set correctly
+	if bytes.Compare(block.SeedHash(), pow.GetSeedHash(block.NumberU64())) != 0 {
+		log.Println("Block had wrong SeedHash")
+		log.Println("Expected: ", pow.GetSeedHash(block.NumberU64()))
+		log.Println("Actual: ", block.SeedHash())
+		return false
+	}
+
+	nonceInt, err := parseNonce(block.Nonce())
+	if err != nil {
+		log.Println("nonce to int err:", err)
+		return false
+	}
+	return pow.verify(block.HashNoNonce(), block.MixDigest(), block.Difficulty(), block.NumberU64(), nonceInt)
+}
+
+func (pow *Ethash) verify(hash []byte, mixDigest []byte, difficulty *big.Int, blockNum uint64, nonce uint64) bool {
+	// First check: make sure header, mixDigest, nonce are correct without hitting the DAG
+	// This is to prevent DOS attacks
+	chash := (*C.uint8_t)(unsafe.Pointer(&hash))
+	cnonce := C.uint64_t(nonce)
+	cmixDigest := (*C.uint8_t)(unsafe.Pointer(&mixDigest))
+	cdifficulty := (*C.uint8_t)(unsafe.Pointer(&difficulty.Bytes()[0]))
+	if C.ethash_quick_check_difficulty(chash, cnonce, cmixDigest, cdifficulty) != 1 {
+		log.Println("Failed to pass quick check.  Are you sure that the mix digest is correct?")
+		return false
+	}
+
+	var pAc *ParamsAndCache
+	// If its an old block (doesn't use the current cache)
+	// get the cache for it but don't update (so we don't need the mutex)
+	// Otherwise, it's the current block or a future.
+	// If current, updateCache will do nothing.
+	if getSeedBlockNum(blockNum) < pow.paramsAndCache.SeedBlockNum {
+		pAc = makeParamsAndCache(pow.chainManager, blockNum)
+	} else {
+		pow.updateCache()
+		pow.cacheMutex.Lock()
+		defer pow.cacheMutex.Unlock()
+		pAc = pow.paramsAndCache
+	}
+
+	C.ethash_light(pow.ret, pAc.cache, pAc.params, chash, cnonce)
+	res := C.ethash_check_difficulty((*C.uint8_t)(unsafe.Pointer(&pow.ret.result[0])), cdifficulty)
+	return res == 1
+}
+
+func (pow *Ethash) GetHashrate() int64 {
+	return pow.HashRate
+}
+
+func (pow *Ethash) Turbo(on bool) {
+	pow.turbo = on
+}
+
+func (pow *Ethash) FullHash(nonce uint64, miningHash []byte) []byte {
+	pow.updateDAG()
+	pow.dagMutex.Lock()
+	defer pow.dagMutex.Unlock()
+	cMiningHash := (*C.uint8_t)(unsafe.Pointer(&miningHash))
+	cnonce := C.uint64_t(nonce)
+	log.Println("seed hash, nonce:", miningHash, nonce)
+	// pow.hash is the output/return of ethash_full
+	C.ethash_full(pow.ret, pow.dag.dag, pow.paramsAndCache.params, cMiningHash, cnonce)
+	ghash_full := C.GoBytes(unsafe.Pointer(&pow.ret.result[0]), 32)
+	return ghash_full
+}
+
+func (pow *Ethash) LightHash(nonce uint64, miningHash []byte) []byte {
+	cMiningHash := (*C.uint8_t)(unsafe.Pointer(&miningHash))
+	cnonce := C.uint64_t(nonce)
+	C.ethash_light(pow.ret, pow.paramsAndCache.cache, pow.paramsAndCache.params, cMiningHash, cnonce)
+	ghash_light := C.GoBytes(unsafe.Pointer(&pow.ret.result[0]), 32)
+	return ghash_light
+}