Move git module to server

src/server/git.rs

@@ -0,0 +1,121 @@
+//! Execute git binary commands.
+
+use std::{
+    error, fmt, io,
+    path::Path,
+    process::{Command, Output},
+};
+
+use log::{trace, warn};
+use regex::bytes::RegexBuilder;
+
+#[derive(Debug)]
+pub enum Error {
+    Io(io::Error),
+    Command(Command, Output),
+}
+
+impl fmt::Display for Error {
+    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
+        match self {
+            Error::Io(e) => e.fmt(f),
+            Error::Command(command, output) => {
+                write!(f, "Command exited with {}", output.status)?;
+                write!(f, "COMMAND: {command:?}")?;
+                if !output.stdout.is_empty() {
+                    let stdout = String::from_utf8_lossy(&output.stdout);
+                    write!(f, "STDOUT:\n{}", stdout.trim_end())?;
+                }
+                if !output.stderr.is_empty() {
+                    let stderr = String::from_utf8_lossy(&output.stderr);
+                    write!(f, "STDERR:\n{}", stderr.trim_end())?;
+                }
+                Ok(())
+            }
+        }
+    }
+}
+
+impl error::Error for Error {}
+
+impl From<io::Error> for Error {
+    fn from(value: io::Error) -> Self {
+        Self::Io(value)
+    }
+}
+
+fn run(mut command: Command) -> Result<Output, Error> {
+    let output = command.output()?;
+    if output.status.success() {
+        trace!("Command exited with {}", output.status);
+        trace!("COMMAND: {command:?}");
+        if !output.stdout.is_empty() {
+            let stdout = String::from_utf8_lossy(&output.stdout);
+            trace!("STDOUT:\n{}", stdout.trim_end());
+        }
+        if !output.stderr.is_empty() {
+            let stderr = String::from_utf8_lossy(&output.stderr);
+            trace!("STDERR:\n{}", stderr.trim_end());
+        }
+        Ok(output)
+    } else {
+        Err(Error::Command(command, output))
+    }
+}
+
+pub fn init_bare(path: &Path) -> Result<(), Error> {
+    let mut command = Command::new("git");
+    command.arg("init").arg("--bare").arg("--").arg(path);
+    run(command)?;
+    Ok(())
+}
+
+pub fn fetch_head(path: &Path, url: &str) -> Result<(), Error> {
+    let mut command = Command::new("git");
+    command
+        .arg("-C")
+        .arg(path)
+        .arg("ls-remote")
+        .arg("--symref")
+        .arg("--")
+        .arg(url)
+        .arg("HEAD"); // Includes other refs like refs/foo/HEAD
+    let output = run(command)?;
+
+    let regex = RegexBuilder::new(r"^ref: (refs/\S+)\s+HEAD$")
+        .multi_line(true)
+        .build()
+        .unwrap();
+    let Some(captures) = regex.captures(&output.stdout) else {
+        warn!("Did not find HEAD of {url}");
+        return Ok(());
+    };
+    let head = String::from_utf8_lossy(captures.get(1).unwrap().as_bytes());
+
+    let mut command = Command::new("git");
+    command
+        .arg("-C")
+        .arg(path)
+        .arg("symbolic-ref")
+        .arg("--")
+        .arg("HEAD")
+        .arg(&head as &str);
+    run(command)?;
+
+    Ok(())
+}
+
+pub fn fetch(path: &Path, url: &str, refspecs: &[String]) -> Result<Output, Error> {
+    let mut command = Command::new("git");
+    command
+        .arg("-C")
+        .arg(path)
+        .arg("fetch")
+        .arg("--prune")
+        .arg("--")
+        .arg(url);
+    for refspec in refspecs {
+        command.arg(refspec);
+    }
+    run(command)
+}