wip - working exampole

Cargo.lock

@@ -47,6 +47,15 @@ version = "1.0.75"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "a4668cab20f66d8d020e1fbc0ebe47217433c1b6c8f2040faf858554e394ace6"
 
+[[package]]
+name = "async-mutex"
+version = "1.4.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "479db852db25d9dbf6204e6cb6253698f175c15726470f78af0d918e99d6156e"
+dependencies = [
+ "event-listener",
+]
+
 [[package]]
 name = "async-stream"
 version = "0.3.5"
@@ -422,6 +431,12 @@ dependencies = [
  "windows-sys",
 ]
 
+[[package]]
+name = "event-listener"
+version = "2.5.3"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "0206175f82b8d6bf6652ff7d71a1e27fd2e4efde587fd368662814d6ec1d9ce0"
+
 [[package]]
 name = "fastrand"
 version = "2.0.1"
@@ -964,6 +979,8 @@ dependencies = [
 name = "ovlach_pdf"
 version = "0.1.0"
 dependencies = [
+ "async-mutex",
+ "async-trait",
  "fern",
  "headless_chrome",
  "log",
@@ -971,6 +988,7 @@ dependencies = [
  "rocket",
  "serde",
  "serde_yaml",
+ "tokio",
 ]
 
 [[package]]

Cargo.toml

@@ -14,3 +14,6 @@ rocket = { version = "0.5.0", features = ["json"] }
 headless_chrome = "1.0.8"
 
 ovlach_data = { git = "ssh://git@gitlab.nanobyte.cz/ondrej/ov-site-api-data.git", branch = "add_missing_fields"}
+async-trait = "0.1.74"
+async-mutex = "1.4.0"
+tokio = { version = "1.34.0", features = ["macros"] }

src/chromium/mod.rs

@@ -0,0 +1 @@
+pub mod rocket;

src/chromium/rocket.rs

@@ -0,0 +1,127 @@
+use std::{sync::{Arc}, time::Duration};
+use async_trait::async_trait;
+use async_mutex::Mutex;
+use headless_chrome::{Browser, LaunchOptions};
+use log::{warn, error};
+use rocket::{fairing::{Fairing, self}, Rocket, Build, catcher::Result, Request, Response, request::{FromRequest, Outcome}};
+
+#[derive(Default)]
+pub struct Chromium {
+}
+
+impl Chromium {
+    pub fn ignite() -> Self {
+        Self::default()
+    }
+
+    pub fn default() -> Self {
+        Self {
+        }
+    }
+}
+
+#[async_trait]
+impl Fairing for Chromium {
+    fn info(&self) -> fairing::Info {
+        fairing::Info {
+            name: "Chromium",
+            kind: fairing::Kind::Ignite,
+        }
+    }
+
+    async fn on_ignite(&self, rocket: Rocket<Build>) -> fairing::Result {
+        let new_rocket = rocket.manage(ChromiumCoordinator::new().await);
+        let coordinator = new_rocket.state::<ChromiumCoordinator>().unwrap();
+        error!("{:p}", &coordinator);
+        Ok(new_rocket)
+    }
+}
+pub struct ChromiumCoordinator {
+    instances: Arc<Mutex<Vec<BrowserHolder>>>,
+}
+
+impl ChromiumCoordinator {
+   const NUMBER_OF_INSTANCES: usize = 1;
+   
+   pub async fn new() -> Self {
+        error!("ChromiumCoordinator::new()");
+        let instances: Arc<Mutex<Vec<BrowserHolder>>> = Arc::new(Mutex::new(Vec::with_capacity(Self::NUMBER_OF_INSTANCES)));
+        while instances.lock().await.len() < Self::NUMBER_OF_INSTANCES {
+            instances.lock().await.push(BrowserHolder { browser: Browser::new(LaunchOptions {
+                idle_browser_timeout: Duration::from_secs(1), // Wait inifinity for commands
+                ..LaunchOptions::default()
+            }).unwrap() });
+        }
+
+        Self { instances }
+   }
+
+   fn spawn_browser(&self) {
+    let instances = self.instances.clone(); 
+    tokio::spawn(async move {
+        error!("Spawn new instance of browser");
+        // Create new instance
+        let browser = Browser::new(LaunchOptions::default()).unwrap();
+        instances.lock().await.push( BrowserHolder {browser });
+    });
+   }
+
+   fn try_get_instance(&self) -> Option<BrowserHolder> {
+        let mut instances = self.instances.lock().await;
+        if instances.len() == 0 {
+            return None;
+        }
+        Some(instances.remove(0))
+   }
+
+   pub async fn try_get_browser(&self) -> std::result::Result<BrowserHolder, ()> {
+        let instances = self.instances.clone(); 
+        
+        let mut loop_count = 0;
+        
+        while instances.lock().await.len() == 0 {
+            warn!("Waiting for Chromium instances to start...");
+            std::thread::sleep(std::time::Duration::from_millis(100));
+            if loop_count > 100 * 10 * 60 {
+                panic!("Can't start Chromium instances");
+            }
+            loop_count += 1;
+        }
+
+        let browser =  self.instances.lock().await.remove(0);
+        self.spawn_browser();
+        // test connection state
+        match browser.browser.get_version() {
+            Ok(_) => Ok(browser),
+            Err(_) => {
+                Err(())
+            }
+        }
+    }
+
+    pub async fn get_browser(&self) -> std::result::Result<BrowserHolder, ()> {
+        loop {
+            match self.try_get_browser().await {
+                Ok(browser) => return Ok(browser),
+                Err(_) => {} // all instances may be dead ... we must wait for new instance
+            }
+        }
+    }
+}
+
+pub struct BrowserHolder {
+    pub browser: Browser,
+}
+
+#[async_trait]
+impl<'r> FromRequest<'r> for BrowserHolder {
+    type Error = ();
+
+    async fn from_request(request: &'r Request<'_>) -> Outcome<Self, ()> {
+        let coordinator = request.rocket().state::<ChromiumCoordinator>().unwrap();
+        error!("{:p}", &coordinator);
+        let browser = coordinator.get_browser().await.unwrap();
+        Outcome::Success(browser)
+    }
+}
+

src/lib.rs

@@ -1,9 +1,13 @@
+use chromium::rocket::Chromium;
 use rocket::{Rocket, Build, routes};
 
 pub mod routes;
+mod chromium;
 
 pub fn rocket_builder() -> Rocket<Build> {
-    rocket::build().mount("/", routes![
-        routes::pdf::render_pdf_cv,
+    rocket::build()
+        .attach(Chromium::ignite())
+        .mount("/", routes![
+            routes::pdf::render_pdf_cv,
         ])
 }

src/routes/pdf.rs

@@ -7,8 +7,9 @@ use headless_chrome::{types::PrintToPdfOptions, LaunchOptions};
 use log::error;
 use rocket::{get, Response, futures::Stream, tokio::net::UnixStream, fs::NamedFile};
 
-fn generate_pdf() {
-    let browser = Browser::new(LaunchOptions::default()).unwrap();
+use crate::chromium::rocket::BrowserHolder;
+
+fn generate_pdf(browser: Browser) {
     let tab = browser.new_tab().unwrap();
     let tab = tab.navigate_to("file:///home/6a6996c0-1609-48b6-8ca6-affbef1b4d1d/Devel/Nanobyte/ovlach/ovlach_pdf/template.html").unwrap().wait_until_navigated().unwrap();
     let options = PrintToPdfOptions{
@@ -34,8 +35,8 @@ fn generate_pdf() {
 }
 
 #[get("/cv/<username>/pdf")]
-pub async fn render_pdf_cv(username: &str) -> NamedFile { 
-    generate_pdf();
+pub async fn render_pdf_cv(username: &str, browser: BrowserHolder) -> NamedFile { 
+    generate_pdf(browser.browser);
     "foo!".to_string();
     NamedFile::open("/tmp/foo.pdf").await.expect("failed to open foo.pdf")
 }