diff options
Diffstat (limited to 'consensus/ethash/algorithm_go1.8.go')
| -rw-r--r-- | consensus/ethash/algorithm_go1.8.go | 34 |
1 files changed, 20 insertions, 14 deletions
diff --git a/consensus/ethash/algorithm_go1.8.go b/consensus/ethash/algorithm_go1.8.go index d691b758f..975fdffe5 100644 --- a/consensus/ethash/algorithm_go1.8.go +++ b/consensus/ethash/algorithm_go1.8.go @@ -20,17 +20,20 @@ package ethash import "math/big" -// 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. +// cacheSize returns the size of the ethash verification cache that belongs to a certain +// block number. func cacheSize(block uint64) uint64 { - // If we have a pre-generated value, use that epoch := int(block / epochLength) - if epoch < len(cacheSizes) { + if epoch < maxEpoch { return cacheSizes[epoch] } - // No known cache size, calculate manually (sanity branch only) + 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 @@ -38,17 +41,20 @@ func cacheSize(block uint64) uint64 { return size } -// 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. +// datasetSize returns the size of the ethash mining dataset that belongs to a certain +// block number. func datasetSize(block uint64) uint64 { - // If we have a pre-generated value, use that epoch := int(block / epochLength) - if epoch < len(datasetSizes) { + if epoch < maxEpoch { return datasetSizes[epoch] } - // No known dataset size, calculate manually (sanity branch only) + 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 |