/
merkle_tree.go
59 lines (54 loc) · 1.47 KB
/
merkle_tree.go
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package common
/*
* Copyright (C) 2019 The onyxchain Authors
* This file is part of The onyxchain library.
*
* The onyxchain 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 onyxchain 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 onyxchain. If not, see <http://www.gnu.org/licenses/>.
*/
import (
"crypto/sha256"
)
// param hashes will be used as workspace
func ComputeMerkleRoot(hashes []Uint256) Uint256 {
if len(hashes) == 0 {
return Uint256{}
}
sha := sha256.New()
var temp Uint256
for len(hashes) != 1 {
n := len(hashes) / 2
for i := 0; i < n; i++ {
sha.Reset()
sha.Write(hashes[2*i][:])
sha.Write(hashes[2*i+1][:])
sha.Sum(temp[:0])
sha.Reset()
sha.Write(temp[:])
sha.Sum(hashes[i][:0])
}
if len(hashes) == 2*n+1 {
sha.Reset()
sha.Write(hashes[2*n][:])
sha.Write(hashes[2*n][:])
sha.Sum(temp[:0])
sha.Reset()
sha.Write(temp[:])
sha.Sum(hashes[n][:0])
hashes = hashes[:n+1]
} else {
hashes = hashes[:n]
}
}
return hashes[0]
}