From 4a737398711c362e220e8ab74561427bc60d82d3 Mon Sep 17 00:00:00 2001
From: Igor Katson <igor.katson@gmail.com>
Date: Mon, 29 Apr 2024 19:28:05 +0100
Subject: [PATCH] Force set file length on stream

---
 TODO.md                                       |  3 +-
 .../src/torrent_state/initializing.rs         |  2 +-
 .../librqbit/src/torrent_state/streaming.rs   | 31 ++++++++++++-------
 3 files changed, 23 insertions(+), 13 deletions(-)

diff --git a/TODO.md b/TODO.md
index 4641d77..705e949 100644
--- a/TODO.md
+++ b/TODO.md
@@ -4,7 +4,7 @@
 - [x] use some concurrent hashmap e.g. flurry or dashmap
 - [x] tracing instead of logging. Debugging peers: RUST_LOG=[{peer=.*}]=debug
       test-log for tests
-- [x] reopen read only is bugged
+- [x] (reopen) read only is bugged
 - [x] initializing/checking
   - [x] blocks the whole process. Need to break it up. On slower devices (rpi) just hangs for a good while
   - [x] checking torrents should be visible right away
@@ -98,3 +98,4 @@ Other:
 
 - [ ] keepalive is useless, the tieout is 120s, and read timeout is 10s. Need to send keepalive only if nothing was done recently.
 - [x] url should have the filename
+- [ ] reopening files: get rid of it!!! Even on Windows it should be alright - no need to reopen them.
diff --git a/crates/librqbit/src/torrent_state/initializing.rs b/crates/librqbit/src/torrent_state/initializing.rs
index d4c0026..453c196 100644
--- a/crates/librqbit/src/torrent_state/initializing.rs
+++ b/crates/librqbit/src/torrent_state/initializing.rs
@@ -1,5 +1,5 @@
 use std::{
-    fs::{File, OpenOptions},
+    fs::OpenOptions,
     sync::{atomic::AtomicU64, Arc},
     time::Instant,
 };
diff --git a/crates/librqbit/src/torrent_state/streaming.rs b/crates/librqbit/src/torrent_state/streaming.rs
index bff03b5..4647037 100644
--- a/crates/librqbit/src/torrent_state/streaming.rs
+++ b/crates/librqbit/src/torrent_state/streaming.rs
@@ -14,7 +14,7 @@ use librqbit_core::lengths::{Lengths, ValidPieceIndex};
 use tokio::io::{AsyncRead, AsyncSeek};
 use tracing::{debug, trace};
 
-use crate::{opened_file::OpenedFile, ManagedTorrent};
+use crate::{opened_file::OpenedFile, type_aliases::OpenedFiles, ManagedTorrent};
 
 use super::ManagedTorrentHandle;
 
@@ -292,9 +292,9 @@ impl Drop for FileStream {
 }
 
 impl ManagedTorrent {
-    fn with_opened_file<F, R>(&self, file_id: usize, f: F) -> anyhow::Result<R>
+    fn with_opened_files<F, R>(&self, f: F) -> anyhow::Result<R>
     where
-        F: FnOnce(&OpenedFile) -> R,
+        F: FnOnce(&OpenedFiles) -> R,
     {
         self.with_state(|s| {
             let files = match s {
@@ -302,11 +302,20 @@ impl ManagedTorrent {
                 crate::ManagedTorrentState::Live(l) => &l.files,
                 s => anyhow::bail!("with_opened_file: invalid state {}", s.name()),
             };
-            let fd = files.get(file_id).context("invalid file id")?;
-            Ok(f(fd))
+            Ok(f(files))
         })
     }
 
+    fn with_opened_file<F, R>(&self, file_id: usize, f: F) -> anyhow::Result<R>
+    where
+        F: FnOnce(&OpenedFile) -> R,
+    {
+        self.with_opened_files(|opened_files| {
+            let fd = opened_files.get(file_id).context("invalid file id")?;
+            Ok(f(fd))
+        })?
+    }
+
     fn streams(&self) -> anyhow::Result<Arc<TorrentStreams>> {
         self.with_state(|s| match s {
             crate::ManagedTorrentState::Paused(p) => Ok(p.streams.clone()),
@@ -343,12 +352,12 @@ impl ManagedTorrent {
             torrent: self,
         };
         if s.torrent.maybe_reconnect_needed_peers_for_file(file_id) {
-            s.torrent.with_opened_file(file_id, |fd| {
-                fd.reopen(false)?;
-                fd.file
-                    .lock()
-                    .set_len(fd.len)
-                    .context("error setting file length")
+            // TODO: get rid of reopening files, it's such a source of bugs and complexity
+            s.torrent.with_opened_files(|files| {
+                for file in files {
+                    file.reopen(false)?;
+                }
+                Ok::<_, anyhow::Error>(())
             })??;
         }
         streams.streams.insert(