/dynja

Jinja pseudo-engine focused on DevEx and Performance

Primary LanguageRustGNU Affero General Public License v3.0AGPL-3.0

Dynja

dynja-logo

Jinja pseudo-engine focused on DevEx and Performance

Why Dynja?

Let's look at two of the alternatives:

  • Askama: extremely fast on benchmarks, but doesn't have a very fun development experience, since you have to recompile your webserver each time you modify a template
  • MiniJinja: decent performance on benchmarks, but has an awesome developer experience, with hot reloading and possibly even live reloading

So let's mix both: use MiniJinja for debug mode (better DevEx), and Askama for release mode (better performance)

And that's what Dynja essentially is

How to use?

Add the dynja dependency to your Cargo.toml, along with the askama dependency. The minijinja dependency isn't necessary, because it is only used internally, whereas askama needs to be exported on release builds.

[dependencies]
dynja = { version = "0.4", features = ["askama_release"] }
askama = "0.12"

Now you can import dynja and use it as if it were askama. Nice huh?

use dynja::Template;

#[derive(Template)]
#[template(path = "index.html")]
struct MyTemplate {
    name: &'static str,
}

fn main() {
    let template = MyTemplate { name: "Test" };
    println!("Template Render: {}", template.render().unwrap());
}

It will automatically choose between minijinja on debug, and askama on release, so you don't have to worry about it.

NOTE: You can use dynja without askama if you wish. Just add the following in your Cargo.toml instead:

dynja = "0.4"

It has optimizations for minijinja on release mode as well, but it won't be as performant as askama.

Read the Considerations section for more information.

Have fun!

Benchmarks

NOTE: These benchmarks are not done properly, so they don't represent a real world scenario. They do let you see the difference between switching the engines though.

Tested on dynja_bench, located on the root directory of this repository.

Dynja 0.4.0 (Debug)

Benchmarking: MiniJinja
<!DOCTYPE html>
<html>
  <head></head>

  <body>
    <h1>Dynja Benchmark</h1>
    <h2>Name: Tests</h2>
    <h2>Number: 1337</h2>
    <h2>Float: 420.0</h2>
  </body>
</html>

Iteration: 999999
Benchmark finished
Time taken to finish iterations: 103629ms (103s)

Dynja 0.4.0 (Release - features = ["askama_release"])

Benchmarking: Askama
<!DOCTYPE html>
<html>
  <head></head>

  <body>
    <h1>Dynja Benchmark</h1>
    <h2>Name: Tests</h2>
    <h2>Number: 1337</h2>
    <h2>Float: 420</h2>
  </body>
</html>

Iteration: 999999
Benchmark finished
Time taken to finish iterations: 937ms (0s)

The release build finished the iterations about 110 times faster than the debug build.

On a side note, this benchmark also doesn't say that minijinja is slow by any means. In other to achieve hot reloading of the templates, we have to clear the cached templates of minijinja for every render(), which means we add a severe bottleneck to its performance to get a better development experience. Here are the results of a test done without the "askama_release" feature, on release mode:

Dynja 0.4.0 (Release)

Benchmarking: MiniJinja
<!DOCTYPE html>
<html>
  <head></head>

  <body>
    <h1>Dynja Benchmark</h1>
    <h2>Name: Tests</h2>
    <h2>Number: 1337</h2>
    <h2>Float: 420.0</h2>
  </body>
</html>

Iteration: 999999
Benchmark finished
Time taken to finish iterations: 2851ms (2s)

License

This project is licensed under the GNU AGPL-3.0. No later versions allowed.

Read the LICENSE file in the root directory of the project for more information.

Considerations

Even though MiniJinja and Askama are both related to Jinja, they are not 100% compatible with each other. So be wary of inconsistencies!

For most cases, the slower performance of MiniJinja won't affect you as much as you think. In the benchmark above (release mode), it still manage to render the template 350,754 times in a single second, which is more than enough for, say, a web server. If you really need that performance edge and you know that your templates are compatible across the engines, Askama still takes the win with 1,067,235 renders per second, according to the benchmark. If you need to make sure that the debug templates are compatible with release templates, stick with MiniJinja.