Parallelize DM Gift Wrap Decryption for lower latency

Co-authored-by: PR0M3TH3AN <[email protected]>

benchmarks/dm_decrypt_bench.js

@@ -0,0 +1,85 @@
+
+import { decryptDM } from "../js/dmDecryptor.js";
+
+// Valid 64-char hex strings
+const WRAP_PUBKEY = "0000000000000000000000000000000000000000000000000000000000000001";
+const SEAL_PUBKEY = "0000000000000000000000000000000000000000000000000000000000000002";
+const SENDER_PUBKEY = "0000000000000000000000000000000000000000000000000000000000000003";
+const RECIPIENT_PUBKEY = "0000000000000000000000000000000000000000000000000000000000000004";
+
+const sealEvent = {
+  id: "seal-event",
+  pubkey: SEAL_PUBKEY,
+  content: "seal-ciphertext",
+  created_at: Math.floor(Date.now() / 1000),
+};
+
+const rumorEvent = {
+  id: "rumor-event",
+  pubkey: SENDER_PUBKEY,
+  content: "Hello World",
+  created_at: Math.floor(Date.now() / 1000),
+  tags: [["p", RECIPIENT_PUBKEY]],
+};
+
+const wrapEvent = {
+  kind: 1059,
+  pubkey: WRAP_PUBKEY,
+  content: "wrap-ciphertext",
+  created_at: Math.floor(Date.now() / 1000),
+  tags: [["p", RECIPIENT_PUBKEY]],
+};
+
+const delay = (ms) => new Promise((resolve) => setTimeout(resolve, ms));
+
+const createDecryptor = (name, shouldFail, delayMs) => {
+  return {
+    scheme: "nip44",
+    supportsGiftWrap: true,
+    decrypt: async (pubkey, ciphertext, context) => {
+      await delay(delayMs);
+      if (shouldFail) {
+        throw new Error(`${name} failed`);
+      }
+
+      // If we are unwrapping the outer wrap, return the seal
+      if (context.stage === "wrap") {
+        return JSON.stringify(sealEvent);
+      }
+      // If we are unwrapping the seal, return the rumor
+      if (context.stage === "seal") {
+        return JSON.stringify(rumorEvent);
+      }
+
+      return "";
+    },
+  };
+};
+
+async function runBenchmark() {
+  console.log("Running DM Decrypt Benchmark...");
+
+  const decryptors = [
+    createDecryptor("D1", true, 100),
+    createDecryptor("D2", true, 100),
+    createDecryptor("D3", false, 50),
+  ];
+
+  const context = {
+    actorPubkey: RECIPIENT_PUBKEY,
+    decryptors: decryptors,
+  };
+
+  const start = performance.now();
+  const result = await decryptDM(wrapEvent, context);
+  const end = performance.now();
+
+  console.log(`Result OK: ${result.ok}`);
+  if (!result.ok) {
+    const errorMessages = result.errors.map(e => ({stage: e.stage, message: e.error.message}));
+    console.log("Errors:", JSON.stringify(errorMessages, null, 2));
+  }
+  console.log(`Time taken: ${(end - start).toFixed(2)}ms`);
+}
+
+runBenchmark();