use document_graphics::{
RasterOptions,
worker::{self, Worker},
};
use std::{
sync::{
Arc,
atomic::{AtomicBool, Ordering},
},
time::Instant,
};
fn main() {
if std::env::args_os().nth(1).as_deref() == Some(std::ffi::OsStr::new("--mermaid-worker")) {
worker::worker_main().unwrap();
return;
}
if std::env::args().any(|arg| arg == "--large") {
large_flowchart();
}
let cancel = Arc::new(AtomicBool::new(false));
let mut worker = Worker::spawn(&std::env::current_exe().unwrap(), "--mermaid-worker").unwrap();
let cases = [
(
"flowchart",
"flowchart LR\n A[Read Markdown] --> B{Diagram?}\n B -->|Yes| C[Preview]\n B -->|No| D[Text]\n C --> E[Read]\n D --> E\n",
Some((705, 181)),
),
(
"sequence",
"sequenceDiagram\n participant R as Reader\n participant V as Viewer\n R->>V: Open file\n activate V\n V-->>R: Rendered preview\n deactivate V\n",
Some((450, 287)),
),
(
"class",
"classDiagram\n class Document {\n +String source\n +render()\n }\n Document --> Renderer\n",
Some((201, 304)),
),
(
"state",
"stateDiagram-v2\n [*] --> Reading\n Reading --> Rendering: diagram\n Rendering --> Reading: next block\n Reading --> [*]\n",
Some((214, 198)),
),
(
"er",
"erDiagram\n DOCUMENT ||--o{ BLOCK : contains\n",
Some((196, 197)),
),
(
"subgraph",
"flowchart LR\n subgraph Input\n A[File] --> B[Parser]\n end\n subgraph Output\n C[Diagram] --> D[Preview]\n end\n B --> C\n",
Some((779, 147)),
),
(
"unicode",
"flowchart LR\n A[Café déjà vu] --> B[Ελληνικά Русский]",
Some((445, 78)),
),
(
"attributes",
"erDiagram\n BOOK {\n int identifier PK,FK,UK\n varchar title \"display name\"\n decimal price\n }\n BOOK ||--o{ PAGE : contains\n PAGE {\n int identifier PK\n int book_id FK\n }",
Some((411, 373)),
),
(
"pie",
"pie showData\n title Café\n \"Thé\": 3\n \"Café\": 7",
Some((454, 360)),
),
(
"mindmap",
"mindmap\n root((Reading))\n Notes\n Ideas\n Diagrams",
Some((543, 103)),
),
(
"timeline",
"timeline\n title History\n 2020 : Launch : Learn\n 2021 : Grow",
Some((340, 280)),
),
(
"journey",
"journey\n title Reading\n section Start\n Open file: 5: Reader\n Read: 4: Reader, Editor",
Some((309, 247)),
),
(
"quadrant",
"quadrantChart\n title Work\n x-axis Low effort --> High effort\n y-axis Low value --> High value\n Task A: [0.2, 0.8]\n Task B: [0.8, 0.3]",
Some((552, 511)),
),
];
let mut times = Vec::new();
for (name, source, expected) in cases {
for light in [false, true] {
let start = Instant::now();
let p = worker
.render(
source,
light,
RasterOptions::scaled(2.),
std::time::Duration::from_secs(2),
&cancel,
)
.unwrap()
.expect(name);
let elapsed = start.elapsed().as_secs_f64() * 1000.;
times.push(elapsed);
if let Some((width, height)) = expected {
assert_eq!(
(p.original_width, p.original_height),
(width, height),
"{name}"
);
if u64::from(width) * u64::from(height) * 4 <= document_graphics::MAX_PIXELS as u64
{
assert_eq!((p.width, p.height), (2 * width, 2 * height), "{name}");
}
}
assert!(p.width as usize * p.height as usize <= document_graphics::MAX_PIXELS);
assert_eq!(p.rgba.len(), (p.width * p.height * 4) as usize);
assert!(p.rgba.as_chunks::<4>().0.iter().any(|p| p[3] > 0));
println!(
"{name}, light={light}: {:.2} ms, {}x{} logical, {} raster bytes",
elapsed,
p.original_width,
p.original_height,
p.rgba.len()
);
}
}
assert!(
worker
.render(
"gantt\nTask: 2025-01-01, 1d\n",
false,
RasterOptions::fit((500, 300)),
std::time::Duration::from_secs(2),
&cancel
)
.unwrap()
.is_none()
);
assert!(
worker
.render(
"flowchart LR\n A[中文]-->B\n",
false,
RasterOptions::fit((500, 300)),
std::time::Duration::from_secs(2),
&cancel
)
.unwrap()
.is_none()
);
for _ in 0..40 {
if worker.requests_completed() >= worker::MAX_REQUESTS {
worker = Worker::spawn(&std::env::current_exe().unwrap(), "--mermaid-worker").unwrap();
}
assert!(
worker
.render(
"flowchart LR; A-->B",
false,
RasterOptions::fit((500, 300)),
std::time::Duration::from_secs(2),
&cancel
)
.unwrap()
.is_some()
);
}
cancel.store(true, Ordering::Relaxed);
assert_eq!(
worker
.render(
"flowchart LR; A-->B",
false,
RasterOptions::fit((500, 300)),
std::time::Duration::from_secs(2),
&cancel
)
.err()
.unwrap()
.kind(),
std::io::ErrorKind::Interrupted
);
println!(
"Mermaid integration passed ({} fixture renders; cold {:.2} ms, warm max {:.2} ms).",
times.len(),
times[0],
times[1..].iter().copied().fold(0., f64::max)
);
}
fn large_flowchart() {
let mut source = String::from("flowchart TD\nN0 --> N1\n");
for n in 1..256 {
source.push_str(&format!("N{n} --> N{}\n", n * 2));
if n % 2 == 0 {
source.push_str(&format!("N{n} --> N{}\n", n + 1));
}
}
source.push_str("classDef marked fill:#ffcc00,stroke:#112233\nclass N0,N2,N510 marked\n");
for light in [false, true] {
let start = Instant::now();
let mut worker =
Worker::spawn(&std::env::current_exe().unwrap(), "--mermaid-worker").unwrap();
let image = worker
.render(
&source,
light,
RasterOptions::scaled(2.),
std::time::Duration::from_secs(2),
&AtomicBool::new(false),
)
.unwrap()
.expect("384-node flowchart");
assert!(image.original_width > 8192);
assert!(image.width as usize * image.height as usize <= document_graphics::MAX_PIXELS);
assert_eq!(image.rgba.len(), (image.width * image.height * 4) as usize);
assert!(image.rgba.as_chunks::<4>().0.iter().any(|p| p[3] > 0));
println!(
"large flowchart, light={light}: cold {:.2} ms, {}x{} logical, {} raster bytes",
start.elapsed().as_secs_f64() * 1000.,
image.original_width,
image.original_height,
image.rgba.len()
);
}
}