Files
tendermint/merkle/simple_tree.go
T
Jae KwonandGitHub 8481c49c82 CacheDB (#67)
* Add CacheDB & SimpleMap
* Generic memBatch; Fix cLevelDB tests
* CacheWrap() for CacheDB and MemDB
* Change Iterator to match LeviGo Iterator
* Fixes from review
* cacheWrapWriteMutex and some race fixes
* Use tmlibs/common
* NewCWWMutex is exposed.  DB can be CacheWrap'd
* Remove GetOK, not needed
* Fsdb (#72)
* Add FSDB
* Review fixes from Anton
* Review changes
* Fixes from review
2017-11-09 17:42:32 -05:00

94 lines
2.3 KiB
Go

/*
Computes a deterministic minimal height merkle tree hash.
If the number of items is not a power of two, some leaves
will be at different levels. Tries to keep both sides of
the tree the same size, but the left may be one greater.
Use this for short deterministic trees, such as the validator list.
For larger datasets, use IAVLTree.
*
/ \
/ \
/ \
/ \
* *
/ \ / \
/ \ / \
/ \ / \
* * * h6
/ \ / \ / \
h0 h1 h2 h3 h4 h5
*/
package merkle
import (
"golang.org/x/crypto/ripemd160"
"github.com/tendermint/go-wire"
. "github.com/tendermint/tmlibs/common"
)
func SimpleHashFromTwoHashes(left []byte, right []byte) []byte {
var n int
var err error
var hasher = ripemd160.New()
wire.WriteByteSlice(left, hasher, &n, &err)
wire.WriteByteSlice(right, hasher, &n, &err)
if err != nil {
PanicCrisis(err)
}
return hasher.Sum(nil)
}
func SimpleHashFromHashes(hashes [][]byte) []byte {
// Recursive impl.
switch len(hashes) {
case 0:
return nil
case 1:
return hashes[0]
default:
left := SimpleHashFromHashes(hashes[:(len(hashes)+1)/2])
right := SimpleHashFromHashes(hashes[(len(hashes)+1)/2:])
return SimpleHashFromTwoHashes(left, right)
}
}
// Convenience for SimpleHashFromHashes.
func SimpleHashFromBinaries(items []interface{}) []byte {
hashes := make([][]byte, len(items))
for i, item := range items {
hashes[i] = SimpleHashFromBinary(item)
}
return SimpleHashFromHashes(hashes)
}
// General Convenience
func SimpleHashFromBinary(item interface{}) []byte {
hasher, n, err := ripemd160.New(), new(int), new(error)
wire.WriteBinary(item, hasher, n, err)
if *err != nil {
PanicCrisis(err)
}
return hasher.Sum(nil)
}
// Convenience for SimpleHashFromHashes.
func SimpleHashFromHashables(items []Hashable) []byte {
hashes := make([][]byte, len(items))
for i, item := range items {
hash := item.Hash()
hashes[i] = hash
}
return SimpleHashFromHashes(hashes)
}
// Convenience for SimpleHashFromHashes.
func SimpleHashFromMap(m map[string]interface{}) []byte {
kpPairsH := MakeSortedKVPairs(m)
return SimpleHashFromHashables(kpPairsH)
}