Benchmark: Overhead of saving and restoring context state

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) { $context.save(); $context.fillStyle = 'rgba(100,150,200,0.9)'; $context.fillRect(0, 0, 1, 1); $context.restore(); }

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: 12 days ago)

User agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10_15_7) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/130.0.0.0 Safari/537.36

Browser/OS: Chrome 130 on Mac OS X 10.15.7

View result in a separate tab

Test name	Executions per second
Not saving and restoring context state	4360.7 Ops/sec
Saving and restoring context state	2477.9 Ops/sec

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

LLMs can make mistakes. Check important info.

Let's break down the provided benchmark JSON and explain what is being tested, compared, and other considerations.

**Benchmark Definition**

The provided benchmark definition represents a JavaScript microbenchmark that tests the overhead of saving and restoring context state in a 2D drawing context using the HTML5 Canvas API. The test creates a canvas element with a size of 800x300 pixels, sets up a 2D drawing context, clears it, and then performs two types of draws:

1. **Not saving and restoring context state**: In this case, the script directly applies the fill style and fills the entire canvas area without saving the current context state.
2. **Saving and restoring context state**: In this variant, the script saves the current context state before applying the fill style and filling the entire canvas area. After that, it restores the original context state.

**Comparison of Options**

The benchmark compares two options:

1. **Not saving and restoring context state**: This approach assumes that the context state is already stored in a register or stack frame when the script executes. In this case, the overhead is only due to the execution time of the draw operations.
2. **Saving and restoring context state**: This approach saves the current context state before applying the fill style and filling the entire canvas area. The restored state is then discarded, which means that the context state needs to be recalculated every time.

**Pros and Cons**

Here are some pros and cons of each option:

* Not saving and restoring context state:
	+ Pros: Less overhead due to reduced number of operations.
	+ Cons: May lead to inaccurate results if the execution time is dominated by other factors, such as garbage collection or caching.
* Saving and restoring context state:
	+ Pros: Can provide more accurate results by accounting for the overhead of saving and restoring the context state.
	+ Cons: Increases the number of operations, which may lead to higher overhead and slower execution times.

**Library and Syntax**

There is no library used in this benchmark. The script uses standard JavaScript features like loops, variables, and the Canvas API.

**Special JS Features or Syntax (None)**

Since there are no special JavaScript features or syntax used in this benchmark, we can move on to the next section.

**Other Alternatives**

Other alternatives for testing this type of benchmark could include:

* Testing with a smaller canvas size
* Using a different drawing primitive, such as `drawImage()`
* Adding more complex shapes or patterns to the draw operations
* Using a different rendering engine or browser

However, these variations would require careful consideration of the potential impact on the accuracy and relevance of the benchmark results.

Overall, this benchmark provides a useful insight into the overhead of saving and restoring context state in JavaScript, which can be important for optimizing performance-critical code.

Related benchmarks:

Overhead of saving and restoring context state (version: 0)

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

Created: 4 years ago by: Registered User

Jump to the latest result

Not saving and restoring context state

Saving and restoring context state

Suite status: <idle, ready to run>

Experimental features:

Fastest: N/A

Slowest: N/A

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