init partial tree

src/index.ts

@@ -13,7 +13,7 @@ export default class MerkleTree {
 
   levels: number
   capacity: number
-  private _hash: HashFunction
+  private _hashFn: HashFunction
   private zeroElement: Element
   private _zeros: Element[]
   private _layers: Array<Element[]>
@@ -27,12 +27,12 @@ export default class MerkleTree {
     if (elements.length > this.capacity) {
       throw new Error('Tree is full')
     }
-    this._hash = hashFunction
+    this._hashFn = hashFunction
     this.zeroElement = zeroElement
     this._zeros = []
     this._zeros[0] = zeroElement
     for (let i = 1; i <= levels; i++) {
-      this._zeros[i] = this._hash(this._zeros[i - 1], this._zeros[i - 1])
+      this._zeros[i] = this._hashFn(this._zeros[i - 1], this._zeros[i - 1])
     }
     this._layers = []
     this._layers[0] = elements.slice()
@@ -43,7 +43,7 @@ export default class MerkleTree {
     for (let level = 1; level <= this.levels; level++) {
       this._layers[level] = []
       for (let i = 0; i < Math.ceil(this._layers[level - 1].length / 2); i++) {
-        this._layers[level][i] = this._hash(
+        this._layers[level][i] = this._hashFn(
           this._layers[level - 1][i * 2],
           i * 2 + 1 < this._layers[level - 1].length
             ? this._layers[level - 1][i * 2 + 1]
@@ -93,7 +93,7 @@ export default class MerkleTree {
       while (index % 2 === 1) {
         level++
         index >>= 1
-        this._layers[level][index] = this._hash(
+        this._layers[level][index] = this._hashFn(
           this._layers[level - 1][index * 2],
           this._layers[level - 1][index * 2 + 1],
         )
@@ -114,7 +114,7 @@ export default class MerkleTree {
     this._layers[0][index] = element
     for (let level = 1; level <= this.levels; level++) {
       index >>= 1
-      this._layers[level][index] = this._hash(
+      this._layers[level][index] = this._hashFn(
         this._layers[level - 1][index * 2],
         index * 2 + 1 < this._layers[level - 1].length
           ? this._layers[level - 1][index * 2 + 1]

src/partialMerkleTree.ts

@@ -0,0 +1,52 @@
+import { Element, HashFunction, ProofPath } from './index'
+
+type LeafWithIndex = { index: number, data: Element }
+
+export class PartialMerkleTree {
+  levels: number
+  private _hash: HashFunction
+  private zeroElement: Element
+  private _zeros: Element[]
+  private _layers: Array<Element[]>
+  private _leaves: Element[]
+  private _leavesAfterEdge: Element[]
+  private _edgeLeaf: LeafWithIndex
+  private _root: string
+  private _hashFn: HashFunction
+  private _edgeLeafProof: ProofPath
+
+  constructor(edgeLeafProof: ProofPath, edgeLeaf: LeafWithIndex, leaves: Element[], root: string, hashFn: HashFunction) {
+    this._edgeLeafProof = edgeLeafProof
+    this._edgeLeaf = edgeLeaf
+    this._leavesAfterEdge = leaves
+    this._root = root
+    this._hashFn = hashFn
+
+  }
+
+  get capacity() {
+    return this.levels ** 2
+  }
+
+  private _buildTree(): void {
+    const edgeLeafIndex = this._edgeLeaf.index
+    this._leaves = [...Array.from({ length: edgeLeafIndex - 1 }, () => null), ...this._leavesAfterEdge]
+    this._layers = [this._leaves]
+    this._rebuild()
+
+  }
+
+  _rebuild() {
+    for (let level = 1; level <= this.levels; level++) {
+      this._layers[level] = []
+      for (let i = 0; i < Math.ceil(this._layers[level - 1].length / 2); i++) {
+        this._layers[level][i] = this._hash(
+          this._layers[level - 1][i * 2],
+          i * 2 + 1 < this._layers[level - 1].length
+            ? this._layers[level - 1][i * 2 + 1]
+            : this._zeros[level - 1],
+        )
+      }
+    }
+  }
+}