tendermint/merkle/simple_map.go

87 lines
1.6 KiB
Go

package merkle
import (
"github.com/tendermint/go-wire"
cmn "github.com/tendermint/tmlibs/common"
"golang.org/x/crypto/ripemd160"
)
type SimpleMap struct {
kvs cmn.KVPairs
sorted bool
}
func NewSimpleMap() *SimpleMap {
return &SimpleMap{
kvs: nil,
sorted: false,
}
}
func (sm *SimpleMap) Set(key string, value interface{}) {
sm.sorted = false
// Is value Hashable?
var vBytes []byte
if hashable, ok := value.(Hashable); ok {
vBytes = hashable.Hash()
} else {
vBytes = wire.BinaryBytes(value)
}
sm.kvs = append(sm.kvs, cmn.KVPair{
Key: []byte(key),
Value: vBytes,
})
}
// Merkle root hash of items sorted by key.
// NOTE: Behavior is undefined when key is duplicate.
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.
// CONTRACT: The returned slice must not be mutated.
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.
type kvPair cmn.KVPair
func (kv kvPair) Hash() []byte {
hasher, n, err := ripemd160.New(), new(int), new(error)
wire.WriteByteSlice(kv.Key, hasher, n, err)
if *err != nil {
panic(*err)
}
wire.WriteByteSlice(kv.Value, hasher, n, err)
if *err != nil {
panic(*err)
}
return hasher.Sum(nil)
}
func hashKVPairs(kvs cmn.KVPairs) []byte {
kvsH := make([]Hashable, 0, len(kvs))
for _, kvp := range kvs {
kvsH = append(kvsH, kvPair(kvp))
}
return SimpleHashFromHashables(kvsH)
}