Draft auto-update process for comet in devtools

devtools/src/comet.rs

@@ -0,0 +1,108 @@
+use crate::executor;
+use crate::runtime::Task;
+
+use std::io;
+use std::process;
+use std::sync::Arc;
+
+pub const COMPATIBLE_REVISION: &str =
+    "69dd2283886dccdaa1ee6e1c274af62f7250bc38";
+
+pub fn launch() -> Task<Result<(), Error>> {
+    executor::try_spawn_blocking(|mut sender| {
+        let cargo_install = process::Command::new("cargo")
+            .args(["install", "--list"])
+            .output()?;
+
+        let installed_packages = String::from_utf8_lossy(&cargo_install.stdout);
+
+        for line in installed_packages.lines() {
+            if !line.starts_with("iced_comet ") {
+                continue;
+            }
+
+            let Some((_, revision)) = line.rsplit_once("?rev=") else {
+                return Err(Error::Outdated { revision: None });
+            };
+
+            let Some((revision, _)) = revision.rsplit_once("#") else {
+                return Err(Error::Outdated { revision: None });
+            };
+
+            if revision != COMPATIBLE_REVISION {
+                return Err(Error::Outdated {
+                    revision: Some(revision.to_owned()),
+                });
+            }
+
+            let _ = process::Command::new("iced_comet")
+                .stdin(process::Stdio::null())
+                .stdout(process::Stdio::null())
+                .stderr(process::Stdio::null())
+                .spawn()?;
+
+            let _ = sender.try_send(());
+            return Ok(());
+        }
+
+        Err(Error::NotFound)
+    })
+}
+
+pub fn install() -> Task<Result<Installation, Error>> {
+    executor::try_spawn_blocking(|mut sender| {
+        use std::io::{BufRead, BufReader};
+        use std::process::{Command, Stdio};
+
+        let install = Command::new("cargo")
+            .args([
+                "install",
+                "--locked",
+                "--git",
+                "https://github.com/iced-rs/comet.git",
+                "--rev",
+                COMPATIBLE_REVISION,
+            ])
+            .stdin(Stdio::null())
+            .stdout(Stdio::null())
+            .stderr(Stdio::piped())
+            .spawn()?;
+
+        let mut stderr =
+            BufReader::new(install.stderr.expect("stderr must be piped"));
+
+        let mut log = String::new();
+
+        while let Ok(n) = stderr.read_line(&mut log) {
+            if n == 0 {
+                break;
+            }
+
+            let _ = sender.try_send(Installation::Logged(log.clone()));
+            log.clear();
+        }
+
+        let _ = sender.try_send(Installation::Finished);
+
+        Ok(())
+    })
+}
+
+#[derive(Debug, Clone)]
+pub enum Installation {
+    Logged(String),
+    Finished,
+}
+
+#[derive(Debug, Clone)]
+pub enum Error {
+    NotFound,
+    Outdated { revision: Option<String> },
+    IoFailed(Arc<io::Error>),
+}
+
+impl From<io::Error> for Error {
+    fn from(error: io::Error) -> Self {
+        Self::IoFailed(Arc::new(error))
+    }
+}