mirror of https://github.com/poanetwork/quorum.git
48 lines
2.0 KiB
Go
48 lines
2.0 KiB
Go
// 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 < len(cacheSizes) {
|
|
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 < len(datasetSizes) {
|
|
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")
|
|
}
|