67 lines
1.6 KiB
Plaintext
67 lines
1.6 KiB
Plaintext
use aiken/bytearray
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use aiken/hash.{Hash, Sha2_256, sha2_256}
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use aiken/list
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use aiken/string
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// MerkleTree in Aiken (ported from: https://github.com/input-output-hk/hydra/blob/master/plutus-merkle-tree/src/Plutus/MerkleTree.hs)
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pub type MerkleTree {
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Empty
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Leaf { hash: Hash<Sha2_256, ByteArray>, value: ByteArray }
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Node { hash: Hash<Sha2_256, ByteArray>, left: MerkleTree, right: MerkleTree }
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}
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pub fn root_hash(t: MerkleTree) -> Hash<Sha2_256, ByteArray> {
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when t is {
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Empty -> #""
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Leaf { hash, .. } -> hash
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Node { hash, .. } -> hash
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}
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}
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pub fn is_equal(a: MerkleTree, b: MerkleTree) -> Bool {
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root_hash(a) == root_hash(b)
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}
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pub fn size(t: MerkleTree) -> Int {
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when t is {
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Empty -> 0
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Leaf{..} -> 1
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Node { left, right, .. } -> size(left) + size(right)
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}
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}
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fn combine_hash(h1: Hash<alg, a>, h2: Hash<alg, a>) -> Hash<alg, a> {
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sha2_256(bytearray.concat(h1, h2))
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}
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pub fn from_list(items0: List<ByteArray>) -> MerkleTree {
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do_from_list(items0, list.length(items0))
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}
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fn do_from_list(items: List<ByteArray>, len: Int) -> MerkleTree {
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when items is {
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[] -> Empty
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[value] -> Leaf { hash: sha2_256(value), value }
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all -> {
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let cutoff: Int = len / 2
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let left =
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all
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|> list.take(cutoff)
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|> do_from_list(cutoff)
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let right =
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all
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|> list.drop(cutoff)
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|> do_from_list(len - cutoff)
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let hash = combine_hash(root_hash(left), root_hash(right))
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Node { hash, left, right }
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}
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}
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}
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test foo() {
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let items = [#"aa", #"bb", #"cc"]
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let mt = from_list(items)
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size(mt) == 3
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}
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