From 0d012d1eddcb9fdedf5855ba0b4d5b64c706a890 Mon Sep 17 00:00:00 2001
From: Jan Lewandowski <lewandowski.jan@o2.pl>
Date: Fri, 6 Sep 2024 18:07:40 +0900
Subject: [PATCH] feat: benchmark for causallyRealted function

---
 package.json                                  |  3 +-
 packages/object/src/hashgraph/index.ts        | 50 +++++++++++--
 .../object/tests/causallyrelated.bench.ts     | 71 +++++++++++++++++++
 3 files changed, 118 insertions(+), 6 deletions(-)
 create mode 100644 packages/object/tests/causallyrelated.bench.ts

diff --git a/package.json b/package.json
index a153b6de..f667bb59 100644
--- a/package.json
+++ b/package.json
@@ -16,7 +16,8 @@
 		"docs": "typedoc",
 		"proto-gen": "buf generate",
 		"release": "release-it",
-		"test": "vitest"
+		"test": "vitest",
+		"bench": "vitest bench"
 	},
 	"devDependencies": {
 		"@biomejs/biome": "^1.8.3",
diff --git a/packages/object/src/hashgraph/index.ts b/packages/object/src/hashgraph/index.ts
index 940b3e56..cd3f8a39 100644
--- a/packages/object/src/hashgraph/index.ts
+++ b/packages/object/src/hashgraph/index.ts
@@ -1,7 +1,7 @@
 import * as crypto from "node:crypto";
 import { BitSet } from "./bitset.js";
 
-type Hash = string;
+export type Hash = string;
 export type Operation<T> = { type: string; value: T | null };
 
 enum OperationType {
@@ -191,7 +191,7 @@ export class HashGraph<T> {
 			while (j < order.length) {
 				const moving = order[j];
 
-				if (!this.areCausallyRelated(anchor, moving)) {
+				if (!this.areCausallyRelatedUsingBitsets(anchor, moving)) {
 					const v1 = this.vertices.get(anchor);
 					const v2 = this.vertices.get(moving);
 					let action: ActionType;
@@ -233,12 +233,11 @@ export class HashGraph<T> {
 		return result;
 	}
 
-	// Time complexity: O(V), Space complexity: O(V)
-	areCausallyRelated(hash1: Hash, hash2: Hash): boolean {
+	// Amortised time complexity: O(1), Amortised space complexity: O(1)
+	areCausallyRelatedUsingBitsets(hash1: Hash, hash2: Hash): boolean {
 		if (!this.arePredecessorsFresh) {
 			this.topologicalSort();
 		}
-
 		const test1 =
 			this.reachablePredecessors
 				.get(hash1)
@@ -250,6 +249,47 @@ export class HashGraph<T> {
 		return test1 || test2;
 	}
 
+	// Time complexity: O(V), Space complexity: O(V)
+	areCausallyRelatedUsingBFS(hash1: Hash, hash2: Hash): boolean {
+		const visited = new Set<Hash>();
+		const stack = [hash1];
+
+		while (stack.length > 0) {
+			const current = stack.pop();
+			if (current === hash2) return true;
+			if (current === undefined) continue;
+			visited.add(current);
+
+			const vertex = this.vertices.get(current);
+			if (!vertex) continue;
+			for (const dep of vertex.dependencies) {
+				if (!visited.has(dep)) {
+					stack.push(dep);
+				}
+			}
+		}
+
+		visited.clear();
+		stack.push(hash2);
+
+		while (stack.length > 0) {
+			const current = stack.pop();
+			if (current === hash1) return true;
+			if (current === undefined) continue;
+			visited.add(current);
+
+			const vertex = this.vertices.get(current);
+			if (!vertex) continue;
+			for (const dep of vertex.dependencies) {
+				if (!visited.has(dep)) {
+					stack.push(dep);
+				}
+			}
+		}
+
+		return false;
+	}
+
 	// Time complexity: O(1), Space complexity: O(1)
 	getFrontier(): Hash[] {
 		return Array.from(this.frontier);
diff --git a/packages/object/tests/causallyrelated.bench.ts b/packages/object/tests/causallyrelated.bench.ts
new file mode 100644
index 00000000..1862eb57
--- /dev/null
+++ b/packages/object/tests/causallyrelated.bench.ts
@@ -0,0 +1,71 @@
+import test from "node:test";
+import { beforeEach, bench, describe } from "vitest";
+import { AddWinsSet } from "../../crdt/src/cros/AddWinsSet/index.js";
+import {
+	type Hash,
+	type TopologyObject,
+	merge,
+	newTopologyObject,
+} from "../src/index.js";
+
+describe("AreCausallyDependent benchmark", async () => {
+	const samples = 100000;
+	const tests: Hash[][] = [];
+
+	const obj1 = await newTopologyObject("peer1", new AddWinsSet<number>());
+	const obj2 = await newTopologyObject("peer2", new AddWinsSet<number>());
+	const obj3 = await newTopologyObject("peer3", new AddWinsSet<number>());
+
+	const cro1 = obj1.cro as AddWinsSet<number>;
+	const cro2 = obj2.cro as AddWinsSet<number>;
+	const cro3 = obj3.cro as AddWinsSet<number>;
+
+	cro1.add(1);
+	merge(obj2, obj1.hashGraph.getAllVertices());
+
+	cro1.add(1);
+	cro1.remove(2);
+	cro2.remove(2);
+	cro2.add(2);
+
+	merge(obj3, obj1.hashGraph.getAllVertices());
+	cro3.add(3);
+	cro1.remove(1);
+
+	merge(obj1, obj2.hashGraph.getAllVertices());
+	cro1.remove(3);
+	cro2.remove(1);
+
+	merge(obj1, obj2.hashGraph.getAllVertices());
+	merge(obj1, obj3.hashGraph.getAllVertices());
+
+	const vertices = obj1.hashGraph.getAllVertices();
+	for (let i = 0; i < samples; i++) {
+		tests.push([
+			vertices[Math.floor(Math.random() * vertices.length)].hash,
+			vertices[Math.floor(Math.random() * vertices.length)].hash,
+		]);
+	}
+
+	bench("Causality check using BFS", async () => {
+		const cro1 = obj1.cro as AddWinsSet<number>;
+
+		for (let i = 0; i < samples; i++) {
+			const result = obj1.hashGraph.areCausallyRelatedUsingBFS(
+				tests[i][0],
+				tests[i][1],
+			);
+		}
+	});
+
+	bench("Causality check using Bitsets", async () => {
+		const cro1 = obj1.cro as AddWinsSet<number>;
+
+		for (let i = 0; i < samples; i++) {
+			const result = obj1.hashGraph.areCausallyRelatedUsingBitsets(
+				tests[i][0],
+				tests[i][1],
+			);
+		}
+	});
+});