Do not reopen files back and forth, less bugs

crates/librqbit/src/chunk_tracker.rs

@@ -156,9 +156,6 @@ impl ChunkTracker {
         &self.have
     }
 
-    pub fn get_selected_pieces(&self) -> &BF {
-        &self.selected
-    }
     pub fn reserve_needed_piece(&mut self, index: ValidPieceIndex) {
         self.queue_pieces.set(index.get() as usize, false)
     }

crates/librqbit/src/opened_file.rs

@@ -7,7 +7,6 @@ use std::{
 use anyhow::Context;
 use librqbit_core::lengths::Lengths;
 use parking_lot::Mutex;
-use tracing::debug;
 
 #[derive(Debug)]
 pub(crate) struct OpenedFile {
@@ -63,22 +62,6 @@ impl OpenedFile {
             piece_range,
         }
     }
-    pub fn reopen(&self, read_only: bool) -> anyhow::Result<()> {
-        let log_suffix = if read_only { " read only" } else { "" };
-
-        let mut open_opts = std::fs::OpenOptions::new();
-        open_opts.read(true);
-        if !read_only {
-            open_opts.write(true).create(false);
-        }
-
-        let mut g = self.file.lock();
-        *g = open_opts
-            .open(&self.filename)
-            .with_context(|| format!("error re-opening {:?}{log_suffix}", self.filename))?;
-        debug!("reopened {:?}{log_suffix}", self.filename);
-        Ok(())
-    }
 
     pub fn take(&self) -> anyhow::Result<File> {
         let mut f = self.file.lock();

crates/librqbit/src/torrent_state/initializing.rs

@@ -121,8 +121,6 @@ impl TorrentStateInitializing {
                         );
                     }
                 }
-
-                file.reopen(true)?;
             }
             Ok::<_, anyhow::Error>(())
         })?;

crates/librqbit/src/torrent_state/live/mod.rs

@@ -176,32 +176,6 @@ pub struct TorrentStateLive {
     cancellation_token: CancellationToken,
 }
 
-fn reopen_necessary_files_for_write(ct: &ChunkTracker, files: &OpenedFiles) -> anyhow::Result<()> {
-    // Reopen files that we don't have, but have selected in write-only mode.
-    for opened_file in files.iter() {
-        let prange = opened_file.piece_range_usize();
-        if prange.is_empty() {
-            continue;
-        }
-        let selected = ct
-            .get_selected_pieces()
-            .get(prange.clone())
-            .with_context(|| format!("bug: bad range get_selected_pieces(), {prange:?}"))?;
-        let have = ct
-            .get_have_pieces()
-            .get(prange.clone())
-            .with_context(|| format!("bug: bad range get_have_pieces(), {prange:?}"))?;
-        let need_write = selected
-            .iter()
-            .zip(have.iter())
-            .any(|(selected, have)| *selected && !*have);
-        if need_write {
-            opened_file.reopen(false)?;
-        }
-    }
-    Ok(())
-}
-
 impl TorrentStateLive {
     pub(crate) fn new(
         paused: TorrentStatePaused,
@@ -216,8 +190,6 @@ impl TorrentStateLive {
         let have_bytes = paused.chunk_tracker.get_hns().have_bytes;
         let lengths = *paused.chunk_tracker.get_lengths();
 
-        reopen_necessary_files_for_write(&paused.chunk_tracker, &paused.files)?;
-
         // TODO: make it configurable
         let file_priorities = {
             let mut pri = (0..paused.files.len()).collect::<Vec<usize>>();
@@ -661,9 +633,7 @@ impl TorrentStateLive {
             .iter()
             .map(|f| f.take_clone())
             .collect::<anyhow::Result<Vec<_>>>()?;
-        for file in files.iter() {
-            file.reopen(true)?;
-        }
+
         let mut chunk_tracker = g
             .chunks
             .take()
@@ -697,7 +667,6 @@ impl TorrentStateLive {
         let mut g = self.lock_write("update_only_files");
         let ct = g.get_chunks_mut()?;
         let hns = ct.update_only_files(self.files.iter().map(|f| f.len), only_files)?;
-        reopen_necessary_files_for_write(ct, &self.files)?;
         if !hns.finished() {
             self.reconnect_all_not_needed_peers();
         }
@@ -721,19 +690,6 @@ impl TorrentStateLive {
             if bytes == 0 {
                 warn!(file_id=idx, piece_id=id.get(), "bug: update_have_on_piece_completed() returned 0, although this piece is present in the file");
             }
-
-            let have_all = self
-                .lock_read("on_piece_completed_reopen")
-                .get_chunks()?
-                .get_have_pieces()
-                .get(opened_file.piece_range_usize())
-                .with_context(|| {
-                    format!("bug: invalid range {:?}", opened_file.piece_range_usize())
-                })?
-                .all();
-            if have_all {
-                opened_file.reopen(true)?;
-            }
         }
 
         if self.is_finished() {