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.
88 lines
1.8 KiB
88 lines
1.8 KiB
package merkle
|
|
|
|
import (
|
|
"github.com/tendermint/go-crypto/tmhash"
|
|
cmn "github.com/tendermint/tmlibs/common"
|
|
)
|
|
|
|
// Merkle tree from a map.
|
|
// Leaves are `hash(key) | hash(value)`.
|
|
// Leaves are sorted before Merkle hashing.
|
|
type simpleMap struct {
|
|
kvs cmn.KVPairs
|
|
sorted bool
|
|
}
|
|
|
|
func newSimpleMap() *simpleMap {
|
|
return &simpleMap{
|
|
kvs: nil,
|
|
sorted: false,
|
|
}
|
|
}
|
|
|
|
// Set hashes the key and value and appends it to the kv pairs.
|
|
func (sm *simpleMap) Set(key string, value Hasher) {
|
|
sm.sorted = false
|
|
|
|
// The value is hashed, so you can
|
|
// check for equality with a cached value (say)
|
|
// and make a determination to fetch or not.
|
|
vhash := value.Hash()
|
|
|
|
sm.kvs = append(sm.kvs, cmn.KVPair{
|
|
Key: []byte(key),
|
|
Value: vhash,
|
|
})
|
|
}
|
|
|
|
// Hash Merkle root hash of items sorted by key
|
|
// (UNSTABLE: and by value too if duplicate key).
|
|
func (sm *simpleMap) Hash() []byte {
|
|
sm.Sort()
|
|
return hashKVPairs(sm.kvs)
|
|
}
|
|
|
|
func (sm *simpleMap) Sort() {
|
|
if sm.sorted {
|
|
return
|
|
}
|
|
sm.kvs.Sort()
|
|
sm.sorted = true
|
|
}
|
|
|
|
// Returns a copy of sorted KVPairs.
|
|
// NOTE these contain the hashed key and value.
|
|
func (sm *simpleMap) KVPairs() cmn.KVPairs {
|
|
sm.Sort()
|
|
kvs := make(cmn.KVPairs, len(sm.kvs))
|
|
copy(kvs, sm.kvs)
|
|
return kvs
|
|
}
|
|
|
|
//----------------------------------------
|
|
|
|
// A local extension to KVPair that can be hashed.
|
|
// Key and value are length prefixed and concatenated,
|
|
// then hashed.
|
|
type KVPair cmn.KVPair
|
|
|
|
func (kv KVPair) Hash() []byte {
|
|
hasher := tmhash.New()
|
|
err := encodeByteSlice(hasher, kv.Key)
|
|
if err != nil {
|
|
panic(err)
|
|
}
|
|
err = encodeByteSlice(hasher, kv.Value)
|
|
if err != nil {
|
|
panic(err)
|
|
}
|
|
return hasher.Sum(nil)
|
|
}
|
|
|
|
func hashKVPairs(kvs cmn.KVPairs) []byte {
|
|
kvsH := make([]Hasher, len(kvs))
|
|
for i, kvp := range kvs {
|
|
kvsH[i] = KVPair(kvp)
|
|
}
|
|
return SimpleHashFromHashers(kvsH)
|
|
}
|