Add statistics. Move client stats from Monitor to EventManager (#2940)

* Add statistics entity. Move client stats from Monitor to EventManager

* Fix warning in no_std

* Make rustfmt happy

* Fix more

* Fix with feature tcp_manager on

* Rename more introspection monitor; Remove unnecessary client_stats

* Fix unused import for no_std

* Fix unused import for prometheus_monitor feature on

* Cleanup docs

libafl/examples/tui_mock/main.rs

@@ -3,7 +3,10 @@
 
 use std::{thread::sleep, time::Duration};
 
-use libafl::monitors::{tui::TuiMonitor, ClientStats, Monitor};
+use libafl::{
+    monitors::{tui::TuiMonitor, Monitor},
+    statistics::{manager::ClientStatsManager, ClientStats},
+};
 use libafl_bolts::ClientId;
 
 pub fn main() {
@@ -14,7 +17,8 @@ pub fn main() {
         executions: 512,
         ..ClientStats::default()
     };
+    let mut client_stats_manager = ClientStatsManager::default();
 
-    monitor.display("Test", ClientId(0));
+    monitor.display(&mut client_stats_manager, "Test", ClientId(0));
     sleep(Duration::from_secs(10));
 }

libafl/src/corpus/minimizer.rs

@@ -18,10 +18,10 @@ use crate::{
     events::{Event, EventFirer, LogSeverity},
     executors::{Executor, HasObservers},
     inputs::Input,
-    monitors::{AggregatorOps, UserStats, UserStatsValue},
     observers::{MapObserver, ObserversTuple},
     schedulers::{LenTimeMulTestcaseScore, RemovableScheduler, Scheduler, TestcaseScore},
     state::{HasCorpus, HasExecutions},
+    statistics::user_stats::{AggregatorOps, UserStats, UserStatsValue},
     Error, HasMetadata, HasScheduler,
 };
 

libafl/src/events/broker_hooks/mod.rs

@@ -15,6 +15,7 @@ use crate::events::llmp::COMPRESS_THRESHOLD;
 use crate::{
     events::{llmp::LLMP_TAG_EVENT_TO_BOTH, BrokerEventResult, Event},
     monitors::Monitor,
+    statistics::manager::ClientStatsManager,
     Error,
 };
 
@@ -37,6 +38,7 @@ pub struct StdLlmpEventHook<I, MT> {
     #[cfg(feature = "llmp_compression")]
     compressor: GzipCompressor,
     phantom: PhantomData<I>,
+    client_stats_manager: ClientStatsManager,
 }
 
 impl<I, MT, SHM, SP> LlmpHook<SHM, SP> for StdLlmpEventHook<I, MT>
@@ -71,7 +73,12 @@ where
                 &*msg
             };
             let event: Event<I> = postcard::from_bytes(event_bytes)?;
-            match Self::handle_in_broker(monitor, client_id, &event)? {
+            match Self::handle_in_broker(
+                monitor,
+                &mut self.client_stats_manager,
+                client_id,
+                &event,
+            )? {
                 BrokerEventResult::Forward => Ok(LlmpMsgHookResult::ForwardToClients),
                 BrokerEventResult::Handled => Ok(LlmpMsgHookResult::Handled),
             }
@@ -81,7 +88,11 @@ where
     }
 
     fn on_timeout(&mut self) -> Result<(), Error> {
-        self.monitor.display("Broker Heartbeat", ClientId(0));
+        self.monitor.display(
+            &mut self.client_stats_manager,
+            "Broker Heartbeat",
+            ClientId(0),
+        );
         Ok(())
     }
 }
@@ -96,6 +107,7 @@ where
             monitor,
             #[cfg(feature = "llmp_compression")]
             compressor: GzipCompressor::with_threshold(COMPRESS_THRESHOLD),
+            client_stats_manager: ClientStatsManager::default(),
             phantom: PhantomData,
         })
     }
@@ -104,6 +116,7 @@ where
     #[expect(clippy::unnecessary_wraps)]
     fn handle_in_broker(
         monitor: &mut MT,
+        client_stats_manager: &mut ClientStatsManager,
         client_id: ClientId,
         event: &Event<I>,
     ) -> Result<BrokerEventResult, Error> {
@@ -119,11 +132,11 @@ where
                     client_id
                 };
 
-                monitor.client_stats_insert(id);
+                client_stats_manager.client_stats_insert(id);
-                monitor.update_client_stats_for(id, |client_stat| {
+                client_stats_manager.update_client_stats_for(id, |client_stat| {
                     client_stat.update_corpus_size(*corpus_size as u64);
                 });
-                monitor.display(event.name(), id);
+                monitor.display(client_stats_manager, event.name(), id);
                 Ok(BrokerEventResult::Forward)
             }
             Event::UpdateExecStats {
@@ -132,56 +145,52 @@ where
                 phantom: _,
             } => {
                 // TODO: The monitor buffer should be added on client add.
-                monitor.client_stats_insert(client_id);
+                client_stats_manager.client_stats_insert(client_id);
-                monitor.update_client_stats_for(client_id, |client_stat| {
+                client_stats_manager.update_client_stats_for(client_id, |client_stat| {
                     client_stat.update_executions(*executions, *time);
                 });
-                monitor.display(event.name(), client_id);
+                monitor.display(client_stats_manager, event.name(), client_id);
                 Ok(BrokerEventResult::Handled)
             }
-            Event::UpdateUserStats {
+            Event::UpdateUserStats { name, value, .. } => {
-                name,
+                client_stats_manager.client_stats_insert(client_id);
-                value,
+                client_stats_manager.update_client_stats_for(client_id, |client_stat| {
-                phantom: _,
-            } => {
-                monitor.client_stats_insert(client_id);
-                monitor.update_client_stats_for(client_id, |client_stat| {
                     client_stat.update_user_stats(name.clone(), value.clone());
                 });
-                monitor.aggregate(name);
+                client_stats_manager.aggregate(name);
-                monitor.display(event.name(), client_id);
+                monitor.display(client_stats_manager, event.name(), client_id);
                 Ok(BrokerEventResult::Handled)
             }
             #[cfg(feature = "introspection")]
             Event::UpdatePerfMonitor {
                 time,
                 executions,
-                introspection_monitor,
+                introspection_stats,
                 phantom: _,
             } => {
                 // TODO: The monitor buffer should be added on client add.
 
                 // Get the client for the staterestorer ID
-                monitor.client_stats_insert(client_id);
+                client_stats_manager.client_stats_insert(client_id);
-                monitor.update_client_stats_for(client_id, |client_stat| {
+                client_stats_manager.update_client_stats_for(client_id, |client_stat| {
                     // Update the normal monitor for this client
                     client_stat.update_executions(*executions, *time);
                     // Update the performance monitor for this client
-                    client_stat.update_introspection_monitor((**introspection_monitor).clone());
+                    client_stat.update_introspection_stats((**introspection_stats).clone());
                 });
 
                 // Display the monitor via `.display` only on core #1
-                monitor.display(event.name(), client_id);
+                monitor.display(client_stats_manager, event.name(), client_id);
 
                 // Correctly handled the event
                 Ok(BrokerEventResult::Handled)
             }
             Event::Objective { objective_size, .. } => {
-                monitor.client_stats_insert(client_id);
+                client_stats_manager.client_stats_insert(client_id);
-                monitor.update_client_stats_for(client_id, |client_stat| {
+                client_stats_manager.update_client_stats_for(client_id, |client_stat| {
                     client_stat.update_objective_size(*objective_size as u64);
                 });
-                monitor.display(event.name(), client_id);
+                monitor.display(client_stats_manager, event.name(), client_id);
                 Ok(BrokerEventResult::Handled)
             }
             Event::Log {

libafl/src/events/mod.rs

@@ -47,8 +47,8 @@ use uuid::Uuid;
 use crate::{
     executors::ExitKind,
     inputs::Input,
-    monitors::UserStats,
     state::{HasExecutions, HasLastReportTime, MaybeHasClientPerfMonitor},
+    statistics::user_stats::UserStats,
     Error, HasMetadata,
 };
 
@@ -107,7 +107,7 @@ pub struct EventManagerId(
 #[cfg(all(unix, feature = "std", feature = "multi_machine"))]
 use crate::events::multi_machine::NodeId;
 #[cfg(feature = "introspection")]
-use crate::monitors::ClientPerfMonitor;
+use crate::statistics::perf_stats::ClientPerfStats;
 use crate::{observers::TimeObserver, stages::HasCurrentStageId};
 
 /// The log event severity
@@ -294,7 +294,7 @@ pub enum Event<I> {
         /// The executions of this client
         executions: u64,
         /// Current performance statistics
-        introspection_monitor: Box<ClientPerfMonitor>,
+        introspection_stats: Box<ClientPerfStats>,
 
         /// phantomm data
         phantom: PhantomData<I>,
@@ -514,17 +514,17 @@ where
     #[cfg(feature = "introspection")]
     {
         state
-            .introspection_monitor_mut()
+            .introspection_stats_mut()
             .set_current_time(libafl_bolts::cpu::read_time_counter());
 
         // Send the current monitor over to the manager. This `.clone` shouldn't be
-        // costly as `ClientPerfMonitor` impls `Copy` since it only contains `u64`s
+        // costly as `ClientPerfStats` impls `Copy` since it only contains `u64`s
         reporter.fire(
             state,
             Event::UpdatePerfMonitor {
                 executions,
                 time: cur,
-                introspection_monitor: Box::new(state.introspection_monitor().clone()),
+                introspection_stats: Box::new(state.introspection_stats().clone()),
                 phantom: PhantomData,
             },
         )?;

libafl/src/events/simple.rs

@@ -34,13 +34,11 @@ use crate::{
     monitors::Monitor,
     stages::HasCurrentStageId,
     state::{HasExecutions, HasLastReportTime, MaybeHasClientPerfMonitor, Stoppable},
+    statistics::manager::ClientStatsManager,
     Error, HasMetadata,
 };
 #[cfg(feature = "std")]
-use crate::{
+use crate::{monitors::SimplePrintingMonitor, state::HasSolutions, statistics::ClientStats};
-    monitors::{ClientStats, SimplePrintingMonitor},
-    state::HasSolutions,
-};
 
 /// The llmp connection from the actual fuzzer to the process supervising it
 const _ENV_FUZZER_SENDER: &str = "_AFL_ENV_FUZZER_SENDER";
@@ -55,6 +53,7 @@ pub struct SimpleEventManager<I, MT, S> {
     /// The events that happened since the last `handle_in_broker`
     events: Vec<Event<I>>,
     phantom: PhantomData<S>,
+    client_stats_manager: ClientStatsManager,
 }
 
 impl<I, MT, S> Debug for SimpleEventManager<I, MT, S>
@@ -84,7 +83,7 @@ where
     }
 
     fn fire(&mut self, _state: &mut S, event: Event<I>) -> Result<(), Error> {
-        match Self::handle_in_broker(&mut self.monitor, &event)? {
+        match Self::handle_in_broker(&mut self.monitor, &mut self.client_stats_manager, &event)? {
             BrokerEventResult::Forward => self.events.push(event),
             BrokerEventResult::Handled => (),
         }
@@ -199,65 +198,70 @@ where
         Self {
             monitor,
             events: vec![],
+            client_stats_manager: ClientStatsManager::default(),
             phantom: PhantomData,
         }
     }
 
     /// Handle arriving events in the broker
     #[expect(clippy::unnecessary_wraps)]
-    fn handle_in_broker(monitor: &mut MT, event: &Event<I>) -> Result<BrokerEventResult, Error> {
+    fn handle_in_broker(
+        monitor: &mut MT,
+        client_stats_manager: &mut ClientStatsManager,
+        event: &Event<I>,
+    ) -> Result<BrokerEventResult, Error> {
         match event {
             Event::NewTestcase { corpus_size, .. } => {
-                monitor.client_stats_insert(ClientId(0));
+                client_stats_manager.client_stats_insert(ClientId(0));
-                monitor.update_client_stats_for(ClientId(0), |client_stat| {
+                client_stats_manager.update_client_stats_for(ClientId(0), |client_stat| {
                     client_stat.update_corpus_size(*corpus_size as u64);
                 });
-                monitor.display(event.name(), ClientId(0));
+                monitor.display(client_stats_manager, event.name(), ClientId(0));
                 Ok(BrokerEventResult::Handled)
             }
             Event::UpdateExecStats {
                 time, executions, ..
             } => {
                 // TODO: The monitor buffer should be added on client add.
-                monitor.client_stats_insert(ClientId(0));
+                client_stats_manager.client_stats_insert(ClientId(0));
-                monitor.update_client_stats_for(ClientId(0), |client_stat| {
+                client_stats_manager.update_client_stats_for(ClientId(0), |client_stat| {
                     client_stat.update_executions(*executions, *time);
                 });
 
-                monitor.display(event.name(), ClientId(0));
+                monitor.display(client_stats_manager, event.name(), ClientId(0));
                 Ok(BrokerEventResult::Handled)
             }
             Event::UpdateUserStats { name, value, .. } => {
-                monitor.client_stats_insert(ClientId(0));
+                client_stats_manager.client_stats_insert(ClientId(0));
-                monitor.update_client_stats_for(ClientId(0), |client_stat| {
+                client_stats_manager.update_client_stats_for(ClientId(0), |client_stat| {
                     client_stat.update_user_stats(name.clone(), value.clone());
                 });
-                monitor.aggregate(name);
+                client_stats_manager.aggregate(name);
-                monitor.display(event.name(), ClientId(0));
+                monitor.display(client_stats_manager, event.name(), ClientId(0));
                 Ok(BrokerEventResult::Handled)
             }
             #[cfg(feature = "introspection")]
             Event::UpdatePerfMonitor {
                 time,
                 executions,
-                introspection_monitor,
+                introspection_stats,
                 ..
             } => {
                 // TODO: The monitor buffer should be added on client add.
-                monitor.client_stats_insert(ClientId(0));
+                client_stats_manager.client_stats_insert(ClientId(0));
-                monitor.update_client_stats_for(ClientId(0), |client_stat| {
+                client_stats_manager.update_client_stats_for(ClientId(0), |client_stat| {
                     client_stat.update_executions(*executions, *time);
-                    client_stat.update_introspection_monitor((**introspection_monitor).clone());
+                    client_stat.update_introspection_stats((**introspection_stats).clone());
                 });
-                monitor.display(event.name(), ClientId(0));
+                monitor.display(client_stats_manager, event.name(), ClientId(0));
                 Ok(BrokerEventResult::Handled)
             }
             Event::Objective { objective_size, .. } => {
-                monitor.client_stats_insert(ClientId(0));
+                client_stats_manager.client_stats_insert(ClientId(0));
-                monitor.update_client_stats_for(ClientId(0), |client_stat| {
+                client_stats_manager.update_client_stats_for(ClientId(0), |client_stat| {
                     client_stat.update_objective_size(*objective_size as u64);
                 });
-                monitor.display(event.name(), ClientId(0));
+                monitor.display(client_stats_manager, event.name(), ClientId(0));
                 Ok(BrokerEventResult::Handled)
             }
             Event::Log {
@@ -327,7 +331,7 @@ where
         self.staterestorer.save(&(
             state,
             self.inner.monitor.start_time(),
-            self.inner.monitor.client_stats(),
+            self.inner.client_stats_manager.client_stats(),
         ))
     }
 }
@@ -543,12 +547,12 @@ where
 
                 // reload the state of the monitor to display the correct stats after restarts
                 monitor.set_start_time(start_time);
-                monitor.update_all_client_stats(clients_stats);
+                let mut this = SimpleRestartingEventManager::launched(monitor, staterestorer);
+                this.inner
+                    .client_stats_manager
+                    .update_all_client_stats(clients_stats);
 
-                (
+                (Some(state), this)
-                    Some(state),
-                    SimpleRestartingEventManager::launched(monitor, staterestorer),
-                )
             }
         };
 

libafl/src/events/tcp.rs

@@ -53,6 +53,7 @@ use crate::{
         HasCurrentTestcase, HasExecutions, HasImported, HasLastReportTime, HasSolutions,
         MaybeHasClientPerfMonitor, Stoppable,
     },
+    statistics::manager::ClientStatsManager,
     Error, HasMetadata,
 };
 
@@ -77,6 +78,7 @@ where
     listener: Option<TcpListener>,
     /// Amount of all clients ever, after which (when all are disconnected) this broker should quit.
     exit_cleanly_after: Option<NonZeroUsize>,
+    client_stats_manager: ClientStatsManager,
     phantom: PhantomData<I>,
 }
 
@@ -100,6 +102,7 @@ where
         Self {
             listener: Some(listener),
             monitor,
+            client_stats_manager: ClientStatsManager::default(),
             phantom: PhantomData,
             exit_cleanly_after: None,
         }
@@ -291,7 +294,12 @@ where
             let event_bytes = &GzipCompressor::new().decompress(event_bytes)?;
 
             let event: Event<I> = postcard::from_bytes(event_bytes)?;
-            match Self::handle_in_broker(&mut self.monitor, client_id, &event)? {
+            match Self::handle_in_broker(
+                &mut self.monitor,
+                &mut self.client_stats_manager,
+                client_id,
+                &event,
+            )? {
                 BrokerEventResult::Forward => {
                     tx_bc.send(buf).expect("Could not send");
                 }
@@ -312,6 +320,7 @@ where
     #[expect(clippy::unnecessary_wraps)]
     fn handle_in_broker(
         monitor: &mut MT,
+        client_stats_manager: &mut ClientStatsManager,
         client_id: ClientId,
         event: &Event<I>,
     ) -> Result<BrokerEventResult, Error> {
@@ -326,11 +335,11 @@ where
                 } else {
                     client_id
                 };
-                monitor.client_stats_insert(id);
+                client_stats_manager.client_stats_insert(id);
-                monitor.update_client_stats_for(id, |client| {
+                client_stats_manager.update_client_stats_for(id, |client| {
                     client.update_corpus_size(*corpus_size as u64);
                 });
-                monitor.display(event.name(), id);
+                monitor.display(client_stats_manager, event.name(), id);
                 Ok(BrokerEventResult::Forward)
             }
             Event::UpdateExecStats {
@@ -339,11 +348,11 @@ where
                 phantom: _,
             } => {
                 // TODO: The monitor buffer should be added on client add.
-                monitor.client_stats_insert(client_id);
+                client_stats_manager.client_stats_insert(client_id);
-                monitor.update_client_stats_for(client_id, |client| {
+                client_stats_manager.update_client_stats_for(client_id, |client| {
                     client.update_executions(*executions, *time);
                 });
-                monitor.display(event.name(), client_id);
+                monitor.display(client_stats_manager, event.name(), client_id);
                 Ok(BrokerEventResult::Handled)
             }
             Event::UpdateUserStats {
@@ -351,44 +360,44 @@ where
                 value,
                 phantom: _,
             } => {
-                monitor.client_stats_insert(client_id);
+                client_stats_manager.client_stats_insert(client_id);
-                monitor.update_client_stats_for(client_id, |client| {
+                client_stats_manager.update_client_stats_for(client_id, |client| {
                     client.update_user_stats(name.clone(), value.clone());
                 });
-                monitor.aggregate(name);
+                client_stats_manager.aggregate(name);
-                monitor.display(event.name(), client_id);
+                monitor.display(client_stats_manager, event.name(), client_id);
                 Ok(BrokerEventResult::Handled)
             }
             #[cfg(feature = "introspection")]
             Event::UpdatePerfMonitor {
                 time,
                 executions,
-                introspection_monitor,
+                introspection_stats,
                 phantom: _,
             } => {
                 // TODO: The monitor buffer should be added on client add.
 
                 // Get the client for the staterestorer ID
-                monitor.client_stats_insert(client_id);
+                client_stats_manager.client_stats_insert(client_id);
-                monitor.update_client_stats_for(client_id, |client| {
+                client_stats_manager.update_client_stats_for(client_id, |client| {
                     // Update the normal monitor for this client
                     client.update_executions(*executions, *time);
                     // Update the performance monitor for this client
-                    client.update_introspection_monitor((**introspection_monitor).clone());
+                    client.update_introspection_stats((**introspection_stats).clone());
                 });
 
                 // Display the monitor via `.display` only on core #1
-                monitor.display(event.name(), client_id);
+                monitor.display(client_stats_manager, event.name(), client_id);
 
                 // Correctly handled the event
                 Ok(BrokerEventResult::Handled)
             }
             Event::Objective { objective_size, .. } => {
-                monitor.client_stats_insert(client_id);
+                client_stats_manager.client_stats_insert(client_id);
-                monitor.update_client_stats_for(client_id, |client| {
+                client_stats_manager.update_client_stats_for(client_id, |client| {
                     client.update_objective_size(*objective_size as u64);
                 });
-                monitor.display(event.name(), client_id);
+                monitor.display(client_stats_manager, event.name(), client_id);
                 Ok(BrokerEventResult::Handled)
             }
             Event::Log {

libafl/src/feedbacks/map.rs

@@ -25,8 +25,8 @@ use crate::{
     events::{Event, EventFirer},
     executors::ExitKind,
     feedbacks::{Feedback, HasObserverHandle, StateInitializer},
-    monitors::{AggregatorOps, UserStats, UserStatsValue},
     observers::{CanTrack, MapObserver},
+    statistics::user_stats::{AggregatorOps, UserStats, UserStatsValue},
     Error, HasMetadata, HasNamedMetadata,
 };
 

libafl/src/feedbacks/mod.rs

@@ -115,7 +115,7 @@ pub trait Feedback<EM, I, OT, S>: StateInitializer<S> + Named {
 
         // Add this stat to the feedback metrics
         state
-            .introspection_monitor_mut()
+            .introspection_stats_mut()
             .update_feedback(self.name(), elapsed);
 
         ret

libafl/src/fuzzer/mod.rs

@@ -11,7 +11,7 @@ use libafl_bolts::{current_time, tuples::MatchName};
 use serde::{de::DeserializeOwned, Serialize};
 
 #[cfg(feature = "introspection")]
-use crate::monitors::PerfFeature;
+use crate::statistics::perf_stats::PerfFeature;
 use crate::{
     corpus::{Corpus, CorpusId, HasCurrentCorpusId, HasTestcase, Testcase},
     events::{
@@ -855,7 +855,7 @@ where
     ) -> Result<CorpusId, Error> {
         // Init timer for scheduler
         #[cfg(feature = "introspection")]
-        state.introspection_monitor_mut().start_timer();
+        state.introspection_stats_mut().start_timer();
 
         // Get the next index from the scheduler
         let id = if let Some(id) = state.current_corpus_id()? {
@@ -868,24 +868,24 @@ where
 
         // Mark the elapsed time for the scheduler
         #[cfg(feature = "introspection")]
-        state.introspection_monitor_mut().mark_scheduler_time();
+        state.introspection_stats_mut().mark_scheduler_time();
 
         // Mark the elapsed time for the scheduler
         #[cfg(feature = "introspection")]
-        state.introspection_monitor_mut().reset_stage_index();
+        state.introspection_stats_mut().reset_stage_index();
 
         // Execute all stages
         stages.perform_all(self, executor, state, manager)?;
 
         // Init timer for manager
         #[cfg(feature = "introspection")]
-        state.introspection_monitor_mut().start_timer();
+        state.introspection_stats_mut().start_timer();
 
         self.process_events(state, executor, manager)?;
 
         // Mark the elapsed time for the manager
         #[cfg(feature = "introspection")]
-        state.introspection_monitor_mut().mark_manager_time();
+        state.introspection_stats_mut().mark_manager_time();
 
         {
             if let Ok(mut testcase) = state.testcase_mut(id) {

libafl/src/lib.rs

@@ -79,6 +79,7 @@ pub mod observers;
 pub mod schedulers;
 pub mod stages;
 pub mod state;
+pub mod statistics;
 
 pub use fuzzer::*;
 pub use libafl_bolts::{nonzero, Error};
@@ -90,7 +91,8 @@ pub mod prelude {
 
     pub use super::{
         corpus::*, events::*, executors::*, feedbacks::*, fuzzer::*, generators::*, inputs::*,
-        monitors::*, mutators::*, observers::*, schedulers::*, stages::*, state::*, *,
+        monitors::*, mutators::*, observers::*, schedulers::*, stages::*, state::*, statistics::*,
+        *,
     };
 }
 

libafl/src/monitors/disk.rs

@@ -1,6 +1,6 @@
 //! Monitors that wrap a base monitor and also log to disk using different formats like `JSON` and `TOML`.
 
-use alloc::{string::String, vec::Vec};
+use alloc::string::String;
 use core::time::Duration;
 use std::{
     fs::{File, OpenOptions},
@@ -11,7 +11,10 @@ use std::{
 use libafl_bolts::{current_time, format_duration_hms, ClientId};
 use serde_json::json;
 
-use crate::monitors::{ClientStats, Monitor, NopMonitor};
+use crate::{
+    monitors::{Monitor, NopMonitor},
+    statistics::manager::ClientStatsManager,
+};
 
 /// Wrap a monitor and log the current state of the monitor into a Toml file.
 #[derive(Debug, Clone)]
@@ -29,16 +32,6 @@ impl<M> Monitor for OnDiskTomlMonitor<M>
 where
     M: Monitor,
 {
-    /// The client monitor, mutable
-    fn client_stats_mut(&mut self) -> &mut Vec<ClientStats> {
-        self.base.client_stats_mut()
-    }
-
-    /// The client monitor
-    fn client_stats(&self) -> &[ClientStats] {
-        self.base.client_stats()
-    }
-
     /// Time this fuzzing run stated
     fn start_time(&self) -> Duration {
         self.base.start_time()
@@ -49,11 +42,12 @@ where
         self.base.set_start_time(time);
     }
 
-    fn aggregate(&mut self, name: &str) {
+    fn display(
-        self.base.aggregate(name);
+        &mut self,
-    }
+        client_stats_manager: &mut ClientStatsManager,
-
+        event_msg: &str,
-    fn display(&mut self, event_msg: &str, sender_id: ClientId) {
+        sender_id: ClientId,
+    ) {
         let cur_time = current_time();
 
         if cur_time - self.last_update >= self.update_interval {
@@ -73,21 +67,22 @@ executions = {}
 exec_sec = {}
 ",
                 format_duration_hms(&(cur_time - self.start_time())),
-                self.client_stats_count(),
+                client_stats_manager.client_stats_count(),
-                self.corpus_size(),
+                client_stats_manager.corpus_size(),
-                self.objective_size(),
+                client_stats_manager.objective_size(),
-                self.total_execs(),
+                client_stats_manager.total_execs(),
-                self.execs_per_sec()
+                client_stats_manager.execs_per_sec()
             )
             .expect("Failed to write to the Toml file");
 
-            for i in 0..(self.client_stats().len()) {
+            for i in 0..(client_stats_manager.client_stats().len()) {
                 let client_id = ClientId(i as u32);
-                let exec_sec = self.update_client_stats_for(client_id, |client_stat| {
+                let exec_sec = client_stats_manager
-                    client_stat.execs_per_sec(cur_time)
+                    .update_client_stats_for(client_id, |client_stat| {
-                });
+                        client_stat.execs_per_sec(cur_time)
+                    });
 
-                let client = self.client_stats_for(client_id);
+                let client = client_stats_manager.client_stats_for(client_id);
 
                 write!(
                     &mut file,
@@ -102,7 +97,7 @@ exec_sec = {}
                 )
                 .expect("Failed to write to the Toml file");
 
-                for (key, val) in &client.user_monitor {
+                for (key, val) in &client.user_stats {
                     let k: String = key
                         .chars()
                         .map(|c| if c.is_whitespace() { '_' } else { c })
@@ -116,7 +111,8 @@ exec_sec = {}
             drop(file);
         }
 
-        self.base.display(event_msg, sender_id);
+        self.base
+            .display(client_stats_manager, event_msg, sender_id);
     }
 }
 
@@ -197,14 +193,6 @@ where
     F: FnMut(&mut M) -> bool,
     M: Monitor,
 {
-    fn client_stats_mut(&mut self) -> &mut Vec<ClientStats> {
-        self.base.client_stats_mut()
-    }
-
-    fn client_stats(&self) -> &[ClientStats] {
-        self.base.client_stats()
-    }
-
     fn start_time(&self) -> Duration {
         self.base.start_time()
     }
@@ -213,7 +201,12 @@ where
         self.base.set_start_time(time);
     }
 
-    fn display(&mut self, event_msg: &str, sender_id: ClientId) {
+    fn display(
+        &mut self,
+        client_stats_manager: &mut ClientStatsManager,
+        event_msg: &str,
+        sender_id: ClientId,
+    ) {
         if (self.log_record)(&mut self.base) {
             let file = OpenOptions::new()
                 .append(true)
@@ -223,15 +216,16 @@ where
 
             let line = json!({
                 "run_time": current_time() - self.base.start_time(),
-                "clients": self.client_stats_count(),
+                "clients": client_stats_manager.client_stats_count(),
-                "corpus": self.base.corpus_size(),
+                "corpus": client_stats_manager.corpus_size(),
-                "objectives": self.base.objective_size(),
+                "objectives": client_stats_manager.objective_size(),
-                "executions": self.base.total_execs(),
+                "executions": client_stats_manager.total_execs(),
-                "exec_sec": self.base.execs_per_sec(),
+                "exec_sec": client_stats_manager.execs_per_sec(),
-                "client_stats": self.client_stats(),
+                "client_stats": client_stats_manager.client_stats(),
             });
             writeln!(&file, "{line}").expect("Unable to write Json to file");
         }
-        self.base.display(event_msg, sender_id);
+        self.base
+            .display(client_stats_manager, event_msg, sender_id);
     }
 }

libafl/src/monitors/disk_aggregate.rs

@@ -1,6 +1,5 @@
 //! Monitors that log aggregated stats to disk.
 
-use alloc::vec::Vec;
 use core::{
     fmt::{Debug, Formatter},
     time::Duration,
@@ -10,13 +9,12 @@ use std::{fs::OpenOptions, io::Write, path::PathBuf};
 use libafl_bolts::{current_time, ClientId};
 use serde_json::json;
 
-use crate::monitors::{Aggregator, ClientStats, Monitor};
+use crate::{monitors::Monitor, statistics::manager::ClientStatsManager};
 
 /// A monitor that wraps another monitor and logs aggregated stats to a JSON file.
 #[derive(Clone)]
 pub struct OnDiskJsonAggregateMonitor<M> {
     base: M,
-    aggregator: Aggregator,
     json_path: PathBuf,
     last_update: Duration,
     update_interval: Duration,
@@ -40,14 +38,6 @@ impl<M> Monitor for OnDiskJsonAggregateMonitor<M>
 where
     M: Monitor,
 {
-    fn client_stats_mut(&mut self) -> &mut Vec<ClientStats> {
-        self.base.client_stats_mut()
-    }
-
-    fn client_stats(&self) -> &[ClientStats] {
-        self.base.client_stats()
-    }
-
     fn set_start_time(&mut self, time: Duration) {
         self.base.set_start_time(time);
     }
@@ -56,14 +46,15 @@ where
         self.base.start_time()
     }
 
-    fn aggregate(&mut self, name: &str) {
+    fn display(
-        self.aggregator.aggregate(name, self.base.client_stats());
+        &mut self,
-        self.base.aggregate(name);
+        client_stats_manager: &mut ClientStatsManager,
-    }
+        event_msg: &str,
-
+        sender_id: ClientId,
-    fn display(&mut self, event_msg: &str, sender_id: ClientId) {
+    ) {
         // First let the base monitor handle its display
-        self.base.display(event_msg, sender_id);
+        self.base
+            .display(client_stats_manager, event_msg, sender_id);
 
         // Write JSON stats if update interval has elapsed
         let cur_time = current_time();
@@ -78,18 +69,18 @@ where
 
             let mut json_value = json!({
                 "run_time": (cur_time - self.start_time()).as_secs(),
-                "clients": self.client_stats_count(),
+                "clients": client_stats_manager.client_stats_count(),
-                "corpus": self.corpus_size(),
+                "corpus": client_stats_manager.corpus_size(),
-                "objectives": self.objective_size(),
+                "objectives": client_stats_manager.objective_size(),
-                "executions": self.total_execs(),
+                "executions": client_stats_manager.total_execs(),
-                "exec_sec": self.execs_per_sec(),
+                "exec_sec": client_stats_manager.execs_per_sec(),
             });
 
             // Add all aggregated values directly to the root
             if let Some(obj) = json_value.as_object_mut() {
                 obj.extend(
-                    self.aggregator
+                    client_stats_manager
-                        .aggregated
+                        .aggregated()
                         .iter()
                         .map(|(k, v)| (k.clone(), json!(v))),
                 );
@@ -116,7 +107,6 @@ impl<M> OnDiskJsonAggregateMonitor<M> {
     {
         Self {
             base,
-            aggregator: Aggregator::new(),
             json_path: json_path.into(),
             last_update: current_time() - update_interval,
             update_interval,

libafl/src/monitors/multi.rs

@@ -1,6 +1,6 @@
 //! The [`MultiMonitor`] displays both cumulative and per-client stats.
 
-use alloc::{string::String, vec::Vec};
+use alloc::string::String;
 use core::{
     fmt::{Debug, Formatter, Write},
     time::Duration,
@@ -8,8 +8,7 @@ use core::{
 
 use libafl_bolts::{current_time, format_duration_hms, ClientId};
 
-use super::Aggregator;
+use crate::{monitors::Monitor, statistics::manager::ClientStatsManager};
-use crate::monitors::{ClientStats, Monitor};
 
 /// Tracking monitor during fuzzing and display both per-client and cumulative info.
 #[derive(Clone)]
@@ -19,8 +18,6 @@ where
 {
     print_fn: F,
     start_time: Duration,
-    client_stats: Vec<ClientStats>,
-    aggregator: Aggregator,
 }
 
 impl<F> Debug for MultiMonitor<F>
@@ -30,7 +27,6 @@ where
     fn fmt(&self, f: &mut Formatter<'_>) -> core::fmt::Result {
         f.debug_struct("MultiMonitor")
             .field("start_time", &self.start_time)
-            .field("client_stats", &self.client_stats)
             .finish_non_exhaustive()
     }
 }
@@ -39,16 +35,6 @@ impl<F> Monitor for MultiMonitor<F>
 where
     F: FnMut(&str),
 {
-    /// the client monitor, mutable
-    fn client_stats_mut(&mut self) -> &mut Vec<ClientStats> {
-        &mut self.client_stats
-    }
-
-    /// the client monitor
-    fn client_stats(&self) -> &[ClientStats] {
-        &self.client_stats
-    }
-
     /// Set creation time
     fn set_start_time(&mut self, time: Duration) {
         self.start_time = time;
@@ -59,11 +45,12 @@ where
         self.start_time
     }
 
-    fn aggregate(&mut self, name: &str) {
+    fn display(
-        self.aggregator.aggregate(name, &self.client_stats);
+        &mut self,
-    }
+        client_stats_manager: &mut ClientStatsManager,
-
+        event_msg: &str,
-    fn display(&mut self, event_msg: &str, sender_id: ClientId) {
+        sender_id: ClientId,
+    ) {
         let sender = format!("#{}", sender_id.0);
         let pad = if event_msg.len() + sender.len() < 13 {
             " ".repeat(13 - event_msg.len() - sender.len())
@@ -75,30 +62,30 @@ where
             "[{}]  (GLOBAL) run time: {}, clients: {}, corpus: {}, objectives: {}, executions: {}, exec/sec: {}",
             head,
             format_duration_hms(&(current_time() - self.start_time)),
-            self.client_stats_count(),
+            client_stats_manager.client_stats_count(),
-            self.corpus_size(),
+            client_stats_manager.corpus_size(),
-            self.objective_size(),
+            client_stats_manager.objective_size(),
-            self.total_execs(),
+            client_stats_manager.total_execs(),
-            self.execs_per_sec_pretty()
+            client_stats_manager.execs_per_sec_pretty()
         );
-        for (key, val) in &self.aggregator.aggregated {
+        for (key, val) in client_stats_manager.aggregated() {
             write!(global_fmt, ", {key}: {val}").unwrap();
         }
 
         (self.print_fn)(&global_fmt);
 
-        self.client_stats_insert(sender_id);
+        client_stats_manager.client_stats_insert(sender_id);
         let cur_time = current_time();
-        let exec_sec =
+        let exec_sec = client_stats_manager
-            self.update_client_stats_for(sender_id, |client| client.execs_per_sec_pretty(cur_time));
+            .update_client_stats_for(sender_id, |client| client.execs_per_sec_pretty(cur_time));
-        let client = self.client_stats_for(sender_id);
+        let client = client_stats_manager.client_stats_for(sender_id);
 
         let pad = " ".repeat(head.len());
         let mut fmt = format!(
             " {}   (CLIENT) corpus: {}, objectives: {}, executions: {}, exec/sec: {}",
             pad, client.corpus_size, client.objective_size, client.executions, exec_sec
         );
-        for (key, val) in &client.user_monitor {
+        for (key, val) in &client.user_stats {
             write!(fmt, ", {key}: {val}").unwrap();
         }
         (self.print_fn)(&fmt);
@@ -107,8 +94,13 @@ where
         #[cfg(feature = "introspection")]
         {
             // Print the client performance monitor. Skip the Client 0 which is the broker
-            for (i, client) in self.client_stats.iter().filter(|x| x.enabled).enumerate() {
+            for (i, client) in client_stats_manager
-                let fmt = format!("Client {:03}:\n{}", i + 1, client.introspection_monitor);
+                .client_stats()
+                .iter()
+                .filter(|x| x.enabled)
+                .enumerate()
+            {
+                let fmt = format!("Client {:03}:\n{}", i + 1, client.introspection_stats);
                 (self.print_fn)(&fmt);
             }
 
@@ -127,8 +119,6 @@ where
         Self {
             print_fn,
             start_time: current_time(),
-            client_stats: vec![],
-            aggregator: Aggregator::new(),
         }
     }
 
@@ -137,8 +127,6 @@ where
         Self {
             print_fn,
             start_time,
-            client_stats: vec![],
-            aggregator: Aggregator::new(),
         }
     }
 }

libafl/src/monitors/prometheus.rs

@@ -27,7 +27,7 @@
 //!
 //! When using docker, you may need to point `prometheus.yml` to the `docker0` interface or `host.docker.internal`
 
-use alloc::{borrow::Cow, fmt::Debug, string::String, vec::Vec};
+use alloc::{borrow::Cow, fmt::Debug, string::String};
 use core::{fmt, fmt::Write, time::Duration};
 use std::{
     string::ToString,
@@ -47,8 +47,10 @@ use prometheus_client::{
 // using tide for the HTTP server library (fast, async, simple)
 use tide::Request;
 
-use super::Aggregator;
+use crate::{
-use crate::monitors::{ClientStats, Monitor, UserStatsValue};
+    monitors::Monitor,
+    statistics::{manager::ClientStatsManager, user_stats::UserStatsValue},
+};
 
 /// Prometheus metrics for global and each client.
 #[derive(Clone, Debug, Default)]
@@ -72,8 +74,6 @@ where
     start_time: Duration,
     prometheus_global_stats: PrometheusStats, // global prometheus metrics
     prometheus_client_stats: PrometheusStats, // per-client prometheus metrics
-    client_stats: Vec<ClientStats>,           // per-client statistics
-    aggregator: Aggregator,                   // aggregator for global custom statistics
 }
 
 impl<F> Debug for PrometheusMonitor<F>
@@ -83,7 +83,6 @@ where
     fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
         f.debug_struct("PrometheusMonitor")
             .field("start_time", &self.start_time)
-            .field("client_stats", &self.client_stats)
             .finish_non_exhaustive()
     }
 }
@@ -92,16 +91,6 @@ impl<F> Monitor for PrometheusMonitor<F>
 where
     F: FnMut(&str),
 {
-    /// the client monitor, mutable
-    fn client_stats_mut(&mut self) -> &mut Vec<ClientStats> {
-        &mut self.client_stats
-    }
-
-    /// the client monitor
-    fn client_stats(&self) -> &[ClientStats] {
-        &self.client_stats
-    }
-
     /// Time this fuzzing run stated
     fn start_time(&self) -> Duration {
         self.start_time
@@ -112,12 +101,12 @@ where
         self.start_time = time;
     }
 
-    /// aggregate client stats
+    fn display(
-    fn aggregate(&mut self, name: &str) {
+        &mut self,
-        self.aggregator.aggregate(name, &self.client_stats);
+        client_stats_manager: &mut ClientStatsManager,
-    }
+        event_msg: &str,
-
+        sender_id: ClientId,
-    fn display(&mut self, event_msg: &str, sender_id: ClientId) {
+    ) {
         // Update the prometheus metrics
         // The gauges must take signed i64's, with max value of 2^63-1 so it is
         // probably fair to error out at a count of nine quintillion across any
@@ -127,7 +116,7 @@ where
         // time since last observation"
 
         // Global (aggregated) metrics
-        let corpus_size = self.corpus_size();
+        let corpus_size = client_stats_manager.corpus_size();
         self.prometheus_global_stats
             .corpus_count
             .get_or_create(&Labels {
@@ -136,7 +125,7 @@ where
             })
             .set(corpus_size.try_into().unwrap());
 
-        let objective_size = self.objective_size();
+        let objective_size = client_stats_manager.objective_size();
         self.prometheus_global_stats
             .objective_count
             .get_or_create(&Labels {
@@ -145,7 +134,7 @@ where
             })
             .set(objective_size.try_into().unwrap());
 
-        let total_execs = self.total_execs();
+        let total_execs = client_stats_manager.total_execs();
         self.prometheus_global_stats
             .executions
             .get_or_create(&Labels {
@@ -154,7 +143,7 @@ where
             })
             .set(total_execs.try_into().unwrap());
 
-        let execs_per_sec = self.execs_per_sec();
+        let execs_per_sec = client_stats_manager.execs_per_sec();
         self.prometheus_global_stats
             .exec_rate
             .get_or_create(&Labels {
@@ -172,7 +161,10 @@ where
             })
             .set(run_time.try_into().unwrap()); // run time in seconds, which can be converted to a time format by Grafana or similar
 
-        let total_clients = self.client_stats_count().try_into().unwrap(); // convert usize to u64 (unlikely that # of clients will be > 2^64 -1...)
+        let total_clients = client_stats_manager
+            .client_stats_count()
+            .try_into()
+            .unwrap(); // convert usize to u64 (unlikely that # of clients will be > 2^64 -1...)
         self.prometheus_global_stats
             .clients_count
             .get_or_create(&Labels {
@@ -186,13 +178,13 @@ where
             "[Prometheus] [{} #GLOBAL] run time: {}, clients: {}, corpus: {}, objectives: {}, executions: {}, exec/sec: {}",
             event_msg,
             format_duration_hms(&(current_time() - self.start_time)),
-            self.client_stats_count(),
+            client_stats_manager.client_stats_count(),
-            self.corpus_size(),
+            client_stats_manager.corpus_size(),
-            self.objective_size(),
+            client_stats_manager.objective_size(),
-            self.total_execs(),
+            client_stats_manager.total_execs(),
-            self.execs_per_sec_pretty()
+            client_stats_manager.execs_per_sec_pretty()
         );
-        for (key, val) in &self.aggregator.aggregated {
+        for (key, val) in client_stats_manager.aggregated() {
             // print global aggregated custom stats
             write!(global_fmt, ", {key}: {val}").unwrap();
             #[expect(clippy::cast_precision_loss)]
@@ -234,8 +226,8 @@ where
 
         // Client-specific metrics
 
-        self.client_stats_insert(sender_id);
+        client_stats_manager.client_stats_insert(sender_id);
-        let client = self.client_stats_for(sender_id);
+        let client = client_stats_manager.client_stats_for(sender_id);
         let mut cur_client_clone = client.clone();
 
         self.prometheus_client_stats
@@ -297,7 +289,7 @@ where
             cur_client_clone.execs_per_sec_pretty(current_time())
         );
 
-        for (key, val) in cur_client_clone.user_monitor {
+        for (key, val) in cur_client_clone.user_stats {
             // print the custom stats for each client
             write!(fmt, ", {key}: {val}").unwrap();
             // Update metrics added to the user_stats hashmap by feedback event-fires
@@ -352,7 +344,6 @@ where
         let prometheus_global_stats_clone = prometheus_global_stats.clone();
         let prometheus_client_stats = PrometheusStats::default();
         let prometheus_client_stats_clone = prometheus_client_stats.clone();
-        let client_stats = Vec::<ClientStats>::default();
 
         // Need to run the metrics server in a different thread to avoid blocking
         thread::spawn(move || {
@@ -369,8 +360,6 @@ where
             start_time: current_time(),
             prometheus_global_stats,
             prometheus_client_stats,
-            client_stats,
-            aggregator: Aggregator::new(),
         }
     }
     /// Creates the monitor with a given `start_time`.
@@ -379,7 +368,6 @@ where
         let prometheus_global_stats_clone = prometheus_global_stats.clone();
         let prometheus_client_stats = PrometheusStats::default();
         let prometheus_client_stats_clone = prometheus_client_stats.clone();
-        let client_stats = Vec::<ClientStats>::default();
 
         thread::spawn(move || {
             block_on(serve_metrics(
@@ -395,8 +383,6 @@ where
             start_time,
             prometheus_global_stats,
             prometheus_client_stats,
-            client_stats,
-            aggregator: Aggregator::new(),
         }
     }
 }

libafl/src/monitors/tui/mod.rs

@@ -29,8 +29,15 @@ use serde_json::Value;
 use typed_builder::TypedBuilder;
 
 #[cfg(feature = "introspection")]
-use super::{ClientPerfMonitor, PerfFeature};
+use crate::statistics::perf_stats::{ClientPerfStats, PerfFeature};
-use crate::monitors::{Aggregator, AggregatorOps, ClientStats, Monitor, UserStats, UserStatsValue};
+use crate::{
+    monitors::Monitor,
+    statistics::{
+        manager::ClientStatsManager,
+        user_stats::{AggregatorOps, UserStats, UserStatsValue},
+        ClientStats,
+    },
+};
 
 #[expect(missing_docs)]
 pub mod ui;
@@ -144,7 +151,7 @@ pub struct PerfTuiContext {
 impl PerfTuiContext {
     /// Get the data for performance metrics
     #[expect(clippy::cast_precision_loss)]
-    pub fn grab_data(&mut self, m: &ClientPerfMonitor) {
+    pub fn grab_data(&mut self, m: &ClientPerfStats) {
         // Calculate the elapsed time from the monitor
         let elapsed: f64 = m.elapsed_cycles() as f64;
 
@@ -315,7 +322,7 @@ impl ClientTuiContext {
             .map_or("0%".to_string(), ToString::to_string);
         self.item_geometry.stability = stability;
 
-        for (key, val) in &client.user_monitor {
+        for (key, val) in &client.user_stats {
             self.user_stats.insert(key.clone(), val.clone());
         }
     }
@@ -388,8 +395,6 @@ pub struct TuiMonitor {
     pub(crate) context: Arc<RwLock<TuiContext>>,
 
     start_time: Duration,
-    client_stats: Vec<ClientStats>,
-    aggregator: Aggregator,
 }
 
 impl From<TuiMonitorConfig> for TuiMonitor {
@@ -403,20 +408,6 @@ impl From<TuiMonitorConfig> for TuiMonitor {
 }
 
 impl Monitor for TuiMonitor {
-    /// The client monitor, mutable
-    /// This also includes disabled "padding" clients.
-    /// Results should be filtered by `.enabled`.
-    fn client_stats_mut(&mut self) -> &mut Vec<ClientStats> {
-        &mut self.client_stats
-    }
-
-    /// The client monitor
-    /// This also includes disabled "padding" clients.
-    /// Results should be filtered by `.enabled`.
-    fn client_stats(&self) -> &[ClientStats] {
-        &self.client_stats
-    }
-
     /// Time this fuzzing run stated
     fn start_time(&self) -> Duration {
         self.start_time
@@ -428,35 +419,41 @@ impl Monitor for TuiMonitor {
     }
 
     #[expect(clippy::cast_sign_loss)]
-    fn display(&mut self, event_msg: &str, sender_id: ClientId) {
+    fn display(
+        &mut self,
+        client_stats_manager: &mut ClientStatsManager,
+        event_msg: &str,
+        sender_id: ClientId,
+    ) {
         let cur_time = current_time();
 
         {
             // TODO implement floating-point support for TimedStat
-            let execsec = self.execs_per_sec() as u64;
+            let execsec = client_stats_manager.execs_per_sec() as u64;
-            let totalexec = self.total_execs();
+            let totalexec = client_stats_manager.total_execs();
             let run_time = cur_time - self.start_time;
-            let total_process_timing = self.process_timing();
+            let total_process_timing = self.process_timing(client_stats_manager);
 
             let mut ctx = self.context.write().unwrap();
             ctx.total_process_timing = total_process_timing;
-            ctx.corpus_size_timed.add(run_time, self.corpus_size());
+            ctx.corpus_size_timed
+                .add(run_time, client_stats_manager.corpus_size());
             ctx.objective_size_timed
-                .add(run_time, self.objective_size());
+                .add(run_time, client_stats_manager.objective_size());
             ctx.execs_per_sec_timed.add(run_time, execsec);
             ctx.total_execs = totalexec;
-            ctx.clients_num = self.client_stats.len();
+            ctx.clients_num = client_stats_manager.client_stats().len();
-            ctx.total_map_density = self.map_density();
+            ctx.total_map_density = get_map_density(client_stats_manager);
-            ctx.total_solutions = self.objective_size();
+            ctx.total_solutions = client_stats_manager.objective_size();
             ctx.total_cycles_done = 0;
-            ctx.total_corpus_count = self.corpus_size();
+            ctx.total_corpus_count = client_stats_manager.corpus_size();
-            ctx.total_item_geometry = self.item_geometry();
+            ctx.total_item_geometry = get_item_geometry(client_stats_manager);
         }
 
-        self.client_stats_insert(sender_id);
+        client_stats_manager.client_stats_insert(sender_id);
-        let exec_sec =
+        let exec_sec = client_stats_manager
-            self.update_client_stats_for(sender_id, |client| client.execs_per_sec_pretty(cur_time));
+            .update_client_stats_for(sender_id, |client| client.execs_per_sec_pretty(cur_time));
-        let client = self.client_stats_for(sender_id);
+        let client = client_stats_manager.client_stats_for(sender_id);
 
         let sender = format!("#{}", sender_id.0);
         let pad = if event_msg.len() + sender.len() < 13 {
@@ -469,15 +466,15 @@ impl Monitor for TuiMonitor {
             "[{}] corpus: {}, objectives: {}, executions: {}, exec/sec: {}",
             head, client.corpus_size, client.objective_size, client.executions, exec_sec
         );
-        for (key, val) in &client.user_monitor {
+        for (key, val) in &client.user_stats {
             write!(fmt, ", {key}: {val}").unwrap();
         }
-        for (key, val) in &self.aggregator.aggregated {
+        for (key, val) in client_stats_manager.aggregated() {
             write!(fmt, ", {key}: {val}").unwrap();
         }
 
         {
-            let client = &self.client_stats()[sender_id.0 as usize];
+            let client = &client_stats_manager.client_stats()[sender_id.0 as usize];
             let mut ctx = self.context.write().unwrap();
             ctx.clients
                 .entry(sender_id.0 as usize)
@@ -492,21 +489,22 @@ impl Monitor for TuiMonitor {
         #[cfg(feature = "introspection")]
         {
             // Print the client performance monitor. Skip the Client IDs that have never sent anything.
-            for (i, client) in self.client_stats.iter().filter(|x| x.enabled).enumerate() {
+            for (i, client) in client_stats_manager
+                .client_stats()
+                .iter()
+                .filter(|x| x.enabled)
+                .enumerate()
+            {
                 self.context
                     .write()
                     .unwrap()
                     .introspection
                     .entry(i + 1)
                     .or_default()
-                    .grab_data(&client.introspection_monitor);
+                    .grab_data(&client.introspection_stats);
             }
         }
     }
-
-    fn aggregate(&mut self, name: &str) {
-        self.aggregator.aggregate(name, &self.client_stats);
-    }
 }
 
 impl TuiMonitor {
@@ -570,71 +568,20 @@ impl TuiMonitor {
         Self {
             context,
             start_time,
-            client_stats: vec![],
-            aggregator: Aggregator::new(),
         }
     }
 
-    fn map_density(&self) -> String {
+    fn process_timing(&self, client_stats_manager: &mut ClientStatsManager) -> ProcessTiming {
-        self.client_stats()
-            .iter()
-            .filter(|client| client.enabled)
-            .filter_map(|client| client.get_user_stats("edges"))
-            .map(ToString::to_string)
-            .fold("0%".to_string(), cmp::max)
-    }
-
-    fn item_geometry(&self) -> ItemGeometry {
-        let mut total_item_geometry = ItemGeometry::new();
-        if self.client_stats.len() < 2 {
-            return total_item_geometry;
-        }
-        let mut ratio_a: u64 = 0;
-        let mut ratio_b: u64 = 0;
-        for client in self.client_stats().iter().filter(|client| client.enabled) {
-            let afl_stats = client
-                .get_user_stats("AflStats")
-                .map_or("None".to_string(), ToString::to_string);
-            let stability = client.get_user_stats("stability").map_or(
-                UserStats::new(UserStatsValue::Ratio(0, 100), AggregatorOps::Avg),
-                Clone::clone,
-            );
-
-            if afl_stats != "None" {
-                let default_json = serde_json::json!({
-                    "pending": 0,
-                    "pend_fav": 0,
-                    "imported": 0,
-                    "own_finds": 0,
-                });
-                let afl_stats_json: Value =
-                    serde_json::from_str(afl_stats.as_str()).unwrap_or(default_json);
-                total_item_geometry.pending +=
-                    afl_stats_json["pending"].as_u64().unwrap_or_default();
-                total_item_geometry.pend_fav +=
-                    afl_stats_json["pend_fav"].as_u64().unwrap_or_default();
-                total_item_geometry.own_finds +=
-                    afl_stats_json["own_finds"].as_u64().unwrap_or_default();
-                total_item_geometry.imported +=
-                    afl_stats_json["imported"].as_u64().unwrap_or_default();
-            }
-
-            if let UserStatsValue::Ratio(a, b) = stability.value() {
-                ratio_a += a;
-                ratio_b += b;
-            }
-        }
-        total_item_geometry.stability = format!("{}%", ratio_a * 100 / ratio_b);
-        total_item_geometry
-    }
-
-    fn process_timing(&mut self) -> ProcessTiming {
         let mut total_process_timing = ProcessTiming::new();
-        total_process_timing.exec_speed = self.execs_per_sec_pretty();
+        total_process_timing.exec_speed = client_stats_manager.execs_per_sec_pretty();
-        if self.client_stats.len() > 1 {
+        if client_stats_manager.client_stats().len() > 1 {
             let mut new_path_time = Duration::default();
             let mut new_objectives_time = Duration::default();
-            for client in self.client_stats().iter().filter(|client| client.enabled) {
+            for client in client_stats_manager
+                .client_stats()
+                .iter()
+                .filter(|client| client.enabled)
+            {
                 new_path_time = client.last_corpus_time.max(new_path_time);
                 new_objectives_time = client.last_objective_time.max(new_objectives_time);
             }
@@ -649,6 +596,61 @@ impl TuiMonitor {
     }
 }
 
+fn get_map_density(client_stats_manager: &ClientStatsManager) -> String {
+    client_stats_manager
+        .client_stats()
+        .iter()
+        .filter(|client| client.enabled)
+        .filter_map(|client| client.get_user_stats("edges"))
+        .map(ToString::to_string)
+        .fold("0%".to_string(), cmp::max)
+}
+
+fn get_item_geometry(client_stats_manager: &ClientStatsManager) -> ItemGeometry {
+    let mut total_item_geometry = ItemGeometry::new();
+    if client_stats_manager.client_stats().len() < 2 {
+        return total_item_geometry;
+    }
+    let mut ratio_a: u64 = 0;
+    let mut ratio_b: u64 = 0;
+    for client in client_stats_manager
+        .client_stats()
+        .iter()
+        .filter(|client| client.enabled)
+    {
+        let afl_stats = client
+            .get_user_stats("AflStats")
+            .map_or("None".to_string(), ToString::to_string);
+        let stability = client.get_user_stats("stability").map_or(
+            UserStats::new(UserStatsValue::Ratio(0, 100), AggregatorOps::Avg),
+            Clone::clone,
+        );
+
+        if afl_stats != "None" {
+            let default_json = serde_json::json!({
+                "pending": 0,
+                "pend_fav": 0,
+                "imported": 0,
+                "own_finds": 0,
+            });
+            let afl_stats_json: Value =
+                serde_json::from_str(afl_stats.as_str()).unwrap_or(default_json);
+            total_item_geometry.pending += afl_stats_json["pending"].as_u64().unwrap_or_default();
+            total_item_geometry.pend_fav += afl_stats_json["pend_fav"].as_u64().unwrap_or_default();
+            total_item_geometry.own_finds +=
+                afl_stats_json["own_finds"].as_u64().unwrap_or_default();
+            total_item_geometry.imported += afl_stats_json["imported"].as_u64().unwrap_or_default();
+        }
+
+        if let UserStatsValue::Ratio(a, b) = stability.value() {
+            ratio_a += a;
+            ratio_b += b;
+        }
+    }
+    total_item_geometry.stability = format!("{}%", ratio_a * 100 / ratio_b);
+    total_item_geometry
+}
+
 fn run_tui_thread<W: Write + Send + Sync + 'static>(
     context: Arc<RwLock<TuiContext>>,
     tick_rate: Duration,

libafl/src/stages/afl_stats.rs

@@ -26,12 +26,12 @@ use crate::{
     corpus::{Corpus, HasCurrentCorpusId, SchedulerTestcaseMetadata, Testcase},
     events::{Event, EventFirer},
     executors::HasObservers,
-    monitors::{AggregatorOps, UserStats, UserStatsValue},
     mutators::Tokens,
     observers::MapObserver,
     schedulers::{minimizer::IsFavoredMetadata, HasQueueCycles},
     stages::{calibrate::UnstableEntriesMetadata, Stage},
     state::{HasCorpus, HasExecutions, HasImported, HasStartTime, Stoppable},
+    statistics::user_stats::{AggregatorOps, UserStats, UserStatsValue},
     std::string::ToString,
     Error, HasMetadata, HasNamedMetadata, HasScheduler,
 };

libafl/src/stages/calibrate.rs

@@ -19,11 +19,11 @@ use crate::{
     feedbacks::{map::MapFeedbackMetadata, HasObserverHandle},
     fuzzer::Evaluator,
     inputs::Input,
-    monitors::{AggregatorOps, UserStats, UserStatsValue},
     observers::{MapObserver, ObserversTuple},
     schedulers::powersched::SchedulerMetadata,
     stages::{RetryCountRestartHelper, Stage},
     state::{HasCorpus, HasCurrentTestcase, HasExecutions},
+    statistics::user_stats::{AggregatorOps, UserStats, UserStatsValue},
     Error, HasMetadata, HasNamedMetadata,
 };
 

libafl/src/stages/concolic.rs

@@ -13,7 +13,7 @@ use libafl_bolts::{
 };
 
 #[cfg(all(feature = "concolic_mutation", feature = "introspection"))]
-use crate::monitors::PerfFeature;
+use crate::statistics::perf_stats::PerfFeature;
 use crate::{
     corpus::HasCurrentCorpusId,
     executors::{Executor, HasObservers},

libafl/src/stages/generalization.rs

@@ -12,7 +12,7 @@ use libafl_bolts::{
 };
 
 #[cfg(feature = "introspection")]
-use crate::monitors::PerfFeature;
+use crate::statistics::perf_stats::PerfFeature;
 use crate::{
     corpus::{Corpus, HasCurrentCorpusId},
     executors::{Executor, HasObservers},

libafl/src/stages/mutational.rs

@@ -10,7 +10,7 @@ use core::{marker::PhantomData, num::NonZeroUsize};
 use libafl_bolts::{rands::Rand, Named};
 
 #[cfg(feature = "introspection")]
-use crate::monitors::PerfFeature;
+use crate::statistics::perf_stats::PerfFeature;
 use crate::{
     corpus::{Corpus, CorpusId, HasCurrentCorpusId, Testcase},
     fuzzer::Evaluator,
@@ -166,7 +166,7 @@ where
         let ret = self.perform_mutational(fuzzer, executor, state, manager);
 
         #[cfg(feature = "introspection")]
-        state.introspection_monitor_mut().finish_stage();
+        state.introspection_stats_mut().finish_stage();
 
         ret
     }

libafl/src/stages/power.rs

@@ -9,7 +9,7 @@ use core::{fmt::Debug, marker::PhantomData};
 use libafl_bolts::Named;
 
 #[cfg(feature = "introspection")]
-use crate::monitors::PerfFeature;
+use crate::statistics::perf_stats::PerfFeature;
 use crate::{
     corpus::HasCurrentCorpusId,
     executors::{Executor, HasObservers},

libafl/src/stages/push/mutational.rs

@@ -12,7 +12,7 @@ use serde::Serialize;
 
 use super::{PushStage, PushStageHelper, PushStageSharedState};
 #[cfg(feature = "introspection")]
-use crate::monitors::PerfFeature;
+use crate::statistics::perf_stats::PerfFeature;
 use crate::{
     corpus::{Corpus, CorpusId},
     events::{EventFirer, ProgressReporter},

libafl/src/stages/sync.rs

@@ -152,7 +152,7 @@ where
         }
 
         #[cfg(feature = "introspection")]
-        state.introspection_monitor_mut().finish_stage();
+        state.introspection_stats_mut().finish_stage();
 
         Ok(())
     }
@@ -315,7 +315,7 @@ where
 
         self.client.process(fuzzer, state, executor, manager)?;
         #[cfg(feature = "introspection")]
-        state.introspection_monitor_mut().finish_stage();
+        state.introspection_stats_mut().finish_stage();
         Ok(())
     }
 }

libafl/src/stages/tmin.rs

@@ -17,7 +17,7 @@ use serde::Serialize;
 #[cfg(feature = "track_hit_feedbacks")]
 use crate::feedbacks::premature_last_result_err;
 #[cfg(feature = "introspection")]
-use crate::monitors::PerfFeature;
+use crate::statistics::perf_stats::PerfFeature;
 use crate::{
     corpus::{Corpus, HasCurrentCorpusId, Testcase},
     events::EventFirer,
@@ -100,7 +100,7 @@ where
         self.perform_minification(fuzzer, executor, state, manager)?;
 
         #[cfg(feature = "introspection")]
-        state.introspection_monitor_mut().finish_stage();
+        state.introspection_stats_mut().finish_stage();
 
         Ok(())
     }

libafl/src/stages/tracing.rs

@@ -9,7 +9,7 @@ use core::{fmt::Debug, marker::PhantomData};
 use libafl_bolts::Named;
 
 #[cfg(feature = "introspection")]
-use crate::monitors::PerfFeature;
+use crate::statistics::perf_stats::PerfFeature;
 use crate::{
     corpus::HasCurrentCorpusId,
     executors::{Executor, HasObservers, ShadowExecutor},

libafl/src/stages/tuneable.rs

@@ -7,7 +7,7 @@ use libafl_bolts::{current_time, impl_serdeany, rands::Rand};
 use serde::{Deserialize, Serialize};
 
 #[cfg(feature = "introspection")]
-use crate::monitors::PerfFeature;
+use crate::statistics::perf_stats::PerfFeature;
 use crate::{
     mark_feature_time,
     mutators::{MutationResult, Mutator},
@@ -213,7 +213,7 @@ where
         let ret = self.perform_mutational(fuzzer, executor, state, manager);
 
         #[cfg(feature = "introspection")]
-        state.introspection_monitor_mut().finish_stage();
+        state.introspection_stats_mut().finish_stage();
 
         ret
     }

libafl/src/state/mod.rs

@@ -27,7 +27,7 @@ mod stack;
 pub use stack::StageStack;
 
 #[cfg(feature = "introspection")]
-use crate::monitors::ClientPerfMonitor;
+use crate::statistics::perf_stats::ClientPerfStats;
 use crate::{
     corpus::{Corpus, CorpusId, HasCurrentCorpusId, HasTestcase, InMemoryCorpus, Testcase},
     events::{Event, EventFirer, LogSeverity},
@@ -109,13 +109,13 @@ pub trait HasRand {
 }
 
 #[cfg(feature = "introspection")]
-/// Trait for offering a [`ClientPerfMonitor`]
+/// Trait for offering a [`ClientPerfStats`]
 pub trait HasClientPerfMonitor {
-    /// [`ClientPerfMonitor`] itself
+    /// [`ClientPerfStats`] itself
-    fn introspection_monitor(&self) -> &ClientPerfMonitor;
+    fn introspection_stats(&self) -> &ClientPerfStats;
 
-    /// Mutatable ref to [`ClientPerfMonitor`]
+    /// Mutatable ref to [`ClientPerfStats`]
-    fn introspection_monitor_mut(&mut self) -> &mut ClientPerfMonitor;
+    fn introspection_stats_mut(&mut self) -> &mut ClientPerfStats;
 }
 
 /// Intermediate trait for `HasClientPerfMonitor`
@@ -225,7 +225,7 @@ pub struct StdState<C, I, R, SC> {
     max_size: usize,
     /// Performance statistics for this fuzzer
     #[cfg(feature = "introspection")]
-    introspection_monitor: ClientPerfMonitor,
+    introspection_stats: ClientPerfStats,
     #[cfg(feature = "std")]
     /// Remaining initial inputs to load, if any
     remaining_initial_files: Option<Vec<PathBuf>>,
@@ -1104,7 +1104,7 @@ where
             max_size: DEFAULT_MAX_SIZE,
             stop_requested: false,
             #[cfg(feature = "introspection")]
-            introspection_monitor: ClientPerfMonitor::new(),
+            introspection_stats: ClientPerfStats::new(),
             #[cfg(feature = "std")]
             remaining_initial_files: None,
             #[cfg(feature = "std")]
@@ -1142,12 +1142,12 @@ impl StdState<InMemoryCorpus<NopInput>, NopInput, StdRand, InMemoryCorpus<NopInp
 
 #[cfg(feature = "introspection")]
 impl<C, I, R, SC> HasClientPerfMonitor for StdState<C, I, R, SC> {
-    fn introspection_monitor(&self) -> &ClientPerfMonitor {
+    fn introspection_stats(&self) -> &ClientPerfStats {
-        &self.introspection_monitor
+        &self.introspection_stats
     }
 
-    fn introspection_monitor_mut(&mut self) -> &mut ClientPerfMonitor {
+    fn introspection_stats_mut(&mut self) -> &mut ClientPerfStats {
-        &mut self.introspection_monitor
+        &mut self.introspection_stats
     }
 }
 
@@ -1295,11 +1295,11 @@ impl<I> HasCurrentStageId for NopState<I> {
 
 #[cfg(feature = "introspection")]
 impl<I> HasClientPerfMonitor for NopState<I> {
-    fn introspection_monitor(&self) -> &ClientPerfMonitor {
+    fn introspection_stats(&self) -> &ClientPerfStats {
         unimplemented!();
     }
 
-    fn introspection_monitor_mut(&mut self) -> &mut ClientPerfMonitor {
+    fn introspection_stats_mut(&mut self) -> &mut ClientPerfStats {
         unimplemented!();
     }
 }

libafl/src/statistics/manager.rs

@@ -0,0 +1,150 @@
+//! Client statistics manager
+
+use alloc::{string::String, vec::Vec};
+use core::time::Duration;
+
+use hashbrown::HashMap;
+use libafl_bolts::{current_time, ClientId};
+use serde::{Deserialize, Serialize};
+
+use super::{user_stats::UserStatsValue, ClientStats};
+
+/// Manager of all client's statistics
+#[derive(Serialize, Deserialize, Debug)]
+pub struct ClientStatsManager {
+    client_stats: Vec<ClientStats>,
+    /// Aggregated user stats value.
+    ///
+    /// This map is updated by event manager, and is read by monitors to display user-defined stats.
+    pub(super) cached_aggregated_user_stats: HashMap<String, UserStatsValue>,
+}
+
+impl ClientStatsManager {
+    /// Create a new client stats manager
+    #[must_use]
+    pub fn new() -> Self {
+        Self {
+            client_stats: vec![],
+            cached_aggregated_user_stats: HashMap::new(),
+        }
+    }
+
+    /// Get all client stats
+    #[must_use]
+    pub fn client_stats(&self) -> &[ClientStats] {
+        &self.client_stats
+    }
+
+    /// Get all client stats
+    pub fn client_stats_mut(&mut self) -> &mut Vec<ClientStats> {
+        &mut self.client_stats
+    }
+
+    /// Amount of elements in the corpus (combined for all children)
+    #[must_use]
+    pub fn corpus_size(&self) -> u64 {
+        self.client_stats()
+            .iter()
+            .fold(0_u64, |acc, x| acc + x.corpus_size)
+    }
+
+    /// Count the number of enabled client stats
+    #[must_use]
+    pub fn client_stats_count(&self) -> usize {
+        self.client_stats()
+            .iter()
+            .filter(|client| client.enabled)
+            .count()
+    }
+
+    /// Amount of elements in the objectives (combined for all children)
+    #[must_use]
+    pub fn objective_size(&self) -> u64 {
+        self.client_stats()
+            .iter()
+            .fold(0_u64, |acc, x| acc + x.objective_size)
+    }
+
+    /// Total executions
+    #[inline]
+    #[must_use]
+    pub fn total_execs(&self) -> u64 {
+        self.client_stats()
+            .iter()
+            .fold(0_u64, |acc, x| acc + x.executions)
+    }
+
+    /// Executions per second
+    #[inline]
+    pub fn execs_per_sec(&mut self) -> f64 {
+        let cur_time = current_time();
+        self.client_stats_mut()
+            .iter_mut()
+            .fold(0.0, |acc, x| acc + x.execs_per_sec(cur_time))
+    }
+
+    /// Executions per second
+    pub fn execs_per_sec_pretty(&mut self) -> String {
+        super::prettify_float(self.execs_per_sec())
+    }
+
+    /// The client monitor for a specific id, creating new if it doesn't exist
+    pub fn client_stats_insert(&mut self, client_id: ClientId) {
+        let total_client_stat_count = self.client_stats().len();
+        for _ in total_client_stat_count..=(client_id.0) as usize {
+            self.client_stats_mut().push(ClientStats {
+                enabled: false,
+                last_window_time: Duration::from_secs(0),
+                start_time: Duration::from_secs(0),
+                ..ClientStats::default()
+            });
+        }
+        self.update_client_stats_for(client_id, |new_stat| {
+            if !new_stat.enabled {
+                let timestamp = current_time();
+                // I have never seen this man in my life
+                new_stat.start_time = timestamp;
+                new_stat.last_window_time = timestamp;
+                new_stat.enabled = true;
+            }
+        });
+    }
+
+    /// Update sepecific client stats.
+    pub fn update_client_stats_for<T, F: FnOnce(&mut ClientStats) -> T>(
+        &mut self,
+        client_id: ClientId,
+        update: F,
+    ) -> T {
+        let client_stat = &mut self.client_stats_mut()[client_id.0 as usize];
+        update(client_stat)
+    }
+
+    /// Update all client stats. This will clear all previous client stats, and fill in the new client stats.
+    pub fn update_all_client_stats(&mut self, new_client_stats: Vec<ClientStats>) {
+        *self.client_stats_mut() = new_client_stats;
+    }
+
+    /// Get immutable reference to client stats
+    #[must_use]
+    pub fn client_stats_for(&self, client_id: ClientId) -> &ClientStats {
+        &self.client_stats()[client_id.0 as usize]
+    }
+
+    /// Aggregate user-defined stats
+    pub fn aggregate(&mut self, name: &str) {
+        super::user_stats::aggregate_user_stats(self, name);
+    }
+
+    /// Get aggregated user-defined stats
+    #[must_use]
+    pub fn aggregated(&self) -> &HashMap<String, UserStatsValue> {
+        &self.cached_aggregated_user_stats
+    }
+}
+
+impl Default for ClientStatsManager {
+    fn default() -> Self {
+        Self::new()
+    }
+}

libafl/src/statistics/mod.rs

@@ -0,0 +1,196 @@
+//! Statistics used for Monitors to display.
+
+pub mod manager;
+#[cfg(feature = "introspection")]
+pub mod perf_stats;
+pub mod user_stats;
+
+use alloc::{borrow::Cow, string::String};
+use core::time::Duration;
+
+use hashbrown::HashMap;
+use libafl_bolts::current_time;
+#[cfg(feature = "introspection")]
+use perf_stats::ClientPerfStats;
+use serde::{Deserialize, Serialize};
+use user_stats::UserStats;
+
+#[cfg(feature = "afl_exec_sec")]
+const CLIENT_STATS_TIME_WINDOW_SECS: u64 = 5; // 5 seconds
+
+/// A simple struct to keep track of client statistics
+#[derive(Debug, Clone, Default, Serialize, Deserialize)]
+pub struct ClientStats {
+    /// If this client is enabled. This is set to `true` the first time we see this client.
+    pub enabled: bool,
+    // monitor (maybe we need a separated struct?)
+    /// The corpus size for this client
+    pub corpus_size: u64,
+    /// The time for the last update of the corpus size
+    pub last_corpus_time: Duration,
+    /// The total executions for this client
+    pub executions: u64,
+    /// The number of executions of the previous state in case a client decrease the number of execution (e.g when restarting without saving the state)
+    pub prev_state_executions: u64,
+    /// The size of the objectives corpus for this client
+    pub objective_size: u64,
+    /// The time for the last update of the objective size
+    pub last_objective_time: Duration,
+    /// The last reported executions for this client
+    #[cfg(feature = "afl_exec_sec")]
+    pub last_window_executions: u64,
+    /// The last executions per sec
+    #[cfg(feature = "afl_exec_sec")]
+    pub last_execs_per_sec: f64,
+    /// The last time we got this information
+    pub last_window_time: Duration,
+    /// the start time of the client
+    pub start_time: Duration,
+    /// User-defined stats
+    pub user_stats: HashMap<Cow<'static, str>, UserStats>,
+    /// Client performance statistics
+    #[cfg(feature = "introspection")]
+    pub introspection_stats: ClientPerfStats,
+}
+
+impl ClientStats {
+    /// We got new information about executions for this client, insert them.
+    #[cfg(feature = "afl_exec_sec")]
+    pub fn update_executions(&mut self, executions: u64, cur_time: Duration) {
+        let diff = cur_time
+            .checked_sub(self.last_window_time)
+            .map_or(0, |d| d.as_secs());
+        if diff > CLIENT_STATS_TIME_WINDOW_SECS {
+            let _: f64 = self.execs_per_sec(cur_time);
+            self.last_window_time = cur_time;
+            self.last_window_executions = self.executions;
+        }
+        if self.executions > self.prev_state_executions + executions {
+            // Something is strange here, sum the executions
+            self.prev_state_executions = self.executions;
+        }
+        self.executions = self.prev_state_executions + executions;
+    }
+
+    /// We got a new information about executions for this client, insert them.
+    #[cfg(not(feature = "afl_exec_sec"))]
+    pub fn update_executions(&mut self, executions: u64, _cur_time: Duration) {
+        if self.executions > self.prev_state_executions + executions {
+            // Something is strange here, sum the executions
+            self.prev_state_executions = self.executions;
+        }
+        self.executions = self.prev_state_executions + executions;
+    }
+
+    /// We got new information about corpus size for this client, insert them.
+    pub fn update_corpus_size(&mut self, corpus_size: u64) {
+        self.corpus_size = corpus_size;
+        self.last_corpus_time = current_time();
+    }
+
+    /// We got a new information about objective corpus size for this client, insert them.
+    pub fn update_objective_size(&mut self, objective_size: u64) {
+        self.objective_size = objective_size;
+    }
+
+    /// Get the calculated executions per second for this client
+    #[expect(clippy::cast_precision_loss, clippy::cast_sign_loss)]
+    #[cfg(feature = "afl_exec_sec")]
+    pub fn execs_per_sec(&mut self, cur_time: Duration) -> f64 {
+        if self.executions == 0 {
+            return 0.0;
+        }
+
+        let elapsed = cur_time
+            .checked_sub(self.last_window_time)
+            .map_or(0.0, |d| d.as_secs_f64());
+        if elapsed as u64 == 0 {
+            return self.last_execs_per_sec;
+        }
+
+        let cur_avg = ((self.executions - self.last_window_executions) as f64) / elapsed;
+        if self.last_window_executions == 0 {
+            self.last_execs_per_sec = cur_avg;
+            return self.last_execs_per_sec;
+        }
+
+        // If there is a dramatic (5x+) jump in speed, reset the indicator more quickly
+        if cur_avg * 5.0 < self.last_execs_per_sec || cur_avg / 5.0 > self.last_execs_per_sec {
+            self.last_execs_per_sec = cur_avg;
+        }
+
+        self.last_execs_per_sec =
+            self.last_execs_per_sec * (1.0 - 1.0 / 16.0) + cur_avg * (1.0 / 16.0);
+        self.last_execs_per_sec
+    }
+
+    /// Get the calculated executions per second for this client
+    #[expect(clippy::cast_precision_loss, clippy::cast_sign_loss)]
+    #[cfg(not(feature = "afl_exec_sec"))]
+    pub fn execs_per_sec(&mut self, cur_time: Duration) -> f64 {
+        if self.executions == 0 {
+            return 0.0;
+        }
+
+        let elapsed = cur_time
+            .checked_sub(self.last_window_time)
+            .map_or(0.0, |d| d.as_secs_f64());
+        if elapsed as u64 == 0 {
+            return 0.0;
+        }
+
+        (self.executions as f64) / elapsed
+    }
+
+    /// Executions per second
+    pub fn execs_per_sec_pretty(&mut self, cur_time: Duration) -> String {
+        prettify_float(self.execs_per_sec(cur_time))
+    }
+
+    /// Update the user-defined stat with name and value
+    pub fn update_user_stats(
+        &mut self,
+        name: Cow<'static, str>,
+        value: UserStats,
+    ) -> Option<UserStats> {
+        self.user_stats.insert(name, value)
+    }
+
+    #[must_use]
+    /// Get a user-defined stat using the name
+    pub fn get_user_stats(&self, name: &str) -> Option<&UserStats> {
+        self.user_stats.get(name)
+    }
+
+    /// Update the current [`ClientPerfStats`] with the given [`ClientPerfStats`]
+    #[cfg(feature = "introspection")]
+    pub fn update_introspection_stats(&mut self, introspection_stats: ClientPerfStats) {
+        self.introspection_stats = introspection_stats;
+    }
+}
+
+/// Prettifies float values for human-readable output
+fn prettify_float(value: f64) -> String {
+    let (value, suffix) = match value {
+        value if value >= 1_000_000.0 => (value / 1_000_000.0, "M"),
+        value if value >= 1_000.0 => (value / 1_000.0, "k"),
+        value => (value, ""),
+    };
+    match value {
+        value if value >= 1_000_000.0 => {
+            format!("{value:.2}{suffix}")
+        }
+        value if value >= 1_000.0 => {
+            format!("{value:.1}{suffix}")
+        }
+        value if value >= 100.0 => {
+            format!("{value:.1}{suffix}")
+        }
+        value if value >= 10.0 => {
+            format!("{value:.2}{suffix}")
+        }
+        value => {
+            format!("{value:.3}{suffix}")
+        }
+    }
+}

libafl/src/statistics/perf_stats.rs

@@ -0,0 +1,424 @@
+//! Statistics related to introspection
+
+use alloc::{string::String, vec::Vec};
+use core::fmt;
+
+use hashbrown::HashMap;
+use serde::{Deserialize, Serialize};
+
+/// Client performance statistics
+#[derive(Serialize, Deserialize, Debug, Clone)]
+pub struct ClientPerfStats {
+    /// Starting counter (in clock cycles from `read_time_counter`)
+    start_time: u64,
+
+    /// Current counter in the fuzzer (in clock cycles from `read_time_counter`
+    current_time: u64,
+
+    /// Clock cycles spent in the scheduler
+    scheduler: u64,
+
+    /// Clock cycles spent in the manager
+    manager: u64,
+
+    /// Current stage index to write the next stage benchmark time
+    curr_stage: u8,
+
+    /// Flag to dictate this stage is in use. Used during printing to not print the empty
+    /// stages if they are not in use.
+    stages_used: Vec<bool>,
+
+    /// Clock cycles spent in the the various features of each stage
+    stages: Vec<[u64; PerfFeature::Count as usize]>,
+
+    /// Clock cycles spent in each feedback mechanism of the fuzzer.
+    feedbacks: HashMap<String, u64>,
+
+    /// Current time set by `start_timer`
+    timer_start: Option<u64>,
+}
+
+/// Various features that are measured for performance
+#[derive(Serialize, Deserialize, Debug, Clone)]
+#[repr(u8)]
+pub enum PerfFeature {
+    /// Getting an input from the corpus
+    GetInputFromCorpus = 0,
+
+    /// Mutating the input
+    Mutate = 1,
+
+    /// Post-Exec Mutator callback
+    MutatePostExec = 2,
+
+    /// Actual time spent executing the target
+    TargetExecution = 3,
+
+    /// Time spent in `pre_exec`
+    PreExec = 4,
+
+    /// Time spent in `post_exec`
+    PostExec = 5,
+
+    /// Time spent in `observer` `pre_exec_all`
+    PreExecObservers = 6,
+
+    /// Time spent in `executor.observers_mut().post_exec_all`
+    PostExecObservers = 7,
+
+    /// Time spent getting the feedback from `is_interesting` from all feedbacks
+    GetFeedbackInterestingAll = 8,
+
+    /// Time spent getting the feedback from `is_interesting` from all objectives
+    GetObjectivesInterestingAll = 9,
+
+    /// Used as a counter to know how many elements are in [`PerfFeature`]. Must be the
+    /// last value in the enum.
+    Count, // !! No more values here since Count is last! !!
+           // !! No more values here since Count is last! !!
+}
+
+// TryFromPrimitive requires `std` so these are implemented manually
+impl From<PerfFeature> for usize {
+    fn from(val: PerfFeature) -> usize {
+        match val {
+            PerfFeature::GetInputFromCorpus => PerfFeature::GetInputFromCorpus as usize,
+            PerfFeature::Mutate => PerfFeature::Mutate as usize,
+            PerfFeature::MutatePostExec => PerfFeature::MutatePostExec as usize,
+            PerfFeature::TargetExecution => PerfFeature::TargetExecution as usize,
+            PerfFeature::PreExec => PerfFeature::PreExec as usize,
+            PerfFeature::PostExec => PerfFeature::PostExec as usize,
+            PerfFeature::PreExecObservers => PerfFeature::PreExecObservers as usize,
+            PerfFeature::PostExecObservers => PerfFeature::PostExecObservers as usize,
+            PerfFeature::GetFeedbackInterestingAll => {
+                PerfFeature::GetFeedbackInterestingAll as usize
+            }
+            PerfFeature::GetObjectivesInterestingAll => {
+                PerfFeature::GetObjectivesInterestingAll as usize
+            }
+            PerfFeature::Count => PerfFeature::Count as usize,
+        }
+    }
+}
+
+// TryFromPrimitive requires `std` so these are implemented manually
+impl From<usize> for PerfFeature {
+    fn from(val: usize) -> PerfFeature {
+        match val {
+            0 => PerfFeature::GetInputFromCorpus,
+            1 => PerfFeature::Mutate,
+            2 => PerfFeature::MutatePostExec,
+            3 => PerfFeature::TargetExecution,
+            4 => PerfFeature::PreExec,
+            5 => PerfFeature::PostExec,
+            6 => PerfFeature::PreExecObservers,
+            7 => PerfFeature::PostExecObservers,
+            8 => PerfFeature::GetFeedbackInterestingAll,
+            9 => PerfFeature::GetObjectivesInterestingAll,
+            _ => panic!("Unknown PerfFeature: {val}"),
+        }
+    }
+}
+
+/// Number of features we can measure for performance
+pub const NUM_PERF_FEATURES: usize = PerfFeature::Count as usize;
+
+impl ClientPerfStats {
+    /// Create a blank [`ClientPerfStats`] with the `start_time` and `current_time` with
+    /// the current clock counter
+    #[must_use]
+    pub fn new() -> Self {
+        let start_time = libafl_bolts::cpu::read_time_counter();
+
+        Self {
+            start_time,
+            current_time: start_time,
+            scheduler: 0,
+            manager: 0,
+            curr_stage: 0,
+            stages: vec![],
+            stages_used: vec![],
+            feedbacks: HashMap::new(),
+            timer_start: None,
+        }
+    }
+
+    /// Set the current time with the given time
+    #[inline]
+    pub fn set_current_time(&mut self, time: u64) {
+        self.current_time = time;
+    }
+
+    /// Start a timer with the current time counter
+    #[inline]
+    pub fn start_timer(&mut self) {
+        self.timer_start = Some(libafl_bolts::cpu::read_time_counter());
+    }
+
+    /// Update the current [`ClientPerfStats`] with the given [`ClientPerfStats`]
+    pub fn update(&mut self, monitor: &ClientPerfStats) {
+        self.set_current_time(monitor.current_time);
+        self.update_scheduler(monitor.scheduler);
+        self.update_manager(monitor.manager);
+        self.update_stages(&monitor.stages);
+        self.update_feedbacks(&monitor.feedbacks);
+    }
+
+    /// Gets the elapsed time since the internal timer started. Resets the timer when
+    /// finished execution.
+    #[inline]
+    fn mark_time(&mut self) -> u64 {
+        match self.timer_start {
+            None => {
+                // Warning message if marking time without starting the timer first
+                log::warn!("Attempted to `mark_time` without starting timer first.");
+
+                // Return 0 for no time marked
+                0
+            }
+            Some(timer_start) => {
+                // Calculate the elapsed time
+                let elapsed = libafl_bolts::cpu::read_time_counter() - timer_start;
+
+                // Reset the timer
+                self.timer_start = None;
+
+                // Return the elapsed time
+                elapsed
+            }
+        }
+    }
+
+    /// Update the time spent in the scheduler with the elapsed time that we have seen
+    #[inline]
+    pub fn mark_scheduler_time(&mut self) {
+        // Get the current elapsed time
+        let elapsed = self.mark_time();
+
+        // Add the time to the scheduler stat
+        self.update_scheduler(elapsed);
+    }
+
+    /// Update the time spent in the scheduler with the elapsed time that we have seen
+    #[inline]
+    pub fn mark_manager_time(&mut self) {
+        // Get the current elapsed time
+        let elapsed = self.mark_time();
+
+        // Add the time the manager stat
+        self.update_manager(elapsed);
+    }
+
+    /// Update the time spent in the given [`PerfFeature`] with the elapsed time that we have seen
+    #[inline]
+    pub fn mark_feature_time(&mut self, feature: PerfFeature) {
+        // Get the current elapsed time
+        let elapsed = self.mark_time();
+
+        // Add the time the the given feature
+        self.update_feature(feature, elapsed);
+    }
+
+    /// Add the given `time` to the `scheduler` monitor
+    #[inline]
+    pub fn update_scheduler(&mut self, time: u64) {
+        self.scheduler = self
+            .scheduler
+            .checked_add(time)
+            .expect("update_scheduler overflow");
+    }
+
+    /// Add the given `time` to the `manager` monitor
+    #[inline]
+    pub fn update_manager(&mut self, time: u64) {
+        self.manager = self
+            .manager
+            .checked_add(time)
+            .expect("update_manager overflow");
+    }
+
+    /// Update the total stage counter and increment the stage counter for the next stage
+    #[inline]
+    pub fn finish_stage(&mut self) {
+        // Increment the stage to the next index. The check is only done if this were to
+        // be used past the length of the `self.stages` buffer
+        self.curr_stage += 1;
+    }
+
+    /// Reset the stage index counter to zero
+    #[inline]
+    pub fn reset_stage_index(&mut self) {
+        self.curr_stage = 0;
+    }
+
+    /// Update the time spent in the feedback
+    pub fn update_feedback(&mut self, name: &str, time: u64) {
+        self.feedbacks.insert(
+            name.into(),
+            self.feedbacks
+                .get(name)
+                .unwrap_or(&0)
+                .checked_add(time)
+                .expect("update_feedback overflow"),
+        );
+    }
+
+    /// Update the time spent in all the feedbacks
+    pub fn update_feedbacks(&mut self, feedbacks: &HashMap<String, u64>) {
+        for (key, value) in feedbacks {
+            self.update_feedback(key, *value);
+        }
+    }
+
+    /// Update the time spent in the stages
+    pub fn update_stages(&mut self, stages: &[[u64; PerfFeature::Count as usize]]) {
+        if self.stages.len() < stages.len() {
+            self.stages
+                .resize(stages.len(), [0; PerfFeature::Count as usize]);
+            self.stages_used.resize(stages.len(), false);
+        }
+        for (stage_index, features) in stages.iter().enumerate() {
+            for (feature_index, feature) in features.iter().enumerate() {
+                self.stages[stage_index][feature_index] = self.stages[stage_index][feature_index]
+                    .checked_add(*feature)
+                    .expect("Stage overflow");
+            }
+        }
+    }
+
+    /// Update the given [`PerfFeature`] with the given `time`
+    pub fn update_feature(&mut self, feature: PerfFeature, time: u64) {
+        // Get the current stage index as `usize`
+        let stage_index: usize = self.curr_stage.into();
+
+        // Get the index of the given feature
+        let feature_index: usize = feature.into();
+
+        if stage_index >= self.stages.len() {
+            self.stages
+                .resize(stage_index + 1, [0; PerfFeature::Count as usize]);
+            self.stages_used.resize(stage_index + 1, false);
+        }
+
+        // Update the given feature
+        self.stages[stage_index][feature_index] = self.stages[stage_index][feature_index]
+            .checked_add(time)
+            .expect("Stage overflow");
+
+        // Set that the current stage is being used
+        self.stages_used[stage_index] = true;
+    }
+
+    /// The elapsed cycles (or time)
+    #[must_use]
+    pub fn elapsed_cycles(&self) -> u64 {
+        self.current_time - self.start_time
+    }
+
+    /// The amount of cycles the `manager` did
+    #[must_use]
+    pub fn manager_cycles(&self) -> u64 {
+        self.manager
+    }
+
+    /// The amount of cycles the `scheduler` did
+    #[must_use]
+    pub fn scheduler_cycles(&self) -> u64 {
+        self.scheduler
+    }
+
+    /// Iterator over all used stages
+    pub fn used_stages(
+        &self,
+    ) -> impl Iterator<Item = (usize, &[u64; PerfFeature::Count as usize])> {
+        let used = self.stages_used.clone();
+        self.stages
+            .iter()
+            .enumerate()
+            .filter(move |(stage_index, _)| used[*stage_index])
+    }
+
+    /// A map of all `feedbacks`
+    #[must_use]
+    pub fn feedbacks(&self) -> &HashMap<String, u64> {
+        &self.feedbacks
+    }
+}
+
+impl fmt::Display for ClientPerfStats {
+    #[expect(clippy::cast_precision_loss)]
+    fn fmt(&self, f: &mut fmt::Formatter) -> Result<(), fmt::Error> {
+        // Calculate the elapsed time from the monitor
+        let elapsed: f64 = self.elapsed_cycles() as f64;
+
+        // Calculate the percentages for each benchmark
+        let scheduler_percent = self.scheduler as f64 / elapsed;
+        let manager_percent = self.manager as f64 / elapsed;
+
+        // Calculate the remaining percentage that has not been benchmarked
+        let mut other_percent = 1.0;
+        other_percent -= scheduler_percent;
+        other_percent -= manager_percent;
+
+        // Create the formatted string
+        writeln!(
+            f,
+            "  {scheduler_percent:6.4}: Scheduler\n  {manager_percent:6.4}: Manager"
+        )?;
+
+        // Calculate each stage
+        // Make sure we only iterate over used stages
+        for (stage_index, features) in self.used_stages() {
+            // Write the stage header
+            writeln!(f, "  Stage {stage_index}:")?;
+
+            for (feature_index, feature) in features.iter().enumerate() {
+                // Calculate this current stage's percentage
+                let feature_percent = *feature as f64 / elapsed;
+
+                // Ignore this feature if it isn't used
+                if feature_percent == 0.0 {
+                    continue;
+                }
+
+                // Update the other percent by removing this current percent
+                other_percent -= feature_percent;
+
+                // Get the actual feature from the feature index for printing its name
+                let feature: PerfFeature = feature_index.into();
+
+                // Write the percentage for this feature
+                writeln!(f, "    {feature_percent:6.4}: {feature:?}")?;
+            }
+        }
+
+        writeln!(f, "  Feedbacks:")?;
+
+        for (feedback_name, feedback_time) in self.feedbacks() {
+            // Calculate this current stage's percentage
+            let feedback_percent = *feedback_time as f64 / elapsed;
+
+            // Ignore this feedback if it isn't used
+            if feedback_percent == 0.0 {
+                continue;
+            }
+
+            // Update the other percent by removing this current percent
+            other_percent -= feedback_percent;
+
+            // Write the percentage for this feedback
+            writeln!(f, "    {feedback_percent:6.4}: {feedback_name}")?;
+        }
+
+        write!(f, "  {other_percent:6.4}: Not Measured")?;
+
+        Ok(())
+    }
+}
+
+impl Default for ClientPerfStats {
+    #[must_use]
+    fn default() -> Self {
+        Self::new()
+    }
+}

libafl/src/statistics/user_stats/mod.rs

@@ -0,0 +1,123 @@
+//! User-defined statistics
+
+mod user_stats_value;
+use alloc::string::ToString;
+use core::fmt;
+
+use serde::{Deserialize, Serialize};
+pub use user_stats_value::*;
+
+use super::manager::ClientStatsManager;
+
+/// user defined stats enum
+#[derive(Serialize, Deserialize, Debug, Clone)]
+pub struct UserStats {
+    value: UserStatsValue,
+    aggregator_op: AggregatorOps,
+}
+
+impl UserStats {
+    /// Get the `AggregatorOps`
+    #[must_use]
+    pub fn aggregator_op(&self) -> &AggregatorOps {
+        &self.aggregator_op
+    }
+    /// Get the actual value for the stats
+    #[must_use]
+    pub fn value(&self) -> &UserStatsValue {
+        &self.value
+    }
+    /// Constructor
+    #[must_use]
+    pub fn new(value: UserStatsValue, aggregator_op: AggregatorOps) -> Self {
+        Self {
+            value,
+            aggregator_op,
+        }
+    }
+}
+
+impl fmt::Display for UserStats {
+    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
+        write!(f, "{}", self.value())
+    }
+}
+
+/// Definition of how we aggregate this across multiple clients
+#[derive(Serialize, Deserialize, Debug, Clone, Copy, Eq, PartialEq)]
+pub enum AggregatorOps {
+    /// Do nothing
+    None,
+    /// Add stats up
+    Sum,
+    /// Average stats out
+    Avg,
+    /// Get the min
+    Min,
+    /// Get the max
+    Max,
+}
+
+/// Aggregate user statistics according to their ops
+pub(super) fn aggregate_user_stats(client_stats_manager: &mut ClientStatsManager, name: &str) {
+    let mut gather = client_stats_manager
+        .client_stats()
+        .iter()
+        .filter_map(|client| client.user_stats.get(name));
+
+    let gather_count = gather.clone().count();
+
+    let (mut init, op) = match gather.next() {
+        Some(x) => (x.value().clone(), *x.aggregator_op()),
+        _ => {
+            return;
+        }
+    };
+
+    for item in gather {
+        match op {
+            AggregatorOps::None => {
+                // Nothing
+                return;
+            }
+            AggregatorOps::Avg | AggregatorOps::Sum => {
+                init = match init.stats_add(item.value()) {
+                    Some(x) => x,
+                    _ => {
+                        return;
+                    }
+                };
+            }
+            AggregatorOps::Min => {
+                init = match init.stats_min(item.value()) {
+                    Some(x) => x,
+                    _ => {
+                        return;
+                    }
+                };
+            }
+            AggregatorOps::Max => {
+                init = match init.stats_max(item.value()) {
+                    Some(x) => x,
+                    _ => {
+                        return;
+                    }
+                };
+            }
+        }
+    }
+
+    if let AggregatorOps::Avg = op {
+        // if avg then divide last.
+        init = match init.stats_div(gather_count) {
+            Some(x) => x,
+            _ => {
+                return;
+            }
+        }
+    }
+
+    client_stats_manager
+        .cached_aggregated_user_stats
+        .insert(name.to_string(), init);
+}

libafl/src/statistics/user_stats/user_stats_value.rs

@@ -0,0 +1,162 @@
+//! Value type of user stats
+
+use alloc::borrow::Cow;
+use core::fmt;
+
+use serde::{Deserialize, Serialize};
+
+/// The actual value for the userstats
+#[derive(Serialize, Deserialize, Debug, Clone)]
+pub enum UserStatsValue {
+    /// A numerical value
+    Number(u64),
+    /// A Float value
+    Float(f64),
+    /// A `String`
+    String(Cow<'static, str>),
+    /// A ratio of two values
+    Ratio(u64, u64),
+    /// Percent
+    Percent(f64),
+}
+
+impl UserStatsValue {
+    /// Check if this guy is numeric
+    #[must_use]
+    pub fn is_numeric(&self) -> bool {
+        match &self {
+            Self::Number(_) | Self::Float(_) | Self::Ratio(_, _) | Self::Percent(_) => true,
+            Self::String(_) => false,
+        }
+    }
+
+    /// Divide by the number of elements
+    #[expect(clippy::cast_precision_loss)]
+    pub fn stats_div(&mut self, divisor: usize) -> Option<Self> {
+        match self {
+            Self::Number(x) => Some(Self::Float(*x as f64 / divisor as f64)),
+            Self::Float(x) => Some(Self::Float(*x / divisor as f64)),
+            Self::Percent(x) => Some(Self::Percent(*x / divisor as f64)),
+            Self::Ratio(x, y) => Some(Self::Percent((*x as f64 / divisor as f64) / *y as f64)),
+            Self::String(_) => None,
+        }
+    }
+
+    /// min user stats with the other
+    #[expect(clippy::cast_precision_loss)]
+    pub fn stats_max(&mut self, other: &Self) -> Option<Self> {
+        match (self, other) {
+            (Self::Number(x), Self::Number(y)) => {
+                if y > x {
+                    Some(Self::Number(*y))
+                } else {
+                    Some(Self::Number(*x))
+                }
+            }
+            (Self::Float(x), Self::Float(y)) => {
+                if y > x {
+                    Some(Self::Float(*y))
+                } else {
+                    Some(Self::Float(*x))
+                }
+            }
+            (Self::Ratio(x, a), Self::Ratio(y, b)) => {
+                let first = *x as f64 / *a as f64;
+                let second = *y as f64 / *b as f64;
+                if first > second {
+                    Some(Self::Percent(first))
+                } else {
+                    Some(Self::Percent(second))
+                }
+            }
+            (Self::Percent(x), Self::Percent(y)) => {
+                if y > x {
+                    Some(Self::Percent(*y))
+                } else {
+                    Some(Self::Percent(*x))
+                }
+            }
+            _ => None,
+        }
+    }
+
+    /// min user stats with the other
+    #[expect(clippy::cast_precision_loss)]
+    pub fn stats_min(&mut self, other: &Self) -> Option<Self> {
+        match (self, other) {
+            (Self::Number(x), Self::Number(y)) => {
+                if y > x {
+                    Some(Self::Number(*x))
+                } else {
+                    Some(Self::Number(*y))
+                }
+            }
+            (Self::Float(x), Self::Float(y)) => {
+                if y > x {
+                    Some(Self::Float(*x))
+                } else {
+                    Some(Self::Float(*y))
+                }
+            }
+            (Self::Ratio(x, a), Self::Ratio(y, b)) => {
+                let first = *x as f64 / *a as f64;
+                let second = *y as f64 / *b as f64;
+                if first > second {
+                    Some(Self::Percent(second))
+                } else {
+                    Some(Self::Percent(first))
+                }
+            }
+            (Self::Percent(x), Self::Percent(y)) => {
+                if y > x {
+                    Some(Self::Percent(*x))
+                } else {
+                    Some(Self::Percent(*y))
+                }
+            }
+            _ => None,
+        }
+    }
+
+    /// add user stats with the other
+    #[expect(clippy::cast_precision_loss)]
+    pub fn stats_add(&mut self, other: &Self) -> Option<Self> {
+        match (self, other) {
+            (Self::Number(x), Self::Number(y)) => Some(Self::Number(*x + *y)),
+            (Self::Float(x), Self::Float(y)) => Some(Self::Float(*x + *y)),
+            (Self::Percent(x), Self::Percent(y)) => Some(Self::Percent(*x + *y)),
+            (Self::Ratio(x, a), Self::Ratio(y, b)) => {
+                let first = *x as f64 / *a as f64;
+                let second = *y as f64 / *b as f64;
+                Some(Self::Percent(first + second))
+            }
+            (Self::Percent(x), Self::Ratio(y, b)) => {
+                let ratio = *y as f64 / *b as f64;
+                Some(Self::Percent(*x + ratio))
+            }
+            (Self::Ratio(x, a), Self::Percent(y)) => {
+                let ratio = *x as f64 / *a as f64;
+                Some(Self::Percent(ratio + *y))
+            }
+            _ => None,
+        }
+    }
+}
+
+impl fmt::Display for UserStatsValue {
+    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
+        match &self {
+            UserStatsValue::Number(n) => write!(f, "{n}"),
+            UserStatsValue::Float(n) => write!(f, "{}", crate::statistics::prettify_float(*n)),
+            UserStatsValue::Percent(n) => write!(f, "{:.3}%", n * 100.0),
+            UserStatsValue::String(s) => write!(f, "{s}"),
+            UserStatsValue::Ratio(a, b) => {
+                if *b == 0 {
+                    write!(f, "{a}/{b}")
+                } else {
+                    write!(f, "{a}/{b} ({}%)", a * 100 / b)
+                }
+            }
+        }
+    }
+}