diff options
Diffstat (limited to 'consensus')
| -rw-r--r-- | consensus/ethash/algorithm.go | 43 | ||||
| -rw-r--r-- | consensus/ethash/algorithm_go1.7.go | 47 | ||||
| -rw-r--r-- | consensus/ethash/algorithm_go1.8.go | 63 | ||||
| -rw-r--r-- | consensus/ethash/algorithm_go1.8_test.go | 37 | ||||
| -rw-r--r-- | consensus/ethash/algorithm_test.go | 16 | ||||
| -rw-r--r-- | consensus/ethash/consensus.go | 10 |
6 files changed, 61 insertions, 155 deletions
diff --git a/consensus/ethash/algorithm.go b/consensus/ethash/algorithm.go index 10767bb31..905a7b1ea 100644 --- a/consensus/ethash/algorithm.go +++ b/consensus/ethash/algorithm.go @@ -19,6 +19,7 @@ package ethash import ( "encoding/binary" "hash" + "math/big" "reflect" "runtime" "sync" @@ -47,6 +48,48 @@ const ( 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) diff --git a/consensus/ethash/algorithm_go1.7.go b/consensus/ethash/algorithm_go1.7.go deleted file mode 100644 index c7f7f48e4..000000000 --- a/consensus/ethash/algorithm_go1.7.go +++ /dev/null @@ -1,47 +0,0 @@ -// 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/>. - -// +build !go1.8 - -package ethash - -// cacheSize calculates and returns the size of the ethash verification cache that -// belongs to a certain block number. 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 cacheSize(block uint64) uint64 { - // If we have a pre-generated value, use that - epoch := int(block / epochLength) - if epoch < maxEpoch { - return cacheSizes[epoch] - } - // We don't have a way to verify primes fast before Go 1.8 - panic("fast prime testing unsupported in Go < 1.8") -} - -// datasetSize calculates and returns the size of the ethash mining dataset that -// belongs to a certain block number. 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 datasetSize(block uint64) uint64 { - // If we have a pre-generated value, use that - epoch := int(block / epochLength) - if epoch < maxEpoch { - return datasetSizes[epoch] - } - // We don't have a way to verify primes fast before Go 1.8 - panic("fast prime testing unsupported in Go < 1.8") -} diff --git a/consensus/ethash/algorithm_go1.8.go b/consensus/ethash/algorithm_go1.8.go deleted file mode 100644 index 975fdffe5..000000000 --- a/consensus/ethash/algorithm_go1.8.go +++ /dev/null @@ -1,63 +0,0 @@ -// 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/>. - -// +build go1.8 - -package ethash - -import "math/big" - -// 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 -} diff --git a/consensus/ethash/algorithm_go1.8_test.go b/consensus/ethash/algorithm_go1.8_test.go deleted file mode 100644 index 6648bd6a9..000000000 --- a/consensus/ethash/algorithm_go1.8_test.go +++ /dev/null @@ -1,37 +0,0 @@ -// 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/>. - -// +build go1.8 - -package ethash - -import "testing" - -// Tests whether the dataset size calculator works correctly by cross checking the -// hard coded lookup table with the value generated by it. -func TestSizeCalculations(t *testing.T) { - // Verify all the cache and dataset sizes from the lookup table. - for epoch, want := range cacheSizes { - if size := calcCacheSize(epoch); size != want { - t.Errorf("cache %d: cache size mismatch: have %d, want %d", epoch, size, want) - } - } - for epoch, want := range datasetSizes { - if size := calcDatasetSize(epoch); size != want { - t.Errorf("dataset %d: dataset size mismatch: have %d, want %d", epoch, size, want) - } - } -} diff --git a/consensus/ethash/algorithm_test.go b/consensus/ethash/algorithm_test.go index a54f3b582..841e39233 100644 --- a/consensus/ethash/algorithm_test.go +++ b/consensus/ethash/algorithm_test.go @@ -30,6 +30,22 @@ import ( "github.com/ethereum/go-ethereum/core/types" ) +// Tests whether the dataset size calculator works correctly by cross checking the +// hard coded lookup table with the value generated by it. +func TestSizeCalculations(t *testing.T) { + // Verify all the cache and dataset sizes from the lookup table. + for epoch, want := range cacheSizes { + if size := calcCacheSize(epoch); size != want { + t.Errorf("cache %d: cache size mismatch: have %d, want %d", epoch, size, want) + } + } + for epoch, want := range datasetSizes { + if size := calcDatasetSize(epoch); size != want { + t.Errorf("dataset %d: dataset size mismatch: have %d, want %d", epoch, size, want) + } + } +} + // Tests that verification caches can be correctly generated. func TestCacheGeneration(t *testing.T) { tests := []struct { diff --git a/consensus/ethash/consensus.go b/consensus/ethash/consensus.go index 92a23d4a4..3f860bf47 100644 --- a/consensus/ethash/consensus.go +++ b/consensus/ethash/consensus.go @@ -53,7 +53,6 @@ var ( errDuplicateUncle = errors.New("duplicate uncle") errUncleIsAncestor = errors.New("uncle is ancestor") errDanglingUncle = errors.New("uncle's parent is not ancestor") - errNonceOutOfRange = errors.New("nonce out of range") errInvalidDifficulty = errors.New("non-positive difficulty") errInvalidMixDigest = errors.New("invalid mix digest") errInvalidPoW = errors.New("invalid proof-of-work") @@ -474,18 +473,13 @@ func (ethash *Ethash) VerifySeal(chain consensus.ChainReader, header *types.Head if ethash.shared != nil { return ethash.shared.VerifySeal(chain, header) } - // Sanity check that the block number is below the lookup table size (60M blocks) - number := header.Number.Uint64() - if number/epochLength >= maxEpoch { - // Go < 1.7 cannot calculate new cache/dataset sizes (no fast prime check) - return errNonceOutOfRange - } // Ensure that we have a valid difficulty for the block if header.Difficulty.Sign() <= 0 { return errInvalidDifficulty } - // Recompute the digest and PoW value and verify against the header + number := header.Number.Uint64() + cache := ethash.cache(number) size := datasetSize(number) if ethash.config.PowMode == ModeTest { |