feat(lib): answer FolderContentsRequest with the folder's listing

"Download folder" in SoulseekQt and Nicotine+ asks the sharer for that one folder (peer code 36) instead of the whole share, and a sharer that never answers leaves the folder download hanging. The requested folder now comes back as a FolderContentsResponse (code 37), which carries a directory listing in the same form a browse does, so the two share one codec. The browse and folder replies also share one reply helper.
2026-09-07 15:21:42 +02:00
parent 53b32e0201
commit 4839e36be8
7 changed files with 266 additions and 55 deletions
@@ -0,0 +1,68 @@
+//! `FolderContentsRequest` (peer code 36) and its reply (code 37): one folder
+//! of a share in the listing form code 5 uses, which is what "download
+//! folder" in other clients asks for.
+
+use crate::message::peer::SharedDirectory;
+use crate::message::peer::shared_file_list::{
+    decompress_body, read_directories, write_directories,
+};
+use crate::message::{Message, MessageHandler};
+use crate::peer::PeerMessage;
+use crate::utils::zlib::compress_stored;
+use std::sync::mpsc::Sender;
+
+pub struct FolderContentsRequest;
+impl MessageHandler<PeerMessage> for FolderContentsRequest {
+    fn get_code(&self) -> u32 {
+        36
+    }
+    fn handle(&self, message: &mut Message, sender: Sender<PeerMessage>) {
+        let token = message.read_int32();
+        let folder = message.read_string();
+        let _ =
+            sender.send(PeerMessage::FolderContentsRequested { token, folder });
+    }
+}
+
+/// Build a `FolderContentsResponse` (peer code 37).
+#[must_use]
+pub fn build_folder_contents(
+    token: u32,
+    folder: &str,
+    dirs: &[SharedDirectory],
+) -> Message {
+    let mut payload = Message::new();
+    payload.write_int32(token).write_string(folder);
+    write_directories(&mut payload, dirs);
+    Message::new()
+        .write_int32(37)
+        .write_raw_bytes(compress_stored(&payload.get_data()))
+        .clone()
+}
+
+/// Parse a `FolderContentsResponse` positioned at its compressed blob, or
+/// `None` when it does not inflate.
+#[must_use]
+pub fn parse_folder_contents(
+    message: &mut Message,
+) -> Option<(u32, String, Vec<SharedDirectory>)> {
+    let mut body = decompress_body(message)?;
+    let token = body.read_int32();
+    let folder = body.read_string();
+    Some((token, folder, read_directories(&mut body)))
+}
+
+#[test]
+fn a_folder_listing_round_trips() {
+    let dirs = vec![SharedDirectory {
+        name: "music\\album".to_string(),
+        files: vec![("one.flac".to_string(), 40), ("two.flac".to_string(), 50)],
+    }];
+    let built = build_folder_contents(7, "music\\album", &dirs);
+    let mut message = Message::new_with_data(built.get_data());
+    message.set_pointer(4);
+    assert_eq!(
+        parse_folder_contents(&mut message),
+        Some((7, "music\\album".to_string(), dirs))
+    );
+}