Benchmark: Overhead of saving and restoring context state 3

HTML Preparation code:

<canvas id="canvas" width="800" height="300"></canvas>

Script Preparation code:

$canvas = document.getElementById('canvas');
$context = $canvas.getContext('2d');
$context.clearRect(0, 0, 800, 300);

$iterations = 500;

Tests:

Not saving and restoring context state
for (let i=0; i<$iterations; ++i) { $context.fillStyle = 'rgba(100,150,200,0.9)'; $context.fillRect(0, 0, 1, 1); }
Saving and restoring context state
for (let i=0; i<$iterations; ++i) { const {fillStyle} = $context; $context.fillStyle = 'rgba(100,150,200,0.9)'; $context.fillRect(0, 0, 1, 1); $context.fillStyle = fillStyle; }

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
Not saving and restoring context state
Saving and restoring context state

Fastest: N/A

Slowest: N/A

Latest run results:

Run details: (Test run date: 2 years ago)

User agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10_15_7) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/116.0.5845.2294 YaBrowser/23.9.0.2294 Yowser/2.5 Safari/537.36

Browser/OS: Yandex Browser 23 on Mac OS X 10.15.7

View result in a separate tab

Not saving and restoring context state

1K/s

Saving and restoring context state

792/s

View exact numbers

Test name	Executions per second
✓ Not saving and restoring context state	1,448 Ops/sec
Saving and restoring context state	792 Ops/sec

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

LLMs can make mistakes. Check important info.

Let's dive into explaining the provided benchmark.

**Benchmark Overview**

The benchmark measures the overhead of saving and restoring context state in JavaScript. It tests two approaches: one where the context state is not saved, and another where it is saved.

**Script Preparation Code**

The script preparation code sets up a canvas element and its 2D drawing context:
```javascript
$canvas = document.getElementById('canvas');
$context = $canvas.getContext('2d');
$context.clearRect(0, 0, 800, 300);
```
This clears the canvas to ensure a consistent starting point for each benchmark run.

**Html Preparation Code**

The HTML preparation code defines an empty canvas element with a width and height:
```html
<canvas id="canvas" width="800" height="300"></canvas>
```
This ensures that all browsers will see the same initial state for the canvas.

**Individual Test Cases**

There are two test cases:

1. **Not saving and restoring context state**
```javascript
for (let i=0; i<$iterations; ++i) {
  $context.fillStyle = 'rgba(100,150,200,0.9)';
  $context.fillRect(0, 0, 1, 1);
}
```
This test case simply draws a single pixel on the canvas repeatedly using the `fillStyle` property directly.

2. **Saving and restoring context state**
```javascript
for (let i=0; i<$iterations; ++i) {
  const {fillStyle} = $context;
  $context.fillStyle = 'rgba(100,150,200,0.9)';
  $context.fillRect(0, 0, 1, 1);
  $context.fillStyle = fillStyle;
}
```
This test case saves the `fillStyle` property before drawing a pixel, restores it immediately after drawing, and then draws another pixel. This simulates saving and restoring context state.

**Pros and Cons**

* **Not Saving and Restoring Context State**
	+ Pros: Simple and straightforward, minimal overhead.
	+ Cons: May lead to inconsistent results due to caching or other optimizations.
* **Saving and Restoring Context State**
	+ Pros: More accurate representation of real-world use cases, can help identify performance issues related to context state management.
	+ Cons: Adds unnecessary overhead, may slow down benchmarked code.

**Library**

In this benchmark, `$context` is an alias for the 2D drawing context of a `<canvas>` element. The `fillStyle` property is used to set the color and alpha value for drawing pixels on the canvas.

**Special JS Feature or Syntax**

None are explicitly mentioned in the provided code. However, it's worth noting that the use of template literals (e.g., `$iterations = 500;`) is a feature introduced in ECMAScript 2015 (ES6).

**Alternatives**

Other ways to measure context state overhead might include:

* Using a library like `fast-canvas` or `jsdom` for more controlled canvas rendering.
* Adding additional rendering steps between the two test cases to increase the difference in execution time.
* Using different caching mechanisms or optimization techniques in the benchmarked code.

Keep in mind that these alternatives may change the nature of the benchmark and affect its results.

Overhead of saving and restoring context state 3 (version: 0) Benchmark.js

Comparing performance of: `Not saving and restoring context state vs Saving and restoring context state`

Created: 2 years ago by: Guest

Go to the latest result

Not saving and restoring context state

Saving and restoring context state

Suite status: <idle, ready to run>

Fastest: N/A

Slowest: N/A

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

Overhead of saving and restoring context state 3 (version: 0) Benchmark.js

Comparing performance of: Not saving and restoring context state vs Saving and restoring context state

Created: 2 years ago by: Guest

Go to the latest result

Not saving and restoring context state

Saving and restoring context state

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: `Not saving and restoring context state vs Saving and restoring context state`