From 9c79d13b1f72ca099555dbbabacca34155fcb64b Mon Sep 17 00:00:00 2001
From: Joeri Exelmans <joeri.exelmans@gmail.com>
Date: Sat, 10 May 2025 11:13:47 +0200
Subject: [PATCH] use performance.now() instead of Date.now() in benchmark

---
 benchmarks/rbtree_bench.js | 46 +++++++++++++++++++++-----------------
 1 file changed, 25 insertions(+), 21 deletions(-)

diff --git a/benchmarks/rbtree_bench.js b/benchmarks/rbtree_bench.js
index 8ef59a6..5c846d4 100644
--- a/benchmarks/rbtree_bench.js
+++ b/benchmarks/rbtree_bench.js
@@ -5,24 +5,24 @@ function benchmark(N) {
   // in-place update of native Map: fastest
   function map() {
     let t = new Map();
-    const startTime = Date.now();
+    const startTime = performance.now();
     for (let i=0; i<N; ++i) {
       t.set(Math.random(), Math.random());
     }
-    const endTime = Date.now();
+    const endTime = performance.now();
     return endTime - startTime;
   }
-  const durInPlace = (N <= 5000000) ? map() : "(skip)";
+  const durInPlace = (N <= 5000000) ? map() : "";
   console.log("in-place:", durInPlace, "ms");
 
   // purely functional red-black tree: slower by constant factor
   function fun() {
     let t = createTree();
-    const startTime = Date.now(); 
+    const startTime = performance.now(); 
     for (let i=0; i<N; ++i) {
       t = t.insert(Math.random(), Math.random());
     }
-    const endTime = Date.now();
+    const endTime = performance.now();
     return endTime - startTime;
   }
   const durFunc = fun();
@@ -32,27 +32,27 @@ function benchmark(N) {
   function funNoGC() {
     const trees = new Array(N);
     let t = createTree();
-    const startTime = Date.now(); 
+    const startTime = performance.now(); 
     for (let i=0; i<N; ++i) {
       trees[i] = t; // prevent garbage collection
       t = t.insert(Math.random(), Math.random());
     }
-    const endTime = Date.now();
+    const endTime = performance.now();
     return endTime - startTime;
     
   }
-  const durFuncNoGC = (N <= 1000000) ? funNoGC() : "(skip)";
+  const durFuncNoGC = (N <= 1000000) ? funNoGC() : "";
   console.log("functional red-black (no GC):", durFuncNoGC, "ms");
 
   // purely functional radix tree
   function trie() {
     let t = emptyTrie;
-    const startTime = Date.now(); 
+    const startTime = performance.now(); 
     for (let i=0; i<N; ++i) {
       // of course we can only insert strings into radix tree:
       t = insert(t)(String(Math.random()*10))(Math.random());
     }
-    const endTime = Date.now();
+    const endTime = performance.now();
     return endTime - startTime;
   }
   const durTrie = trie();
@@ -62,52 +62,52 @@ function benchmark(N) {
   function trieNoGC() {
     const trees = new Array(N);
     let t = emptyTrie;
-    const startTime = Date.now(); 
+    const startTime = performance.now(); 
     for (let i=0; i<N; ++i) {
       trees[i] = t; // prevent garbage collection
       // of course we can only insert strings into radix tree:
       t = insert(t)(String(Math.random()*10))(Math.random());
     }
-    const endTime = Date.now();
+    const endTime = performance.now();
     return endTime - startTime;
   }
-  const durTrieNoGC = (N <= 1000000) ? trieNoGC() : "(skip)";
+  const durTrieNoGC = (N <= 1000000) ? trieNoGC() : "";
   console.log("functional radix trie (no GC):", durTrieNoGC, "ms");
 
   // defensive copy of native Map: slowest (won't scale)
   function copying() {
     let t = new Map();
-    const startTime = Date.now();
+    const startTime = performance.now();
     for (let i=0; i<N; ++i) {
       t = new Map(t);
       t.set(Math.random(), Math.random());
     }
-    const endTime = Date.now();
+    const endTime = performance.now();
     return endTime - startTime;
   }
-  const durCopying = (N <= 10000) ? copying() : "(skip)";
+  const durCopying = (N <= 10000) ? copying() : "";
   console.log("copying:", durCopying, "ms");
 
   // defensive copy of native Map (no garbage collection): slower than slowest
   function copyingNoGC() {
     const maps = new Array(N);
     let t = new Map();
-    const startTime = Date.now();
+    const startTime = performance.now();
     for (let i=0; i<N; ++i) {
       maps[i] = t; // prevent garbage collection
       t = new Map(t);
       t.set(Math.random(), Math.random());
     }
-    const endTime = Date.now();
+    const endTime = performance.now();
     return endTime - startTime;
   }
-  const durCopyingNoGC = (N <= 10000) ? copyingNoGC() : "(skip)";
+  const durCopyingNoGC = (N <= 10000) ? copyingNoGC() : "";
   console.log("copying (no GC):", durCopyingNoGC, "ms");
 
   return [N, durInPlace, durFunc, durFuncNoGC, durTrie, durTrieNoGC, durCopying, durCopyingNoGC];
 }
 
-const startTime = Date.now();
+const startTime = performance.now();
 
 const results = [];
 const datapoints = [100, 200, 500, 1000, 2000, 5000, 10000, 20000, 50000, 100000, 200000, 500000, 1000000, 2000000];
@@ -118,11 +118,15 @@ for (let i=0; i<datapoints.length; i++) {
   results.push(benchmark(N));
 }
 
-const endTime = Date.now();
+const endTime = performance.now();
 
 console.log("Benchmark took", endTime-startTime, "ms");
 
+console.log();
 console.log("N;in-place;pure-redblack;pure-redblack-NoGC;pure-radix;pure-radix-NoGC;copying;copying-NoGC");
 for (const [N, ...rest] of results) {
   console.log(`${N};${rest.join(';')}`);
 }
+console.log();
+console.log("now go and paste the above CSV in this spreadsheet:");
+console.log("  https://docs.google.com/spreadsheets/d/1WAl5yCZ0UA0XCBn4xphz4foynQpXih4e59kvkbUANRA/edit?usp=sharing");
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