From cc943fed50ab67ff1ed26cf82efe803a22f3f010 Mon Sep 17 00:00:00 2001
From: Kieran <kieran@harkin.me>
Date: Tue, 13 Jun 2023 17:06:47 +0100
Subject: [PATCH] try improve performance of diffFilters

---
 package.json                                 |  2 +-
 packages/system/src/RequestBuilder.ts        |  4 ++--
 packages/system/src/RequestSplitter.ts       | 22 ++++++++++++++++++--
 packages/system/tests/RequestBuilder.test.ts |  4 ++--
 4 files changed, 25 insertions(+), 7 deletions(-)

diff --git a/package.json b/package.json
index d05a6602..286263aa 100644
--- a/package.json
+++ b/package.json
@@ -6,7 +6,7 @@
   "scripts": {
     "build": "yarn workspace @snort/system build && yarn workspace @snort/app build",
     "start": "yarn workspace @snort/system build && yarn workspace @snort/app start",
-    "test": "yarn workspace @snort/app test"
+    "test": "yarn workspace @snort/system build && yarn workspace @snort/app test && yarn workspace @snort/system test"
   },
   "devDependencies": {
     "@tauri-apps/cli": "^1.2.3",
diff --git a/packages/system/src/RequestBuilder.ts b/packages/system/src/RequestBuilder.ts
index b93dc648..0bc23a53 100644
--- a/packages/system/src/RequestBuilder.ts
+++ b/packages/system/src/RequestBuilder.ts
@@ -95,8 +95,6 @@ export class RequestBuilder {
 
   /**
    * Detects a change in request from a previous set of filters
-   * @param q All previous filters merged
-   * @returns
    */
   buildDiff(relays: RelayCache, filters: Array<FlatReqFilter>): Array<BuiltRawReqFilter> {
     const start = unixNowMs();
@@ -114,6 +112,8 @@ export class RequestBuilder {
           relay: a.relay,
         };
       });
+    } else {
+      this.#log(`Wasted ${ts} ms detecting no changes!`);
     }
     return [];
   }
diff --git a/packages/system/src/RequestSplitter.ts b/packages/system/src/RequestSplitter.ts
index 7f430895..8863776b 100644
--- a/packages/system/src/RequestSplitter.ts
+++ b/packages/system/src/RequestSplitter.ts
@@ -3,9 +3,27 @@ import { FlatReqFilter } from "./RequestExpander";
 import { flatMerge } from "./RequestMerger";
 
 export function diffFilters(prev: Array<FlatReqFilter>, next: Array<FlatReqFilter>, calcRemoved?: boolean) {
-  const added = next.filter(a => !prev.some(b => flatFilterEq(a, b)));
-  const removed = calcRemoved ? prev.filter(a => !next.some(b => flatFilterEq(a, b))) : [];
+  const added = [];
+  const removed = [];
 
+  for (let x = 0; x < next.length; x++) {
+    const px = prev.findIndex(a => flatFilterEq(a, next[x]));
+    if (px !== -1) {
+      prev.splice(px, 1);
+    } else {
+      added.push(next[x]);
+    }
+  }
+  if (calcRemoved) {
+    for (let x = 0; x < prev.length; x++) {
+      const px = next.findIndex(a => flatFilterEq(a, prev[x]));
+      if (px !== -1) {
+        next.splice(px, 1);
+      } else {
+        removed.push(prev[x]);
+      }
+    }
+  }
   const changed = added.length > 0 || removed.length > 0;
   return {
     added: changed ? flatMerge(added) : [],
diff --git a/packages/system/tests/RequestBuilder.test.ts b/packages/system/tests/RequestBuilder.test.ts
index 62919c36..530d7e0b 100644
--- a/packages/system/tests/RequestBuilder.test.ts
+++ b/packages/system/tests/RequestBuilder.test.ts
@@ -167,7 +167,7 @@ describe("RequestBuilder", () => {
 
 describe("build diff, large follow list", () => {
   const f = [];
-  for (let x = 0; x < 500; x++) {
+  for (let x = 0; x < 2500; x++) {
     const bytes = crypto.getRandomValues(new Uint8Array(32));
     f.push(bytesToHex(bytes));
   }
@@ -194,6 +194,6 @@ describe("build diff, large follow list", () => {
   const start2 = unixNowMs();
   const b = rb.buildDiff(DummyCache, rb.buildRaw().flatMap(expandFilter));
   expect(b).toEqual([]);
-  expect(unixNowMs() - start2).toBeLessThan(200);
+  expect(unixNowMs() - start2).toBeLessThan(100);
 
 })
\ No newline at end of file