feat: continuing work on downloading files

sparse-05/sparse-05-client/src/commands/connect/commands/download.rs

@@ -16,13 +16,13 @@ pub async fn download_file(
     remote_file: PathBuf,
     local_path: PathBuf,
 ) -> anyhow::Result<()> {
-    let mut file = fs::OpenOptions::new().read(true).open(&local_path).await?;
-    let file_size = file.metadata().await?.len();
+    let mut file = fs::OpenOptions::new()
+        .write(true)
+        .create(true)
+        .open(&local_path)
+        .await?;
 
-    let command = Command::StartUploadFile(
-        remote_path,
-        (file_size / FILE_TRANSFER_PACKET_SIZE as u64) + 1,
-    );
+    let command = Command::StartDownloadFile(remote_file);
     conn.send_command(command).await?;
 
     let id = loop {

sparse-05/sparse-05-client/src/commands/connect/shell.rs

@@ -215,8 +215,11 @@ pub(super) async fn shell(
                 }),
                 _,
             ) => {
-                if let Err(e) =
-                    commands::download::download(Arc::clone(&connection), remote_file, local_path)
+                if let Err(e) = commands::download::download_file(
+                    Arc::clone(&connection),
+                    remote_file,
+                    local_path,
+                )
                 .await
                 {
                     eprintln!("{e:?}")

sparse-05/sparse-05-common/src/lib.rs

@@ -74,13 +74,14 @@ pub mod messages {
 
         OpenedTTY(u64),
         ClosedTTY(u64),
-        SendTTYData(u64, Vec<u64>),
+        SendTTYData(u64, Vec<u8>),
 
         UploadFileID(u64),
         UploadFileStatus(u64, Vec<u64>),
 
-        StartDownloadFile(u64),
-        DownloadFileSegment(u64, u64, Vec<u64>),
+        StartDownloadFile(u64, u64),
+        GetDownloadFileStatus(u64, Vec<u64>),
+        DownloadFileSegment(u64, u64, Vec<u8>),
     }
 
     #[derive(Serialize_repr, Deserialize_repr, Debug, Clone, Copy)]

sparse-05/sparse-05-server/src/connection.rs

@@ -217,6 +217,7 @@ fn authenticate<F: Fn()>(
 }
 
 mod command;
+mod download_file;
 mod upload_file;
 
 fn handle_full_connection<F>(
@@ -232,7 +233,7 @@ where
 
     let commands = Arc::new(Mutex::new(HashMap::new()));
     let uploaded_files = Arc::new(Mutex::new(HashMap::new()));
-    /*let mut downloaded_files = HashMap::new();*/
+    let download_files = Arc::new(Mutex::new(HashMap::new()));
 
     std::thread::scope(|s| -> anyhow::Result<()> {
         loop {
@@ -327,8 +328,36 @@ where
                     }
                 }
 
-                Command::StartDownloadFile(_) => {}
-                Command::DownloadFileStatus(_, _) => {}
+                Command::StartDownloadFile(path) => {
+                    let download_files_clone = download_files.clone();
+                    let Ok(mut lock) = download_files.lock() else {
+                        continue;
+                    };
+
+                    let handler = match download_file::start_file_download(
+                        &s,
+                        path,
+                        conninfo.clone(),
+                        download_files_clone,
+                    ) {
+                        Ok(handler) => handler,
+                        Err(e) => {
+                            eprintln!("error starting file upload: {e:?}");
+                            continue;
+                        }
+                    };
+
+                    lock.insert(handler.id, handler);
+                }
+                Command::DownloadFileStatus(id, needed) => {
+                    let Ok(lock) = download_files.lock() else {
+                        continue;
+                    };
+
+                    if let Some(handler) = lock.get(&id) {
+                        let _ = handler.download_status.send(needed);
+                    }
+                }
 
                 Command::Disconnect => {
                     break;

sparse-05/sparse-05-server/src/connection/download_file.rs

@@ -0,0 +1,98 @@
+use std::{
+    collections::HashMap,
+    fs::{self, OpenOptions},
+    io::Write,
+    path::PathBuf,
+    sync::{
+        atomic::{AtomicU64, Ordering},
+        mpsc::{channel, Sender},
+        Arc, Mutex,
+    },
+    thread::Scope,
+    time::Duration,
+};
+
+use sparse_05_common::messages::{Response, FILE_BUFFER_BUFFER_SIZE, FILE_TRANSFER_PACKET_SIZE};
+
+use super::ConnectionInformation;
+
+static CURRENT_FILE_DOWNLOAD_ID: AtomicU64 = AtomicU64::new(0);
+
+pub(super) struct DownloadFileHandler {
+    pub id: u64,
+    pub download_status: Sender<Vec<u64>>,
+}
+
+pub(super) fn start_file_download<'a, 'b: 'a>(
+    s: &'a Scope<'a, 'b>,
+    file_path: PathBuf,
+    conninfo: ConnectionInformation,
+    download_file_map: Arc<Mutex<HashMap<u64, DownloadFileHandler>>>,
+) -> anyhow::Result<DownloadFileHandler> {
+    let (download_status, receive_download_status) = channel();
+
+    let id = CURRENT_FILE_DOWNLOAD_ID.fetch_add(1, Ordering::Relaxed);
+    let id_2 = id;
+
+    s.spawn(move || -> anyhow::Result<()> {
+        let mut file = OpenOptions::new().read(true).open(&file_path)?;
+        let file_size = file.metadata()?.len();
+
+        conninfo.send(conninfo.encrypt_and_sign_resp(Response::StartDownloadFile(
+            id,
+            (file_size / FILE_TRANSFER_PACKET_SIZE as u64) + 1,
+        ))?)?;
+
+        let mut current_packet_count = 0;
+
+        while current_packet_count < packet_count {
+            let mut buffers: Vec<Option<Vec<u8>>> = vec![None; FILE_BUFFER_BUFFER_SIZE];
+
+            loop {
+                let Ok((i, buffer)) = data_receiver.recv_timeout(Duration::from_millis(250)) else {
+                    let up_to = receive_request_status.recv()?;
+
+                    let needed = buffers[..up_to as usize]
+                        .iter()
+                        .enumerate()
+                        .flat_map(|(i, b)| match b {
+                            Some(..) => None,
+                            None => Some(i as u64),
+                        })
+                        .collect::<Vec<_>>();
+
+                    let is_empty = needed.is_empty();
+
+                    conninfo.send(
+                        conninfo.encrypt_and_sign_resp(Response::UploadFileStatus(id, needed))?,
+                    )?;
+
+                    if is_empty {
+                        current_packet_count += up_to;
+                        break;
+                    } else {
+                        continue;
+                    }
+                };
+                buffers[i as usize] = Some(buffer);
+            }
+
+            for buffer in buffers {
+                let Some(buffer) = buffer else { break };
+                target_file.write(&buffer)?;
+            }
+        }
+
+        let Ok(mut lock) = download_file_map.lock() else {
+            return Ok(());
+        };
+        lock.remove(&id);
+
+        Ok(())
+    });
+
+    Ok(DownloadFileHandler {
+        id: id_2,
+        download_status,
+    })
+}