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authorDeterminant <[email protected]>2020-06-28 14:47:41 -0400
committerDeterminant <[email protected]>2020-06-28 14:47:41 -0400
commitd235e2c6a5788ec4a6cff15a16f56b38a3876a0d (patch)
tree5f2727f7a50ee5840f889c82776d3a30a88dd59b /consensus/ethash
parent13ebd8bd9468e9d769d598b0ca2afb72ba78cb97 (diff)
...
Diffstat (limited to 'consensus/ethash')
-rw-r--r--consensus/ethash/algorithm.go1148
-rw-r--r--consensus/ethash/api.go118
-rw-r--r--consensus/ethash/consensus.go637
-rw-r--r--consensus/ethash/ethash.go717
-rw-r--r--consensus/ethash/sealer.go371
5 files changed, 2991 insertions, 0 deletions
diff --git a/consensus/ethash/algorithm.go b/consensus/ethash/algorithm.go
new file mode 100644
index 0000000..2b66c33
--- /dev/null
+++ b/consensus/ethash/algorithm.go
@@ -0,0 +1,1148 @@
+// Copyright 2017 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 ethash
+
+import (
+ "encoding/binary"
+ "hash"
+ "math/big"
+ "reflect"
+ "runtime"
+ "sync"
+ "sync/atomic"
+ "time"
+ "unsafe"
+
+ "github.com/ava-labs/go-ethereum/common"
+ "github.com/ava-labs/go-ethereum/common/bitutil"
+ "github.com/ava-labs/go-ethereum/crypto"
+ "github.com/ava-labs/go-ethereum/log"
+ "golang.org/x/crypto/sha3"
+)
+
+const (
+ datasetInitBytes = 1 << 30 // Bytes in dataset at genesis
+ datasetGrowthBytes = 1 << 23 // Dataset growth per epoch
+ cacheInitBytes = 1 << 24 // Bytes in cache at genesis
+ cacheGrowthBytes = 1 << 17 // Cache growth per epoch
+ epochLength = 30000 // Blocks per epoch
+ mixBytes = 128 // Width of mix
+ hashBytes = 64 // Hash length in bytes
+ hashWords = 16 // Number of 32 bit ints in a hash
+ datasetParents = 256 // Number of parents of each dataset element
+ cacheRounds = 3 // Number of rounds in cache production
+ loopAccesses = 64 // Number of accesses in hashimoto loop
+)
+
+// cacheSize returns the size of the ethash verification cache that belongs to a certain
+// block number.
+func cacheSize(block uint64) uint64 {
+ epoch := int(block / epochLength)
+ if epoch < maxEpoch {
+ return cacheSizes[epoch]
+ }
+ return calcCacheSize(epoch)
+}
+
+// calcCacheSize calculates the cache size for epoch. The cache size grows linearly,
+// however, we always take the highest prime below the linearly growing threshold in order
+// to reduce the risk of accidental regularities leading to cyclic behavior.
+func calcCacheSize(epoch int) uint64 {
+ size := cacheInitBytes + cacheGrowthBytes*uint64(epoch) - hashBytes
+ for !new(big.Int).SetUint64(size / hashBytes).ProbablyPrime(1) { // Always accurate for n < 2^64
+ size -= 2 * hashBytes
+ }
+ return size
+}
+
+// datasetSize returns the size of the ethash mining dataset that belongs to a certain
+// block number.
+func datasetSize(block uint64) uint64 {
+ epoch := int(block / epochLength)
+ if epoch < maxEpoch {
+ return datasetSizes[epoch]
+ }
+ return calcDatasetSize(epoch)
+}
+
+// calcDatasetSize calculates the dataset size for epoch. The dataset size grows linearly,
+// however, we always take the highest prime below the linearly growing threshold in order
+// to reduce the risk of accidental regularities leading to cyclic behavior.
+func calcDatasetSize(epoch int) uint64 {
+ size := datasetInitBytes + datasetGrowthBytes*uint64(epoch) - mixBytes
+ for !new(big.Int).SetUint64(size / mixBytes).ProbablyPrime(1) { // Always accurate for n < 2^64
+ size -= 2 * mixBytes
+ }
+ return size
+}
+
+// hasher is a repetitive hasher allowing the same hash data structures to be
+// reused between hash runs instead of requiring new ones to be created.
+type hasher func(dest []byte, data []byte)
+
+// makeHasher creates a repetitive hasher, allowing the same hash data structures to
+// be reused between hash runs instead of requiring new ones to be created. The returned
+// function is not thread safe!
+func makeHasher(h hash.Hash) hasher {
+ // sha3.state supports Read to get the sum, use it to avoid the overhead of Sum.
+ // Read alters the state but we reset the hash before every operation.
+ type readerHash interface {
+ hash.Hash
+ Read([]byte) (int, error)
+ }
+ rh, ok := h.(readerHash)
+ if !ok {
+ panic("can't find Read method on hash")
+ }
+ outputLen := rh.Size()
+ return func(dest []byte, data []byte) {
+ rh.Reset()
+ rh.Write(data)
+ rh.Read(dest[:outputLen])
+ }
+}
+
+// seedHash is the seed to use for generating a verification cache and the mining
+// dataset.
+func seedHash(block uint64) []byte {
+ seed := make([]byte, 32)
+ if block < epochLength {
+ return seed
+ }
+ keccak256 := makeHasher(sha3.NewLegacyKeccak256())
+ for i := 0; i < int(block/epochLength); i++ {
+ keccak256(seed, seed)
+ }
+ return seed
+}
+
+// generateCache creates a verification cache of a given size for an input seed.
+// The cache production process involves first sequentially filling up 32 MB of
+// memory, then performing two passes of Sergio Demian Lerner's RandMemoHash
+// algorithm from Strict Memory Hard Hashing Functions (2014). The output is a
+// set of 524288 64-byte values.
+// This method places the result into dest in machine byte order.
+func generateCache(dest []uint32, epoch uint64, seed []byte) {
+ // Print some debug logs to allow analysis on low end devices
+ logger := log.New("epoch", epoch)
+
+ start := time.Now()
+ defer func() {
+ elapsed := time.Since(start)
+
+ logFn := logger.Debug
+ if elapsed > 3*time.Second {
+ logFn = logger.Info
+ }
+ logFn("Generated ethash verification cache", "elapsed", common.PrettyDuration(elapsed))
+ }()
+ // Convert our destination slice to a byte buffer
+ header := *(*reflect.SliceHeader)(unsafe.Pointer(&dest))
+ header.Len *= 4
+ header.Cap *= 4
+ cache := *(*[]byte)(unsafe.Pointer(&header))
+
+ // Calculate the number of theoretical rows (we'll store in one buffer nonetheless)
+ size := uint64(len(cache))
+ rows := int(size) / hashBytes
+
+ // Start a monitoring goroutine to report progress on low end devices
+ var progress uint32
+
+ done := make(chan struct{})
+ defer close(done)
+
+ go func() {
+ for {
+ select {
+ case <-done:
+ return
+ case <-time.After(3 * time.Second):
+ logger.Info("Generating ethash verification cache", "percentage", atomic.LoadUint32(&progress)*100/uint32(rows)/4, "elapsed", common.PrettyDuration(time.Since(start)))
+ }
+ }
+ }()
+ // Create a hasher to reuse between invocations
+ keccak512 := makeHasher(sha3.NewLegacyKeccak512())
+
+ // Sequentially produce the initial dataset
+ keccak512(cache, seed)
+ for offset := uint64(hashBytes); offset < size; offset += hashBytes {
+ keccak512(cache[offset:], cache[offset-hashBytes:offset])
+ atomic.AddUint32(&progress, 1)
+ }
+ // Use a low-round version of randmemohash
+ temp := make([]byte, hashBytes)
+
+ for i := 0; i < cacheRounds; i++ {
+ for j := 0; j < rows; j++ {
+ var (
+ srcOff = ((j - 1 + rows) % rows) * hashBytes
+ dstOff = j * hashBytes
+ xorOff = (binary.LittleEndian.Uint32(cache[dstOff:]) % uint32(rows)) * hashBytes
+ )
+ bitutil.XORBytes(temp, cache[srcOff:srcOff+hashBytes], cache[xorOff:xorOff+hashBytes])
+ keccak512(cache[dstOff:], temp)
+
+ atomic.AddUint32(&progress, 1)
+ }
+ }
+ // Swap the byte order on big endian systems and return
+ if !isLittleEndian() {
+ swap(cache)
+ }
+}
+
+// swap changes the byte order of the buffer assuming a uint32 representation.
+func swap(buffer []byte) {
+ for i := 0; i < len(buffer); i += 4 {
+ binary.BigEndian.PutUint32(buffer[i:], binary.LittleEndian.Uint32(buffer[i:]))
+ }
+}
+
+// fnv is an algorithm inspired by the FNV hash, which in some cases is used as
+// a non-associative substitute for XOR. Note that we multiply the prime with
+// the full 32-bit input, in contrast with the FNV-1 spec which multiplies the
+// prime with one byte (octet) in turn.
+func fnv(a, b uint32) uint32 {
+ return a*0x01000193 ^ b
+}
+
+// fnvHash mixes in data into mix using the ethash fnv method.
+func fnvHash(mix []uint32, data []uint32) {
+ for i := 0; i < len(mix); i++ {
+ mix[i] = mix[i]*0x01000193 ^ data[i]
+ }
+}
+
+// generateDatasetItem combines data from 256 pseudorandomly selected cache nodes,
+// and hashes that to compute a single dataset node.
+func generateDatasetItem(cache []uint32, index uint32, keccak512 hasher) []byte {
+ // Calculate the number of theoretical rows (we use one buffer nonetheless)
+ rows := uint32(len(cache) / hashWords)
+
+ // Initialize the mix
+ mix := make([]byte, hashBytes)
+
+ binary.LittleEndian.PutUint32(mix, cache[(index%rows)*hashWords]^index)
+ for i := 1; i < hashWords; i++ {
+ binary.LittleEndian.PutUint32(mix[i*4:], cache[(index%rows)*hashWords+uint32(i)])
+ }
+ keccak512(mix, mix)
+
+ // Convert the mix to uint32s to avoid constant bit shifting
+ intMix := make([]uint32, hashWords)
+ for i := 0; i < len(intMix); i++ {
+ intMix[i] = binary.LittleEndian.Uint32(mix[i*4:])
+ }
+ // fnv it with a lot of random cache nodes based on index
+ for i := uint32(0); i < datasetParents; i++ {
+ parent := fnv(index^i, intMix[i%16]) % rows
+ fnvHash(intMix, cache[parent*hashWords:])
+ }
+ // Flatten the uint32 mix into a binary one and return
+ for i, val := range intMix {
+ binary.LittleEndian.PutUint32(mix[i*4:], val)
+ }
+ keccak512(mix, mix)
+ return mix
+}
+
+// generateDataset generates the entire ethash dataset for mining.
+// This method places the result into dest in machine byte order.
+func generateDataset(dest []uint32, epoch uint64, cache []uint32) {
+ // Print some debug logs to allow analysis on low end devices
+ logger := log.New("epoch", epoch)
+
+ start := time.Now()
+ defer func() {
+ elapsed := time.Since(start)
+
+ logFn := logger.Debug
+ if elapsed > 3*time.Second {
+ logFn = logger.Info
+ }
+ logFn("Generated ethash verification cache", "elapsed", common.PrettyDuration(elapsed))
+ }()
+
+ // Figure out whether the bytes need to be swapped for the machine
+ swapped := !isLittleEndian()
+
+ // Convert our destination slice to a byte buffer
+ header := *(*reflect.SliceHeader)(unsafe.Pointer(&dest))
+ header.Len *= 4
+ header.Cap *= 4
+ dataset := *(*[]byte)(unsafe.Pointer(&header))
+
+ // Generate the dataset on many goroutines since it takes a while
+ threads := runtime.NumCPU()
+ size := uint64(len(dataset))
+
+ var pend sync.WaitGroup
+ pend.Add(threads)
+
+ var progress uint32
+ for i := 0; i < threads; i++ {
+ go func(id int) {
+ defer pend.Done()
+
+ // Create a hasher to reuse between invocations
+ keccak512 := makeHasher(sha3.NewLegacyKeccak512())
+
+ // Calculate the data segment this thread should generate
+ batch := uint32((size + hashBytes*uint64(threads) - 1) / (hashBytes * uint64(threads)))
+ first := uint32(id) * batch
+ limit := first + batch
+ if limit > uint32(size/hashBytes) {
+ limit = uint32(size / hashBytes)
+ }
+ // Calculate the dataset segment
+ percent := uint32(size / hashBytes / 100)
+ for index := first; index < limit; index++ {
+ item := generateDatasetItem(cache, index, keccak512)
+ if swapped {
+ swap(item)
+ }
+ copy(dataset[index*hashBytes:], item)
+
+ if status := atomic.AddUint32(&progress, 1); status%percent == 0 {
+ logger.Info("Generating DAG in progress", "percentage", uint64(status*100)/(size/hashBytes), "elapsed", common.PrettyDuration(time.Since(start)))
+ }
+ }
+ }(i)
+ }
+ // Wait for all the generators to finish and return
+ pend.Wait()
+}
+
+// hashimoto aggregates data from the full dataset in order to produce our final
+// value for a particular header hash and nonce.
+func hashimoto(hash []byte, nonce uint64, size uint64, lookup func(index uint32) []uint32) ([]byte, []byte) {
+ // Calculate the number of theoretical rows (we use one buffer nonetheless)
+ rows := uint32(size / mixBytes)
+
+ // Combine header+nonce into a 64 byte seed
+ seed := make([]byte, 40)
+ copy(seed, hash)
+ binary.LittleEndian.PutUint64(seed[32:], nonce)
+
+ seed = crypto.Keccak512(seed)
+ seedHead := binary.LittleEndian.Uint32(seed)
+
+ // Start the mix with replicated seed
+ mix := make([]uint32, mixBytes/4)
+ for i := 0; i < len(mix); i++ {
+ mix[i] = binary.LittleEndian.Uint32(seed[i%16*4:])
+ }
+ // Mix in random dataset nodes
+ temp := make([]uint32, len(mix))
+
+ for i := 0; i < loopAccesses; i++ {
+ parent := fnv(uint32(i)^seedHead, mix[i%len(mix)]) % rows
+ for j := uint32(0); j < mixBytes/hashBytes; j++ {
+ copy(temp[j*hashWords:], lookup(2*parent+j))
+ }
+ fnvHash(mix, temp)
+ }
+ // Compress mix
+ for i := 0; i < len(mix); i += 4 {
+ mix[i/4] = fnv(fnv(fnv(mix[i], mix[i+1]), mix[i+2]), mix[i+3])
+ }
+ mix = mix[:len(mix)/4]
+
+ digest := make([]byte, common.HashLength)
+ for i, val := range mix {
+ binary.LittleEndian.PutUint32(digest[i*4:], val)
+ }
+ return digest, crypto.Keccak256(append(seed, digest...))
+}
+
+// hashimotoLight aggregates data from the full dataset (using only a small
+// in-memory cache) in order to produce our final value for a particular header
+// hash and nonce.
+func hashimotoLight(size uint64, cache []uint32, hash []byte, nonce uint64) ([]byte, []byte) {
+ keccak512 := makeHasher(sha3.NewLegacyKeccak512())
+
+ lookup := func(index uint32) []uint32 {
+ rawData := generateDatasetItem(cache, index, keccak512)
+
+ data := make([]uint32, len(rawData)/4)
+ for i := 0; i < len(data); i++ {
+ data[i] = binary.LittleEndian.Uint32(rawData[i*4:])
+ }
+ return data
+ }
+ return hashimoto(hash, nonce, size, lookup)
+}
+
+// hashimotoFull aggregates data from the full dataset (using the full in-memory
+// dataset) in order to produce our final value for a particular header hash and
+// nonce.
+func hashimotoFull(dataset []uint32, hash []byte, nonce uint64) ([]byte, []byte) {
+ lookup := func(index uint32) []uint32 {
+ offset := index * hashWords
+ return dataset[offset : offset+hashWords]
+ }
+ return hashimoto(hash, nonce, uint64(len(dataset))*4, lookup)
+}
+
+const maxEpoch = 2048
+
+// datasetSizes is a lookup table for the ethash dataset size for the first 2048
+// epochs (i.e. 61440000 blocks).
+var datasetSizes = [maxEpoch]uint64{
+ 1073739904, 1082130304, 1090514816, 1098906752, 1107293056,
+ 1115684224, 1124070016, 1132461952, 1140849536, 1149232768,
+ 1157627776, 1166013824, 1174404736, 1182786944, 1191180416,
+ 1199568512, 1207958912, 1216345216, 1224732032, 1233124736,
+ 1241513344, 1249902464, 1258290304, 1266673792, 1275067264,
+ 1283453312, 1291844992, 1300234112, 1308619904, 1317010048,
+ 1325397376, 1333787776, 1342176128, 1350561664, 1358954368,
+ 1367339392, 1375731584, 1384118144, 1392507008, 1400897408,
+ 1409284736, 1417673344, 1426062464, 1434451072, 1442839168,
+ 1451229056, 1459615616, 1468006016, 1476394112, 1484782976,
+ 1493171584, 1501559168, 1509948032, 1518337664, 1526726528,
+ 1535114624, 1543503488, 1551892096, 1560278656, 1568669056,
+ 1577056384, 1585446272, 1593831296, 1602219392, 1610610304,
+ 1619000192, 1627386752, 1635773824, 1644164224, 1652555648,
+ 1660943488, 1669332608, 1677721216, 1686109312, 1694497664,
+ 1702886272, 1711274624, 1719661184, 1728047744, 1736434816,
+ 1744829056, 1753218944, 1761606272, 1769995904, 1778382464,
+ 1786772864, 1795157888, 1803550592, 1811937664, 1820327552,
+ 1828711552, 1837102976, 1845488768, 1853879936, 1862269312,
+ 1870656896, 1879048064, 1887431552, 1895825024, 1904212096,
+ 1912601216, 1920988544, 1929379456, 1937765504, 1946156672,
+ 1954543232, 1962932096, 1971321728, 1979707264, 1988093056,
+ 1996487552, 2004874624, 2013262208, 2021653888, 2030039936,
+ 2038430848, 2046819968, 2055208576, 2063596672, 2071981952,
+ 2080373632, 2088762752, 2097149056, 2105539712, 2113928576,
+ 2122315136, 2130700672, 2139092608, 2147483264, 2155872128,
+ 2164257664, 2172642176, 2181035392, 2189426048, 2197814912,
+ 2206203008, 2214587264, 2222979712, 2231367808, 2239758208,
+ 2248145024, 2256527744, 2264922752, 2273312128, 2281701248,
+ 2290086272, 2298476672, 2306867072, 2315251072, 2323639168,
+ 2332032128, 2340420224, 2348808064, 2357196416, 2365580416,
+ 2373966976, 2382363008, 2390748544, 2399139968, 2407530368,
+ 2415918976, 2424307328, 2432695424, 2441084288, 2449472384,
+ 2457861248, 2466247808, 2474637184, 2483026816, 2491414144,
+ 2499803776, 2508191872, 2516582272, 2524970368, 2533359232,
+ 2541743488, 2550134144, 2558525056, 2566913408, 2575301504,
+ 2583686528, 2592073856, 2600467328, 2608856192, 2617240448,
+ 2625631616, 2634022016, 2642407552, 2650796416, 2659188352,
+ 2667574912, 2675965312, 2684352896, 2692738688, 2701130624,
+ 2709518464, 2717907328, 2726293376, 2734685056, 2743073152,
+ 2751462016, 2759851648, 2768232832, 2776625536, 2785017728,
+ 2793401984, 2801794432, 2810182016, 2818571648, 2826959488,
+ 2835349376, 2843734144, 2852121472, 2860514432, 2868900992,
+ 2877286784, 2885676928, 2894069632, 2902451584, 2910843008,
+ 2919234688, 2927622784, 2936011648, 2944400768, 2952789376,
+ 2961177728, 2969565568, 2977951616, 2986338944, 2994731392,
+ 3003120256, 3011508352, 3019895936, 3028287104, 3036675968,
+ 3045063808, 3053452928, 3061837696, 3070228352, 3078615424,
+ 3087003776, 3095394944, 3103782272, 3112173184, 3120562048,
+ 3128944768, 3137339264, 3145725056, 3154109312, 3162505088,
+ 3170893184, 3179280256, 3187669376, 3196056704, 3204445568,
+ 3212836736, 3221224064, 3229612928, 3238002304, 3246391168,
+ 3254778496, 3263165824, 3271556224, 3279944576, 3288332416,
+ 3296719232, 3305110912, 3313500032, 3321887104, 3330273152,
+ 3338658944, 3347053184, 3355440512, 3363827072, 3372220288,
+ 3380608384, 3388997504, 3397384576, 3405774208, 3414163072,
+ 3422551936, 3430937984, 3439328384, 3447714176, 3456104576,
+ 3464493952, 3472883584, 3481268864, 3489655168, 3498048896,
+ 3506434432, 3514826368, 3523213952, 3531603584, 3539987072,
+ 3548380288, 3556763264, 3565157248, 3573545344, 3581934464,
+ 3590324096, 3598712704, 3607098752, 3615488384, 3623877248,
+ 3632265856, 3640646528, 3649043584, 3657430144, 3665821568,
+ 3674207872, 3682597504, 3690984832, 3699367808, 3707764352,
+ 3716152448, 3724541056, 3732925568, 3741318016, 3749706368,
+ 3758091136, 3766481536, 3774872704, 3783260032, 3791650432,
+ 3800036224, 3808427648, 3816815488, 3825204608, 3833592704,
+ 3841981568, 3850370432, 3858755968, 3867147904, 3875536256,
+ 3883920512, 3892313728, 3900702592, 3909087872, 3917478784,
+ 3925868416, 3934256512, 3942645376, 3951032192, 3959422336,
+ 3967809152, 3976200064, 3984588416, 3992974976, 4001363584,
+ 4009751168, 4018141312, 4026530432, 4034911616, 4043308928,
+ 4051695488, 4060084352, 4068472448, 4076862848, 4085249408,
+ 4093640576, 4102028416, 4110413696, 4118805632, 4127194496,
+ 4135583104, 4143971968, 4152360832, 4160746112, 4169135744,
+ 4177525888, 4185912704, 4194303616, 4202691968, 4211076736,
+ 4219463552, 4227855488, 4236246656, 4244633728, 4253022848,
+ 4261412224, 4269799808, 4278184832, 4286578048, 4294962304,
+ 4303349632, 4311743104, 4320130432, 4328521088, 4336909184,
+ 4345295488, 4353687424, 4362073472, 4370458496, 4378852736,
+ 4387238528, 4395630208, 4404019072, 4412407424, 4420790656,
+ 4429182848, 4437571456, 4445962112, 4454344064, 4462738048,
+ 4471119232, 4479516544, 4487904128, 4496289664, 4504682368,
+ 4513068416, 4521459584, 4529846144, 4538232704, 4546619776,
+ 4555010176, 4563402112, 4571790208, 4580174464, 4588567936,
+ 4596957056, 4605344896, 4613734016, 4622119808, 4630511488,
+ 4638898816, 4647287936, 4655675264, 4664065664, 4672451968,
+ 4680842624, 4689231488, 4697620352, 4706007424, 4714397056,
+ 4722786176, 4731173248, 4739562368, 4747951744, 4756340608,
+ 4764727936, 4773114496, 4781504384, 4789894784, 4798283648,
+ 4806667648, 4815059584, 4823449472, 4831835776, 4840226176,
+ 4848612224, 4857003392, 4865391488, 4873780096, 4882169728,
+ 4890557312, 4898946944, 4907333248, 4915722368, 4924110976,
+ 4932499328, 4940889728, 4949276032, 4957666432, 4966054784,
+ 4974438016, 4982831488, 4991221376, 4999607168, 5007998848,
+ 5016386432, 5024763776, 5033164672, 5041544576, 5049941888,
+ 5058329728, 5066717056, 5075107456, 5083494272, 5091883904,
+ 5100273536, 5108662144, 5117048192, 5125436032, 5133827456,
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+ 16215177344, 16223567744, 16231956352, 16240344704, 16248731008,
+ 16257117824, 16265504384, 16273898624, 16282281856, 16290668672,
+ 16299064192, 16307449216, 16315842176, 16324230016, 16332613504,
+ 16341006464, 16349394304, 16357783168, 16366172288, 16374561664,
+ 16382951296, 16391337856, 16399726208, 16408116352, 16416505472,
+ 16424892032, 16433282176, 16441668224, 16450058624, 16458448768,
+ 16466836864, 16475224448, 16483613056, 16492001408, 16500391808,
+ 16508779648, 16517166976, 16525555328, 16533944192, 16542330752,
+ 16550719616, 16559110528, 16567497088, 16575888512, 16584274816,
+ 16592665472, 16601051008, 16609442944, 16617832064, 16626218624,
+ 16634607488, 16642996096, 16651385728, 16659773824, 16668163712,
+ 16676552576, 16684938112, 16693328768, 16701718144, 16710095488,
+ 16718492288, 16726883968, 16735272832, 16743661184, 16752049792,
+ 16760436608, 16768827008, 16777214336, 16785599104, 16793992832,
+ 16802381696, 16810768768, 16819151744, 16827542656, 16835934848,
+ 16844323712, 16852711552, 16861101952, 16869489536, 16877876864,
+ 16886265728, 16894653056, 16903044736, 16911431296, 16919821696,
+ 16928207488, 16936592768, 16944987776, 16953375616, 16961763968,
+ 16970152832, 16978540928, 16986929536, 16995319168, 17003704448,
+ 17012096896, 17020481152, 17028870784, 17037262208, 17045649536,
+ 17054039936, 17062426496, 17070814336, 17079205504, 17087592064,
+ 17095978112, 17104369024, 17112759424, 17121147776, 17129536384,
+ 17137926016, 17146314368, 17154700928, 17163089792, 17171480192,
+ 17179864192, 17188256896, 17196644992, 17205033856, 17213423488,
+ 17221811072, 17230198912, 17238588032, 17246976896, 17255360384,
+ 17263754624, 17272143232, 17280530048, 17288918912, 17297309312,
+ 17305696384, 17314085504, 17322475136, 17330863744, 17339252096,
+ 17347640192, 17356026496, 17364413824, 17372796544, 17381190016,
+ 17389583488, 17397972608, 17406360704, 17414748544, 17423135872,
+ 17431527296, 17439915904, 17448303232, 17456691584, 17465081728,
+ 17473468288, 17481857408, 17490247552, 17498635904, 17507022464,
+ 17515409024, 17523801728, 17532189824, 17540577664, 17548966016,
+ 17557353344, 17565741184, 17574131584, 17582519168, 17590907008,
+ 17599296128, 17607687808, 17616076672, 17624455808, 17632852352,
+ 17641238656, 17649630848, 17658018944, 17666403968, 17674794112,
+ 17683178368, 17691573376, 17699962496, 17708350592, 17716739968,
+ 17725126528, 17733517184, 17741898112, 17750293888, 17758673024,
+ 17767070336, 17775458432, 17783848832, 17792236928, 17800625536,
+ 17809012352, 17817402752, 17825785984, 17834178944, 17842563968,
+ 17850955648, 17859344512, 17867732864, 17876119424, 17884511872,
+ 17892900224, 17901287296, 17909677696, 17918058112, 17926451072,
+ 17934843776, 17943230848, 17951609216, 17960008576, 17968397696,
+ 17976784256, 17985175424, 17993564032, 18001952128, 18010339712,
+ 18018728576, 18027116672, 18035503232, 18043894144, 18052283264,
+ 18060672128, 18069056384, 18077449856, 18085837184, 18094225792,
+ 18102613376, 18111004544, 18119388544, 18127781248, 18136170368,
+ 18144558976, 18152947328, 18161336192, 18169724288, 18178108544,
+ 18186498944, 18194886784, 18203275648, 18211666048, 18220048768,
+ 18228444544, 18236833408, 18245220736}
+
+// cacheSizes is a lookup table for the ethash verification cache size for the
+// first 2048 epochs (i.e. 61440000 blocks).
+var cacheSizes = [maxEpoch]uint64{
+ 16776896, 16907456, 17039296, 17170112, 17301056, 17432512, 17563072,
+ 17693888, 17824192, 17955904, 18087488, 18218176, 18349504, 18481088,
+ 18611392, 18742336, 18874304, 19004224, 19135936, 19267264, 19398208,
+ 19529408, 19660096, 19791424, 19922752, 20053952, 20184896, 20315968,
+ 20446912, 20576576, 20709184, 20840384, 20971072, 21102272, 21233216,
+ 21364544, 21494848, 21626816, 21757376, 21887552, 22019392, 22151104,
+ 22281536, 22412224, 22543936, 22675264, 22806464, 22935872, 23068096,
+ 23198272, 23330752, 23459008, 23592512, 23723968, 23854912, 23986112,
+ 24116672, 24247616, 24378688, 24509504, 24640832, 24772544, 24903488,
+ 25034432, 25165376, 25296704, 25427392, 25558592, 25690048, 25820096,
+ 25951936, 26081728, 26214208, 26345024, 26476096, 26606656, 26737472,
+ 26869184, 26998208, 27131584, 27262528, 27393728, 27523904, 27655744,
+ 27786688, 27917888, 28049344, 28179904, 28311488, 28441792, 28573504,
+ 28700864, 28835648, 28966208, 29096768, 29228608, 29359808, 29490752,
+ 29621824, 29752256, 29882816, 30014912, 30144448, 30273728, 30406976,
+ 30538432, 30670784, 30799936, 30932672, 31063744, 31195072, 31325248,
+ 31456192, 31588288, 31719232, 31850432, 31981504, 32110784, 32243392,
+ 32372672, 32505664, 32636608, 32767808, 32897344, 33029824, 33160768,
+ 33289664, 33423296, 33554368, 33683648, 33816512, 33947456, 34076992,
+ 34208704, 34340032, 34471744, 34600256, 34734016, 34864576, 34993984,
+ 35127104, 35258176, 35386688, 35518528, 35650624, 35782336, 35910976,
+ 36044608, 36175808, 36305728, 36436672, 36568384, 36699968, 36830656,
+ 36961984, 37093312, 37223488, 37355072, 37486528, 37617472, 37747904,
+ 37879232, 38009792, 38141888, 38272448, 38403392, 38535104, 38660672,
+ 38795584, 38925632, 39059264, 39190336, 39320768, 39452096, 39581632,
+ 39713984, 39844928, 39974848, 40107968, 40238144, 40367168, 40500032,
+ 40631744, 40762816, 40894144, 41023552, 41155904, 41286208, 41418304,
+ 41547712, 41680448, 41811904, 41942848, 42073792, 42204992, 42334912,
+ 42467008, 42597824, 42729152, 42860096, 42991552, 43122368, 43253696,
+ 43382848, 43515712, 43646912, 43777088, 43907648, 44039104, 44170432,
+ 44302144, 44433344, 44564288, 44694976, 44825152, 44956864, 45088448,
+ 45219008, 45350464, 45481024, 45612608, 45744064, 45874496, 46006208,
+ 46136768, 46267712, 46399424, 46529344, 46660672, 46791488, 46923328,
+ 47053504, 47185856, 47316928, 47447872, 47579072, 47710144, 47839936,
+ 47971648, 48103232, 48234176, 48365248, 48496192, 48627136, 48757312,
+ 48889664, 49020736, 49149248, 49283008, 49413824, 49545152, 49675712,
+ 49807168, 49938368, 50069056, 50200256, 50331584, 50462656, 50593472,
+ 50724032, 50853952, 50986048, 51117632, 51248576, 51379904, 51510848,
+ 51641792, 51773248, 51903296, 52035136, 52164032, 52297664, 52427968,
+ 52557376, 52690112, 52821952, 52952896, 53081536, 53213504, 53344576,
+ 53475776, 53608384, 53738816, 53870528, 54000832, 54131776, 54263744,
+ 54394688, 54525248, 54655936, 54787904, 54918592, 55049152, 55181248,
+ 55312064, 55442752, 55574336, 55705024, 55836224, 55967168, 56097856,
+ 56228672, 56358592, 56490176, 56621888, 56753728, 56884928, 57015488,
+ 57146816, 57278272, 57409216, 57540416, 57671104, 57802432, 57933632,
+ 58064576, 58195264, 58326976, 58457408, 58588864, 58720192, 58849984,
+ 58981696, 59113024, 59243456, 59375552, 59506624, 59637568, 59768512,
+ 59897792, 60030016, 60161984, 60293056, 60423872, 60554432, 60683968,
+ 60817216, 60948032, 61079488, 61209664, 61341376, 61471936, 61602752,
+ 61733696, 61865792, 61996736, 62127808, 62259136, 62389568, 62520512,
+ 62651584, 62781632, 62910784, 63045056, 63176128, 63307072, 63438656,
+ 63569216, 63700928, 63831616, 63960896, 64093888, 64225088, 64355392,
+ 64486976, 64617664, 64748608, 64879424, 65009216, 65142464, 65273792,
+ 65402816, 65535424, 65666752, 65797696, 65927744, 66060224, 66191296,
+ 66321344, 66453056, 66584384, 66715328, 66846656, 66977728, 67108672,
+ 67239104, 67370432, 67501888, 67631296, 67763776, 67895104, 68026304,
+ 68157248, 68287936, 68419264, 68548288, 68681408, 68811968, 68942912,
+ 69074624, 69205568, 69337024, 69467584, 69599168, 69729472, 69861184,
+ 69989824, 70122944, 70253888, 70385344, 70515904, 70647232, 70778816,
+ 70907968, 71040832, 71171648, 71303104, 71432512, 71564992, 71695168,
+ 71826368, 71958464, 72089536, 72219712, 72350144, 72482624, 72613568,
+ 72744512, 72875584, 73006144, 73138112, 73268672, 73400128, 73530944,
+ 73662272, 73793344, 73924544, 74055104, 74185792, 74316992, 74448832,
+ 74579392, 74710976, 74841664, 74972864, 75102784, 75233344, 75364544,
+ 75497024, 75627584, 75759296, 75890624, 76021696, 76152256, 76283072,
+ 76414144, 76545856, 76676672, 76806976, 76937792, 77070016, 77200832,
+ 77331392, 77462464, 77593664, 77725376, 77856448, 77987776, 78118336,
+ 78249664, 78380992, 78511424, 78642496, 78773056, 78905152, 79033664,
+ 79166656, 79297472, 79429568, 79560512, 79690816, 79822784, 79953472,
+ 80084672, 80214208, 80346944, 80477632, 80608576, 80740288, 80870848,
+ 81002048, 81133504, 81264448, 81395648, 81525952, 81657536, 81786304,
+ 81919808, 82050112, 82181312, 82311616, 82443968, 82573376, 82705984,
+ 82835776, 82967744, 83096768, 83230528, 83359552, 83491264, 83622464,
+ 83753536, 83886016, 84015296, 84147776, 84277184, 84409792, 84540608,
+ 84672064, 84803008, 84934336, 85065152, 85193792, 85326784, 85458496,
+ 85589312, 85721024, 85851968, 85982656, 86112448, 86244416, 86370112,
+ 86506688, 86637632, 86769344, 86900672, 87031744, 87162304, 87293632,
+ 87424576, 87555392, 87687104, 87816896, 87947968, 88079168, 88211264,
+ 88341824, 88473152, 88603712, 88735424, 88862912, 88996672, 89128384,
+ 89259712, 89390272, 89521984, 89652544, 89783872, 89914816, 90045376,
+ 90177088, 90307904, 90438848, 90569152, 90700096, 90832832, 90963776,
+ 91093696, 91223744, 91356992, 91486784, 91618496, 91749824, 91880384,
+ 92012224, 92143552, 92273344, 92405696, 92536768, 92666432, 92798912,
+ 92926016, 93060544, 93192128, 93322816, 93453632, 93583936, 93715136,
+ 93845056, 93977792, 94109504, 94240448, 94371776, 94501184, 94632896,
+ 94764224, 94895552, 95023424, 95158208, 95287744, 95420224, 95550016,
+ 95681216, 95811904, 95943872, 96075328, 96203584, 96337856, 96468544,
+ 96599744, 96731072, 96860992, 96992576, 97124288, 97254848, 97385536,
+ 97517248, 97647808, 97779392, 97910464, 98041408, 98172608, 98303168,
+ 98434496, 98565568, 98696768, 98827328, 98958784, 99089728, 99220928,
+ 99352384, 99482816, 99614272, 99745472, 99876416, 100007104,
+ 100138048, 100267072, 100401088, 100529984, 100662592, 100791872,
+ 100925248, 101056064, 101187392, 101317952, 101449408, 101580608,
+ 101711296, 101841728, 101973824, 102104896, 102235712, 102366016,
+ 102498112, 102628672, 102760384, 102890432, 103021888, 103153472,
+ 103284032, 103415744, 103545152, 103677248, 103808576, 103939648,
+ 104070976, 104201792, 104332736, 104462528, 104594752, 104725952,
+ 104854592, 104988608, 105118912, 105247808, 105381184, 105511232,
+ 105643072, 105774784, 105903296, 106037056, 106167872, 106298944,
+ 106429504, 106561472, 106691392, 106822592, 106954304, 107085376,
+ 107216576, 107346368, 107478464, 107609792, 107739712, 107872192,
+ 108003136, 108131392, 108265408, 108396224, 108527168, 108657344,
+ 108789568, 108920384, 109049792, 109182272, 109312576, 109444928,
+ 109572928, 109706944, 109837888, 109969088, 110099648, 110230976,
+ 110362432, 110492992, 110624704, 110755264, 110886208, 111017408,
+ 111148864, 111279296, 111410752, 111541952, 111673024, 111803456,
+ 111933632, 112066496, 112196416, 112328512, 112457792, 112590784,
+ 112715968, 112852672, 112983616, 113114944, 113244224, 113376448,
+ 113505472, 113639104, 113770304, 113901376, 114031552, 114163264,
+ 114294592, 114425536, 114556864, 114687424, 114818624, 114948544,
+ 115080512, 115212224, 115343296, 115473472, 115605184, 115736128,
+ 115867072, 115997248, 116128576, 116260288, 116391488, 116522944,
+ 116652992, 116784704, 116915648, 117046208, 117178304, 117308608,
+ 117440192, 117569728, 117701824, 117833024, 117964096, 118094656,
+ 118225984, 118357312, 118489024, 118617536, 118749632, 118882112,
+ 119012416, 119144384, 119275328, 119406016, 119537344, 119668672,
+ 119798464, 119928896, 120061376, 120192832, 120321728, 120454336,
+ 120584512, 120716608, 120848192, 120979136, 121109056, 121241408,
+ 121372352, 121502912, 121634752, 121764416, 121895744, 122027072,
+ 122157632, 122289088, 122421184, 122550592, 122682944, 122813888,
+ 122945344, 123075776, 123207488, 123338048, 123468736, 123600704,
+ 123731264, 123861952, 123993664, 124124608, 124256192, 124386368,
+ 124518208, 124649024, 124778048, 124911296, 125041088, 125173696,
+ 125303744, 125432896, 125566912, 125696576, 125829056, 125958592,
+ 126090304, 126221248, 126352832, 126483776, 126615232, 126746432,
+ 126876608, 127008704, 127139392, 127270336, 127401152, 127532224,
+ 127663552, 127794752, 127925696, 128055232, 128188096, 128319424,
+ 128449856, 128581312, 128712256, 128843584, 128973632, 129103808,
+ 129236288, 129365696, 129498944, 129629888, 129760832, 129892288,
+ 130023104, 130154048, 130283968, 130416448, 130547008, 130678336,
+ 130807616, 130939456, 131071552, 131202112, 131331776, 131464384,
+ 131594048, 131727296, 131858368, 131987392, 132120256, 132250816,
+ 132382528, 132513728, 132644672, 132774976, 132905792, 133038016,
+ 133168832, 133299392, 133429312, 133562048, 133692992, 133823296,
+ 133954624, 134086336, 134217152, 134348608, 134479808, 134607296,
+ 134741056, 134872384, 135002944, 135134144, 135265472, 135396544,
+ 135527872, 135659072, 135787712, 135921472, 136052416, 136182848,
+ 136313792, 136444864, 136576448, 136707904, 136837952, 136970048,
+ 137099584, 137232064, 137363392, 137494208, 137625536, 137755712,
+ 137887424, 138018368, 138149824, 138280256, 138411584, 138539584,
+ 138672832, 138804928, 138936128, 139066688, 139196864, 139328704,
+ 139460032, 139590208, 139721024, 139852864, 139984576, 140115776,
+ 140245696, 140376512, 140508352, 140640064, 140769856, 140902336,
+ 141032768, 141162688, 141294016, 141426496, 141556544, 141687488,
+ 141819584, 141949888, 142080448, 142212544, 142342336, 142474432,
+ 142606144, 142736192, 142868288, 142997824, 143129408, 143258944,
+ 143392448, 143523136, 143653696, 143785024, 143916992, 144045632,
+ 144177856, 144309184, 144440768, 144570688, 144701888, 144832448,
+ 144965056, 145096384, 145227584, 145358656, 145489856, 145620928,
+ 145751488, 145883072, 146011456, 146144704, 146275264, 146407232,
+ 146538176, 146668736, 146800448, 146931392, 147062336, 147193664,
+ 147324224, 147455936, 147586624, 147717056, 147848768, 147979456,
+ 148110784, 148242368, 148373312, 148503232, 148635584, 148766144,
+ 148897088, 149028416, 149159488, 149290688, 149420224, 149551552,
+ 149683136, 149814976, 149943616, 150076352, 150208064, 150338624,
+ 150470464, 150600256, 150732224, 150862784, 150993088, 151125952,
+ 151254976, 151388096, 151519168, 151649728, 151778752, 151911104,
+ 152042944, 152174144, 152304704, 152435648, 152567488, 152698816,
+ 152828992, 152960576, 153091648, 153222976, 153353792, 153484096,
+ 153616192, 153747008, 153878336, 154008256, 154139968, 154270912,
+ 154402624, 154533824, 154663616, 154795712, 154926272, 155057984,
+ 155188928, 155319872, 155450816, 155580608, 155712064, 155843392,
+ 155971136, 156106688, 156237376, 156367424, 156499264, 156630976,
+ 156761536, 156892352, 157024064, 157155008, 157284416, 157415872,
+ 157545536, 157677248, 157810496, 157938112, 158071744, 158203328,
+ 158334656, 158464832, 158596288, 158727616, 158858048, 158988992,
+ 159121216, 159252416, 159381568, 159513152, 159645632, 159776192,
+ 159906496, 160038464, 160169536, 160300352, 160430656, 160563008,
+ 160693952, 160822208, 160956352, 161086784, 161217344, 161349184,
+ 161480512, 161611456, 161742272, 161873216, 162002752, 162135872,
+ 162266432, 162397888, 162529216, 162660032, 162790976, 162922048,
+ 163052096, 163184576, 163314752, 163446592, 163577408, 163707968,
+ 163839296, 163969984, 164100928, 164233024, 164364224, 164494912,
+ 164625856, 164756672, 164887616, 165019072, 165150016, 165280064,
+ 165412672, 165543104, 165674944, 165805888, 165936832, 166067648,
+ 166198336, 166330048, 166461248, 166591552, 166722496, 166854208,
+ 166985408, 167116736, 167246656, 167378368, 167508416, 167641024,
+ 167771584, 167903168, 168034112, 168164032, 168295744, 168427456,
+ 168557632, 168688448, 168819136, 168951616, 169082176, 169213504,
+ 169344832, 169475648, 169605952, 169738048, 169866304, 169999552,
+ 170131264, 170262464, 170393536, 170524352, 170655424, 170782016,
+ 170917696, 171048896, 171179072, 171310784, 171439936, 171573184,
+ 171702976, 171835072, 171966272, 172097216, 172228288, 172359232,
+ 172489664, 172621376, 172747712, 172883264, 173014208, 173144512,
+ 173275072, 173407424, 173539136, 173669696, 173800768, 173931712,
+ 174063424, 174193472, 174325696, 174455744, 174586816, 174718912,
+ 174849728, 174977728, 175109696, 175242688, 175374272, 175504832,
+ 175636288, 175765696, 175898432, 176028992, 176159936, 176291264,
+ 176422592, 176552512, 176684864, 176815424, 176946496, 177076544,
+ 177209152, 177340096, 177470528, 177600704, 177731648, 177864256,
+ 177994816, 178126528, 178257472, 178387648, 178518464, 178650176,
+ 178781888, 178912064, 179044288, 179174848, 179305024, 179436736,
+ 179568448, 179698496, 179830208, 179960512, 180092608, 180223808,
+ 180354752, 180485696, 180617152, 180748096, 180877504, 181009984,
+ 181139264, 181272512, 181402688, 181532608, 181663168, 181795136,
+ 181926592, 182057536, 182190016, 182320192, 182451904, 182582336,
+ 182713792, 182843072, 182976064, 183107264, 183237056, 183368384,
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+ 184286656, 184417984, 184548928, 184680128, 184810816, 184941248,
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+ 185859904, 185989696, 186121664, 186252992, 186383552, 186514112,
+ 186645952, 186777152, 186907328, 187037504, 187170112, 187301824,
+ 187429184, 187562048, 187693504, 187825472, 187957184, 188087104,
+ 188218304, 188349376, 188481344, 188609728, 188743616, 188874304,
+ 189005248, 189136448, 189265088, 189396544, 189528128, 189660992,
+ 189791936, 189923264, 190054208, 190182848, 190315072, 190447424,
+ 190577984, 190709312, 190840768, 190971328, 191102656, 191233472,
+ 191364032, 191495872, 191626816, 191758016, 191888192, 192020288,
+ 192148928, 192282176, 192413504, 192542528, 192674752, 192805952,
+ 192937792, 193068608, 193198912, 193330496, 193462208, 193592384,
+ 193723456, 193854272, 193985984, 194116672, 194247232, 194379712,
+ 194508352, 194641856, 194772544, 194900672, 195035072, 195166016,
+ 195296704, 195428032, 195558592, 195690304, 195818176, 195952576,
+ 196083392, 196214336, 196345792, 196476736, 196607552, 196739008,
+ 196869952, 197000768, 197130688, 197262784, 197394368, 197523904,
+ 197656384, 197787584, 197916608, 198049472, 198180544, 198310208,
+ 198442432, 198573632, 198705088, 198834368, 198967232, 199097792,
+ 199228352, 199360192, 199491392, 199621696, 199751744, 199883968,
+ 200014016, 200146624, 200276672, 200408128, 200540096, 200671168,
+ 200801984, 200933312, 201062464, 201194944, 201326144, 201457472,
+ 201588544, 201719744, 201850816, 201981632, 202111552, 202244032,
+ 202374464, 202505152, 202636352, 202767808, 202898368, 203030336,
+ 203159872, 203292608, 203423296, 203553472, 203685824, 203816896,
+ 203947712, 204078272, 204208192, 204341056, 204472256, 204603328,
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+ 210239296, 210370112, 210501568, 210630976, 210763712, 210894272,
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+ 263716672, 263847872, 263978944, 264108608, 264241088, 264371648,
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+ 270791744, 270924736, 271056832, 271186112, 271317184, 271449536,
+ 271580992, 271711936, 271843136, 271973056, 272105408, 272236352,
+ 272367296, 272498368, 272629568, 272759488, 272891456, 273022784,
+ 273153856, 273284672, 273415616, 273547072, 273677632, 273808448,
+ 273937088, 274071488, 274200896, 274332992, 274463296, 274595392,
+ 274726208, 274857536, 274988992, 275118656, 275250496, 275382208,
+ 275513024, 275643968, 275775296, 275906368, 276037184, 276167872,
+ 276297664, 276429376, 276560576, 276692672, 276822976, 276955072,
+ 277085632, 277216832, 277347008, 277478848, 277609664, 277740992,
+ 277868608, 278002624, 278134336, 278265536, 278395328, 278526784,
+ 278657728, 278789824, 278921152, 279052096, 279182912, 279313088,
+ 279443776, 279576256, 279706048, 279838528, 279969728, 280099648,
+ 280230976, 280361408, 280493632, 280622528, 280755392, 280887104,
+ 281018176, 281147968, 281278912, 281411392, 281542592, 281673152,
+ 281803712, 281935552, 282066496, 282197312, 282329024, 282458816,
+ 282590272, 282720832, 282853184, 282983744, 283115072, 283246144,
+ 283377344, 283508416, 283639744, 283770304, 283901504, 284032576,
+ 284163136, 284294848, 284426176, 284556992, 284687296, 284819264,
+ 284950208, 285081536}
diff --git a/consensus/ethash/api.go b/consensus/ethash/api.go
new file mode 100644
index 0000000..34ed386
--- /dev/null
+++ b/consensus/ethash/api.go
@@ -0,0 +1,118 @@
+// Copyright 2018 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 ethash
+
+import (
+ "errors"
+
+ "github.com/ava-labs/coreth/core/types"
+ "github.com/ava-labs/go-ethereum/common"
+ "github.com/ava-labs/go-ethereum/common/hexutil"
+)
+
+var errEthashStopped = errors.New("ethash stopped")
+
+// API exposes ethash related methods for the RPC interface.
+type API struct {
+ ethash *Ethash // Make sure the mode of ethash is normal.
+}
+
+// GetWork returns a work package for external miner.
+//
+// The work package consists of 3 strings:
+// result[0] - 32 bytes hex encoded current block header pow-hash
+// result[1] - 32 bytes hex encoded seed hash used for DAG
+// result[2] - 32 bytes hex encoded boundary condition ("target"), 2^256/difficulty
+// result[3] - hex encoded block number
+func (api *API) GetWork() ([4]string, error) {
+ if api.ethash.config.PowMode != ModeNormal && api.ethash.config.PowMode != ModeTest {
+ return [4]string{}, errors.New("not supported")
+ }
+
+ var (
+ workCh = make(chan [4]string, 1)
+ errc = make(chan error, 1)
+ )
+
+ select {
+ case api.ethash.fetchWorkCh <- &sealWork{errc: errc, res: workCh}:
+ case <-api.ethash.exitCh:
+ return [4]string{}, errEthashStopped
+ }
+
+ select {
+ case work := <-workCh:
+ return work, nil
+ case err := <-errc:
+ return [4]string{}, err
+ }
+}
+
+// SubmitWork can be used by external miner to submit their POW solution.
+// It returns an indication if the work was accepted.
+// Note either an invalid solution, a stale work a non-existent work will return false.
+func (api *API) SubmitWork(nonce types.BlockNonce, hash, digest common.Hash) bool {
+ if api.ethash.config.PowMode != ModeNormal && api.ethash.config.PowMode != ModeTest {
+ return false
+ }
+
+ var errc = make(chan error, 1)
+
+ select {
+ case api.ethash.submitWorkCh <- &mineResult{
+ nonce: nonce,
+ mixDigest: digest,
+ hash: hash,
+ errc: errc,
+ }:
+ case <-api.ethash.exitCh:
+ return false
+ }
+
+ err := <-errc
+ return err == nil
+}
+
+// SubmitHashrate can be used for remote miners to submit their hash rate.
+// This enables the node to report the combined hash rate of all miners
+// which submit work through this node.
+//
+// It accepts the miner hash rate and an identifier which must be unique
+// between nodes.
+func (api *API) SubmitHashRate(rate hexutil.Uint64, id common.Hash) bool {
+ if api.ethash.config.PowMode != ModeNormal && api.ethash.config.PowMode != ModeTest {
+ return false
+ }
+
+ var done = make(chan struct{}, 1)
+
+ select {
+ case api.ethash.submitRateCh <- &hashrate{done: done, rate: uint64(rate), id: id}:
+ case <-api.ethash.exitCh:
+ return false
+ }
+
+ // Block until hash rate submitted successfully.
+ <-done
+
+ return true
+}
+
+// GetHashrate returns the current hashrate for local CPU miner and remote miner.
+func (api *API) GetHashrate() uint64 {
+ return uint64(api.ethash.Hashrate())
+}
diff --git a/consensus/ethash/consensus.go b/consensus/ethash/consensus.go
new file mode 100644
index 0000000..d9130ec
--- /dev/null
+++ b/consensus/ethash/consensus.go
@@ -0,0 +1,637 @@
+// Copyright 2017 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 ethash
+
+import (
+ "bytes"
+ "errors"
+ "fmt"
+ "math/big"
+ "runtime"
+ "time"
+
+ "github.com/ava-labs/coreth/consensus"
+ "github.com/ava-labs/coreth/consensus/misc"
+ "github.com/ava-labs/coreth/core/state"
+ "github.com/ava-labs/coreth/core/types"
+ "github.com/ava-labs/coreth/params"
+ "github.com/ava-labs/go-ethereum/common"
+ "github.com/ava-labs/go-ethereum/common/math"
+ "github.com/ava-labs/go-ethereum/rlp"
+ mapset "github.com/deckarep/golang-set"
+ "golang.org/x/crypto/sha3"
+)
+
+// Ethash proof-of-work protocol constants.
+var (
+ FrontierBlockReward = big.NewInt(5e+18) // Block reward in wei for successfully mining a block
+ ByzantiumBlockReward = big.NewInt(3e+18) // Block reward in wei for successfully mining a block upward from Byzantium
+ ConstantinopleBlockReward = big.NewInt(2e+18) // Block reward in wei for successfully mining a block upward from Constantinople
+ maxUncles = 2 // Maximum number of uncles allowed in a single block
+ allowedFutureBlockTime = 15 * time.Second // Max time from current time allowed for blocks, before they're considered future blocks
+
+ // calcDifficultyConstantinople is the difficulty adjustment algorithm for Constantinople.
+ // It returns the difficulty that a new block should have when created at time given the
+ // parent block's time and difficulty. The calculation uses the Byzantium rules, but with
+ // bomb offset 5M.
+ // Specification EIP-1234: https://eips.ethereum.org/EIPS/eip-1234
+ calcDifficultyConstantinople = makeDifficultyCalculator(big.NewInt(5000000))
+
+ // calcDifficultyByzantium is the difficulty adjustment algorithm. It returns
+ // the difficulty that a new block should have when created at time given the
+ // parent block's time and difficulty. The calculation uses the Byzantium rules.
+ // Specification EIP-649: https://eips.ethereum.org/EIPS/eip-649
+ calcDifficultyByzantium = makeDifficultyCalculator(big.NewInt(3000000))
+)
+
+// Various error messages to mark blocks invalid. These should be private to
+// prevent engine specific errors from being referenced in the remainder of the
+// codebase, inherently breaking if the engine is swapped out. Please put common
+// error types into the consensus package.
+var (
+ errZeroBlockTime = errors.New("timestamp equals parent's")
+ errTooManyUncles = errors.New("too many uncles")
+ errDuplicateUncle = errors.New("duplicate uncle")
+ errUncleIsAncestor = errors.New("uncle is ancestor")
+ errDanglingUncle = errors.New("uncle's parent is not ancestor")
+ errInvalidDifficulty = errors.New("non-positive difficulty")
+ errInvalidMixDigest = errors.New("invalid mix digest")
+ errInvalidPoW = errors.New("invalid proof-of-work")
+)
+
+// Author implements consensus.Engine, returning the header's coinbase as the
+// proof-of-work verified author of the block.
+func (ethash *Ethash) Author(header *types.Header) (common.Address, error) {
+ return header.Coinbase, nil
+}
+
+// VerifyHeader checks whether a header conforms to the consensus rules of the
+// stock Ethereum ethash engine.
+func (ethash *Ethash) VerifyHeader(chain consensus.ChainReader, header *types.Header, seal bool) error {
+ // If we're running a full engine faking, accept any input as valid
+ if ethash.config.PowMode == ModeFullFake {
+ return nil
+ }
+ // Short circuit if the header is known, or it's parent not
+ number := header.Number.Uint64()
+ if chain.GetHeader(header.Hash(), number) != nil {
+ return nil
+ }
+ parent := chain.GetHeader(header.ParentHash, number-1)
+ if parent == nil {
+ return consensus.ErrUnknownAncestor
+ }
+ // Sanity checks passed, do a proper verification
+ return ethash.verifyHeader(chain, header, parent, false, seal)
+}
+
+// VerifyHeaders is similar to VerifyHeader, but verifies a batch of headers
+// concurrently. The method returns a quit channel to abort the operations and
+// a results channel to retrieve the async verifications.
+func (ethash *Ethash) VerifyHeaders(chain consensus.ChainReader, headers []*types.Header, seals []bool) (chan<- struct{}, <-chan error) {
+ // If we're running a full engine faking, accept any input as valid
+ if ethash.config.PowMode == ModeFullFake || len(headers) == 0 {
+ abort, results := make(chan struct{}), make(chan error, len(headers))
+ for i := 0; i < len(headers); i++ {
+ results <- nil
+ }
+ return abort, results
+ }
+
+ // Spawn as many workers as allowed threads
+ workers := runtime.GOMAXPROCS(0)
+ if len(headers) < workers {
+ workers = len(headers)
+ }
+
+ // Create a task channel and spawn the verifiers
+ var (
+ inputs = make(chan int)
+ done = make(chan int, workers)
+ errors = make([]error, len(headers))
+ abort = make(chan struct{})
+ )
+ for i := 0; i < workers; i++ {
+ go func() {
+ for index := range inputs {
+ errors[index] = ethash.verifyHeaderWorker(chain, headers, seals, index)
+ done <- index
+ }
+ }()
+ }
+
+ errorsOut := make(chan error, len(headers))
+ go func() {
+ defer close(inputs)
+ var (
+ in, out = 0, 0
+ checked = make([]bool, len(headers))
+ inputs = inputs
+ )
+ for {
+ select {
+ case inputs <- in:
+ if in++; in == len(headers) {
+ // Reached end of headers. Stop sending to workers.
+ inputs = nil
+ }
+ case index := <-done:
+ for checked[index] = true; checked[out]; out++ {
+ errorsOut <- errors[out]
+ if out == len(headers)-1 {
+ return
+ }
+ }
+ case <-abort:
+ return
+ }
+ }
+ }()
+ return abort, errorsOut
+}
+
+func (ethash *Ethash) verifyHeaderWorker(chain consensus.ChainReader, headers []*types.Header, seals []bool, index int) error {
+ var parent *types.Header
+ if index == 0 {
+ parent = chain.GetHeader(headers[0].ParentHash, headers[0].Number.Uint64()-1)
+ } else if headers[index-1].Hash() == headers[index].ParentHash {
+ parent = headers[index-1]
+ }
+ if parent == nil {
+ return consensus.ErrUnknownAncestor
+ }
+ if chain.GetHeader(headers[index].Hash(), headers[index].Number.Uint64()) != nil {
+ return nil // known block
+ }
+ return ethash.verifyHeader(chain, headers[index], parent, false, seals[index])
+}
+
+// VerifyUncles verifies that the given block's uncles conform to the consensus
+// rules of the stock Ethereum ethash engine.
+func (ethash *Ethash) VerifyUncles(chain consensus.ChainReader, block *types.Block) error {
+ // If we're running a full engine faking, accept any input as valid
+ if ethash.config.PowMode == ModeFullFake {
+ return nil
+ }
+ // Verify that there are at most 2 uncles included in this block
+ if len(block.Uncles()) > maxUncles {
+ return errTooManyUncles
+ }
+ if len(block.Uncles()) == 0 {
+ return nil
+ }
+ // Gather the set of past uncles and ancestors
+ uncles, ancestors := mapset.NewSet(), make(map[common.Hash]*types.Header)
+
+ number, parent := block.NumberU64()-1, block.ParentHash()
+ for i := 0; i < 7; i++ {
+ ancestor := chain.GetBlock(parent, number)
+ if ancestor == nil {
+ break
+ }
+ ancestors[ancestor.Hash()] = ancestor.Header()
+ for _, uncle := range ancestor.Uncles() {
+ uncles.Add(uncle.Hash())
+ }
+ parent, number = ancestor.ParentHash(), number-1
+ }
+ ancestors[block.Hash()] = block.Header()
+ uncles.Add(block.Hash())
+
+ // Verify each of the uncles that it's recent, but not an ancestor
+ for _, uncle := range block.Uncles() {
+ // Make sure every uncle is rewarded only once
+ hash := uncle.Hash()
+ if uncles.Contains(hash) {
+ return errDuplicateUncle
+ }
+ uncles.Add(hash)
+
+ // Make sure the uncle has a valid ancestry
+ if ancestors[hash] != nil {
+ return errUncleIsAncestor
+ }
+ if ancestors[uncle.ParentHash] == nil || uncle.ParentHash == block.ParentHash() {
+ return errDanglingUncle
+ }
+ if err := ethash.verifyHeader(chain, uncle, ancestors[uncle.ParentHash], true, true); err != nil {
+ return err
+ }
+ }
+ return nil
+}
+
+// verifyHeader checks whether a header conforms to the consensus rules of the
+// stock Ethereum ethash engine.
+// See YP section 4.3.4. "Block Header Validity"
+func (ethash *Ethash) verifyHeader(chain consensus.ChainReader, header, parent *types.Header, uncle bool, seal bool) error {
+ // Ensure that the header's extra-data section is of a reasonable size
+ if uint64(len(header.Extra)) > params.MaximumExtraDataSize {
+ return fmt.Errorf("extra-data too long: %d > %d", len(header.Extra), params.MaximumExtraDataSize)
+ }
+ // Verify the header's timestamp
+ if !uncle {
+ if header.Time > uint64(time.Now().Add(allowedFutureBlockTime).Unix()) {
+ return consensus.ErrFutureBlock
+ }
+ }
+ if header.Time <= parent.Time {
+ return errZeroBlockTime
+ }
+ // Verify the block's difficulty based in it's timestamp and parent's difficulty
+ expected := ethash.CalcDifficulty(chain, header.Time, parent)
+
+ if expected.Cmp(header.Difficulty) != 0 {
+ return fmt.Errorf("invalid difficulty: have %v, want %v", header.Difficulty, expected)
+ }
+ // Verify that the gas limit is <= 2^63-1
+ cap := uint64(0x7fffffffffffffff)
+ if header.GasLimit > cap {
+ return fmt.Errorf("invalid gasLimit: have %v, max %v", header.GasLimit, cap)
+ }
+ // Verify that the gasUsed is <= gasLimit
+ if header.GasUsed > header.GasLimit {
+ return fmt.Errorf("invalid gasUsed: have %d, gasLimit %d", header.GasUsed, header.GasLimit)
+ }
+
+ // Verify that the gas limit remains within allowed bounds
+ diff := int64(parent.GasLimit) - int64(header.GasLimit)
+ if diff < 0 {
+ diff *= -1
+ }
+ limit := parent.GasLimit / params.GasLimitBoundDivisor
+
+ if uint64(diff) >= limit || header.GasLimit < params.MinGasLimit {
+ return fmt.Errorf("invalid gas limit: have %d, want %d += %d", header.GasLimit, parent.GasLimit, limit)
+ }
+ // Verify that the block number is parent's +1
+ if diff := new(big.Int).Sub(header.Number, parent.Number); diff.Cmp(big.NewInt(1)) != 0 {
+ return consensus.ErrInvalidNumber
+ }
+ // Verify the engine specific seal securing the block
+ if seal {
+ if err := ethash.VerifySeal(chain, header); err != nil {
+ return err
+ }
+ }
+ // If all checks passed, validate any special fields for hard forks
+ if err := misc.VerifyDAOHeaderExtraData(chain.Config(), header); err != nil {
+ return err
+ }
+ if err := misc.VerifyForkHashes(chain.Config(), header, uncle); err != nil {
+ return err
+ }
+ return nil
+}
+
+// CalcDifficulty is the difficulty adjustment algorithm. It returns
+// the difficulty that a new block should have when created at time
+// given the parent block's time and difficulty.
+func (ethash *Ethash) CalcDifficulty(chain consensus.ChainReader, time uint64, parent *types.Header) *big.Int {
+ return CalcDifficulty(chain.Config(), time, parent)
+}
+
+// CalcDifficulty is the difficulty adjustment algorithm. It returns
+// the difficulty that a new block should have when created at time
+// given the parent block's time and difficulty.
+func CalcDifficulty(config *params.ChainConfig, time uint64, parent *types.Header) *big.Int {
+ next := new(big.Int).Add(parent.Number, big1)
+ switch {
+ case config.IsConstantinople(next):
+ return calcDifficultyConstantinople(time, parent)
+ case config.IsByzantium(next):
+ return calcDifficultyByzantium(time, parent)
+ case config.IsHomestead(next):
+ return calcDifficultyHomestead(time, parent)
+ default:
+ return calcDifficultyFrontier(time, parent)
+ }
+}
+
+// Some weird constants to avoid constant memory allocs for them.
+var (
+ expDiffPeriod = big.NewInt(100000)
+ big1 = big.NewInt(1)
+ big2 = big.NewInt(2)
+ big9 = big.NewInt(9)
+ big10 = big.NewInt(10)
+ bigMinus99 = big.NewInt(-99)
+)
+
+// makeDifficultyCalculator creates a difficultyCalculator with the given bomb-delay.
+// the difficulty is calculated with Byzantium rules, which differs from Homestead in
+// how uncles affect the calculation
+func makeDifficultyCalculator(bombDelay *big.Int) func(time uint64, parent *types.Header) *big.Int {
+ // Note, the calculations below looks at the parent number, which is 1 below
+ // the block number. Thus we remove one from the delay given
+ bombDelayFromParent := new(big.Int).Sub(bombDelay, big1)
+ return func(time uint64, parent *types.Header) *big.Int {
+ // https://github.com/ethereum/EIPs/issues/100.
+ // algorithm:
+ // diff = (parent_diff +
+ // (parent_diff / 2048 * max((2 if len(parent.uncles) else 1) - ((timestamp - parent.timestamp) // 9), -99))
+ // ) + 2^(periodCount - 2)
+
+ bigTime := new(big.Int).SetUint64(time)
+ bigParentTime := new(big.Int).SetUint64(parent.Time)
+
+ // holds intermediate values to make the algo easier to read & audit
+ x := new(big.Int)
+ y := new(big.Int)
+
+ // (2 if len(parent_uncles) else 1) - (block_timestamp - parent_timestamp) // 9
+ x.Sub(bigTime, bigParentTime)
+ x.Div(x, big9)
+ if parent.UncleHash == types.EmptyUncleHash {
+ x.Sub(big1, x)
+ } else {
+ x.Sub(big2, x)
+ }
+ // max((2 if len(parent_uncles) else 1) - (block_timestamp - parent_timestamp) // 9, -99)
+ if x.Cmp(bigMinus99) < 0 {
+ x.Set(bigMinus99)
+ }
+ // parent_diff + (parent_diff / 2048 * max((2 if len(parent.uncles) else 1) - ((timestamp - parent.timestamp) // 9), -99))
+ y.Div(parent.Difficulty, params.DifficultyBoundDivisor)
+ x.Mul(y, x)
+ x.Add(parent.Difficulty, x)
+
+ // minimum difficulty can ever be (before exponential factor)
+ if x.Cmp(params.MinimumDifficulty) < 0 {
+ x.Set(params.MinimumDifficulty)
+ }
+ // calculate a fake block number for the ice-age delay
+ // Specification: https://eips.ethereum.org/EIPS/eip-1234
+ fakeBlockNumber := new(big.Int)
+ if parent.Number.Cmp(bombDelayFromParent) >= 0 {
+ fakeBlockNumber = fakeBlockNumber.Sub(parent.Number, bombDelayFromParent)
+ }
+ // for the exponential factor
+ periodCount := fakeBlockNumber
+ periodCount.Div(periodCount, expDiffPeriod)
+
+ // the exponential factor, commonly referred to as "the bomb"
+ // diff = diff + 2^(periodCount - 2)
+ if periodCount.Cmp(big1) > 0 {
+ y.Sub(periodCount, big2)
+ y.Exp(big2, y, nil)
+ x.Add(x, y)
+ }
+ return x
+ }
+}
+
+// calcDifficultyHomestead is the difficulty adjustment algorithm. It returns
+// the difficulty that a new block should have when created at time given the
+// parent block's time and difficulty. The calculation uses the Homestead rules.
+func calcDifficultyHomestead(time uint64, parent *types.Header) *big.Int {
+ // https://github.com/ethereum/EIPs/blob/master/EIPS/eip-2.md
+ // algorithm:
+ // diff = (parent_diff +
+ // (parent_diff / 2048 * max(1 - (block_timestamp - parent_timestamp) // 10, -99))
+ // ) + 2^(periodCount - 2)
+
+ bigTime := new(big.Int).SetUint64(time)
+ bigParentTime := new(big.Int).SetUint64(parent.Time)
+
+ // holds intermediate values to make the algo easier to read & audit
+ x := new(big.Int)
+ y := new(big.Int)
+
+ // 1 - (block_timestamp - parent_timestamp) // 10
+ x.Sub(bigTime, bigParentTime)
+ x.Div(x, big10)
+ x.Sub(big1, x)
+
+ // max(1 - (block_timestamp - parent_timestamp) // 10, -99)
+ if x.Cmp(bigMinus99) < 0 {
+ x.Set(bigMinus99)
+ }
+ // (parent_diff + parent_diff // 2048 * max(1 - (block_timestamp - parent_timestamp) // 10, -99))
+ y.Div(parent.Difficulty, params.DifficultyBoundDivisor)
+ x.Mul(y, x)
+ x.Add(parent.Difficulty, x)
+
+ // minimum difficulty can ever be (before exponential factor)
+ if x.Cmp(params.MinimumDifficulty) < 0 {
+ x.Set(params.MinimumDifficulty)
+ }
+ // for the exponential factor
+ periodCount := new(big.Int).Add(parent.Number, big1)
+ periodCount.Div(periodCount, expDiffPeriod)
+
+ // the exponential factor, commonly referred to as "the bomb"
+ // diff = diff + 2^(periodCount - 2)
+ if periodCount.Cmp(big1) > 0 {
+ y.Sub(periodCount, big2)
+ y.Exp(big2, y, nil)
+ x.Add(x, y)
+ }
+ return x
+}
+
+// calcDifficultyFrontier is the difficulty adjustment algorithm. It returns the
+// difficulty that a new block should have when created at time given the parent
+// block's time and difficulty. The calculation uses the Frontier rules.
+func calcDifficultyFrontier(time uint64, parent *types.Header) *big.Int {
+ diff := new(big.Int)
+ adjust := new(big.Int).Div(parent.Difficulty, params.DifficultyBoundDivisor)
+ bigTime := new(big.Int)
+ bigParentTime := new(big.Int)
+
+ bigTime.SetUint64(time)
+ bigParentTime.SetUint64(parent.Time)
+
+ if bigTime.Sub(bigTime, bigParentTime).Cmp(params.DurationLimit) < 0 {
+ diff.Add(parent.Difficulty, adjust)
+ } else {
+ diff.Sub(parent.Difficulty, adjust)
+ }
+ if diff.Cmp(params.MinimumDifficulty) < 0 {
+ diff.Set(params.MinimumDifficulty)
+ }
+
+ periodCount := new(big.Int).Add(parent.Number, big1)
+ periodCount.Div(periodCount, expDiffPeriod)
+ if periodCount.Cmp(big1) > 0 {
+ // diff = diff + 2^(periodCount - 2)
+ expDiff := periodCount.Sub(periodCount, big2)
+ expDiff.Exp(big2, expDiff, nil)
+ diff.Add(diff, expDiff)
+ diff = math.BigMax(diff, params.MinimumDifficulty)
+ }
+ return diff
+}
+
+// VerifySeal implements consensus.Engine, checking whether the given block satisfies
+// the PoW difficulty requirements.
+func (ethash *Ethash) VerifySeal(chain consensus.ChainReader, header *types.Header) error {
+ return ethash.verifySeal(chain, header, false)
+}
+
+// verifySeal checks whether a block satisfies the PoW difficulty requirements,
+// either using the usual ethash cache for it, or alternatively using a full DAG
+// to make remote mining fast.
+func (ethash *Ethash) verifySeal(chain consensus.ChainReader, header *types.Header, fulldag bool) error {
+ // If we're running a fake PoW, accept any seal as valid
+ if ethash.config.PowMode == ModeFake || ethash.config.PowMode == ModeFullFake {
+ time.Sleep(ethash.fakeDelay)
+ if ethash.fakeFail == header.Number.Uint64() {
+ return errInvalidPoW
+ }
+ return nil
+ }
+ // If we're running a shared PoW, delegate verification to it
+ if ethash.shared != nil {
+ return ethash.shared.verifySeal(chain, header, fulldag)
+ }
+ // Ensure that we have a valid difficulty for the block
+ if header.Difficulty.Sign() <= 0 {
+ return errInvalidDifficulty
+ }
+ // Recompute the digest and PoW values
+ number := header.Number.Uint64()
+
+ var (
+ digest []byte
+ result []byte
+ )
+ // If fast-but-heavy PoW verification was requested, use an ethash dataset
+ if fulldag {
+ dataset := ethash.dataset(number, true)
+ if dataset.generated() {
+ digest, result = hashimotoFull(dataset.dataset, ethash.SealHash(header).Bytes(), header.Nonce.Uint64())
+
+ // Datasets are unmapped in a finalizer. Ensure that the dataset stays alive
+ // until after the call to hashimotoFull so it's not unmapped while being used.
+ runtime.KeepAlive(dataset)
+ } else {
+ // Dataset not yet generated, don't hang, use a cache instead
+ fulldag = false
+ }
+ }
+ // If slow-but-light PoW verification was requested (or DAG not yet ready), use an ethash cache
+ if !fulldag {
+ cache := ethash.cache(number)
+
+ size := datasetSize(number)
+ if ethash.config.PowMode == ModeTest {
+ size = 32 * 1024
+ }
+ digest, result = hashimotoLight(size, cache.cache, ethash.SealHash(header).Bytes(), header.Nonce.Uint64())
+
+ // Caches are unmapped in a finalizer. Ensure that the cache stays alive
+ // until after the call to hashimotoLight so it's not unmapped while being used.
+ runtime.KeepAlive(cache)
+ }
+ // Verify the calculated values against the ones provided in the header
+ if !bytes.Equal(header.MixDigest[:], digest) {
+ return errInvalidMixDigest
+ }
+ target := new(big.Int).Div(two256, header.Difficulty)
+ if new(big.Int).SetBytes(result).Cmp(target) > 0 {
+ return errInvalidPoW
+ }
+ return nil
+}
+
+// Prepare implements consensus.Engine, initializing the difficulty field of a
+// header to conform to the ethash protocol. The changes are done inline.
+func (ethash *Ethash) Prepare(chain consensus.ChainReader, header *types.Header) error {
+ parent := chain.GetHeader(header.ParentHash, header.Number.Uint64()-1)
+ if parent == nil {
+ return consensus.ErrUnknownAncestor
+ }
+ header.Difficulty = ethash.CalcDifficulty(chain, header.Time, parent)
+ return nil
+}
+
+// Finalize implements consensus.Engine, accumulating the block and uncle rewards,
+// setting the final state on the header
+func (ethash *Ethash) Finalize(chain consensus.ChainReader, header *types.Header, state *state.StateDB, txs []*types.Transaction, uncles []*types.Header) {
+ // Accumulate any block and uncle rewards and commit the final state root
+ accumulateRewards(chain.Config(), state, header, uncles)
+ header.Root = state.IntermediateRoot(chain.Config().IsEIP158(header.Number))
+}
+
+// FinalizeAndAssemble implements consensus.Engine, accumulating the block and
+// uncle rewards, setting the final state and assembling the block.
+func (ethash *Ethash) FinalizeAndAssemble(chain consensus.ChainReader, header *types.Header, state *state.StateDB, txs []*types.Transaction, uncles []*types.Header, receipts []*types.Receipt) (*types.Block, error) {
+ // Accumulate any block and uncle rewards and commit the final state root
+ accumulateRewards(chain.Config(), state, header, uncles)
+ header.Root = state.IntermediateRoot(chain.Config().IsEIP158(header.Number))
+
+ // Header seems complete, assemble into a block and return
+ return types.NewBlock(header, txs, uncles, receipts), nil
+}
+
+// SealHash returns the hash of a block prior to it being sealed.
+func (ethash *Ethash) SealHash(header *types.Header) (hash common.Hash) {
+ hasher := sha3.NewLegacyKeccak256()
+
+ rlp.Encode(hasher, []interface{}{
+ header.ParentHash,
+ header.UncleHash,
+ header.Coinbase,
+ header.Root,
+ header.TxHash,
+ header.ReceiptHash,
+ header.Bloom,
+ header.Difficulty,
+ header.Number,
+ header.GasLimit,
+ header.GasUsed,
+ header.Time,
+ header.Extra,
+ })
+ hasher.Sum(hash[:0])
+ return hash
+}
+
+// Some weird constants to avoid constant memory allocs for them.
+var (
+ big8 = big.NewInt(8)
+ big32 = big.NewInt(32)
+)
+
+// AccumulateRewards credits the coinbase of the given block with the mining
+// reward. The total reward consists of the static block reward and rewards for
+// included uncles. The coinbase of each uncle block is also rewarded.
+func accumulateRewards(config *params.ChainConfig, state *state.StateDB, header *types.Header, uncles []*types.Header) {
+ // Select the correct block reward based on chain progression
+ blockReward := FrontierBlockReward
+ if config.IsByzantium(header.Number) {
+ blockReward = ByzantiumBlockReward
+ }
+ if config.IsConstantinople(header.Number) {
+ blockReward = ConstantinopleBlockReward
+ }
+ // Accumulate the rewards for the miner and any included uncles
+ reward := new(big.Int).Set(blockReward)
+ r := new(big.Int)
+ for _, uncle := range uncles {
+ r.Add(uncle.Number, big8)
+ r.Sub(r, header.Number)
+ r.Mul(r, blockReward)
+ r.Div(r, big8)
+ state.AddBalance(uncle.Coinbase, r)
+
+ r.Div(blockReward, big32)
+ reward.Add(reward, r)
+ }
+ state.AddBalance(header.Coinbase, reward)
+}
diff --git a/consensus/ethash/ethash.go b/consensus/ethash/ethash.go
new file mode 100644
index 0000000..53420d0
--- /dev/null
+++ b/consensus/ethash/ethash.go
@@ -0,0 +1,717 @@
+// Copyright 2017 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 ethash implements the ethash proof-of-work consensus engine.
+package ethash
+
+import (
+ "errors"
+ "fmt"
+ "math"
+ "math/big"
+ "math/rand"
+ "os"
+ "path/filepath"
+ "reflect"
+ "runtime"
+ "strconv"
+ "sync"
+ "sync/atomic"
+ "time"
+ "unsafe"
+
+ "github.com/ava-labs/coreth/consensus"
+ "github.com/ava-labs/coreth/core/types"
+ "github.com/ava-labs/coreth/rpc"
+ "github.com/ava-labs/go-ethereum/common"
+ "github.com/ava-labs/go-ethereum/log"
+ "github.com/ava-labs/go-ethereum/metrics"
+ mmap "github.com/edsrzf/mmap-go"
+ "github.com/hashicorp/golang-lru/simplelru"
+)
+
+var ErrInvalidDumpMagic = errors.New("invalid dump magic")
+
+var (
+ // two256 is a big integer representing 2^256
+ two256 = new(big.Int).Exp(big.NewInt(2), big.NewInt(256), big.NewInt(0))
+
+ // sharedEthash is a full instance that can be shared between multiple users.
+ sharedEthash = New(Config{"", 3, 0, "", 1, 0, ModeNormal}, nil, false)
+
+ // algorithmRevision is the data structure version used for file naming.
+ algorithmRevision = 23
+
+ // dumpMagic is a dataset dump header to sanity check a data dump.
+ dumpMagic = []uint32{0xbaddcafe, 0xfee1dead}
+)
+
+// isLittleEndian returns whether the local system is running in little or big
+// endian byte order.
+func isLittleEndian() bool {
+ n := uint32(0x01020304)
+ return *(*byte)(unsafe.Pointer(&n)) == 0x04
+}
+
+// memoryMap tries to memory map a file of uint32s for read only access.
+func memoryMap(path string) (*os.File, mmap.MMap, []uint32, error) {
+ file, err := os.OpenFile(path, os.O_RDONLY, 0644)
+ if err != nil {
+ return nil, nil, nil, err
+ }
+ mem, buffer, err := memoryMapFile(file, false)
+ if err != nil {
+ file.Close()
+ return nil, nil, nil, err
+ }
+ for i, magic := range dumpMagic {
+ if buffer[i] != magic {
+ mem.Unmap()
+ file.Close()
+ return nil, nil, nil, ErrInvalidDumpMagic
+ }
+ }
+ return file, mem, buffer[len(dumpMagic):], err
+}
+
+// memoryMapFile tries to memory map an already opened file descriptor.
+func memoryMapFile(file *os.File, write bool) (mmap.MMap, []uint32, error) {
+ // Try to memory map the file
+ flag := mmap.RDONLY
+ if write {
+ flag = mmap.RDWR
+ }
+ mem, err := mmap.Map(file, flag, 0)
+ if err != nil {
+ return nil, nil, err
+ }
+ // Yay, we managed to memory map the file, here be dragons
+ header := *(*reflect.SliceHeader)(unsafe.Pointer(&mem))
+ header.Len /= 4
+ header.Cap /= 4
+
+ return mem, *(*[]uint32)(unsafe.Pointer(&header)), nil
+}
+
+// memoryMapAndGenerate tries to memory map a temporary file of uint32s for write
+// access, fill it with the data from a generator and then move it into the final
+// path requested.
+func memoryMapAndGenerate(path string, size uint64, generator func(buffer []uint32)) (*os.File, mmap.MMap, []uint32, error) {
+ // Ensure the data folder exists
+ if err := os.MkdirAll(filepath.Dir(path), 0755); err != nil {
+ return nil, nil, nil, err
+ }
+ // Create a huge temporary empty file to fill with data
+ temp := path + "." + strconv.Itoa(rand.Int())
+
+ dump, err := os.Create(temp)
+ if err != nil {
+ return nil, nil, nil, err
+ }
+ if err = dump.Truncate(int64(len(dumpMagic))*4 + int64(size)); err != nil {
+ return nil, nil, nil, err
+ }
+ // Memory map the file for writing and fill it with the generator
+ mem, buffer, err := memoryMapFile(dump, true)
+ if err != nil {
+ dump.Close()
+ return nil, nil, nil, err
+ }
+ copy(buffer, dumpMagic)
+
+ data := buffer[len(dumpMagic):]
+ generator(data)
+
+ if err := mem.Unmap(); err != nil {
+ return nil, nil, nil, err
+ }
+ if err := dump.Close(); err != nil {
+ return nil, nil, nil, err
+ }
+ if err := os.Rename(temp, path); err != nil {
+ return nil, nil, nil, err
+ }
+ return memoryMap(path)
+}
+
+// lru tracks caches or datasets by their last use time, keeping at most N of them.
+type lru struct {
+ what string
+ new func(epoch uint64) interface{}
+ mu sync.Mutex
+ // Items are kept in a LRU cache, but there is a special case:
+ // We always keep an item for (highest seen epoch) + 1 as the 'future item'.
+ cache *simplelru.LRU
+ future uint64
+ futureItem interface{}
+}
+
+// newlru create a new least-recently-used cache for either the verification caches
+// or the mining datasets.
+func newlru(what string, maxItems int, new func(epoch uint64) interface{}) *lru {
+ if maxItems <= 0 {
+ maxItems = 1
+ }
+ cache, _ := simplelru.NewLRU(maxItems, func(key, value interface{}) {
+ log.Trace("Evicted ethash "+what, "epoch", key)
+ })
+ return &lru{what: what, new: new, cache: cache}
+}
+
+// get retrieves or creates an item for the given epoch. The first return value is always
+// non-nil. The second return value is non-nil if lru thinks that an item will be useful in
+// the near future.
+func (lru *lru) get(epoch uint64) (item, future interface{}) {
+ lru.mu.Lock()
+ defer lru.mu.Unlock()
+
+ // Get or create the item for the requested epoch.
+ item, ok := lru.cache.Get(epoch)
+ if !ok {
+ if lru.future > 0 && lru.future == epoch {
+ item = lru.futureItem
+ } else {
+ log.Trace("Requiring new ethash "+lru.what, "epoch", epoch)
+ item = lru.new(epoch)
+ }
+ lru.cache.Add(epoch, item)
+ }
+ // Update the 'future item' if epoch is larger than previously seen.
+ if epoch < maxEpoch-1 && lru.future < epoch+1 {
+ log.Trace("Requiring new future ethash "+lru.what, "epoch", epoch+1)
+ future = lru.new(epoch + 1)
+ lru.future = epoch + 1
+ lru.futureItem = future
+ }
+ return item, future
+}
+
+// cache wraps an ethash cache with some metadata to allow easier concurrent use.
+type cache struct {
+ epoch uint64 // Epoch for which this cache is relevant
+ dump *os.File // File descriptor of the memory mapped cache
+ mmap mmap.MMap // Memory map itself to unmap before releasing
+ cache []uint32 // The actual cache data content (may be memory mapped)
+ once sync.Once // Ensures the cache is generated only once
+}
+
+// newCache creates a new ethash verification cache and returns it as a plain Go
+// interface to be usable in an LRU cache.
+func newCache(epoch uint64) interface{} {
+ return &cache{epoch: epoch}
+}
+
+// generate ensures that the cache content is generated before use.
+func (c *cache) generate(dir string, limit int, test bool) {
+ c.once.Do(func() {
+ size := cacheSize(c.epoch*epochLength + 1)
+ seed := seedHash(c.epoch*epochLength + 1)
+ if test {
+ size = 1024
+ }
+ // If we don't store anything on disk, generate and return.
+ if dir == "" {
+ c.cache = make([]uint32, size/4)
+ generateCache(c.cache, c.epoch, seed)
+ return
+ }
+ // Disk storage is needed, this will get fancy
+ var endian string
+ if !isLittleEndian() {
+ endian = ".be"
+ }
+ path := filepath.Join(dir, fmt.Sprintf("cache-R%d-%x%s", algorithmRevision, seed[:8], endian))
+ logger := log.New("epoch", c.epoch)
+
+ // We're about to mmap the file, ensure that the mapping is cleaned up when the
+ // cache becomes unused.
+ runtime.SetFinalizer(c, (*cache).finalizer)
+
+ // Try to load the file from disk and memory map it
+ var err error
+ c.dump, c.mmap, c.cache, err = memoryMap(path)
+ if err == nil {
+ logger.Debug("Loaded old ethash cache from disk")
+ return
+ }
+ logger.Debug("Failed to load old ethash cache", "err", err)
+
+ // No previous cache available, create a new cache file to fill
+ c.dump, c.mmap, c.cache, err = memoryMapAndGenerate(path, size, func(buffer []uint32) { generateCache(buffer, c.epoch, seed) })
+ if err != nil {
+ logger.Error("Failed to generate mapped ethash cache", "err", err)
+
+ c.cache = make([]uint32, size/4)
+ generateCache(c.cache, c.epoch, seed)
+ }
+ // Iterate over all previous instances and delete old ones
+ for ep := int(c.epoch) - limit; ep >= 0; ep-- {
+ seed := seedHash(uint64(ep)*epochLength + 1)
+ path := filepath.Join(dir, fmt.Sprintf("cache-R%d-%x%s", algorithmRevision, seed[:8], endian))
+ os.Remove(path)
+ }
+ })
+}
+
+// finalizer unmaps the memory and closes the file.
+func (c *cache) finalizer() {
+ if c.mmap != nil {
+ c.mmap.Unmap()
+ c.dump.Close()
+ c.mmap, c.dump = nil, nil
+ }
+}
+
+// dataset wraps an ethash dataset with some metadata to allow easier concurrent use.
+type dataset struct {
+ epoch uint64 // Epoch for which this cache is relevant
+ dump *os.File // File descriptor of the memory mapped cache
+ mmap mmap.MMap // Memory map itself to unmap before releasing
+ dataset []uint32 // The actual cache data content
+ once sync.Once // Ensures the cache is generated only once
+ done uint32 // Atomic flag to determine generation status
+}
+
+// newDataset creates a new ethash mining dataset and returns it as a plain Go
+// interface to be usable in an LRU cache.
+func newDataset(epoch uint64) interface{} {
+ return &dataset{epoch: epoch}
+}
+
+// generate ensures that the dataset content is generated before use.
+func (d *dataset) generate(dir string, limit int, test bool) {
+ d.once.Do(func() {
+ // Mark the dataset generated after we're done. This is needed for remote
+ defer atomic.StoreUint32(&d.done, 1)
+
+ csize := cacheSize(d.epoch*epochLength + 1)
+ dsize := datasetSize(d.epoch*epochLength + 1)
+ seed := seedHash(d.epoch*epochLength + 1)
+ if test {
+ csize = 1024
+ dsize = 32 * 1024
+ }
+ // If we don't store anything on disk, generate and return
+ if dir == "" {
+ cache := make([]uint32, csize/4)
+ generateCache(cache, d.epoch, seed)
+
+ d.dataset = make([]uint32, dsize/4)
+ generateDataset(d.dataset, d.epoch, cache)
+
+ return
+ }
+ // Disk storage is needed, this will get fancy
+ var endian string
+ if !isLittleEndian() {
+ endian = ".be"
+ }
+ path := filepath.Join(dir, fmt.Sprintf("full-R%d-%x%s", algorithmRevision, seed[:8], endian))
+ logger := log.New("epoch", d.epoch)
+
+ // We're about to mmap the file, ensure that the mapping is cleaned up when the
+ // cache becomes unused.
+ runtime.SetFinalizer(d, (*dataset).finalizer)
+
+ // Try to load the file from disk and memory map it
+ var err error
+ d.dump, d.mmap, d.dataset, err = memoryMap(path)
+ if err == nil {
+ logger.Debug("Loaded old ethash dataset from disk")
+ return
+ }
+ logger.Debug("Failed to load old ethash dataset", "err", err)
+
+ // No previous dataset available, create a new dataset file to fill
+ cache := make([]uint32, csize/4)
+ generateCache(cache, d.epoch, seed)
+
+ d.dump, d.mmap, d.dataset, err = memoryMapAndGenerate(path, dsize, func(buffer []uint32) { generateDataset(buffer, d.epoch, cache) })
+ if err != nil {
+ logger.Error("Failed to generate mapped ethash dataset", "err", err)
+
+ d.dataset = make([]uint32, dsize/2)
+ generateDataset(d.dataset, d.epoch, cache)
+ }
+ // Iterate over all previous instances and delete old ones
+ for ep := int(d.epoch) - limit; ep >= 0; ep-- {
+ seed := seedHash(uint64(ep)*epochLength + 1)
+ path := filepath.Join(dir, fmt.Sprintf("full-R%d-%x%s", algorithmRevision, seed[:8], endian))
+ os.Remove(path)
+ }
+ })
+}
+
+// generated returns whether this particular dataset finished generating already
+// or not (it may not have been started at all). This is useful for remote miners
+// to default to verification caches instead of blocking on DAG generations.
+func (d *dataset) generated() bool {
+ return atomic.LoadUint32(&d.done) == 1
+}
+
+// finalizer closes any file handlers and memory maps open.
+func (d *dataset) finalizer() {
+ if d.mmap != nil {
+ d.mmap.Unmap()
+ d.dump.Close()
+ d.mmap, d.dump = nil, nil
+ }
+}
+
+// MakeCache generates a new ethash cache and optionally stores it to disk.
+func MakeCache(block uint64, dir string) {
+ c := cache{epoch: block / epochLength}
+ c.generate(dir, math.MaxInt32, false)
+}
+
+// MakeDataset generates a new ethash dataset and optionally stores it to disk.
+func MakeDataset(block uint64, dir string) {
+ d := dataset{epoch: block / epochLength}
+ d.generate(dir, math.MaxInt32, false)
+}
+
+// Mode defines the type and amount of PoW verification an ethash engine makes.
+type Mode uint
+
+const (
+ ModeNormal Mode = iota
+ ModeShared
+ ModeTest
+ ModeFake
+ ModeFullFake
+)
+
+// Config are the configuration parameters of the ethash.
+type Config struct {
+ CacheDir string
+ CachesInMem int
+ CachesOnDisk int
+ DatasetDir string
+ DatasetsInMem int
+ DatasetsOnDisk int
+ PowMode Mode
+}
+
+// sealTask wraps a seal block with relative result channel for remote sealer thread.
+type sealTask struct {
+ block *types.Block
+ results chan<- *types.Block
+}
+
+// mineResult wraps the pow solution parameters for the specified block.
+type mineResult struct {
+ nonce types.BlockNonce
+ mixDigest common.Hash
+ hash common.Hash
+
+ errc chan error
+}
+
+// hashrate wraps the hash rate submitted by the remote sealer.
+type hashrate struct {
+ id common.Hash
+ ping time.Time
+ rate uint64
+
+ done chan struct{}
+}
+
+// sealWork wraps a seal work package for remote sealer.
+type sealWork struct {
+ errc chan error
+ res chan [4]string
+}
+
+// Ethash is a consensus engine based on proof-of-work implementing the ethash
+// algorithm.
+type Ethash struct {
+ config Config
+
+ caches *lru // In memory caches to avoid regenerating too often
+ datasets *lru // In memory datasets to avoid regenerating too often
+
+ // Mining related fields
+ rand *rand.Rand // Properly seeded random source for nonces
+ threads int // Number of threads to mine on if mining
+ update chan struct{} // Notification channel to update mining parameters
+ hashrate metrics.Meter // Meter tracking the average hashrate
+
+ // Remote sealer related fields
+ workCh chan *sealTask // Notification channel to push new work and relative result channel to remote sealer
+ fetchWorkCh chan *sealWork // Channel used for remote sealer to fetch mining work
+ submitWorkCh chan *mineResult // Channel used for remote sealer to submit their mining result
+ fetchRateCh chan chan uint64 // Channel used to gather submitted hash rate for local or remote sealer.
+ submitRateCh chan *hashrate // Channel used for remote sealer to submit their mining hashrate
+
+ // The fields below are hooks for testing
+ shared *Ethash // Shared PoW verifier to avoid cache regeneration
+ fakeFail uint64 // Block number which fails PoW check even in fake mode
+ fakeDelay time.Duration // Time delay to sleep for before returning from verify
+
+ lock sync.Mutex // Ensures thread safety for the in-memory caches and mining fields
+ closeOnce sync.Once // Ensures exit channel will not be closed twice.
+ exitCh chan chan error // Notification channel to exiting backend threads
+}
+
+// New creates a full sized ethash PoW scheme and starts a background thread for
+// remote mining, also optionally notifying a batch of remote services of new work
+// packages.
+func New(config Config, notify []string, noverify bool) *Ethash {
+ if config.CachesInMem <= 0 {
+ log.Warn("One ethash cache must always be in memory", "requested", config.CachesInMem)
+ config.CachesInMem = 1
+ }
+ if config.CacheDir != "" && config.CachesOnDisk > 0 {
+ log.Info("Disk storage enabled for ethash caches", "dir", config.CacheDir, "count", config.CachesOnDisk)
+ }
+ if config.DatasetDir != "" && config.DatasetsOnDisk > 0 {
+ log.Info("Disk storage enabled for ethash DAGs", "dir", config.DatasetDir, "count", config.DatasetsOnDisk)
+ }
+ ethash := &Ethash{
+ config: config,
+ caches: newlru("cache", config.CachesInMem, newCache),
+ datasets: newlru("dataset", config.DatasetsInMem, newDataset),
+ update: make(chan struct{}),
+ hashrate: metrics.NewMeterForced(),
+ workCh: make(chan *sealTask),
+ fetchWorkCh: make(chan *sealWork),
+ submitWorkCh: make(chan *mineResult),
+ fetchRateCh: make(chan chan uint64),
+ submitRateCh: make(chan *hashrate),
+ exitCh: make(chan chan error),
+ }
+ go ethash.remote(notify, noverify)
+ return ethash
+}
+
+// NewTester creates a small sized ethash PoW scheme useful only for testing
+// purposes.
+func NewTester(notify []string, noverify bool) *Ethash {
+ ethash := &Ethash{
+ config: Config{PowMode: ModeTest},
+ caches: newlru("cache", 1, newCache),
+ datasets: newlru("dataset", 1, newDataset),
+ update: make(chan struct{}),
+ hashrate: metrics.NewMeterForced(),
+ workCh: make(chan *sealTask),
+ fetchWorkCh: make(chan *sealWork),
+ submitWorkCh: make(chan *mineResult),
+ fetchRateCh: make(chan chan uint64),
+ submitRateCh: make(chan *hashrate),
+ exitCh: make(chan chan error),
+ }
+ go ethash.remote(notify, noverify)
+ return ethash
+}
+
+// NewFaker creates a ethash consensus engine with a fake PoW scheme that accepts
+// all blocks' seal as valid, though they still have to conform to the Ethereum
+// consensus rules.
+func NewFaker() *Ethash {
+ return &Ethash{
+ config: Config{
+ PowMode: ModeFake,
+ },
+ }
+}
+
+// NewFakeFailer creates a ethash consensus engine with a fake PoW scheme that
+// accepts all blocks as valid apart from the single one specified, though they
+// still have to conform to the Ethereum consensus rules.
+func NewFakeFailer(fail uint64) *Ethash {
+ return &Ethash{
+ config: Config{
+ PowMode: ModeFake,
+ },
+ fakeFail: fail,
+ }
+}
+
+// NewFakeDelayer creates a ethash consensus engine with a fake PoW scheme that
+// accepts all blocks as valid, but delays verifications by some time, though
+// they still have to conform to the Ethereum consensus rules.
+func NewFakeDelayer(delay time.Duration) *Ethash {
+ return &Ethash{
+ config: Config{
+ PowMode: ModeFake,
+ },
+ fakeDelay: delay,
+ }
+}
+
+// NewFullFaker creates an ethash consensus engine with a full fake scheme that
+// accepts all blocks as valid, without checking any consensus rules whatsoever.
+func NewFullFaker() *Ethash {
+ return &Ethash{
+ config: Config{
+ PowMode: ModeFullFake,
+ },
+ }
+}
+
+// NewShared creates a full sized ethash PoW shared between all requesters running
+// in the same process.
+func NewShared() *Ethash {
+ return &Ethash{shared: sharedEthash}
+}
+
+// Close closes the exit channel to notify all backend threads exiting.
+func (ethash *Ethash) Close() error {
+ var err error
+ ethash.closeOnce.Do(func() {
+ // Short circuit if the exit channel is not allocated.
+ if ethash.exitCh == nil {
+ return
+ }
+ errc := make(chan error)
+ ethash.exitCh <- errc
+ err = <-errc
+ close(ethash.exitCh)
+ })
+ return err
+}
+
+// cache tries to retrieve a verification cache for the specified block number
+// by first checking against a list of in-memory caches, then against caches
+// stored on disk, and finally generating one if none can be found.
+func (ethash *Ethash) cache(block uint64) *cache {
+ epoch := block / epochLength
+ currentI, futureI := ethash.caches.get(epoch)
+ current := currentI.(*cache)
+
+ // Wait for generation finish.
+ current.generate(ethash.config.CacheDir, ethash.config.CachesOnDisk, ethash.config.PowMode == ModeTest)
+
+ // If we need a new future cache, now's a good time to regenerate it.
+ if futureI != nil {
+ future := futureI.(*cache)
+ go future.generate(ethash.config.CacheDir, ethash.config.CachesOnDisk, ethash.config.PowMode == ModeTest)
+ }
+ return current
+}
+
+// dataset tries to retrieve a mining dataset for the specified block number
+// by first checking against a list of in-memory datasets, then against DAGs
+// stored on disk, and finally generating one if none can be found.
+//
+// If async is specified, not only the future but the current DAG is also
+// generates on a background thread.
+func (ethash *Ethash) dataset(block uint64, async bool) *dataset {
+ // Retrieve the requested ethash dataset
+ epoch := block / epochLength
+ currentI, futureI := ethash.datasets.get(epoch)
+ current := currentI.(*dataset)
+
+ // If async is specified, generate everything in a background thread
+ if async && !current.generated() {
+ go func() {
+ current.generate(ethash.config.DatasetDir, ethash.config.DatasetsOnDisk, ethash.config.PowMode == ModeTest)
+
+ if futureI != nil {
+ future := futureI.(*dataset)
+ future.generate(ethash.config.DatasetDir, ethash.config.DatasetsOnDisk, ethash.config.PowMode == ModeTest)
+ }
+ }()
+ } else {
+ // Either blocking generation was requested, or already done
+ current.generate(ethash.config.DatasetDir, ethash.config.DatasetsOnDisk, ethash.config.PowMode == ModeTest)
+
+ if futureI != nil {
+ future := futureI.(*dataset)
+ go future.generate(ethash.config.DatasetDir, ethash.config.DatasetsOnDisk, ethash.config.PowMode == ModeTest)
+ }
+ }
+ return current
+}
+
+// Threads returns the number of mining threads currently enabled. This doesn't
+// necessarily mean that mining is running!
+func (ethash *Ethash) Threads() int {
+ ethash.lock.Lock()
+ defer ethash.lock.Unlock()
+
+ return ethash.threads
+}
+
+// SetThreads updates the number of mining threads currently enabled. Calling
+// this method does not start mining, only sets the thread count. If zero is
+// specified, the miner will use all cores of the machine. Setting a thread
+// count below zero is allowed and will cause the miner to idle, without any
+// work being done.
+func (ethash *Ethash) SetThreads(threads int) {
+ ethash.lock.Lock()
+ defer ethash.lock.Unlock()
+
+ // If we're running a shared PoW, set the thread count on that instead
+ if ethash.shared != nil {
+ ethash.shared.SetThreads(threads)
+ return
+ }
+ // Update the threads and ping any running seal to pull in any changes
+ ethash.threads = threads
+ select {
+ case ethash.update <- struct{}{}:
+ default:
+ }
+}
+
+// Hashrate implements PoW, returning the measured rate of the search invocations
+// per second over the last minute.
+// Note the returned hashrate includes local hashrate, but also includes the total
+// hashrate of all remote miner.
+func (ethash *Ethash) Hashrate() float64 {
+ // Short circuit if we are run the ethash in normal/test mode.
+ if ethash.config.PowMode != ModeNormal && ethash.config.PowMode != ModeTest {
+ return ethash.hashrate.Rate1()
+ }
+ var res = make(chan uint64, 1)
+
+ select {
+ case ethash.fetchRateCh <- res:
+ case <-ethash.exitCh:
+ // Return local hashrate only if ethash is stopped.
+ return ethash.hashrate.Rate1()
+ }
+
+ // Gather total submitted hash rate of remote sealers.
+ return ethash.hashrate.Rate1() + float64(<-res)
+}
+
+// APIs implements consensus.Engine, returning the user facing RPC APIs.
+func (ethash *Ethash) APIs(chain consensus.ChainReader) []rpc.API {
+ // In order to ensure backward compatibility, we exposes ethash RPC APIs
+ // to both eth and ethash namespaces.
+ return []rpc.API{
+ {
+ Namespace: "eth",
+ Version: "1.0",
+ Service: &API{ethash},
+ Public: true,
+ },
+ {
+ Namespace: "ethash",
+ Version: "1.0",
+ Service: &API{ethash},
+ Public: true,
+ },
+ }
+}
+
+// SeedHash is the seed to use for generating a verification cache and the mining
+// dataset.
+func SeedHash(block uint64) []byte {
+ return seedHash(block)
+}
diff --git a/consensus/ethash/sealer.go b/consensus/ethash/sealer.go
new file mode 100644
index 0000000..799be05
--- /dev/null
+++ b/consensus/ethash/sealer.go
@@ -0,0 +1,371 @@
+// Copyright 2017 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 ethash
+
+import (
+ "bytes"
+ crand "crypto/rand"
+ "encoding/json"
+ "errors"
+ "math"
+ "math/big"
+ "math/rand"
+ "net/http"
+ "runtime"
+ "sync"
+ "time"
+
+ "github.com/ava-labs/coreth/consensus"
+ "github.com/ava-labs/coreth/core/types"
+ "github.com/ava-labs/go-ethereum/common"
+ "github.com/ava-labs/go-ethereum/common/hexutil"
+ "github.com/ava-labs/go-ethereum/log"
+)
+
+const (
+ // staleThreshold is the maximum depth of the acceptable stale but valid ethash solution.
+ staleThreshold = 7
+)
+
+var (
+ errNoMiningWork = errors.New("no mining work available yet")
+ errInvalidSealResult = errors.New("invalid or stale proof-of-work solution")
+)
+
+// Seal implements consensus.Engine, attempting to find a nonce that satisfies
+// the block's difficulty requirements.
+func (ethash *Ethash) Seal(chain consensus.ChainReader, block *types.Block, results chan<- *types.Block, stop <-chan struct{}) error {
+ // If we're running a fake PoW, simply return a 0 nonce immediately
+ if ethash.config.PowMode == ModeFake || ethash.config.PowMode == ModeFullFake {
+ header := block.Header()
+ header.Nonce, header.MixDigest = types.BlockNonce{}, common.Hash{}
+ select {
+ case results <- block.WithSeal(header):
+ default:
+ log.Warn("Sealing result is not read by miner", "mode", "fake", "sealhash", ethash.SealHash(block.Header()))
+ }
+ return nil
+ }
+ // If we're running a shared PoW, delegate sealing to it
+ if ethash.shared != nil {
+ return ethash.shared.Seal(chain, block, results, stop)
+ }
+ // Create a runner and the multiple search threads it directs
+ abort := make(chan struct{})
+
+ ethash.lock.Lock()
+ threads := ethash.threads
+ if ethash.rand == nil {
+ seed, err := crand.Int(crand.Reader, big.NewInt(math.MaxInt64))
+ if err != nil {
+ ethash.lock.Unlock()
+ return err
+ }
+ ethash.rand = rand.New(rand.NewSource(seed.Int64()))
+ }
+ ethash.lock.Unlock()
+ if threads == 0 {
+ threads = runtime.NumCPU()
+ }
+ if threads < 0 {
+ threads = 0 // Allows disabling local mining without extra logic around local/remote
+ }
+ // Push new work to remote sealer
+ if ethash.workCh != nil {
+ ethash.workCh <- &sealTask{block: block, results: results}
+ }
+ var (
+ pend sync.WaitGroup
+ locals = make(chan *types.Block)
+ )
+ for i := 0; i < threads; i++ {
+ pend.Add(1)
+ go func(id int, nonce uint64) {
+ defer pend.Done()
+ ethash.mine(block, id, nonce, abort, locals)
+ }(i, uint64(ethash.rand.Int63()))
+ }
+ // Wait until sealing is terminated or a nonce is found
+ go func() {
+ var result *types.Block
+ select {
+ case <-stop:
+ // Outside abort, stop all miner threads
+ close(abort)
+ case result = <-locals:
+ // One of the threads found a block, abort all others
+ select {
+ case results <- result:
+ default:
+ log.Warn("Sealing result is not read by miner", "mode", "local", "sealhash", ethash.SealHash(block.Header()))
+ }
+ close(abort)
+ case <-ethash.update:
+ // Thread count was changed on user request, restart
+ close(abort)
+ if err := ethash.Seal(chain, block, results, stop); err != nil {
+ log.Error("Failed to restart sealing after update", "err", err)
+ }
+ }
+ // Wait for all miners to terminate and return the block
+ pend.Wait()
+ }()
+ return nil
+}
+
+// mine is the actual proof-of-work miner that searches for a nonce starting from
+// seed that results in correct final block difficulty.
+func (ethash *Ethash) mine(block *types.Block, id int, seed uint64, abort chan struct{}, found chan *types.Block) {
+ // Extract some data from the header
+ var (
+ header = block.Header()
+ hash = ethash.SealHash(header).Bytes()
+ target = new(big.Int).Div(two256, header.Difficulty)
+ number = header.Number.Uint64()
+ dataset = ethash.dataset(number, false)
+ )
+ // Start generating random nonces until we abort or find a good one
+ var (
+ attempts = int64(0)
+ nonce = seed
+ )
+ logger := log.New("miner", id)
+ logger.Trace("Started ethash search for new nonces", "seed", seed)
+search:
+ for {
+ select {
+ case <-abort:
+ // Mining terminated, update stats and abort
+ logger.Trace("Ethash nonce search aborted", "attempts", nonce-seed)
+ ethash.hashrate.Mark(attempts)
+ break search
+
+ default:
+ // We don't have to update hash rate on every nonce, so update after after 2^X nonces
+ attempts++
+ if (attempts % (1 << 15)) == 0 {
+ ethash.hashrate.Mark(attempts)
+ attempts = 0
+ }
+ // Compute the PoW value of this nonce
+ digest, result := hashimotoFull(dataset.dataset, hash, nonce)
+ if new(big.Int).SetBytes(result).Cmp(target) <= 0 {
+ // Correct nonce found, create a new header with it
+ header = types.CopyHeader(header)
+ header.Nonce = types.EncodeNonce(nonce)
+ header.MixDigest = common.BytesToHash(digest)
+
+ // Seal and return a block (if still needed)
+ select {
+ case found <- block.WithSeal(header):
+ logger.Trace("Ethash nonce found and reported", "attempts", nonce-seed, "nonce", nonce)
+ case <-abort:
+ logger.Trace("Ethash nonce found but discarded", "attempts", nonce-seed, "nonce", nonce)
+ }
+ break search
+ }
+ nonce++
+ }
+ }
+ // Datasets are unmapped in a finalizer. Ensure that the dataset stays live
+ // during sealing so it's not unmapped while being read.
+ runtime.KeepAlive(dataset)
+}
+
+// remote is a standalone goroutine to handle remote mining related stuff.
+func (ethash *Ethash) remote(notify []string, noverify bool) {
+ var (
+ works = make(map[common.Hash]*types.Block)
+ rates = make(map[common.Hash]hashrate)
+
+ results chan<- *types.Block
+ currentBlock *types.Block
+ currentWork [4]string
+
+ notifyTransport = &http.Transport{}
+ notifyClient = &http.Client{
+ Transport: notifyTransport,
+ Timeout: time.Second,
+ }
+ notifyReqs = make([]*http.Request, len(notify))
+ )
+ // notifyWork notifies all the specified mining endpoints of the availability of
+ // new work to be processed.
+ notifyWork := func() {
+ work := currentWork
+ blob, _ := json.Marshal(work)
+
+ for i, url := range notify {
+ // Terminate any previously pending request and create the new work
+ if notifyReqs[i] != nil {
+ notifyTransport.CancelRequest(notifyReqs[i])
+ }
+ notifyReqs[i], _ = http.NewRequest("POST", url, bytes.NewReader(blob))
+ notifyReqs[i].Header.Set("Content-Type", "application/json")
+
+ // Push the new work concurrently to all the remote nodes
+ go func(req *http.Request, url string) {
+ res, err := notifyClient.Do(req)
+ if err != nil {
+ log.Warn("Failed to notify remote miner", "err", err)
+ } else {
+ log.Trace("Notified remote miner", "miner", url, "hash", log.Lazy{Fn: func() common.Hash { return common.HexToHash(work[0]) }}, "target", work[2])
+ res.Body.Close()
+ }
+ }(notifyReqs[i], url)
+ }
+ }
+ // makeWork creates a work package for external miner.
+ //
+ // The work package consists of 3 strings:
+ // result[0], 32 bytes hex encoded current block header pow-hash
+ // result[1], 32 bytes hex encoded seed hash used for DAG
+ // result[2], 32 bytes hex encoded boundary condition ("target"), 2^256/difficulty
+ // result[3], hex encoded block number
+ makeWork := func(block *types.Block) {
+ hash := ethash.SealHash(block.Header())
+
+ currentWork[0] = hash.Hex()
+ currentWork[1] = common.BytesToHash(SeedHash(block.NumberU64())).Hex()
+ currentWork[2] = common.BytesToHash(new(big.Int).Div(two256, block.Difficulty()).Bytes()).Hex()
+ currentWork[3] = hexutil.EncodeBig(block.Number())
+
+ // Trace the seal work fetched by remote sealer.
+ currentBlock = block
+ works[hash] = block
+ }
+ // submitWork verifies the submitted pow solution, returning
+ // whether the solution was accepted or not (not can be both a bad pow as well as
+ // any other error, like no pending work or stale mining result).
+ submitWork := func(nonce types.BlockNonce, mixDigest common.Hash, sealhash common.Hash) bool {
+ if currentBlock == nil {
+ log.Error("Pending work without block", "sealhash", sealhash)
+ return false
+ }
+ // Make sure the work submitted is present
+ block := works[sealhash]
+ if block == nil {
+ log.Warn("Work submitted but none pending", "sealhash", sealhash, "curnumber", currentBlock.NumberU64())
+ return false
+ }
+ // Verify the correctness of submitted result.
+ header := block.Header()
+ header.Nonce = nonce
+ header.MixDigest = mixDigest
+
+ start := time.Now()
+ if !noverify {
+ if err := ethash.verifySeal(nil, header, true); err != nil {
+ log.Warn("Invalid proof-of-work submitted", "sealhash", sealhash, "elapsed", common.PrettyDuration(time.Since(start)), "err", err)
+ return false
+ }
+ }
+ // Make sure the result channel is assigned.
+ if results == nil {
+ log.Warn("Ethash result channel is empty, submitted mining result is rejected")
+ return false
+ }
+ log.Trace("Verified correct proof-of-work", "sealhash", sealhash, "elapsed", common.PrettyDuration(time.Since(start)))
+
+ // Solutions seems to be valid, return to the miner and notify acceptance.
+ solution := block.WithSeal(header)
+
+ // The submitted solution is within the scope of acceptance.
+ if solution.NumberU64()+staleThreshold > currentBlock.NumberU64() {
+ select {
+ case results <- solution:
+ log.Debug("Work submitted is acceptable", "number", solution.NumberU64(), "sealhash", sealhash, "hash", solution.Hash())
+ return true
+ default:
+ log.Warn("Sealing result is not read by miner", "mode", "remote", "sealhash", sealhash)
+ return false
+ }
+ }
+ // The submitted block is too old to accept, drop it.
+ log.Warn("Work submitted is too old", "number", solution.NumberU64(), "sealhash", sealhash, "hash", solution.Hash())
+ return false
+ }
+
+ ticker := time.NewTicker(5 * time.Second)
+ defer ticker.Stop()
+
+ for {
+ select {
+ case work := <-ethash.workCh:
+ // Update current work with new received block.
+ // Note same work can be past twice, happens when changing CPU threads.
+ results = work.results
+
+ makeWork(work.block)
+
+ // Notify and requested URLs of the new work availability
+ notifyWork()
+
+ case work := <-ethash.fetchWorkCh:
+ // Return current mining work to remote miner.
+ if currentBlock == nil {
+ work.errc <- errNoMiningWork
+ } else {
+ work.res <- currentWork
+ }
+
+ case result := <-ethash.submitWorkCh:
+ // Verify submitted PoW solution based on maintained mining blocks.
+ if submitWork(result.nonce, result.mixDigest, result.hash) {
+ result.errc <- nil
+ } else {
+ result.errc <- errInvalidSealResult
+ }
+
+ case result := <-ethash.submitRateCh:
+ // Trace remote sealer's hash rate by submitted value.
+ rates[result.id] = hashrate{rate: result.rate, ping: time.Now()}
+ close(result.done)
+
+ case req := <-ethash.fetchRateCh:
+ // Gather all hash rate submitted by remote sealer.
+ var total uint64
+ for _, rate := range rates {
+ // this could overflow
+ total += rate.rate
+ }
+ req <- total
+
+ case <-ticker.C:
+ // Clear stale submitted hash rate.
+ for id, rate := range rates {
+ if time.Since(rate.ping) > 10*time.Second {
+ delete(rates, id)
+ }
+ }
+ // Clear stale pending blocks
+ if currentBlock != nil {
+ for hash, block := range works {
+ if block.NumberU64()+staleThreshold <= currentBlock.NumberU64() {
+ delete(works, hash)
+ }
+ }
+ }
+
+ case errc := <-ethash.exitCh:
+ // Exit remote loop if ethash is closed and return relevant error.
+ errc <- nil
+ log.Trace("Ethash remote sealer is exiting")
+ return
+ }
+ }
+}