Incremental Merkle Trees (Solidity)
Incremental Merkle tree Solidity libraries.
## Libraries:
✔️ [IncrementalBinaryTree](https://github.com/privacy-scaling-explorations/zk-kit/blob/main/packages/incremental-merkle-tree.sol/contracts/IncrementalBinaryTree.sol) (Poseidon)\
✔️ [IncrementalQuinTree](https://github.com/privacy-scaling-explorations/zk-kit/blob/main/packages/incremental-merkle-tree.sol/contracts/IncrementalQuinTree.sol) (Poseidon)
> The methods of each library are always the same (i.e `insert`, `update`, `remove`, `verify`).
---
## 🛠 Install
### npm or yarn
Install the `@zk-kit/incremental-merkle-tree.sol` package with npm:
```bash
npm i @zk-kit/incremental-merkle-tree.sol --save
```
or yarn:
```bash
yarn add @zk-kit/incremental-merkle-tree.sol
```
## 📜 Usage
### Importing and using the library
```solidity
// SPDX-License-Identifier: MIT
pragma solidity ^0.8.4;
import "@zk-kit/incremental-merkle-tree.sol/IncrementalBinaryTree.sol";
contract Example {
using IncrementalBinaryTree for IncrementalTreeData;
event TreeCreated(bytes32 id, uint256 depth);
event LeafInserted(bytes32 indexed treeId, uint256 leaf, uint256 root);
event LeafUpdated(bytes32 indexed treeId, uint256 leaf, uint256 root);
event LeafRemoved(bytes32 indexed treeId, uint256 leaf, uint256 root);
mapping(bytes32 => IncrementalTreeData) public trees;
function createTree(bytes32 _id, uint256 _depth) external {
require(trees[_id].depth == 0, "Example: tree already exists");
trees[_id].init(_depth, 0);
emit TreeCreated(_id, _depth);
}
function insertLeaf(bytes32 _treeId, uint256 _leaf) external {
require(trees[_treeId].depth != 0, "Example: tree does not exist");
trees[_treeId].insert(_leaf);
emit LeafInserted(_treeId, _leaf, trees[_treeId].root);
}
function updateLeaf(
bytes32 _treeId,
uint256 _leaf,
uint256 _newLeaf,
uint256[] calldata _proofSiblings,
uint8[] calldata _proofPathIndices
) external {
require(trees[_treeId].depth != 0, "Example: tree does not exist");
trees[_treeId].update(_leaf, _newLeaf, _proofSiblings, _proofPathIndices);
emit LeafUpdated(_treeId, _newLeaf, trees[_treeId].root);
}
function removeLeaf(
bytes32 _treeId,
uint256 _leaf,
uint256[] calldata _proofSiblings,
uint8[] calldata _proofPathIndices
) external {
require(trees[_treeId].depth != 0, "Example: tree does not exist");
trees[_treeId].remove(_leaf, _proofSiblings, _proofPathIndices);
emit LeafRemoved(_treeId, _leaf, trees[_treeId].root);
}
}
```
### Creating an Hardhat task to deploy the contract
```typescript
import { poseidon_gencontract as poseidonContract } from "circomlibjs"
import { Contract } from "ethers"
import { task, types } from "hardhat/config"
task("deploy:example", "Deploy an Example contract")
.addOptionalParam("logs", "Print the logs", true, types.boolean)
.setAction(async ({ logs }, { ethers }): Promise => {
const poseidonT3ABI = poseidonContract.generateABI(2)
const poseidonT3Bytecode = poseidonContract.createCode(2)
const [signer] = await ethers.getSigners()
const PoseidonLibT3Factory = new ethers.ContractFactory(poseidonT3ABI, poseidonT3Bytecode, signer)
const poseidonT3Lib = await PoseidonLibT3Factory.deploy()
await poseidonT3Lib.deployed()
logs && console.log(`PoseidonT3 library has been deployed to: ${poseidonT3Lib.address}`)
const IncrementalBinaryTreeLibFactory = await ethers.getContractFactory("IncrementalBinaryTree", {
libraries: {
PoseidonT3: poseidonT3Lib.address
}
})
const incrementalBinaryTreeLib = await IncrementalBinaryTreeLibFactory.deploy()
await incrementalBinaryTreeLib.deployed()
logs && console.log(`IncrementalBinaryTree library has been deployed to: ${incrementalBinaryTreeLib.address}`)
const ContractFactory = await ethers.getContractFactory("Example", {
libraries: {
IncrementalBinaryTree: incrementalBinaryTreeLib.address
}
})
const contract = await ContractFactory.deploy()
await contract.deployed()
logs && console.log(`Example contract has been deployed to: ${contract.address}`)
return contract
})
```
## Contacts
### Developers
- e-mail : me@cedoor.dev
- github : [@cedoor](https://github.com/cedoor)
- website : https://cedoor.dev