You can not select more than 25 topics
Topics must start with a letter or number, can include dashes ('-') and can be up to 35 characters long.
47 lines
1.0 KiB
47 lines
1.0 KiB
package merkle
|
|
|
|
import (
|
|
"math/bits"
|
|
)
|
|
|
|
// SimpleHashFromByteSlices computes a Merkle tree where the leaves are the byte slice,
|
|
// in the provided order.
|
|
func SimpleHashFromByteSlices(items [][]byte) []byte {
|
|
switch len(items) {
|
|
case 0:
|
|
return nil
|
|
case 1:
|
|
return leafHash(items[0])
|
|
default:
|
|
k := getSplitPoint(len(items))
|
|
left := SimpleHashFromByteSlices(items[:k])
|
|
right := SimpleHashFromByteSlices(items[k:])
|
|
return innerHash(left, right)
|
|
}
|
|
}
|
|
|
|
// SimpleHashFromMap computes a Merkle tree from sorted map.
|
|
// Like calling SimpleHashFromHashers with
|
|
// `item = []byte(Hash(key) | Hash(value))`,
|
|
// sorted by `item`.
|
|
func SimpleHashFromMap(m map[string][]byte) []byte {
|
|
sm := newSimpleMap()
|
|
for k, v := range m {
|
|
sm.Set(k, v)
|
|
}
|
|
return sm.Hash()
|
|
}
|
|
|
|
// getSplitPoint returns the largest power of 2 less than length
|
|
func getSplitPoint(length int) int {
|
|
if length < 1 {
|
|
panic("Trying to split a tree with size < 1")
|
|
}
|
|
uLength := uint(length)
|
|
bitlen := bits.Len(uLength)
|
|
k := 1 << uint(bitlen-1)
|
|
if k == length {
|
|
k >>= 1
|
|
}
|
|
return k
|
|
}
|