simpler serialization

.github/workflows/build.yml

@@ -1,4 +1,4 @@
-name: Node.js CI
+name: build
 
 on:
   pull_request:
@@ -16,6 +16,14 @@ jobs:
           node-version: 14.7.0
       - run: npm ci
       - run: npm run test
+      - name: Telegram Failure Notification
+        uses: appleboy/telegram-action@0.0.7
+        if: failure()
+        with:
+          message: ❗ Build failed for [${{ github.repository }}](https://github.com/${{ github.repository }}/actions) because of ${{ github.actor }}
+          format: markdown
+          to: ${{ secrets.TELEGRAM_CHAT_ID }}
+          token: ${{ secrets.TELEGRAM_BOT_TOKEN }}
 
   lint:
     runs-on: ubuntu-latest
@@ -26,6 +34,14 @@ jobs:
           node-version: 14.7.0
       - run: npm ci
       - run: npm run lint
+      - name: Telegram Failure Notification
+        uses: appleboy/telegram-action@0.0.7
+        if: failure()
+        with:
+          message: ❗ Build failed for [${{ github.repository }}](https://github.com/${{ github.repository }}/actions) because of ${{ github.actor }}
+          format: markdown
+          to: ${{ secrets.TELEGRAM_CHAT_ID }}
+          token: ${{ secrets.TELEGRAM_BOT_TOKEN }}
 
   publish:
     runs-on: ubuntu-latest
@@ -65,3 +81,12 @@ jobs:
           message: 🚀 Published [${{ steps.vars.outputs.repo_name }}](https://github.com/${{ github.repository }}) version [${{ steps.vars.outputs.version }}](https://www.npmjs.com/package/${{ steps.vars.outputs.repo_name }}/v/${{ steps.vars.outputs.version }}) to npm
           debug: true
           format: markdown
+
+      - name: Telegram Failure Notification
+        uses: appleboy/telegram-action@0.0.7
+        if: failure()
+        with:
+          message: ❗ Failed to publish [${{ steps.vars.outputs.repo_name }}](https://github.com/${{ github.repository }}/actions) because of ${{ env.GITHUB_ACTOR }}
+          format: markdown
+          to: ${{ secrets.TELEGRAM_CHAT_ID }}
+          token: ${{ secrets.TELEGRAM_BOT_TOKEN }}

README.md

@@ -1,4 +1,4 @@
-# Merkle Tree [![GitHub Workflow Status](https://img.shields.io/github/workflow/status/tornadocash/fixed-merkle-tree/Node.js%20CI)](https://github.com/tornadocash/fixed-merkle-tree/actions) [![npm](https://img.shields.io/npm/v/fixed-merkle-tree)](https://www.npmjs.com/package/fixed-merkle-tree)
+# Merkle Tree [![GitHub Workflow Status](https://img.shields.io/github/workflow/status/tornadocash/fixed-merkle-tree/build)](https://github.com/tornadocash/fixed-merkle-tree/actions) [![npm](https://img.shields.io/npm/v/fixed-merkle-tree)](https://www.npmjs.com/package/fixed-merkle-tree)
 
 This is a fixed depth merkle tree implementation with sequential inserts
 

package-lock.json

@@ -1,6 +1,6 @@
 {
   "name": "fixed-merkle-tree",
-  "version": "0.3.3",
+  "version": "0.3.4",
   "lockfileVersion": 1,
   "requires": true,
   "dependencies": {

package.json

@@ -1,6 +1,6 @@
 {
   "name": "fixed-merkle-tree",
-  "version": "0.3.3",
+  "version": "0.5.0",
   "description": "Fixed depth merkle tree implementation with sequential inserts",
   "main": "src/merkleTree.js",
   "scripts": {
@@ -19,7 +19,7 @@
   ],
   "dependencies": {
     "snarkjs": "git+https://github.com/tornadocash/snarkjs.git#869181cfaf7526fe8972073d31655493a04326d5",
-    "circomlib": "git+https://github.com/tornadocash/circomlib.git#6282474dc03e47a7cba1486e6ac8df08842314c3"
+    "circomlib": "git+https://github.com/tornadocash/circomlib.git#5beb6aee94923052faeecea40135d45b6ce6172c"
   },
   "devDependencies": {
     "babel-eslint": "^10.1.0",

src/merkleTree.js

@@ -152,6 +152,36 @@ class MerkleTree {
   elements() {
     return this._layers[0].slice()
   }
+
+  /**
+   * Serialize entire tree state including intermediate layers into a plain object
+   * Deserializing it back will not require to recompute any hashes
+   * Elements are not converted to a plain type, this is responsibility of the caller
+   */
+  serialize() {
+    return {
+      levels: this.levels,
+      _zeros: this._zeros,
+      _layers: this._layers,
+    }
+  }
+
+  /**
+   * Deserialize data into a MerkleTree instance
+   * Make sure to provide the same hashFunction as was used in the source tree,
+   * otherwise the tree state will be invalid
+   *
+   * @param data
+   * @param hashFunction
+   * @returns {MerkleTree}
+   */
+  static deserialize(data, hashFunction) {
+    const instance = Object.assign(Object.create(this.prototype), data)
+    instance._hash = hashFunction || defaultHash
+    instance.capacity = 1 << instance.levels
+    instance.zeroElement = instance._zeros[0]
+    return instance
+  }
 }
 
 module.exports = MerkleTree

test/merkleTree.test.js

@@ -202,4 +202,19 @@ describe('MerkleTree', () => {
       ])
     })
   })
+
+  describe('#serialize', () => {
+    it('should work', () => {
+      const src = new MerkleTree(10, [1, 2, 3])
+      const data = src.serialize()
+      const dst = MerkleTree.deserialize(data)
+
+      src.root().should.equal(dst.root())
+
+      src.insert(10)
+      dst.insert(10)
+
+      src.root().should.equal(dst.root())
+    })
+  })
 })