Benchmark: weakmap vs closure

Script Preparation code:

function A() {
	var x = 0;
	return {
		incr() { x ++ },
		get() { return x },
	}
}
var closure = A();
closure.incr()

var wm = new WeakMap();
function B() {
	var x = {
		incr() { wm.set(x, (wm.get(x) || 1)+1) },
		get() { return wm.get(x) },
	}
	return x
}
var weakmap = B();
weakmap.incr()

Tests:

closure get
closure.get()
weakmap get
weakmap.get()
closure incr
closure.incr()
weakmap incr
weakmap.incr()

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
closure get
weakmap get
closure incr
weakmap incr

Fastest: N/A

Slowest: N/A

Autogenerated LLM Summary (model llama3.2:3b, generated 29 days ago):

LLMs can make mistakes. Check important info.

**Benchmark Overview**

The provided benchmark, "weakmap vs closure", is designed to compare the performance of two approaches: using closures (a JavaScript concept where a function has access to its own scope) and WeakMaps (a JavaScript data structure that stores key-value pairs with optional garbage collection).

**Options Compared**

The benchmark compares the following options:

1. **Closure**: A closure-based approach, where an object is returned by a function, allowing access to its internal state.
2. **WeakMap**: A WeakMap-based approach, where a WeakMap data structure is used to store key-value pairs.

**Pros and Cons of Each Approach**

* **Closure:**
	+ Pros:
		- Easy to implement and understand
		- Allows for simple and intuitive access to internal state
	+ Cons:
		- Performance can be slower due to the overhead of creating a new object and function scope
		- Not designed for fast lookups or high-performance applications
* **WeakMap:**
	+ Pros:
		- Fast lookups and insertion/deletion operations (due to the WeakMap's garbage collection)
		- Suitable for high-performance applications where low latency is critical
	+ Cons:
		- More complex to implement and understand, especially for those without prior experience with WeakMaps
		- Requires manual management of objects to be stored in the WeakMap

**Library Usage**

In this benchmark, the `WeakMap` library is used. A WeakMap is a data structure that stores key-value pairs where each key is an object, and the value can be any type of object. The WeakMap does not prevent the garbage collector from freeing up memory occupied by its values when they are no longer referenced elsewhere in the program.

**Special JS Feature/Syntax**

There are two special features used in this benchmark:

* **Arrow Functions**: Used to define small, anonymous functions (e.g., `incr()` and `get()`).
* **Function Scopes**: Used to create closures by returning objects from a function (e.g., `A()`).

**Other Considerations**

When deciding between the closure-based and WeakMap approaches, consider the trade-offs:

* If simplicity and ease of use are more important than performance, the closure-based approach might be suitable.
* If high-performance requirements and low latency are crucial, the WeakMap-based approach is likely a better choice.

**Alternatives**

Other data structures or approaches that could be used to compare with WeakMaps include:

* **Arrays**: For storing key-value pairs with fast lookups
* **Hash Tables**: For storing key-value pairs with fast lookups (similar to WeakMaps but without garbage collection)
* **Objects**: For storing key-value pairs, but without the benefits of WeakMap's garbage collection

Keep in mind that this benchmark is specifically designed to compare Closures and Weak Maps.

Latest run results:

Run details: (Test run date: 5 years ago)

User agent: Mozilla/5.0 (X11; Linux x86_64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/73.0.3683.75 Safari/537.36

Browser/OS: Chrome 73 on Linux

View result in a separate tab

Test name	Executions per second
closure get	14974797.0 Ops/sec
weakmap get	6575907.0 Ops/sec
closure incr	15423466.0 Ops/sec
weakmap incr	4132445.0 Ops/sec

Related benchmarks:

weakmap vs closure (version: 0)

Comparing performance of: closure get vs weakmap get vs closure incr vs weakmap incr

Created: 5 years ago by: Guest

Jump to the latest result

closure get

weakmap get

closure incr

weakmap incr

Suite status: <idle, ready to run>

Experimental features:

Fastest: N/A

Slowest: N/A

Autogenerated LLM Summary (model llama3.2:3b, generated 29 days ago):