split up librqbit torrent state into smaller files

crates/librqbit/src/http_api.rs

@@ -19,12 +19,12 @@ use tracing::{info, warn};
 use axum::Router;
 
 use crate::http_api_error::{ApiError, ApiErrorExt};
-use crate::peer_state::PeerStatsFilter;
 use crate::session::{
     AddTorrent, AddTorrentOptions, AddTorrentResponse, ListOnlyResponse, Session,
 };
 use crate::torrent_manager::TorrentManagerHandle;
-use crate::torrent_state::StatsSnapshot;
+use crate::torrent_state::peer::stats::snapshot::{PeerStatsFilter, PeerStatsSnapshot};
+use crate::torrent_state::stats::snapshot::StatsSnapshot;
 
 // Public API
 #[derive(Clone)]
@@ -386,11 +386,7 @@ impl ApiInternal {
         make_torrent_details(&info_hash, handle.torrent_state().info(), only_files)
     }
 
-    fn api_peer_stats(
-        &self,
-        idx: usize,
-        filter: PeerStatsFilter,
-    ) -> Result<crate::peer_state::PeerStatsSnapshot> {
+    fn api_peer_stats(&self, idx: usize, filter: PeerStatsFilter) -> Result<PeerStatsSnapshot> {
         let handle = self.mgr_handle(idx)?;
         Ok(handle.torrent_state().per_peer_stats_snapshot(filter))
     }

crates/librqbit/src/lib.rs

@@ -6,7 +6,6 @@ pub mod http_api_client;
 mod http_api_error;
 pub mod peer_connection;
 pub mod peer_info_reader;
-pub mod peer_state;
 pub mod session;
 pub mod spawn_utils;
 pub mod torrent_manager;

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

@@ -39,6 +39,10 @@
 // > so don't lock them both at the same time at all, or at the worst lock them in the
 // > same order (peers one first, then the global one).
 
+pub mod peer;
+pub mod peers;
+pub mod stats;
+
 use std::{
     collections::HashMap,
     fs::File,
@@ -55,7 +59,6 @@ use anyhow::{bail, Context};
 use backoff::backoff::Backoff;
 use buffers::{ByteBuf, ByteString};
 use clone_to_owned::CloneToOwned;
-use dashmap::DashMap;
 use futures::{stream::FuturesUnordered, StreamExt};
 use librqbit_core::{
     id20::Id20,
@@ -66,7 +69,6 @@ use parking_lot::{Mutex, RwLock, RwLockReadGuard, RwLockWriteGuard};
 use peer_binary_protocol::{
     extended::handshake::ExtendedHandshake, Handshake, Message, MessageOwned, Piece, Request,
 };
-use serde::Serialize;
 use sha1w::Sha1;
 use tokio::{
     sync::{
@@ -83,140 +85,29 @@ use crate::{
     peer_connection::{
         PeerConnection, PeerConnectionHandler, PeerConnectionOptions, WriterRequest,
     },
-    peer_state::{
-        atomic_inc, AggregatePeerStatsAtomic, InflightRequest, LivePeerState, Peer, PeerCounters,
-        PeerRx, PeerState, PeerStatsFilter, PeerStatsSnapshot, PeerTx, SendMany,
-    },
     spawn_utils::{spawn, BlockingSpawner},
     type_aliases::{PeerHandle, BF},
 };
 
+use self::{
+    peer::{
+        stats::{
+            atomic::PeerCounters as AtomicPeerCounters,
+            snapshot::{PeerStatsFilter, PeerStatsSnapshot},
+        },
+        InflightRequest, PeerState, PeerTx, SendMany,
+    },
+    peers::PeerStates,
+    stats::{atomic::AtomicStats, snapshot::StatsSnapshot},
+};
+
+use super::utils::{timeit, TimedExistence};
+
 pub struct InflightPiece {
     pub peer: PeerHandle,
     pub started: Instant,
 }
 
-#[derive(Default)]
-pub struct PeerStates {
-    stats: AggregatePeerStatsAtomic,
-    states: DashMap<PeerHandle, Peer>,
-}
-
-#[derive(Debug, Default, Serialize, PartialEq, Eq)]
-pub struct AggregatePeerStats {
-    pub queued: usize,
-    pub connecting: usize,
-    pub live: usize,
-    pub seen: usize,
-    pub dead: usize,
-    pub not_needed: usize,
-}
-
-impl<'a> From<&'a AggregatePeerStatsAtomic> for AggregatePeerStats {
-    fn from(s: &'a AggregatePeerStatsAtomic) -> Self {
-        let ordering = Ordering::Relaxed;
-        Self {
-            queued: s.queued.load(ordering) as usize,
-            connecting: s.connecting.load(ordering) as usize,
-            live: s.live.load(ordering) as usize,
-            seen: s.seen.load(ordering) as usize,
-            dead: s.dead.load(ordering) as usize,
-            not_needed: s.not_needed.load(ordering) as usize,
-        }
-    }
-}
-
-impl PeerStates {
-    pub fn stats(&self) -> AggregatePeerStats {
-        AggregatePeerStats::from(&self.stats)
-    }
-
-    pub fn add_if_not_seen(&self, addr: SocketAddr) -> Option<PeerHandle> {
-        use dashmap::mapref::entry::Entry;
-        match self.states.entry(addr) {
-            Entry::Occupied(_) => None,
-            Entry::Vacant(vac) => {
-                vac.insert(Default::default());
-                atomic_inc(&self.stats.queued);
-                atomic_inc(&self.stats.seen);
-                Some(addr)
-            }
-        }
-    }
-    pub fn with_peer<R>(&self, addr: PeerHandle, f: impl FnOnce(&Peer) -> R) -> Option<R> {
-        self.states.get(&addr).map(|e| f(e.value()))
-    }
-
-    pub fn with_peer_mut<R>(
-        &self,
-        addr: PeerHandle,
-        reason: &'static str,
-        f: impl FnOnce(&mut Peer) -> R,
-    ) -> Option<R> {
-        timeit(reason, || self.states.get_mut(&addr))
-            .map(|e| f(TimedExistence::new(e, reason).value_mut()))
-    }
-    pub fn with_live<R>(&self, addr: PeerHandle, f: impl FnOnce(&LivePeerState) -> R) -> Option<R> {
-        self.states
-            .get(&addr)
-            .and_then(|e| match &e.value().state.get() {
-                PeerState::Live(l) => Some(f(l)),
-                _ => None,
-            })
-    }
-    pub fn with_live_mut<R>(
-        &self,
-        addr: PeerHandle,
-        reason: &'static str,
-        f: impl FnOnce(&mut LivePeerState) -> R,
-    ) -> Option<R> {
-        self.with_peer_mut(addr, reason, |peer| peer.state.get_live_mut().map(f))
-            .flatten()
-    }
-
-    pub fn drop_peer(&self, handle: PeerHandle) -> Option<Peer> {
-        let p = self.states.remove(&handle).map(|r| r.1)?;
-        self.stats.dec(p.state.get());
-        Some(p)
-    }
-
-    pub fn mark_peer_interested(&self, handle: PeerHandle, is_interested: bool) -> Option<bool> {
-        self.with_live_mut(handle, "mark_peer_interested", |live| {
-            let prev = live.peer_interested;
-            live.peer_interested = is_interested;
-            prev
-        })
-    }
-    pub fn update_bitfield_from_vec(&self, handle: PeerHandle, bitfield: Vec<u8>) -> Option<()> {
-        self.with_live_mut(handle, "update_bitfield_from_vec", |live| {
-            live.bitfield = BF::from_vec(bitfield);
-        })
-    }
-    pub fn mark_peer_connecting(&self, h: PeerHandle) -> anyhow::Result<(PeerRx, PeerTx)> {
-        let rx = self
-            .with_peer_mut(h, "mark_peer_connecting", |peer| {
-                peer.state
-                    .queued_to_connecting(&self.stats)
-                    .context("invalid peer state")
-            })
-            .context("peer not found in states")??;
-        Ok(rx)
-    }
-
-    fn reset_peer_backoff(&self, handle: PeerHandle) {
-        self.with_peer_mut(handle, "reset_peer_backoff", |p| {
-            p.stats.backoff.reset();
-        });
-    }
-
-    fn mark_peer_not_needed(&self, handle: PeerHandle) -> Option<PeerState> {
-        let prev = self.with_peer_mut(handle, "mark_peer_not_needed", |peer| {
-            peer.state.to_not_needed(&self.stats)
-        })?;
-        Some(prev)
-    }
-}
-
 pub struct TorrentStateLocked {
     // What chunks we have and need.
     pub chunks: ChunkTracker,
@@ -226,54 +117,6 @@ pub struct TorrentStateLocked {
     pub inflight_pieces: HashMap<ValidPieceIndex, InflightPiece>,
 }
 
-#[derive(Default, Debug)]
-struct AtomicStats {
-    have_bytes: AtomicU64,
-    downloaded_and_checked_bytes: AtomicU64,
-    downloaded_and_checked_pieces: AtomicU64,
-    uploaded_bytes: AtomicU64,
-    fetched_bytes: AtomicU64,
-    total_piece_download_ms: AtomicU64,
-}
-
-impl AtomicStats {
-    fn average_piece_download_time(&self) -> Option<Duration> {
-        let d = self.downloaded_and_checked_pieces.load(Ordering::Acquire);
-        let t = self.total_piece_download_ms.load(Ordering::Acquire);
-        if d == 0 {
-            return None;
-        }
-        Some(Duration::from_secs_f64(t as f64 / d as f64 / 1000f64))
-    }
-}
-
-#[derive(Debug, Serialize)]
-pub struct StatsSnapshot {
-    pub have_bytes: u64,
-    pub downloaded_and_checked_bytes: u64,
-    pub downloaded_and_checked_pieces: u64,
-    pub fetched_bytes: u64,
-    pub uploaded_bytes: u64,
-    pub initially_needed_bytes: u64,
-    pub remaining_bytes: u64,
-    pub total_bytes: u64,
-    #[serde(skip)]
-    pub time: Instant,
-    pub total_piece_download_ms: u64,
-    pub peer_stats: AggregatePeerStats,
-}
-
-impl StatsSnapshot {
-    pub fn average_piece_download_time(&self) -> Option<Duration> {
-        let d = self.downloaded_and_checked_pieces;
-        let t = self.total_piece_download_ms;
-        if d == 0 {
-            return None;
-        }
-        Some(Duration::from_secs_f64(t as f64 / d as f64 / 1000f64))
-    }
-}
-
 #[derive(Default)]
 pub struct TorrentStateOptions {
     pub peer_connect_timeout: Option<Duration>,
@@ -303,105 +146,6 @@ pub struct TorrentState {
     finished_notify: Notify,
 }
 
-// Used during debugging to see if some locks take too long.
-#[cfg(not(feature = "timed_existence"))]
-mod timed_existence {
-    use std::ops::{Deref, DerefMut};
-
-    pub struct TimedExistence<T>(T);
-
-    impl<T> TimedExistence<T> {
-        #[inline(always)]
-        pub fn new(object: T, _reason: &'static str) -> Self {
-            Self(object)
-        }
-    }
-
-    impl<T> Deref for TimedExistence<T> {
-        type Target = T;
-
-        #[inline(always)]
-        fn deref(&self) -> &Self::Target {
-            &self.0
-        }
-    }
-
-    impl<T> DerefMut for TimedExistence<T> {
-        #[inline(always)]
-        fn deref_mut(&mut self) -> &mut Self::Target {
-            &mut self.0
-        }
-    }
-
-    #[inline(always)]
-    pub fn timeit<R>(_n: impl std::fmt::Display, f: impl FnOnce() -> R) -> R {
-        f()
-    }
-}
-
-#[cfg(feature = "timed_existence")]
-mod timed_existence {
-    use std::ops::{Deref, DerefMut};
-    use std::time::{Duration, Instant};
-    use tracing::warn;
-
-    const MAX: Duration = Duration::from_millis(1);
-
-    // Prints if the object exists for too long.
-    // This is used to track long-lived locks for debugging.
-    pub struct TimedExistence<T> {
-        object: T,
-        reason: &'static str,
-        started: Instant,
-    }
-
-    impl<T> TimedExistence<T> {
-        pub fn new(object: T, reason: &'static str) -> Self {
-            Self {
-                object,
-                reason,
-                started: Instant::now(),
-            }
-        }
-    }
-
-    impl<T> Drop for TimedExistence<T> {
-        fn drop(&mut self) {
-            let elapsed = self.started.elapsed();
-            let reason = self.reason;
-            if elapsed > MAX {
-                warn!("elapsed on lock {reason:?}: {elapsed:?}")
-            }
-        }
-    }
-
-    impl<T> Deref for TimedExistence<T> {
-        type Target = T;
-
-        fn deref(&self) -> &Self::Target {
-            &self.object
-        }
-    }
-
-    impl<T> DerefMut for TimedExistence<T> {
-        fn deref_mut(&mut self) -> &mut Self::Target {
-            &mut self.object
-        }
-    }
-
-    pub fn timeit<R>(name: impl std::fmt::Display, f: impl FnOnce() -> R) -> R {
-        let now = Instant::now();
-        let r = f();
-        let elapsed = now.elapsed();
-        if elapsed > MAX {
-            warn!("elapsed on \"{name:}\": {elapsed:?}")
-        }
-        r
-    }
-}
-
-pub use timed_existence::{timeit, TimedExistence};
-
 impl TorrentState {
     #[allow(clippy::too_many_arguments)]
     pub fn new(
@@ -734,7 +478,7 @@ struct PeerHandlerLocked {
 // This state tracks a live peer.
 struct PeerHandler {
     state: Arc<TorrentState>,
-    counters: Arc<PeerCounters>,
+    counters: Arc<AtomicPeerCounters>,
     // Semantically, we don't need an RwLock here, as this is only requested from
     // one future (requester + manage_peer).
     //

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

@@ -1,3 +1,5 @@
+pub mod stats;
+
 use std::collections::HashSet;
 use std::sync::atomic::{AtomicU32, AtomicU64, Ordering};
 use std::sync::Arc;
@@ -13,6 +15,8 @@ use tokio::sync::mpsc::{unbounded_channel, UnboundedReceiver, UnboundedSender};
 use crate::peer_connection::WriterRequest;
 use crate::type_aliases::BF;
 
+use super::peers::stats::atomic::AggregatePeerStatsAtomic;
+
 #[derive(Debug, Hash, PartialEq, Eq)]
 pub struct InflightRequest {
     pub piece: ValidPieceIndex,
@@ -45,85 +49,10 @@ impl SendMany for PeerTx {
     }
 }
 
-#[derive(Default, Debug)]
-pub struct PeerCounters {
-    pub fetched_bytes: AtomicU64,
-    pub total_time_connecting_ms: AtomicU64,
-    pub connection_attempts: AtomicU32,
-    pub connections: AtomicU32,
-    pub errors: AtomicU32,
-    pub fetched_chunks: AtomicU32,
-    pub downloaded_and_checked_pieces: AtomicU32,
-    pub downloaded_and_checked_bytes: AtomicU64,
-}
-
-#[derive(Debug)]
-pub struct PeerStats {
-    pub counters: Arc<PeerCounters>,
-    pub backoff: ExponentialBackoff,
-}
-
-impl Default for PeerStats {
-    fn default() -> Self {
-        Self {
-            counters: Arc::new(Default::default()),
-            backoff: ExponentialBackoffBuilder::new()
-                .with_initial_interval(Duration::from_secs(10))
-                .with_multiplier(6.)
-                .with_max_interval(Duration::from_secs(3600))
-                .with_max_elapsed_time(Some(Duration::from_secs(86400)))
-                .build(),
-        }
-    }
-}
-
 #[derive(Debug, Default)]
 pub struct Peer {
     pub state: PeerStateNoMut,
-    pub stats: PeerStats,
-}
-
-#[derive(Debug, Default, Serialize)]
-pub struct AggregatePeerStatsAtomic {
-    pub queued: AtomicU32,
-    pub connecting: AtomicU32,
-    pub live: AtomicU32,
-    pub seen: AtomicU32,
-    pub dead: AtomicU32,
-    pub not_needed: AtomicU32,
-}
-
-pub fn atomic_inc(c: &AtomicU32) -> u32 {
-    c.fetch_add(1, Ordering::Relaxed)
-}
-
-pub fn atomic_dec(c: &AtomicU32) -> u32 {
-    c.fetch_sub(1, Ordering::Relaxed)
-}
-
-impl AggregatePeerStatsAtomic {
-    pub fn counter(&self, state: &PeerState) -> &AtomicU32 {
-        match state {
-            PeerState::Connecting(_) => &self.connecting,
-            PeerState::Live(_) => &self.live,
-            PeerState::Queued => &self.queued,
-            PeerState::Dead => &self.dead,
-            PeerState::NotNeeded => &self.not_needed,
-        }
-    }
-
-    pub fn inc(&self, state: &PeerState) {
-        atomic_inc(self.counter(state));
-    }
-
-    pub fn dec(&self, state: &PeerState) {
-        atomic_dec(self.counter(state));
-    }
-
-    pub fn incdec(&self, old: &PeerState, new: &PeerState) {
-        self.dec(old);
-        self.inc(new);
-    }
+    pub stats: stats::atomic::PeerStats,
 }
 
 #[derive(Debug, Default)]
@@ -268,82 +197,3 @@ impl LivePeerState {
             .map_or(false, |s| s.all())
     }
 }
-
-mod peer_stats_snapshot {
-    use std::{collections::HashMap, sync::atomic::Ordering};
-
-    use serde::{Deserialize, Serialize};
-
-    use crate::peer_state::PeerState;
-
-    #[derive(Serialize, Deserialize)]
-    pub struct PeerCounters {
-        pub fetched_bytes: u64,
-        pub total_time_connecting_ms: u64,
-        pub connection_attempts: u32,
-        pub connections: u32,
-        pub errors: u32,
-        pub fetched_chunks: u32,
-        pub downloaded_and_checked_pieces: u32,
-    }
-
-    #[derive(Serialize, Deserialize)]
-    pub struct PeerStats {
-        pub counters: PeerCounters,
-        pub state: &'static str,
-    }
-
-    impl From<&crate::peer_state::PeerCounters> for PeerCounters {
-        fn from(counters: &crate::peer_state::PeerCounters) -> Self {
-            Self {
-                fetched_bytes: counters.fetched_bytes.load(Ordering::Relaxed),
-                total_time_connecting_ms: counters.total_time_connecting_ms.load(Ordering::Relaxed),
-                connection_attempts: counters.connection_attempts.load(Ordering::Relaxed),
-                connections: counters.connections.load(Ordering::Relaxed),
-                errors: counters.errors.load(Ordering::Relaxed),
-                fetched_chunks: counters.fetched_chunks.load(Ordering::Relaxed),
-                downloaded_and_checked_pieces: counters
-                    .downloaded_and_checked_pieces
-                    .load(Ordering::Relaxed),
-            }
-        }
-    }
-
-    impl From<&crate::peer_state::Peer> for PeerStats {
-        fn from(peer: &crate::peer_state::Peer) -> Self {
-            Self {
-                counters: peer.stats.counters.as_ref().into(),
-                state: peer.state.get().name(),
-            }
-        }
-    }
-
-    #[derive(Serialize)]
-    pub struct PeerStatsSnapshot {
-        pub peers: HashMap<String, PeerStats>,
-    }
-
-    #[derive(Clone, Copy, Default, Deserialize)]
-    pub enum PeerStatsFilterState {
-        All,
-        #[default]
-        Live,
-    }
-
-    impl PeerStatsFilterState {
-        pub fn matches(&self, s: &PeerState) -> bool {
-            match (self, s) {
-                (Self::All, _) => true,
-                (Self::Live, PeerState::Live(_)) => true,
-                _ => false,
-            }
-        }
-    }
-
-    #[derive(Default, Deserialize)]
-    pub struct PeerStatsFilter {
-        pub state: PeerStatsFilterState,
-    }
-}
-
-pub use peer_stats_snapshot::{PeerStatsFilter, PeerStatsSnapshot};

crates/librqbit/src/torrent_state/live/peer/stats/atomic.rs

@@ -0,0 +1,41 @@
+use std::{
+    sync::{
+        atomic::{AtomicU32, AtomicU64},
+        Arc,
+    },
+    time::Duration,
+};
+
+use backoff::{ExponentialBackoff, ExponentialBackoffBuilder};
+
+#[derive(Default, Debug)]
+pub struct PeerCounters {
+    pub fetched_bytes: AtomicU64,
+    pub total_time_connecting_ms: AtomicU64,
+    pub connection_attempts: AtomicU32,
+    pub connections: AtomicU32,
+    pub errors: AtomicU32,
+    pub fetched_chunks: AtomicU32,
+    pub downloaded_and_checked_pieces: AtomicU32,
+    pub downloaded_and_checked_bytes: AtomicU64,
+}
+
+#[derive(Debug)]
+pub struct PeerStats {
+    pub counters: Arc<PeerCounters>,
+    pub backoff: ExponentialBackoff,
+}
+
+impl Default for PeerStats {
+    fn default() -> Self {
+        Self {
+            counters: Arc::new(Default::default()),
+            backoff: ExponentialBackoffBuilder::new()
+                .with_initial_interval(Duration::from_secs(10))
+                .with_multiplier(6.)
+                .with_max_interval(Duration::from_secs(3600))
+                .with_max_elapsed_time(Some(Duration::from_secs(86400)))
+                .build(),
+        }
+    }
+}

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

@@ -0,0 +1,2 @@
+pub mod atomic;
+pub mod snapshot;

crates/librqbit/src/torrent_state/live/peer/stats/snapshot.rs

@@ -0,0 +1,74 @@
+use std::{collections::HashMap, sync::atomic::Ordering};
+
+use serde::{Deserialize, Serialize};
+
+use crate::torrent_state::live::peer::{Peer, PeerState};
+
+#[derive(Serialize, Deserialize)]
+pub struct PeerCounters {
+    pub fetched_bytes: u64,
+    pub total_time_connecting_ms: u64,
+    pub connection_attempts: u32,
+    pub connections: u32,
+    pub errors: u32,
+    pub fetched_chunks: u32,
+    pub downloaded_and_checked_pieces: u32,
+}
+
+#[derive(Serialize, Deserialize)]
+pub struct PeerStats {
+    pub counters: PeerCounters,
+    pub state: &'static str,
+}
+
+impl From<&super::atomic::PeerCounters> for PeerCounters {
+    fn from(counters: &super::atomic::PeerCounters) -> Self {
+        Self {
+            fetched_bytes: counters.fetched_bytes.load(Ordering::Relaxed),
+            total_time_connecting_ms: counters.total_time_connecting_ms.load(Ordering::Relaxed),
+            connection_attempts: counters.connection_attempts.load(Ordering::Relaxed),
+            connections: counters.connections.load(Ordering::Relaxed),
+            errors: counters.errors.load(Ordering::Relaxed),
+            fetched_chunks: counters.fetched_chunks.load(Ordering::Relaxed),
+            downloaded_and_checked_pieces: counters
+                .downloaded_and_checked_pieces
+                .load(Ordering::Relaxed),
+        }
+    }
+}
+
+impl From<&Peer> for PeerStats {
+    fn from(peer: &Peer) -> Self {
+        Self {
+            counters: peer.stats.counters.as_ref().into(),
+            state: peer.state.get().name(),
+        }
+    }
+}
+
+#[derive(Serialize)]
+pub struct PeerStatsSnapshot {
+    pub peers: HashMap<String, PeerStats>,
+}
+
+#[derive(Clone, Copy, Default, Deserialize)]
+pub enum PeerStatsFilterState {
+    All,
+    #[default]
+    Live,
+}
+
+impl PeerStatsFilterState {
+    pub fn matches(&self, s: &PeerState) -> bool {
+        match (self, s) {
+            (Self::All, _) => true,
+            (Self::Live, PeerState::Live(_)) => true,
+            _ => false,
+        }
+    }
+}
+
+#[derive(Default, Deserialize)]
+pub struct PeerStatsFilter {
+    pub state: PeerStatsFilterState,
+}

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

@@ -0,0 +1,114 @@
+use std::net::SocketAddr;
+
+use anyhow::Context;
+use backoff::backoff::Backoff;
+use dashmap::DashMap;
+
+use crate::{
+    torrent_state::utils::{atomic_inc, TimedExistence},
+    type_aliases::{PeerHandle, BF},
+};
+
+use self::stats::{atomic::AggregatePeerStatsAtomic, snapshot::AggregatePeerStats};
+
+use super::peer::{LivePeerState, Peer, PeerRx, PeerState, PeerTx};
+
+pub mod stats;
+
+#[derive(Default)]
+pub struct PeerStates {
+    pub stats: AggregatePeerStatsAtomic,
+    pub states: DashMap<PeerHandle, Peer>,
+}
+
+impl PeerStates {
+    pub fn stats(&self) -> AggregatePeerStats {
+        AggregatePeerStats::from(&self.stats)
+    }
+
+    pub fn add_if_not_seen(&self, addr: SocketAddr) -> Option<PeerHandle> {
+        use dashmap::mapref::entry::Entry;
+        match self.states.entry(addr) {
+            Entry::Occupied(_) => None,
+            Entry::Vacant(vac) => {
+                vac.insert(Default::default());
+                atomic_inc(&self.stats.queued);
+                atomic_inc(&self.stats.seen);
+                Some(addr)
+            }
+        }
+    }
+    pub fn with_peer<R>(&self, addr: PeerHandle, f: impl FnOnce(&Peer) -> R) -> Option<R> {
+        self.states.get(&addr).map(|e| f(e.value()))
+    }
+
+    pub fn with_peer_mut<R>(
+        &self,
+        addr: PeerHandle,
+        reason: &'static str,
+        f: impl FnOnce(&mut Peer) -> R,
+    ) -> Option<R> {
+        use crate::torrent_state::utils::timeit;
+        timeit(reason, || self.states.get_mut(&addr))
+            .map(|e| f(TimedExistence::new(e, reason).value_mut()))
+    }
+    pub fn with_live<R>(&self, addr: PeerHandle, f: impl FnOnce(&LivePeerState) -> R) -> Option<R> {
+        self.states
+            .get(&addr)
+            .and_then(|e| match &e.value().state.get() {
+                PeerState::Live(l) => Some(f(l)),
+                _ => None,
+            })
+    }
+    pub fn with_live_mut<R>(
+        &self,
+        addr: PeerHandle,
+        reason: &'static str,
+        f: impl FnOnce(&mut LivePeerState) -> R,
+    ) -> Option<R> {
+        self.with_peer_mut(addr, reason, |peer| peer.state.get_live_mut().map(f))
+            .flatten()
+    }
+
+    pub fn drop_peer(&self, handle: PeerHandle) -> Option<Peer> {
+        let p = self.states.remove(&handle).map(|r| r.1)?;
+        self.stats.dec(p.state.get());
+        Some(p)
+    }
+
+    pub fn mark_peer_interested(&self, handle: PeerHandle, is_interested: bool) -> Option<bool> {
+        self.with_live_mut(handle, "mark_peer_interested", |live| {
+            let prev = live.peer_interested;
+            live.peer_interested = is_interested;
+            prev
+        })
+    }
+    pub fn update_bitfield_from_vec(&self, handle: PeerHandle, bitfield: Vec<u8>) -> Option<()> {
+        self.with_live_mut(handle, "update_bitfield_from_vec", |live| {
+            live.bitfield = BF::from_vec(bitfield);
+        })
+    }
+    pub fn mark_peer_connecting(&self, h: PeerHandle) -> anyhow::Result<(PeerRx, PeerTx)> {
+        let rx = self
+            .with_peer_mut(h, "mark_peer_connecting", |peer| {
+                peer.state
+                    .queued_to_connecting(&self.stats)
+                    .context("invalid peer state")
+            })
+            .context("peer not found in states")??;
+        Ok(rx)
+    }
+
+    pub fn reset_peer_backoff(&self, handle: PeerHandle) {
+        self.with_peer_mut(handle, "reset_peer_backoff", |p| {
+            p.stats.backoff.reset();
+        });
+    }
+
+    pub fn mark_peer_not_needed(&self, handle: PeerHandle) -> Option<PeerState> {
+        let prev = self.with_peer_mut(handle, "mark_peer_not_needed", |peer| {
+            peer.state.to_not_needed(&self.stats)
+        })?;
+        Some(prev)
+    }
+}

crates/librqbit/src/torrent_state/live/peers/stats/atomic.rs

@@ -0,0 +1,43 @@
+use std::sync::atomic::AtomicU32;
+
+use serde::Serialize;
+
+use crate::torrent_state::{
+    live::peer::PeerState,
+    utils::{atomic_dec, atomic_inc},
+};
+
+#[derive(Debug, Default, Serialize)]
+pub struct AggregatePeerStatsAtomic {
+    pub queued: AtomicU32,
+    pub connecting: AtomicU32,
+    pub live: AtomicU32,
+    pub seen: AtomicU32,
+    pub dead: AtomicU32,
+    pub not_needed: AtomicU32,
+}
+
+impl AggregatePeerStatsAtomic {
+    pub fn counter(&self, state: &PeerState) -> &AtomicU32 {
+        match state {
+            PeerState::Connecting(_) => &self.connecting,
+            PeerState::Live(_) => &self.live,
+            PeerState::Queued => &self.queued,
+            PeerState::Dead => &self.dead,
+            PeerState::NotNeeded => &self.not_needed,
+        }
+    }
+
+    pub fn inc(&self, state: &PeerState) {
+        atomic_inc(self.counter(state));
+    }
+
+    pub fn dec(&self, state: &PeerState) {
+        atomic_dec(self.counter(state));
+    }
+
+    pub fn incdec(&self, old: &PeerState, new: &PeerState) {
+        self.dec(old);
+        self.inc(new);
+    }
+}

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

@@ -0,0 +1,2 @@
+pub mod atomic;
+pub mod snapshot;

crates/librqbit/src/torrent_state/live/peers/stats/snapshot.rs

@@ -0,0 +1,29 @@
+use std::sync::atomic::Ordering;
+
+use serde::Serialize;
+
+use super::atomic::AggregatePeerStatsAtomic;
+
+#[derive(Debug, Default, Serialize, PartialEq, Eq)]
+pub struct AggregatePeerStats {
+    pub queued: usize,
+    pub connecting: usize,
+    pub live: usize,
+    pub seen: usize,
+    pub dead: usize,
+    pub not_needed: usize,
+}
+
+impl<'a> From<&'a AggregatePeerStatsAtomic> for AggregatePeerStats {
+    fn from(s: &'a AggregatePeerStatsAtomic) -> Self {
+        let ordering = Ordering::Relaxed;
+        Self {
+            queued: s.queued.load(ordering) as usize,
+            connecting: s.connecting.load(ordering) as usize,
+            live: s.live.load(ordering) as usize,
+            seen: s.seen.load(ordering) as usize,
+            dead: s.dead.load(ordering) as usize,
+            not_needed: s.not_needed.load(ordering) as usize,
+        }
+    }
+}

crates/librqbit/src/torrent_state/live/stats/atomic.rs

@@ -0,0 +1,25 @@
+use std::{
+    sync::atomic::{AtomicU64, Ordering},
+    time::Duration,
+};
+
+#[derive(Default, Debug)]
+pub struct AtomicStats {
+    pub have_bytes: AtomicU64,
+    pub downloaded_and_checked_bytes: AtomicU64,
+    pub downloaded_and_checked_pieces: AtomicU64,
+    pub uploaded_bytes: AtomicU64,
+    pub fetched_bytes: AtomicU64,
+    pub total_piece_download_ms: AtomicU64,
+}
+
+impl AtomicStats {
+    pub fn average_piece_download_time(&self) -> Option<Duration> {
+        let d = self.downloaded_and_checked_pieces.load(Ordering::Acquire);
+        let t = self.total_piece_download_ms.load(Ordering::Acquire);
+        if d == 0 {
+            return None;
+        }
+        Some(Duration::from_secs_f64(t as f64 / d as f64 / 1000f64))
+    }
+}

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

@@ -0,0 +1,2 @@
+pub mod atomic;
+pub mod snapshot;

crates/librqbit/src/torrent_state/live/stats/snapshot.rs

@@ -0,0 +1,32 @@
+use std::time::{Duration, Instant};
+
+use serde::Serialize;
+
+use crate::torrent_state::live::peers::stats::snapshot::AggregatePeerStats;
+
+#[derive(Debug, Serialize)]
+pub struct StatsSnapshot {
+    pub have_bytes: u64,
+    pub downloaded_and_checked_bytes: u64,
+    pub downloaded_and_checked_pieces: u64,
+    pub fetched_bytes: u64,
+    pub uploaded_bytes: u64,
+    pub initially_needed_bytes: u64,
+    pub remaining_bytes: u64,
+    pub total_bytes: u64,
+    #[serde(skip)]
+    pub time: Instant,
+    pub total_piece_download_ms: u64,
+    pub peer_stats: AggregatePeerStats,
+}
+
+impl StatsSnapshot {
+    pub fn average_piece_download_time(&self) -> Option<Duration> {
+        let d = self.downloaded_and_checked_pieces;
+        let t = self.total_piece_download_ms;
+        if d == 0 {
+            return None;
+        }
+        Some(Duration::from_secs_f64(t as f64 / d as f64 / 1000f64))
+    }
+}

crates/librqbit/src/torrent_state/mod.rs

@@ -1,3 +1,5 @@
+pub mod utils;
+
 pub mod live;
 
 pub use live::*;

crates/librqbit/src/torrent_state/utils.rs

@@ -0,0 +1,108 @@
+use std::sync::atomic::{AtomicU32, Ordering};
+
+pub fn atomic_inc(c: &AtomicU32) -> u32 {
+    c.fetch_add(1, Ordering::Relaxed)
+}
+
+pub fn atomic_dec(c: &AtomicU32) -> u32 {
+    c.fetch_sub(1, Ordering::Relaxed)
+}
+
+// Used during debugging to see if some locks take too long.
+#[cfg(not(feature = "timed_existence"))]
+mod timed_existence {
+    use std::ops::{Deref, DerefMut};
+
+    pub struct TimedExistence<T>(T);
+
+    impl<T> TimedExistence<T> {
+        #[inline(always)]
+        pub fn new(object: T, _reason: &'static str) -> Self {
+            Self(object)
+        }
+    }
+
+    impl<T> Deref for TimedExistence<T> {
+        type Target = T;
+
+        #[inline(always)]
+        fn deref(&self) -> &Self::Target {
+            &self.0
+        }
+    }
+
+    impl<T> DerefMut for TimedExistence<T> {
+        #[inline(always)]
+        fn deref_mut(&mut self) -> &mut Self::Target {
+            &mut self.0
+        }
+    }
+
+    #[inline(always)]
+    pub fn timeit<R>(_n: impl std::fmt::Display, f: impl FnOnce() -> R) -> R {
+        f()
+    }
+}
+
+#[cfg(feature = "timed_existence")]
+mod timed_existence {
+    use std::ops::{Deref, DerefMut};
+    use std::time::{Duration, Instant};
+    use tracing::warn;
+
+    const MAX: Duration = Duration::from_millis(1);
+
+    // Prints if the object exists for too long.
+    // This is used to track long-lived locks for debugging.
+    pub struct TimedExistence<T> {
+        object: T,
+        reason: &'static str,
+        started: Instant,
+    }
+
+    impl<T> TimedExistence<T> {
+        pub fn new(object: T, reason: &'static str) -> Self {
+            Self {
+                object,
+                reason,
+                started: Instant::now(),
+            }
+        }
+    }
+
+    impl<T> Drop for TimedExistence<T> {
+        fn drop(&mut self) {
+            let elapsed = self.started.elapsed();
+            let reason = self.reason;
+            if elapsed > MAX {
+                warn!("elapsed on lock {reason:?}: {elapsed:?}")
+            }
+        }
+    }
+
+    impl<T> Deref for TimedExistence<T> {
+        type Target = T;
+
+        fn deref(&self) -> &Self::Target {
+            &self.object
+        }
+    }
+
+    impl<T> DerefMut for TimedExistence<T> {
+        fn deref_mut(&mut self) -> &mut Self::Target {
+            &mut self.object
+        }
+    }
+
+    pub fn timeit<R>(name: impl std::fmt::Display, f: impl FnOnce() -> R) -> R {
+        let now = Instant::now();
+        let r = f();
+        let elapsed = now.elapsed();
+        if elapsed > MAX {
+            warn!("elapsed on \"{name:}\": {elapsed:?}")
+        }
+        r
+    }
+}
+
+pub use timed_existence::{timeit, TimedExistence};

crates/rqbit/src/main.rs

@@ -11,7 +11,6 @@ use librqbit::{
         Session, SessionOptions,
     },
     spawn_utils::{spawn, BlockingSpawner},
-    torrent_state::timeit,
 };
 use size_format::SizeFormatterBinary as SF;
 use tracing::{error, info, span, warn, Level};
@@ -244,7 +243,7 @@ async fn async_main(opts: Opts, spawner: BlockingSpawner) -> anyhow::Result<()>
                                 info!("[{}] initializing", idx);
                             },
                             ManagedTorrentState::Running(handle) => {
-                                let stats = timeit("stats_snapshot", || handle.torrent_state().stats_snapshot());
+                                let stats = handle.torrent_state().stats_snapshot();
                                 let speed = handle.speed_estimator();
                                 let total = stats.total_bytes;
                                 let progress = stats.total_bytes - stats.remaining_bytes;