Benchmark: set vs weakset - MeasureThat.net

Script Preparation code:

var objs = Array(100).fill().map(() => { return {} })
var obj = objs[50]

var set = new Set()
var weakset = new WeakSet()

var times = 100
while (times--) {
	set.add(objs[times])
	weakset.add(objs[times])
}

Tests:

set
set.has(obj)
weak set
weakset.has(obj)

Historical Performance Data aggregated from 15 community runs

Desktop Results:

Chrome 15 runs

weak set

71.9M/s

set

62.1M/s

Fastest: weak set (1.2x faster)

View exact numbers

✓ weak set: 71,942,016 ops/sec
• set: 62,059,076 ops/sec

Results show median performance across all community submissions. Run this benchmark yourself to verify on your device.

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
set
weak set

Fastest: N/A

Slowest: N/A

Latest run results:

Run details: (Test run date: one year ago)

User agent: Mozilla/5.0 (X11; Linux x86_64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/120.0.0.0 Safari/537.36

Browser/OS: Chrome 120 on Linux

View result in a separate tab

weak set

79.3M/s

set

62.1M/s

View exact numbers

Test name	Executions per second
✓ weak set	79,336,336 Ops/sec
set	62,059,076 Ops/sec

Autogenerated LLM Summary (model llama3.2:3b, generated one year ago):

LLMs can make mistakes. Check important info.

Let's dive into the world of JavaScript microbenchmarks on MeasureThat.net.

**Benchmark Definition:**

The benchmark is designed to compare the performance of two data structures in JavaScript: `Set` and `WeakSet`. The script preparation code creates an array of 100 objects, adds these objects to both sets, and then measures how quickly each set can check if a specific object is present using the `has()` method.

**Options Compared:**

Two options are compared:

1. **Set**: A regular JavaScript `Set` data structure.
2. **WeakSet**: A weak reference implementation of a `Set` data structure, which allows garbage collection to occur even if an object is no longer referenced elsewhere in the code.

**Pros and Cons:**

**Regular Set (Set)**

Pros:

* Fast lookup times due to its hash-based implementation
* No overhead from garbage collection
* Can handle arbitrary JavaScript objects

Cons:

* Does not account for memory leaks or circular references, which can lead to performance issues

**WeakSet**

Pros:

* Automatically releases memory when an object is no longer referenced elsewhere in the code
* Handles circular references and memory leaks more efficiently than a regular Set
* Still provides fast lookup times due to its hash-based implementation

Cons:

* May have slower performance due to garbage collection overhead
* Requires careful management of object lifetimes to avoid unnecessary garbage collection

**Library:**

In this benchmark, the `WeakSet` library is not explicitly mentioned. However, it's worth noting that WeakSets are a built-in JavaScript feature since ECMAScript 2011 (ES6). They provide a way to create weak references to objects, which can help prevent memory leaks and circular references.

**Special JS Feature/Syntax:**

This benchmark does not use any special JavaScript features or syntax. It's a straightforward test of the performance of `Set` and `WeakSet`.

**Alternatives:**

If you're interested in exploring alternative data structures for JavaScript, consider:

1. **Object**: A JavaScript object is not typically used as a data structure for fast lookups, but it can be used with techniques like caching or hashing to improve performance.
2. **Map**: A `Map` data structure provides fast key-value lookups and can be more efficient than a Set for certain use cases.
3. **Custom Data Structures**: You can create custom data structures using JavaScript classes, objects, and arrays to optimize performance for specific use cases.

In summary, the MeasureThat.net benchmark is designed to compare the performance of regular `Set` and weakly-referenced `WeakSet` data structures in JavaScript. Understanding the pros and cons of each approach will help you choose the best solution for your specific use case.

set vs weakset (version: 0) Benchmark.js

Comparing performance of: `set vs weak set`

Created: 2 years ago by: Registered User

Go to the latest result

set

weak set

Historical Performance Data aggregated from 15 community runs

Desktop Results:

Chrome 15 runs

Suite status: <idle, ready to run>

Fastest: N/A

Slowest: N/A

Autogenerated LLM Summary (model llama3.2:3b, generated one year ago):

set vs weakset (version: 0) Benchmark.js

Comparing performance of: set vs weak set

Created: 2 years ago by: Registered User

Go to the latest result

set

weak set

Historical Performance Data aggregated from 15 community runs

Desktop Results:

Chrome 15 runs

Suite status: <idle, ready to run>

Fastest: N/A

Slowest: N/A

Autogenerated LLM Summary (model llama3.2:3b, generated one year ago):

Related benchmarks

Comparing performance of: `set vs weak set`