GrammalecteClient/src/server.rs

use crate::server::utils::{get_free_port, wait_for_port};
use mktemp::Temp;
use std::error::Error;
use std::io::{Cursor, Read};
use std::process::{Child, Stdio};
use zip::ZipArchive;

pub struct EmbeddedServer {
    _srv_dir: Temp,
    port: u16,
    child: Child,
}

impl EmbeddedServer {
    /// Start embedded Grammalecte server on a random free port
    pub fn start() -> Result<Self, Box<dyn Error>> {
        Self::start_listen_on_port(get_free_port()?)
    }

    /// Start embedded Grammalecte server on a given port
    pub fn start_listen_on_port(port: u16) -> Result<Self, Box<dyn Error>> {
        log::info!("Will start server");
        // First, unpack server
        let dest = mktemp::Temp::new_dir()?;
        let cursor = Cursor::new(include_bytes!("GrammalecteDist.zip"));
        let mut zip = ZipArchive::new(cursor)?;
        for i in 0..zip.len() {
            let mut file = zip.by_index(i)?;
            if file.is_dir() {
                log::debug!("Create directory: {}", file.name());
                std::fs::create_dir_all(dest.join(file.name()))?;
            } else {
                log::debug!("Decompress file: {}", file.name());

                let mut buff = Vec::with_capacity(file.size() as usize);
                file.read_to_end(&mut buff)?;

                std::fs::write(dest.join(file.name()), buff)?;
            }
        }

        log::info!("Will start to listen on port {}", port);

        let server_file = dest
            .join("grammalecte/grammalecte-server.py")
            .to_string_lossy()
            .to_string();
        log::info!("Will execute file {}", server_file);

        // Start server
        let child = std::process::Command::new("/usr/bin/python3")
            .arg(server_file)
            .arg("-p")
            .arg(port.to_string())
            .stdout(Stdio::null())
            .stderr(Stdio::null())
            .spawn()?;

        wait_for_port(port)?;

        Ok(Self {
            _srv_dir: dest,
            port,
            child,
        })
    }

    /// Get embedde instance base URL
    pub fn base_url(&self) -> String {
        format!("http://localhost:{}", self.port)
    }
}

impl Drop for EmbeddedServer {
    fn drop(&mut self) {
        let _ = self.child.kill();
    }
}

mod utils {
    use std::io::ErrorKind;
    use std::time::Duration;

    /// Get a free port
    pub fn get_free_port() -> std::io::Result<u16> {
        let mut port = 0;

        while !(2000..=64000).contains(&port) {
            port = rand::random::<u16>() % 64000;
        }

        while port_scanner::scan_port(port) {
            port += 1;
        }

        Ok(port)
    }

    pub fn wait_for_port(port: u16) -> std::io::Result<()> {
        for _ in 0..50 {
            if port_scanner::scan_port(port) {
                return Ok(());
            }
            std::thread::sleep(Duration::from_millis(100));
        }

        Err(std::io::Error::new(
            ErrorKind::Other,
            format!("Port {} did not open in time!", port),
        ))?
    }
}