implement temporary data cleanup on commit preload content

Cargo.toml

@@ -21,7 +21,6 @@ tokio = { version = "1.45", features = ["full"] }
 tracing-subscriber = "0.3"
 url = "2.5"
 urlencoding = "2.1"
-walkdir = "2.5"
 
 [patch.crates-io]
 librqbit = { git = "https://github.com/ikatson/rqbit.git", rev="b580a9610ae7c6eaacd305a3905f7e2d3202ca69", package = "librqbit" }

src/main.rs

@@ -116,12 +116,9 @@ async fn main() -> Result<()> {
                             only_files: Some(Vec::with_capacity(
                                 config.preload_max_filecount.unwrap_or_default(),
                             )),
-                            // the destination folder to preload files match `only_files_regex`
+                            // the destination folder to preload files match `preload_regex`
                             // * e.g. images for audio albums
-                            output_folder: preload
-                                .output_folder(&i)?
-                                .to_str()
-                                .map(|s| s.to_string()),
+                            output_folder: preload.tmp(&i)?.to_str().map(|s| s.to_string()),
                             ..Default::default()
                         }),
                     ),
@@ -170,9 +167,9 @@ async fn main() -> Result<()> {
                             session.unpause(&mt).await?;
                             // await for `preload_regex` files download to continue
                             mt.wait_until_completed().await?;
-                            // cleanup irrelevant files (see rqbit#408)
-                            preload.cleanup(&i, Some(keep_files))?;
-                            preload.persist_torrent_bytes(&i, &bytes)?;
+                            // persist torrent bytes and preloaded content,
+                            // cleanup tmp (see rqbit#408)
+                            preload.commit(&i, &bytes, Some(keep_files))?;
                             // remove torrent from session as indexed
                             session
                                 .delete(librqbit::api::TorrentIdOrHash::Id(id), false)

src/preload.rs

@@ -31,35 +31,66 @@ impl Preload {
 
     // Actions
 
-    /// Recursively remove all files under the `infohash` location (see rqbit#408)
-    pub fn cleanup(&self, info_hash: &str, keep_filenames: Option<HashSet<PathBuf>>) -> Result<()> {
-        for e in walkdir::WalkDir::new(self.output_folder(info_hash)?) {
-            let e = e?;
-            let p = e.into_path();
-            if p.is_file() && keep_filenames.as_ref().is_none_or(|k| !k.contains(&p)) {
-                fs::remove_file(p)?;
+    /// Persist torrent bytes and preloaded content, cleanup tmp (see rqbit#408)
+    pub fn commit(
+        &self,
+        info_hash: &str,
+        torrent_bytes: &[u8],
+        persist_files: Option<HashSet<PathBuf>>,
+    ) -> Result<()> {
+        // persist torrent bytes to file
+        fs::write(self.torrent(info_hash)?, torrent_bytes)?;
+        // persist preload files
+        let mut d = PathBuf::from(&self.root);
+        d.push(info_hash);
+        if d.exists() {
+            // clean previous data
+            fs::remove_dir_all(&d)?
+        }
+        if let Some(f) = persist_files {
+            let r = d.components().count(); // count root offset once
+            for p in f {
+                // make sure preload path is referring to the expected location
+                let o = p.canonicalize()?;
+                if !o.starts_with(&self.root) || o.is_dir() {
+                    bail!("Unexpected canonical path `{}`", o.to_string_lossy())
+                }
+                // build new permanent path /root/info-hash
+                let mut n = PathBuf::from(&d);
+                for component in o.components().skip(r) {
+                    n.push(component)
+                }
+                // make sure segments count is same to continue
+                if o.components().count() != n.components().count() {
+                    bail!(
+                        "Unexpected components count: `{}` > `{}`",
+                        o.to_string_lossy(),
+                        n.to_string_lossy(),
+                    )
+                }
+                // fs::create_dir_all(n.parent().unwrap())?;
+                fs::rename(o, n)?
             }
-        } // remove empty directories @TODO
+        }
+        // cleanup temporary files
+        let t = self.tmp(info_hash)?;
+        if t.exists() {
+            fs::remove_dir_all(t)?
+        }
         Ok(())
     }
 
-    pub fn persist_torrent_bytes(&self, info_hash: &str, contents: &[u8]) -> Result<PathBuf> {
-        let p = self.torrent(info_hash)?;
-        fs::write(&p, contents)?;
-        Ok(p)
-    }
-
     // Getters
 
-    /// * creates new directory if not exists
-    pub fn output_folder(&self, info_hash: &str) -> Result<PathBuf> {
+    /// * creates new temporary directory if not exists
+    pub fn tmp(&self, info_hash: &str) -> Result<PathBuf> {
         if !is_info_hash(info_hash) {
             bail!("Invalid info-hash `{info_hash}`")
         }
         let mut p = PathBuf::from(&self.root);
-        p.push(info_hash);
+        p.push(tmp(info_hash));
         if p.is_file() {
-            bail!("Output directory for info-hash `{info_hash}` is file")
+            bail!("Output directory `{}` is file", p.to_string_lossy())
         }
         if !p.exists() {
             fs::create_dir(&p)?
@@ -88,3 +119,7 @@ impl Preload {
 fn is_info_hash(value: &str) -> bool {
     value.len() == 40 && value.chars().all(|c| c.is_ascii_hexdigit())
 }
+
+fn tmp(info_hash: &str) -> String {
+    format!(".{info_hash}")
+}