file transfer: improve / fix

crates/lanspread-peer/src/peer.rs

@@ -3,7 +3,10 @@ use std::{convert::TryInto, path::Path};
 use bytes::Bytes;
 use lanspread_db::db::GameFileDescription;
 use lanspread_utils::maybe_addr;
-use s2n_quic::stream::SendStream;
+use s2n_quic::{
+    connection,
+    stream::{Error as StreamError, SendStream},
+};
 use tokio::{
     io::{AsyncReadExt, AsyncSeekExt},
     time::Instant,
@@ -33,6 +36,8 @@ async fn stream_file_bytes(
     }
 
     let mut remaining = length.unwrap_or(u64::MAX);
+    let expect_exact = length.is_some();
+    let mut transfer_complete = matches!(length, Some(0));
     let mut total_bytes = 0u64;
     let mut last_total_bytes = 0u64;
     let mut timestamp = Instant::now();
@@ -47,6 +52,9 @@ async fn stream_file_bytes(
 
         let bytes_read = file.read(&mut buf[..read_len]).await?;
         if bytes_read == 0 {
+            if !expect_exact {
+                transfer_complete = true;
+            }
             break;
         }
 
@@ -54,6 +62,11 @@ async fn stream_file_bytes(
         remaining = remaining.saturating_sub(bytes_read as u64);
         total_bytes += bytes_read as u64;
 
+        if expect_exact && remaining == 0 {
+            transfer_complete = true;
+            break;
+        }
+
         if last_total_bytes + 10_000_000 < total_bytes {
             let elapsed = timestamp.elapsed();
             let diff_bytes = total_bytes - last_total_bytes;
@@ -76,10 +89,26 @@ async fn stream_file_bytes(
         validated_path.display()
     );
 
-    tx.close().await?;
+    match tx.close().await {
+        Ok(()) => {}
+        Err(err) if transfer_complete && is_clean_remote_close(&err) => {
+            log::debug!("{remote_addr} closed stream after transfer completion: {err}");
+        }
+        Err(err) => return Err(err.into()),
+    }
     Ok(())
 }
 
+fn is_clean_remote_close(err: &StreamError) -> bool {
+    matches!(
+        err,
+        StreamError::ConnectionError {
+            error: connection::Error::Closed { .. },
+            ..
+        }
+    )
+}
+
 pub async fn send_game_file_data(
     game_file_desc: &GameFileDescription,
     tx: &mut SendStream,