Crate nam_sparse_merkle_tree

Constructs a new SparseMerkleTree<H, V, S>.

Examples

use nam_sparse_merkle_tree::{
    blake2b::Blake2bHasher, default_store::DefaultStore,
    error::Error, MerkleProof,
    SparseMerkleTree, traits::Value, H256, Hash,
};
use blake2b_rs::{Blake2b, Blake2bBuilder};

// define SMT
type SMT = SparseMerkleTree<Blake2bHasher, Hash, Word, DefaultStore<Hash, Word, 32>, 32>;

// define SMT value
#[derive(Default, Clone, PartialEq)]
pub struct Word(String, H256);
impl Value for Word {
   fn as_slice(&self) -> &[u8] {
       self.1.as_slice()
   }
   fn zero() -> Self {
       Default::default()
   }
}

// helper function
fn new_blake2b() -> Blake2b {
    Blake2bBuilder::new(32).personal(b"SMT").build()
}

fn construct_smt() {
    let mut tree = SMT::default();  
    for (i, word) in "The quick brown fox jumps over the lazy dog"
        .split_whitespace()
        .enumerate()
    {
        let key: Hash = {
            let mut buf = [0u8; 32];
            let mut hasher = new_blake2b();
            hasher.update(&(i as u32).to_le_bytes());
            hasher.finalize(&mut buf);
            buf.into()
        };
        let hash: H256 = {
            let mut buf = [0u8; 32];
            if !word.is_empty() {
                let mut hasher = new_blake2b();
                hasher.update(word.as_bytes());
                hasher.finalize(&mut buf);
            }
            buf.into()
        };
        let value = Word(word.to_string(), hash);
        // insert key value into tree
        tree.update(key, value).expect("update");
    }

    println!("SMT root is {:?} ", tree.root());
}

Re-exports

pub use h256::Hash;

pub use h256::H256;

pub use internal_key::InternalKey;

pub use merkle_proof::CompiledMerkleProof;

pub use merkle_proof::MerkleProof;

pub use traits::Key;

pub use tree::SparseMerkleTree;

Modules

blake2b

default_store

error

h256

internal_key

merge

merkle_proof

proof_ics23

sha256

traits

tree

Constants

EXPECTED_PATH_SIZE

Expected path size: log2(256) * 2, used for hint vector capacity

KEY_LIMIT

Key limit size

TREE_HEIGHT

Height of sparse merkle tree