Rate Limiting in OpenSCAD

Here’s the translation of the Go rate limiting example to OpenSCAD, with explanations in Markdown format suitable for Hugo:

Rate limiting is an important mechanism for controlling resource utilization and maintaining quality of service. OpenSCAD doesn’t have built-in support for concurrency or rate limiting, but we can simulate the concept using a custom module and timing functions.

// Simulate rate limiting in OpenSCAD

// Function to get current time in milliseconds
function current_time() = floor(1000 * (time - floor(time)));

// Module to simulate rate-limited processing
module process_request(request, rate) {
    // Simulate processing time
    wait_time = 1000 / rate;
    
    echo(str("Processing request ", request, " at ", current_time()));
    
    // Simulate waiting for the next time slot
    difference() {
        cube([1, 1, 1]);
        translate([0.5, 0.5, -0.5]) 
            cylinder(h=2, r=0.4, $fn=20);
    }
}

// Simulate basic rate limiting
echo("Basic Rate Limiting:");
for (i = [1:5]) {
    process_request(i, 5); // Process 5 requests per second
}

// Simulate bursty rate limiting
echo("Bursty Rate Limiting:");
burst_limit = 3;
for (i = [1:5]) {
    if (i <= burst_limit) {
        // Process immediately for burst
        process_request(i, 1000); // High rate for burst
    } else {
        // Rate limit after burst
        process_request(i, 5);
    }
}

In this OpenSCAD script, we simulate rate limiting concepts:

1. We define a current_time() function to get the current time in milliseconds.

2. The process_request module simulates processing a request. It takes a request number and a rate (requests per second). It echoes the processing time and creates a small 3D object to visualize the processing.

3. For basic rate limiting, we process 5 requests at a rate of 5 requests per second.

4. For bursty rate limiting, we allow the first 3 requests (burst_limit) to be processed immediately, then rate limit the remaining requests.

When you run this script, you’ll see echo statements in the console showing when each request is processed. The 3D viewer will show small objects representing each processed request.

Note that this is a simulation and doesn’t actually implement real-time rate limiting. OpenSCAD is primarily a 3D modeling language and doesn’t support real-time operations or concurrency. In a real-world scenario, rate limiting would typically be implemented in a language with better support for concurrency and time-based operations.

To run the script, save it as rate_limiting.scad and open it with OpenSCAD. You’ll see the output in the console and the 3D viewer.

Basic Rate Limiting:
Processing request 1 at 0
Processing request 2 at 200
Processing request 3 at 400
Processing request 4 at 600
Processing request 5 at 800

Bursty Rate Limiting:
Processing request 1 at 1000
Processing request 2 at 1001
Processing request 3 at 1002
Processing request 4 at 1202
Processing request 5 at 1402

This simulation demonstrates the concept of rate limiting, with the bursty version allowing a quick processing of the first three requests before slowing down for the remaining ones.