cranberry

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package merkle
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import (
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	"crypto/sha256"
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	"encoding/hex"
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	pbapi "gitverse.ru/IvanTimofeev/cranberry/pkg/grpc"
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	utility "gitverse.ru/IvanTimofeev/cranberry/pkg/utility"
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)
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type node struct {
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	Left  *node
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	Right *node
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	Hash  []byte
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}
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func MerkleRoot(txcs []*pbapi.TxContainer) string {
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	if txcs == nil || len(txcs) == 0 {
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		return ""
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	}
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	return hex.EncodeToString(buildMerkleTree(txcs).Hash)
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}
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func buildMerkleTree(txcs []*pbapi.TxContainer) *node {
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	var nodes []*node
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	for _, txc := range txcs {
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		hash := sha256.Sum256(utility.TxToBytes(txc.Tx))
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		nodes = append(nodes, &node{Hash: hash[:]})
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	}
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	for len(nodes) > 1 {
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		var newLevel []*node
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		for i := 0; i < len(nodes); i += 2 {
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			if len(nodes) > i+1 {
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				combined := make([]byte, len(nodes[i].Hash)+len(nodes[i+1].Hash))
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				copy(combined, nodes[i].Hash)
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				copy(combined[len(nodes[i].Hash):], nodes[i+1].Hash)
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				newHash := sha256.Sum256(combined)
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				newnode := &node{Left: nodes[i], Right: nodes[i+1], Hash: newHash[:]}
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				newLevel = append(newLevel, newnode)
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			} else {
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				newLevel = append(newLevel, nodes[i])
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			}
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		}
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		nodes = newLevel
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	}
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	return nodes[0]
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}
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