Init commit

src/git_fs/head.rs

@@ -0,0 +1,51 @@
+use std::{
+    fs::File,
+    io::prelude::*,
+    path::Path,
+};
+
+use crate::GIT_DIR;
+use crate::git_fs::read_lines;
+
+#[derive(Debug)]
+pub struct Head {
+    pub ref_to: String,
+}
+
+impl Head {
+    pub fn load() -> Result<Self, ()> {
+        let path = Path::new(GIT_DIR).join("HEAD");
+
+        let mut lines = match read_lines(path) {
+            Err(_) => return Err(()),
+            Ok(lines) => lines,
+        };
+
+        let content = match lines.next() {
+            Some(Ok(line)) => line,
+            _ => return Err(()),
+        };
+
+        match content.split_once(": ") {
+            None => Err(()),
+            Some((_, r)) => Ok(Head { ref_to: String::from(r) })
+        }
+    }
+
+    pub fn save(&self) -> Result<(), ()> {
+        let path = Path::new(GIT_DIR).join("HEAD");
+        let mut content = String::from("ref: ");
+        content.push_str(&self.ref_to);
+        content.push_str("\n");
+
+        let mut file = match File::create(&path) {
+            Err(_) => return Err(()),
+            Ok(file) => file,
+        };
+
+        match file.write(content.as_bytes()) {
+            Err(_) => Err(()),
+            Ok(_) => Ok(()),
+        }
+    }
+}