Upload src/lib/merkle.ts with huggingface_hub

src/lib/merkle.ts

@@ -0,0 +1,62 @@
+export interface FileNode {
+  path: string;
+  size: number;
+}
+
+export interface MerkleLeaf {
+  path: string;
+  size: number;
+  hash: string;
+}
+
+export interface MerkleTree {
+  root: string;
+  leaves: MerkleLeaf[];
+  levels: string[][];
+  leafCount: number;
+}
+
+async function sha256Hex(input: string): Promise<string> {
+  const encoder = new TextEncoder();
+  const data = encoder.encode(input);
+  const buf = await crypto.subtle.digest("SHA-256", data);
+  return Array.from(new Uint8Array(buf))
+    .map((b) => b.toString(16).padStart(2, "0"))
+    .join("");
+}
+
+export async function buildMerkleTree(files: FileNode[]): Promise<MerkleTree> {
+  if (!files.length) {
+    return { root: "", leaves: [], levels: [], leafCount: 0 };
+  }
+
+  const leaves: MerkleLeaf[] = [];
+  for (const f of files) {
+    const hash = await sha256Hex(`${f.path}:${f.size}`);
+    leaves.push({ path: f.path, size: f.size, hash });
+  }
+
+  leaves.sort((a, b) => a.hash.localeCompare(b.hash));
+
+  let current = leaves.map((l) => l.hash);
+  const levels: string[][] = [current.slice()];
+
+  while (current.length > 1) {
+    const next: string[] = [];
+    for (let i = 0; i < current.length; i += 2) {
+      const left = current[i];
+      const right = current[i + 1] ?? left;
+      const combined = await sha256Hex(`${left}${right}`);
+      next.push(combined);
+    }
+    current = next;
+    levels.push(current.slice());
+  }
+
+  return {
+    root: current[0] ?? "",
+    leaves,
+    levels,
+    leafCount: leaves.length,
+  };
+}