ye

Dockerfile

@@ -18,8 +18,8 @@ RUN apt-get update && apt-get install libssl-dev -y
 
 RUN mkdir /store
 
-RUN touch /store/store.xmlfrag
+RUN touch /store/store.xmlfrag && touch /store/tmpfile.xmlfrag
 
 COPY ./templates/ /app/templates
 
-CMD [ "/app/linky", "/store/store.xmlfrag" ]
+CMD [ "/app/linky", "/store/store.xmlfrag", "/store/tmpfile.xmlfrag" ]

src/main.rs

@@ -27,12 +27,12 @@ static SECRET_KEY: LazyLock<Key> = LazyLock::new(Key::generate);
 #[tokio::main]
 async fn main() {
     let args: Vec<String> = env::args().collect();
-    if args.len() < 2 {
+    if args.len() < 3 {
         println!("Need file argument.");
         exit(1);
     }
 
-    let store = Arc::new(Mutex::new(LinkFile::new(&args[1])));
+    let store = Arc::new(Mutex::new(LinkFile::new(&args[1], &args[2])));
 
     let authenticated = Router::new()
         .route("/rss.xml", get(get_rss))

src/writer.rs

@@ -2,7 +2,9 @@ use anyhow::{Context, Result};
 use minijinja::{context, Environment};
 use quick_xml::escape::escape;
 use reqwest::Client;
-use std::fs::{File, OpenOptions};
+use std::fs;
+use std::fs::File;
+use std::io;
 use std::io::Write;
 use std::path::{Path, PathBuf};
 use std::time::Duration;
@@ -17,9 +19,9 @@ const TEMPLATE_STRING: &str = "
 ";
 
 pub struct LinkFile {
-    file: File,
     client: Client,
     path: PathBuf,
+    copy_path: PathBuf,
 }
 
 async fn get_link_title(client: &Client, link: &str) -> Result<String> {
@@ -40,14 +42,31 @@ async fn get_link_title(client: &Client, link: &str) -> Result<String> {
     Ok(node.inner_text(dom.parser()).to_string())
 }
 
+fn prepend_file(
+    data: &[u8],
+    file_path: impl AsRef<Path>,
+    copy_path: impl AsRef<Path>,
+) -> io::Result<()> {
+    let mut tmp = File::create(&copy_path)?;
+    let mut src = File::open(&file_path)?;
+
+    tmp.write_all(data)?;
+
+    io::copy(&mut src, &mut tmp)?;
+
+    fs::remove_file(&file_path)?;
+    fs::rename(&copy_path, &file_path)?;
+
+    Ok(())
+}
+
 impl LinkFile {
-    pub fn new(path: impl AsRef<Path> + Clone) -> Self {
-        let file = OpenOptions::new().append(true).open(path.clone()).unwrap();
+    pub fn new(path: impl AsRef<Path> + Clone, tempfile: impl AsRef<Path> + Clone) -> Self {
         let client = Client::new();
         Self {
-            file,
             client,
             path: path.as_ref().to_path_buf(),
+            copy_path: tempfile.as_ref().to_path_buf(),
         }
     }
 
@@ -61,14 +80,17 @@ impl LinkFile {
         env.add_template("rss_fragment", TEMPLATE_STRING)?;
         let template = env.get_template("rss_fragment")?;
 
-        self.file.write_all(
+        prepend_file(
             template
                 .render(context! {
                 title => title,
                 link => escape(link).to_string(),
                 })?
                 .as_bytes(),
+            self.path.clone(),
+            self.copy_path.clone(),
         )?;
+
         Ok(())
     }
 
@@ -84,7 +106,7 @@ mod tests {
 
     #[test]
     fn test_linkfile() {
-        let mut linkfile = LinkFile::new("./store.xmlfrag");
+        let mut linkfile = LinkFile::new("./store.xmlfrag", "./copy_store.xmlfrag");
         linkfile.add_link("https://evilmuff.in").unwrap();
     }
 }