Benchmark: assign after allocate object vs re-use object

Script Preparation code:

var reused = {
	color: [1, 1, 1, 1],
  	position: [1, 1],
};

var map = new Map();
for (let i = 0; i < 1000000; i += 1) {
	map.set(`${i}`, {
	  color: [1, 1, 1, 1],
	  position: [1, 1],
      size: 99, // dummy key
	});  
}

Tests:

allocate
for (let i = 0; i < 10000; i += 1) { const target = map.get(`${i}`); Object.assign(target, { color: [i, i, i, i], position: [i, i], }); }
reuse
for (let i = 0; i < 10000; i += 1) { const target = map.get(`${i}`); reused = { color: [i, i, i, i], position: [i, i], }; Object.assign(target, reused); }

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
allocate
reuse

Fastest: N/A

Slowest: N/A

Latest run results:

Run details: (Test run date: 3 years ago)

User agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 11_2_3) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/89.0.4389.90 Safari/537.36

Browser/OS: Chrome 89 on Mac OS X 11.2.3

View result in a separate tab

Test name	Executions per second
allocate	543.3 Ops/sec
reuse	348.4 Ops/sec

Autogenerated LLM Summary (model llama3.1:latest, generated 2 months ago):

LLMs can make mistakes. Check important info.

Let's break down what's being tested in this benchmark.

**The Benchmark**

The test case is called "assign after allocate object vs re-use object". This means we're comparing two different approaches to updating objects in JavaScript.

**The Options Being Compared**

There are two test cases: "allocate" and "reuse".

1. **"Allocate"**: In this approach, a new object is created on every iteration of the loop using `Object.assign()`. The object being updated is retrieved from a Map using `map.get(`${i}`)`.
2. **"Reuse"**: In this approach, an existing object (`reused`) is used and updated in-place using `Object.assign()`.

**Pros/Cons of Each Approach**

1. **Allocate**:
	* Pros: No need to worry about updating a shared object, which can lead to unexpected behavior.
	* Cons: Creates a new object on every iteration, which can be memory-intensive for large loops.
2. **Reuse**:
	* Pros: Can reduce memory allocation overhead by reusing the same object throughout the loop.
	* Cons: Requires careful management of the shared object to prevent unintended updates.

**Other Considerations**

1. **Map usage**: The test case uses a Map (`map`) to store and retrieve objects. This suggests that the objects being updated are likely to be small in size, making the use of a Map efficient.
2. **Object creation**: The preparation code creates an initial object `reused` with some default properties. This implies that the objects being created are similar in structure.

**The Library Used**

None mentioned in this test case.

**JS Feature or Syntax Used**

None special JS feature or syntax is used in this test case, so there's nothing to mention here.

**Alternatives**

1. **Using a single object with mutable properties**: Instead of creating a new object on every iteration, you could use an existing object and update its properties directly.
2. **Using a library like Lodash for immutable data structures**: Libraries like Lodash provide efficient ways to work with immutable data structures, which can help reduce memory allocation overhead.

I hope this explanation helps you understand what's being tested in this benchmark!

Related benchmarks:

assign after allocate object vs re-use object (version: 0)

Comparing performance of: allocate vs reuse

Created: 3 years ago by: Guest

Jump to the latest result

allocate

reuse

Suite status: <idle, ready to run>

Experimental features:

Fastest: N/A

Slowest: N/A

Autogenerated LLM Summary (model llama3.1:latest, generated 2 months ago):