Add alternative time binner

items_2/src/eventsdim0.rs

@@ -5,6 +5,7 @@ use crate::{Empty, Events, ScalarOps, WithLen};
 use crate::{TimeBinnable, TimeBinnableType, TimeBinnableTypeAggregator, TimeBinner};
 use err::Error;
 use netpod::log::*;
+use netpod::timeunits::SEC;
 use netpod::NanoRange;
 use serde::{Deserialize, Serialize};
 use std::any::Any;
@@ -53,15 +54,25 @@ where
     NTY: fmt::Debug,
 {
     fn fmt(&self, fmt: &mut fmt::Formatter) -> fmt::Result {
-        write!(
-            fmt,
-            "count {}  ts {:?} .. {:?}  vals {:?} .. {:?}",
-            self.tss.len(),
-            self.tss.front(),
-            self.tss.back(),
-            self.values.front(),
-            self.values.back(),
-        )
+        if true {
+            write!(
+                fmt,
+                "EventsDim0 {{ count {}  ts {:?}  vals {:?} }}",
+                self.tss.len(),
+                self.tss.iter().map(|x| x / SEC).collect::<Vec<_>>(),
+                self.values,
+            )
+        } else {
+            write!(
+                fmt,
+                "EventsDim0 {{ count {}  ts {:?} .. {:?}  vals {:?} .. {:?} }}",
+                self.tss.len(),
+                self.tss.front().map(|x| x / SEC),
+                self.tss.back().map(|x| x / SEC),
+                self.values.front(),
+                self.values.back(),
+            )
+        }
     }
 }
 
@@ -539,7 +550,8 @@ impl<NTY: ScalarOps> Events for EventsDim0<NTY> {
     }
 
     fn take_new_events_until_ts(&mut self, ts_end: u64) -> Box<dyn Events> {
-        let n1 = self.tss.iter().take_while(|&&x| x < ts_end).count();
+        // TODO improve the search
+        let n1 = self.tss.iter().take_while(|&&x| x <= ts_end).count();
         let tss = self.tss.drain(..n1).collect();
         let pulses = self.pulses.drain(..n1).collect();
         let values = self.values.drain(..n1).collect();
@@ -547,6 +559,32 @@ impl<NTY: ScalarOps> Events for EventsDim0<NTY> {
         Box::new(ret)
     }
 
+    fn move_into_fresh(&mut self, ts_end: u64) -> Box<dyn Events> {
+        // TODO improve the search
+        let n1 = self.tss.iter().take_while(|&&x| x <= ts_end).count();
+        let tss = self.tss.drain(..n1).collect();
+        let pulses = self.pulses.drain(..n1).collect();
+        let values = self.values.drain(..n1).collect();
+        let ret = Self { tss, pulses, values };
+        Box::new(ret)
+    }
+
+    fn move_into_existing(&mut self, tgt: &mut Box<dyn Events>, ts_end: u64) -> Result<(), ()> {
+        // TODO as_any and as_any_mut are declared on unrealted traits. Simplify.
+        if let Some(tgt) = tgt.as_any_mut().downcast_mut::<Self>() {
+            // TODO improve the search
+            let n1 = self.tss.iter().take_while(|&&x| x <= ts_end).count();
+            // TODO make it harder to forget new members when the struct may get modified in the future
+            tgt.tss.extend(self.tss.drain(..n1));
+            tgt.pulses.extend(self.pulses.drain(..n1));
+            tgt.values.extend(self.values.drain(..n1));
+            Ok(())
+        } else {
+            eprintln!("downcast to EventsDim0 FAILED");
+            Err(())
+        }
+    }
+
     fn ts_min(&self) -> Option<u64> {
         self.tss.front().map(|&x| x)
     }

items_2/src/items_2.rs

@@ -1,10 +1,14 @@
 pub mod binsdim0;
 pub mod eventsdim0;
 pub mod merger;
+pub mod merger_cev;
 pub mod streams;
 #[cfg(test)]
 pub mod test;
+pub mod testgen;
+pub mod timebin;
 
+use crate::streams::Collector;
 use chrono::{DateTime, TimeZone, Utc};
 use futures_util::FutureExt;
 use futures_util::Stream;
@@ -14,6 +18,7 @@ use items::RangeCompletableItem;
 use items::Sitemty;
 use items::StreamItem;
 use items::SubFrId;
+use merger_cev::MergeableCev;
 use netpod::log::*;
 use netpod::timeunits::*;
 use netpod::{AggKind, NanoRange, ScalarType, Shape};
@@ -27,8 +32,6 @@ use std::time::Instant;
 use streams::Collectable;
 use streams::ToJsonResult;
 
-use crate::streams::Collector;
-
 pub fn bool_is_false(x: &bool) -> bool {
     *x == false
 }
@@ -276,6 +279,8 @@ pub trait TimeBinner: Send {
     fn set_range_complete(&mut self);
 }
 
+// TODO remove the Any bound. Factor out into custom AsAny trait.
+
 /// Provides a time-binned representation of the implementing type.
 /// In contrast to `TimeBinnableType` this is meant for trait objects.
 pub trait TimeBinnable: fmt::Debug + WithLen + RangeOverlapInfo + Any + Send {
@@ -287,6 +292,8 @@ pub trait TimeBinnable: fmt::Debug + WithLen + RangeOverlapInfo + Any + Send {
     fn to_box_to_json_result(&self) -> Box<dyn ToJsonResult>;
 }
 
+// TODO can I remove the Any bound?
+
 /// Container of some form of events, for use as trait object.
 pub trait Events: fmt::Debug + Any + Collectable + TimeBinnable + Send + erased_serde::Serialize {
     fn as_time_binnable(&self) -> &dyn TimeBinnable;
@@ -296,6 +303,8 @@ pub trait Events: fmt::Debug + Any + Collectable + TimeBinnable + Send + erased_
     fn ts_min(&self) -> Option<u64>;
     fn ts_max(&self) -> Option<u64>;
     fn take_new_events_until_ts(&mut self, ts_end: u64) -> Box<dyn Events>;
+    fn move_into_fresh(&mut self, ts_end: u64) -> Box<dyn Events>;
+    fn move_into_existing(&mut self, tgt: &mut Box<dyn Events>, ts_end: u64) -> Result<(), ()>;
     fn clone_dyn(&self) -> Box<dyn Events>;
     fn partial_eq_dyn(&self, other: &dyn Events) -> bool;
     fn serde_id(&self) -> &'static str;
@@ -304,6 +313,35 @@ pub trait Events: fmt::Debug + Any + Collectable + TimeBinnable + Send + erased_
 
 erased_serde::serialize_trait_object!(Events);
 
+impl crate::merger::Mergeable for Box<dyn Events> {
+    fn len(&self) -> usize {
+        self.as_ref().len()
+    }
+
+    fn ts_min(&self) -> Option<u64> {
+        self.as_ref().ts_min()
+    }
+
+    fn ts_max(&self) -> Option<u64> {
+        self.as_ref().ts_max()
+    }
+
+    fn is_compatible_target(&self, _tgt: &Self) -> bool {
+        // TODO currently unused
+        todo!()
+    }
+
+    fn move_into_fresh(&mut self, ts_end: u64) -> Self {
+        self.as_mut().move_into_fresh(ts_end)
+    }
+
+    fn move_into_existing(&mut self, tgt: &mut Self, ts_end: u64) -> Result<(), merger::MergeError> {
+        self.as_mut()
+            .move_into_existing(tgt, ts_end)
+            .map_err(|()| merger::MergeError::NotCompatible)
+    }
+}
+
 impl PartialEq for Box<dyn Events> {
     fn eq(&self, other: &Self) -> bool {
         Events::partial_eq_dyn(self.as_ref(), other.as_ref())
@@ -319,7 +357,7 @@ impl WithLen for EventsCollector {
 }
 
 impl Collector for EventsCollector {
-    fn ingest(&mut self, src: &mut dyn Collectable) {
+    fn ingest(&mut self, _src: &mut dyn Collectable) {
         todo!()
     }
 
@@ -534,6 +572,7 @@ pub fn empty_binned_dyn(scalar_type: &ScalarType, shape: &Shape, agg_kind: &AggK
     }
 }
 
+// TODO maybe rename to ChannelStatus?
 #[derive(Clone, Debug, PartialEq, Serialize, Deserialize)]
 pub enum ConnStatus {
     Connect,
@@ -546,20 +585,9 @@ pub struct ConnStatusEvent {
     pub status: ConnStatus,
 }
 
-trait MergableEvents: Any {
-    fn ts_min(&self) -> Option<u64>;
-    fn ts_max(&self) -> Option<u64>;
-}
-
-impl<T: MergableEvents> MergableEvents for Box<T> {
-    fn ts_min(&self) -> Option<u64> {
-        eprintln!("TODO MergableEvents for Box<T>");
-        err::todoval()
-    }
-
-    fn ts_max(&self) -> Option<u64> {
-        eprintln!("TODO MergableEvents for Box<T>");
-        err::todoval()
+impl ConnStatusEvent {
+    pub fn new(ts: u64, status: ConnStatus) -> Self {
+        Self { ts, status }
     }
 }
 
@@ -717,7 +745,7 @@ impl PartialEq for ChannelEvents {
     }
 }
 
-impl MergableEvents for ChannelEvents {
+impl MergeableCev for ChannelEvents {
     fn ts_min(&self) -> Option<u64> {
         use ChannelEvents::*;
         match self {
@@ -732,6 +760,179 @@ impl MergableEvents for ChannelEvents {
     }
 }
 
+impl crate::merger::Mergeable for ChannelEvents {
+    fn len(&self) -> usize {
+        match self {
+            ChannelEvents::Events(k) => k.len(),
+            ChannelEvents::Status(_) => 1,
+        }
+    }
+
+    fn ts_min(&self) -> Option<u64> {
+        match self {
+            ChannelEvents::Events(k) => k.ts_min(),
+            ChannelEvents::Status(k) => Some(k.ts),
+        }
+    }
+
+    fn ts_max(&self) -> Option<u64> {
+        match self {
+            ChannelEvents::Events(k) => k.ts_max(),
+            ChannelEvents::Status(k) => Some(k.ts),
+        }
+    }
+
+    fn is_compatible_target(&self, tgt: &Self) -> bool {
+        use ChannelEvents::*;
+        match self {
+            Events(_) => {
+                // TODO better to delegate this to inner type?
+                if let Events(_) = tgt {
+                    true
+                } else {
+                    false
+                }
+            }
+            Status(_) => {
+                // TODO better to delegate this to inner type?
+                if let Status(_) = tgt {
+                    true
+                } else {
+                    false
+                }
+            }
+        }
+    }
+
+    fn move_into_fresh(&mut self, ts_end: u64) -> Self {
+        match self {
+            ChannelEvents::Events(k) => ChannelEvents::Events(k.move_into_fresh(ts_end)),
+            ChannelEvents::Status(k) => ChannelEvents::Status(k.clone()),
+        }
+    }
+
+    fn move_into_existing(&mut self, tgt: &mut Self, ts_end: u64) -> Result<(), merger::MergeError> {
+        match self {
+            ChannelEvents::Events(k) => match tgt {
+                ChannelEvents::Events(tgt) => k.move_into_existing(tgt, ts_end),
+                ChannelEvents::Status(_) => Err(merger::MergeError::NotCompatible),
+            },
+            ChannelEvents::Status(_) => match tgt {
+                ChannelEvents::Events(_) => Err(merger::MergeError::NotCompatible),
+                ChannelEvents::Status(_) => Err(merger::MergeError::Full),
+            },
+        }
+    }
+}
+
+impl Collectable for ChannelEvents {
+    fn new_collector(&self) -> Box<dyn Collector> {
+        match self {
+            ChannelEvents::Events(_item) => todo!(),
+            ChannelEvents::Status(_) => todo!(),
+        }
+    }
+
+    fn as_any_mut(&mut self) -> &mut dyn Any {
+        self
+    }
+}
+
+pub struct ChannelEventsTimeBinner {
+    // TODO `ConnStatus` contains all the changes that can happen to a connection, but
+    // here we would rather require a simplified current state for binning purpose.
+    edges: Vec<u64>,
+    do_time_weight: bool,
+    conn_state: ConnStatus,
+    binner: Option<Box<dyn crate::TimeBinner>>,
+}
+
+impl fmt::Debug for ChannelEventsTimeBinner {
+    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
+        f.debug_struct("ChannelEventsTimeBinner")
+            .field("conn_state", &self.conn_state)
+            .finish()
+    }
+}
+
+impl crate::timebin::TimeBinner for ChannelEventsTimeBinner {
+    type Input = ChannelEvents;
+    type Output = Box<dyn crate::TimeBinned>;
+
+    fn ingest(&mut self, item: &mut Self::Input) {
+        match item {
+            ChannelEvents::Events(item) => {
+                if self.binner.is_none() {
+                    let binner = item.time_binner_new(self.edges.clone(), self.do_time_weight);
+                    self.binner = Some(binner);
+                }
+                match self.binner.as_mut() {
+                    Some(binner) => binner.ingest(item.as_time_binnable()),
+                    None => {
+                        error!("ingest without active binner item {item:?}");
+                        ()
+                    }
+                }
+            }
+            ChannelEvents::Status(item) => {
+                warn!("TODO consider channel status in time binning {item:?}");
+            }
+        }
+    }
+
+    fn set_range_complete(&mut self) {
+        match self.binner.as_mut() {
+            Some(binner) => binner.set_range_complete(),
+            None => (),
+        }
+    }
+
+    fn bins_ready_count(&self) -> usize {
+        match &self.binner {
+            Some(binner) => binner.bins_ready_count(),
+            None => 0,
+        }
+    }
+
+    fn bins_ready(&mut self) -> Option<Self::Output> {
+        match self.binner.as_mut() {
+            Some(binner) => binner.bins_ready(),
+            None => None,
+        }
+    }
+
+    fn push_in_progress(&mut self, push_empty: bool) {
+        match self.binner.as_mut() {
+            Some(binner) => binner.push_in_progress(push_empty),
+            None => (),
+        }
+    }
+
+    fn cycle(&mut self) {
+        match self.binner.as_mut() {
+            Some(binner) => binner.cycle(),
+            None => (),
+        }
+    }
+}
+
+impl crate::timebin::TimeBinnable for ChannelEvents {
+    type TimeBinner = ChannelEventsTimeBinner;
+
+    fn time_binner_new(&self, edges: Vec<u64>, do_time_weight: bool) -> Self::TimeBinner {
+        let (binner, status) = match self {
+            ChannelEvents::Events(_events) => (None, ConnStatus::Connect),
+            ChannelEvents::Status(status) => (None, status.status.clone()),
+        };
+        ChannelEventsTimeBinner {
+            edges,
+            do_time_weight,
+            conn_state: status,
+            binner,
+        }
+    }
+}
+
 // TODO do this with some blanket impl:
 impl Collectable for Box<dyn Collectable> {
     fn new_collector(&self) -> Box<dyn streams::Collector> {

items_2/src/merger.rs

@@ -1,5 +1,6 @@
-use crate::{ChannelEvents, Error, MergableEvents};
+use crate::Error;
 use futures_util::{Stream, StreamExt};
+use items::sitem_data;
 use items::{RangeCompletableItem, Sitemty, StreamItem};
 use netpod::log::*;
 use std::fmt;
@@ -7,50 +8,126 @@ use std::ops::ControlFlow;
 use std::pin::Pin;
 use std::task::{Context, Poll};
 
-type MergeInp = Pin<Box<dyn Stream<Item = Sitemty<ChannelEvents>> + Send>>;
+#[allow(unused)]
+macro_rules! trace2 {
+    ($($arg:tt)*) => ();
+    ($($arg:tt)*) => (eprintln!($($arg)*));
+}
 
-pub struct ChannelEventsMerger {
-    inps: Vec<Option<MergeInp>>,
-    items: Vec<Option<ChannelEvents>>,
+#[allow(unused)]
+macro_rules! trace3 {
+    ($($arg:tt)*) => ();
+    ($($arg:tt)*) => (eprintln!($($arg)*));
+}
+
+#[allow(unused)]
+macro_rules! trace4 {
+    ($($arg:tt)*) => ();
+    ($($arg:tt)*) => (eprintln!($($arg)*));
+}
+
+#[derive(Debug)]
+pub enum MergeError {
+    NotCompatible,
+    Full,
+}
+
+impl From<MergeError> for err::Error {
+    fn from(e: MergeError) -> Self {
+        format!("{e:?}").into()
+    }
+}
+
+pub trait Mergeable<Rhs = Self>: fmt::Debug + Unpin {
+    fn len(&self) -> usize;
+    fn ts_min(&self) -> Option<u64>;
+    fn ts_max(&self) -> Option<u64>;
+    // TODO remove, useless.
+    fn is_compatible_target(&self, tgt: &Rhs) -> bool;
+
+    // TODO rename to `append_*` to make it clear that they simply append, but not re-sort.
+    fn move_into_fresh(&mut self, ts_end: u64) -> Rhs;
+    fn move_into_existing(&mut self, tgt: &mut Rhs, ts_end: u64) -> Result<(), MergeError>;
+}
+
+type MergeInp<T> = Pin<Box<dyn Stream<Item = Sitemty<T>> + Send>>;
+
+pub struct Merger<T> {
+    inps: Vec<Option<MergeInp<T>>>,
+    items: Vec<Option<T>>,
+    out: Option<T>,
+    do_clear_out: bool,
+    out_max_len: usize,
     range_complete: bool,
     done: bool,
     done2: bool,
+    done3: bool,
     complete: bool,
 }
 
-impl fmt::Debug for ChannelEventsMerger {
+impl<T> fmt::Debug for Merger<T>
+where
+    T: Mergeable,
+{
     fn fmt(&self, fmt: &mut fmt::Formatter) -> fmt::Result {
         let inps: Vec<_> = self.inps.iter().map(|x| x.is_some()).collect();
         fmt.debug_struct(std::any::type_name::<Self>())
             .field("inps", &inps)
             .field("items", &self.items)
+            .field("out_max_len", &self.out_max_len)
             .field("range_complete", &self.range_complete)
             .field("done", &self.done)
             .field("done2", &self.done2)
+            .field("done3", &self.done3)
             .finish()
     }
 }
 
-impl ChannelEventsMerger {
-    pub fn new(inps: Vec<MergeInp>) -> Self {
+impl<T> Merger<T>
+where
+    T: Mergeable,
+{
+    pub fn new(inps: Vec<MergeInp<T>>, out_max_len: usize) -> Self {
         let n = inps.len();
         Self {
-            done: false,
-            done2: false,
-            complete: false,
             inps: inps.into_iter().map(|x| Some(x)).collect(),
             items: (0..n).into_iter().map(|_| None).collect(),
+            out: None,
+            do_clear_out: false,
+            out_max_len,
             range_complete: false,
+            done: false,
+            done2: false,
+            done3: false,
+            complete: false,
         }
     }
 
-    fn process(mut self: Pin<&mut Self>, _cx: &mut Context) -> Result<ControlFlow<ChannelEvents>, Error> {
+    fn take_into_output_all(&mut self, src: &mut T) -> Result<(), MergeError> {
+        // TODO optimize the case when some large batch should be added to some existing small batch already in out.
+        // TODO maybe use two output slots?
+        self.take_into_output_upto(src, u64::MAX)
+    }
+
+    fn take_into_output_upto(&mut self, src: &mut T, upto: u64) -> Result<(), MergeError> {
+        // TODO optimize the case when some large batch should be added to some existing small batch already in out.
+        // TODO maybe use two output slots?
+        if self.out.is_none() {
+            trace2!("move into fresh");
+            self.out = Some(src.move_into_fresh(upto));
+            Ok(())
+        } else {
+            let out = self.out.as_mut().unwrap();
+            src.move_into_existing(out, upto)
+        }
+    }
+
+    fn process(mut self: Pin<&mut Self>, _cx: &mut Context) -> Result<ControlFlow<()>, Error> {
         use ControlFlow::*;
         let mut tslows = [None, None];
         for (i1, itemopt) in self.items.iter_mut().enumerate() {
             if let Some(item) = itemopt {
-                let t1 = item.ts_min();
-                if let Some(t1) = t1 {
+                if let Some(t1) = item.ts_min() {
                     if let Some((_, a)) = tslows[0] {
                         if t1 < a {
                             tslows[1] = tslows[0];
@@ -70,58 +147,72 @@ impl ChannelEventsMerger {
                         tslows[0] = Some((i1, t1));
                     }
                 } else {
-                    match item {
-                        ChannelEvents::Events(_) => {
-                            trace!("events item without ts min discovered {item:?}");
-                            itemopt.take();
-                            return Ok(Continue(()));
-                        }
-                        ChannelEvents::Status(_) => {
-                            return Err(format!("channel status without timestamp").into());
-                        }
-                    }
+                    // the item seems empty.
+                    trace2!("empty item, something to do here?");
+                    *itemopt = None;
+                    return Ok(Continue(()));
                 }
             }
         }
+        trace4!("tslows {tslows:?}");
         if let Some((il0, _tl0)) = tslows[0] {
             if let Some((_il1, tl1)) = tslows[1] {
+                // There is a second input, take only up to the second highest timestamp
                 let item = self.items[il0].as_mut().unwrap();
-                match item {
-                    ChannelEvents::Events(item) => {
-                        if let Some(th0) = item.ts_max() {
-                            if th0 < tl1 {
-                                let ret = self.items[il0].take().unwrap();
-                                Ok(Break(ret))
-                            } else {
-                                let ritem = item.take_new_events_until_ts(tl1);
-                                if item.len() == 0 {
-                                    // TODO should never be here
-                                    self.items[il0] = None;
-                                }
-                                Ok(Break(ChannelEvents::Events(ritem)))
+                if let Some(th0) = item.ts_max() {
+                    if th0 <= tl1 {
+                        // Can take the whole item
+                        let mut item = self.items[il0].take().unwrap();
+                        trace3!("Take all from item {item:?}");
+                        match self.take_into_output_all(&mut item) {
+                            Ok(()) => Ok(Break(())),
+                            Err(MergeError::Full) | Err(MergeError::NotCompatible) => {
+                                // TODO count for stats
+                                trace3!("Put item back");
+                                self.items[il0] = Some(item);
+                                self.do_clear_out = true;
+                                Ok(Break(()))
+                            }
+                        }
+                    } else {
+                        // Take only up to the lowest ts of the second-lowest input
+                        let mut item = self.items[il0].take().unwrap();
+                        trace3!("Take up to {tl1} from item {item:?}");
+                        match self.take_into_output_upto(&mut item, tl1) {
+                            Ok(()) => {
+                                if item.len() == 0 {
+                                    // TODO should never be here because we should have taken the whole item
+                                    Err(format!("Should have taken the whole item instead").into())
+                                } else {
+                                    self.items[il0] = Some(item);
+                                    Ok(Break(()))
+                                }
+                            }
+                            Err(MergeError::Full) | Err(MergeError::NotCompatible) => {
+                                // TODO count for stats
+                                trace3!("Put item back");
+                                self.items[il0] = Some(item);
+                                self.do_clear_out = true;
+                                Ok(Break(()))
                             }
-                        } else {
-                            // TODO should never be here because ts-max should always exist here.
-                            let ritem = item.take_new_events_until_ts(tl1);
-                            if item.len() == 0 {}
-                            Ok(Break(ChannelEvents::Events(ritem)))
                         }
                     }
-                    ChannelEvents::Status(_) => {
-                        let ret = self.items[il0].take().unwrap();
-                        Ok(Break(ret))
-                    }
+                } else {
+                    // TODO should never be here because ts-max should always exist here.
+                    Err(format!("selected input without max ts").into())
                 }
             } else {
-                let item = self.items[il0].as_mut().unwrap();
-                match item {
-                    ChannelEvents::Events(_) => {
-                        let ret = self.items[il0].take().unwrap();
-                        Ok(Break(ret))
-                    }
-                    ChannelEvents::Status(_) => {
-                        let ret = self.items[il0].take().unwrap();
-                        Ok(Break(ret))
+                // No other input, take the whole item
+                let mut item = self.items[il0].take().unwrap();
+                trace3!("Take all from item (no other input) {item:?}");
+                match self.take_into_output_all(&mut item) {
+                    Ok(()) => Ok(Break(())),
+                    Err(_) => {
+                        // TODO count for stats
+                        trace3!("Put item back");
+                        self.items[il0] = Some(item);
+                        self.do_clear_out = true;
+                        Ok(Break(()))
                     }
                 }
             }
@@ -131,6 +222,7 @@ impl ChannelEventsMerger {
     }
 
     fn refill(mut self: Pin<&mut Self>, cx: &mut Context) -> ControlFlow<Poll<Error>> {
+        trace4!("refill");
         use ControlFlow::*;
         use Poll::*;
         let mut has_pending = false;
@@ -138,6 +230,7 @@ impl ChannelEventsMerger {
             let item = &self.items[i1];
             if item.is_none() {
                 while let Some(inp) = &mut self.inps[i1] {
+                    trace4!("refill while");
                     match inp.poll_next_unpin(cx) {
                         Ready(Some(Ok(k))) => {
                             match k {
@@ -149,22 +242,6 @@ impl ChannelEventsMerger {
                                         eprintln!("TODO inp RangeComplete which does not fill slot");
                                     }
                                     RangeCompletableItem::Data(k) => {
-                                        match &k {
-                                            ChannelEvents::Events(events) => {
-                                                if events.len() == 0 {
-                                                    warn!("empty events item {events:?}");
-                                                } else {
-                                                    trace!(
-                                                        "\nrefilled with events {}\nREFILLED\n{:?}\n\n",
-                                                        events.len(),
-                                                        events
-                                                    );
-                                                }
-                                            }
-                                            ChannelEvents::Status(_) => {
-                                                eprintln!("TODO inp Status which does not fill slot");
-                                            }
-                                        }
                                         self.items[i1] = Some(k);
                                         break;
                                     }
@@ -186,6 +263,8 @@ impl ChannelEventsMerger {
                         }
                     }
                 }
+            } else {
+                trace4!("refill  inp {}  has {}", i1, item.as_ref().unwrap().len());
             }
         }
         if has_pending {
@@ -195,17 +274,13 @@ impl ChannelEventsMerger {
         }
     }
 
-    fn poll2(mut self: Pin<&mut Self>, cx: &mut Context) -> ControlFlow<Poll<Option<Result<ChannelEvents, Error>>>> {
+    fn poll3(
+        mut self: Pin<&mut Self>,
+        cx: &mut Context,
+        has_pending: bool,
+    ) -> ControlFlow<Poll<Option<Result<T, Error>>>> {
         use ControlFlow::*;
         use Poll::*;
-        let mut has_pending = false;
-        match Self::refill(Pin::new(&mut self), cx) {
-            Break(Ready(e)) => return Break(Ready(Some(Err(e)))),
-            Break(Pending) => {
-                has_pending = true;
-            }
-            Continue(()) => {}
-        }
         let ninps = self.inps.iter().filter(|a| a.is_some()).count();
         let nitems = self.items.iter().filter(|a| a.is_some()).count();
         let nitemsmissing = self
@@ -214,6 +289,7 @@ impl ChannelEventsMerger {
             .zip(self.items.iter())
             .filter(|(a, b)| a.is_some() && b.is_none())
             .count();
+        trace3!("ninps {ninps}  nitems {nitems}  nitemsmissing {nitemsmissing}");
         if ninps == 0 && nitems == 0 {
             self.done = true;
             Break(Ready(None))
@@ -226,33 +302,74 @@ impl ChannelEventsMerger {
             }
         } else {
             match Self::process(Pin::new(&mut self), cx) {
-                Ok(Break(item)) => Break(Ready(Some(Ok(item)))),
-                Ok(Continue(())) => Continue(()),
+                Ok(Break(())) => {
+                    if let Some(o) = self.out.as_ref() {
+                        // A good threshold varies according to scalar type and shape.
+                        // TODO replace this magic number by a bound on the bytes estimate.
+                        if o.len() >= self.out_max_len || self.do_clear_out {
+                            trace3!("decide to output");
+                            self.do_clear_out = false;
+                            Break(Ready(Some(Ok(self.out.take().unwrap()))))
+                        } else {
+                            trace4!("output not yet");
+                            Continue(())
+                        }
+                    } else {
+                        trace3!("no output candidate");
+                        Continue(())
+                    }
+                }
+                Ok(Continue(())) => {
+                    trace2!("process returned with Continue");
+                    Continue(())
+                }
                 Err(e) => Break(Ready(Some(Err(e)))),
             }
         }
     }
+
+    fn poll2(mut self: Pin<&mut Self>, cx: &mut Context) -> ControlFlow<Poll<Option<Result<T, Error>>>> {
+        use ControlFlow::*;
+        use Poll::*;
+        match Self::refill(Pin::new(&mut self), cx) {
+            Break(Ready(e)) => Break(Ready(Some(Err(e)))),
+            Break(Pending) => Self::poll3(self, cx, true),
+            Continue(()) => Self::poll3(self, cx, false),
+        }
+    }
 }
 
-impl Stream for ChannelEventsMerger {
-    type Item = Sitemty<ChannelEvents>;
+impl<T> Stream for Merger<T>
+where
+    T: Mergeable,
+{
+    type Item = Sitemty<T>;
 
     fn poll_next(mut self: Pin<&mut Self>, cx: &mut Context) -> Poll<Option<Self::Item>> {
         use Poll::*;
-        const NAME: &str = "ChannelEventsMerger";
+        const NAME: &str = "Merger_mergeable";
         let span = span!(Level::TRACE, NAME);
         let _spanguard = span.enter();
         loop {
+            trace3!("{NAME}  poll");
             break if self.complete {
                 panic!("poll after complete");
-            } else if self.done2 {
+            } else if self.done3 {
                 self.complete = true;
                 Ready(None)
+            } else if self.done2 {
+                self.done3 = true;
+                if self.range_complete {
+                    warn!("TODO emit range complete only if all inputs signaled complete");
+                    trace!("{NAME}  emit RangeComplete");
+                    Ready(Some(Ok(StreamItem::DataItem(RangeCompletableItem::RangeComplete))))
+                } else {
+                    continue;
+                }
             } else if self.done {
                 self.done2 = true;
-                if self.range_complete {
-                    trace!("MERGER EMITTING ChannelEvents::RangeComplete");
-                    Ready(Some(Ok(StreamItem::DataItem(RangeCompletableItem::RangeComplete))))
+                if let Some(out) = self.out.take() {
+                    Ready(Some(sitem_data(out)))
                 } else {
                     continue;
                 }
@@ -260,18 +377,7 @@ impl Stream for ChannelEventsMerger {
                 match Self::poll2(self.as_mut(), cx) {
                     ControlFlow::Continue(()) => continue,
                     ControlFlow::Break(k) => match k {
-                        Ready(Some(Ok(ChannelEvents::Events(item)))) => {
-                            trace!("\n\nMERGER EMITTING\n{:?}\n\n", item);
-                            Ready(Some(Ok(StreamItem::DataItem(RangeCompletableItem::Data(
-                                ChannelEvents::Events(item),
-                            )))))
-                        }
-                        Ready(Some(Ok(ChannelEvents::Status(item)))) => {
-                            trace!("\n\nMERGER EMITTING\n{:?}\n\n", item);
-                            Ready(Some(Ok(StreamItem::DataItem(RangeCompletableItem::Data(
-                                ChannelEvents::Status(item),
-                            )))))
-                        }
+                        Ready(Some(Ok(item))) => Ready(Some(sitem_data(item))),
                         Ready(Some(Err(e))) => {
                             self.done = true;
                             Ready(Some(Err(e.into())))

items_2/src/merger_cev.rs

@@ -0,0 +1,295 @@
+use crate::{ChannelEvents, Error};
+use futures_util::{Stream, StreamExt};
+use items::{RangeCompletableItem, Sitemty, StreamItem};
+use netpod::log::*;
+use std::any::Any;
+use std::fmt;
+use std::ops::ControlFlow;
+use std::pin::Pin;
+use std::task::{Context, Poll};
+
+pub trait MergeableCev: Any {
+    fn ts_min(&self) -> Option<u64>;
+    fn ts_max(&self) -> Option<u64>;
+}
+
+type MergeInp = Pin<Box<dyn Stream<Item = Sitemty<ChannelEvents>> + Send>>;
+
+pub struct ChannelEventsMerger {
+    inps: Vec<Option<MergeInp>>,
+    items: Vec<Option<ChannelEvents>>,
+    range_complete: bool,
+    done: bool,
+    done2: bool,
+    complete: bool,
+}
+
+impl fmt::Debug for ChannelEventsMerger {
+    fn fmt(&self, fmt: &mut fmt::Formatter) -> fmt::Result {
+        let inps: Vec<_> = self.inps.iter().map(|x| x.is_some()).collect();
+        fmt.debug_struct(std::any::type_name::<Self>())
+            .field("inps", &inps)
+            .field("items", &self.items)
+            .field("range_complete", &self.range_complete)
+            .field("done", &self.done)
+            .field("done2", &self.done2)
+            .finish()
+    }
+}
+
+impl ChannelEventsMerger {
+    pub fn new(inps: Vec<MergeInp>) -> Self {
+        let n = inps.len();
+        Self {
+            done: false,
+            done2: false,
+            complete: false,
+            inps: inps.into_iter().map(|x| Some(x)).collect(),
+            items: (0..n).into_iter().map(|_| None).collect(),
+            range_complete: false,
+        }
+    }
+
+    fn process(mut self: Pin<&mut Self>, _cx: &mut Context) -> Result<ControlFlow<ChannelEvents>, Error> {
+        use ControlFlow::*;
+        let mut tslows = [None, None];
+        for (i1, itemopt) in self.items.iter_mut().enumerate() {
+            if let Some(item) = itemopt {
+                let t1 = item.ts_min();
+                if let Some(t1) = t1 {
+                    if let Some((_, a)) = tslows[0] {
+                        if t1 < a {
+                            tslows[1] = tslows[0];
+                            tslows[0] = Some((i1, t1));
+                        } else {
+                            if let Some((_, b)) = tslows[1] {
+                                if t1 < b {
+                                    tslows[1] = Some((i1, t1));
+                                } else {
+                                    // nothing to do
+                                }
+                            } else {
+                                tslows[1] = Some((i1, t1));
+                            }
+                        }
+                    } else {
+                        tslows[0] = Some((i1, t1));
+                    }
+                } else {
+                    match item {
+                        ChannelEvents::Events(_) => {
+                            trace!("events item without ts min discovered {item:?}");
+                            itemopt.take();
+                            return Ok(Continue(()));
+                        }
+                        ChannelEvents::Status(_) => {
+                            return Err(format!("channel status without timestamp").into());
+                        }
+                    }
+                }
+            }
+        }
+        if let Some((il0, _tl0)) = tslows[0] {
+            if let Some((_il1, tl1)) = tslows[1] {
+                let item = self.items[il0].as_mut().unwrap();
+                match item {
+                    ChannelEvents::Events(item) => {
+                        if let Some(th0) = item.ts_max() {
+                            if th0 < tl1 {
+                                let ret = self.items[il0].take().unwrap();
+                                Ok(Break(ret))
+                            } else {
+                                let ritem = item.take_new_events_until_ts(tl1);
+                                if item.len() == 0 {
+                                    // TODO should never be here
+                                    self.items[il0] = None;
+                                }
+                                Ok(Break(ChannelEvents::Events(ritem)))
+                            }
+                        } else {
+                            // TODO should never be here because ts-max should always exist here.
+                            let ritem = item.take_new_events_until_ts(tl1);
+                            if item.len() == 0 {}
+                            Ok(Break(ChannelEvents::Events(ritem)))
+                        }
+                    }
+                    ChannelEvents::Status(_) => {
+                        let ret = self.items[il0].take().unwrap();
+                        Ok(Break(ret))
+                    }
+                }
+            } else {
+                let item = self.items[il0].as_mut().unwrap();
+                match item {
+                    ChannelEvents::Events(_) => {
+                        let ret = self.items[il0].take().unwrap();
+                        Ok(Break(ret))
+                    }
+                    ChannelEvents::Status(_) => {
+                        let ret = self.items[il0].take().unwrap();
+                        Ok(Break(ret))
+                    }
+                }
+            }
+        } else {
+            Err(format!("after low ts search nothing found").into())
+        }
+    }
+
+    fn refill(mut self: Pin<&mut Self>, cx: &mut Context) -> ControlFlow<Poll<Error>> {
+        use ControlFlow::*;
+        use Poll::*;
+        let mut has_pending = false;
+        for i1 in 0..self.inps.len() {
+            let item = &self.items[i1];
+            if item.is_none() {
+                while let Some(inp) = &mut self.inps[i1] {
+                    match inp.poll_next_unpin(cx) {
+                        Ready(Some(Ok(k))) => {
+                            match k {
+                                StreamItem::DataItem(k) => match k {
+                                    RangeCompletableItem::RangeComplete => {
+                                        trace!("---------------------  ChannelEvents::RangeComplete \n======================");
+                                        // TODO track range complete for all inputs, it's only complete if all inputs are complete.
+                                        self.range_complete = true;
+                                        eprintln!("TODO inp RangeComplete which does not fill slot");
+                                    }
+                                    RangeCompletableItem::Data(k) => {
+                                        match &k {
+                                            ChannelEvents::Events(events) => {
+                                                if events.len() == 0 {
+                                                    warn!("empty events item {events:?}");
+                                                } else {
+                                                    trace!(
+                                                        "\nrefilled with events {}\nREFILLED\n{:?}\n\n",
+                                                        events.len(),
+                                                        events
+                                                    );
+                                                }
+                                            }
+                                            ChannelEvents::Status(_) => {
+                                                eprintln!("TODO inp Status which does not fill slot");
+                                            }
+                                        }
+                                        self.items[i1] = Some(k);
+                                        break;
+                                    }
+                                },
+                                StreamItem::Log(_) => {
+                                    eprintln!("TODO inp Log which does not fill slot");
+                                }
+                                StreamItem::Stats(_) => {
+                                    eprintln!("TODO inp Stats which does not fill slot");
+                                }
+                            }
+                        }
+                        Ready(Some(Err(e))) => return Break(Ready(e.into())),
+                        Ready(None) => {
+                            self.inps[i1] = None;
+                        }
+                        Pending => {
+                            has_pending = true;
+                        }
+                    }
+                }
+            }
+        }
+        if has_pending {
+            Break(Pending)
+        } else {
+            Continue(())
+        }
+    }
+
+    fn poll2(mut self: Pin<&mut Self>, cx: &mut Context) -> ControlFlow<Poll<Option<Result<ChannelEvents, Error>>>> {
+        use ControlFlow::*;
+        use Poll::*;
+        let mut has_pending = false;
+        match Self::refill(Pin::new(&mut self), cx) {
+            Break(Ready(e)) => return Break(Ready(Some(Err(e)))),
+            Break(Pending) => {
+                has_pending = true;
+            }
+            Continue(()) => {}
+        }
+        let ninps = self.inps.iter().filter(|a| a.is_some()).count();
+        let nitems = self.items.iter().filter(|a| a.is_some()).count();
+        let nitemsmissing = self
+            .inps
+            .iter()
+            .zip(self.items.iter())
+            .filter(|(a, b)| a.is_some() && b.is_none())
+            .count();
+        if ninps == 0 && nitems == 0 {
+            self.done = true;
+            Break(Ready(None))
+        } else if nitemsmissing != 0 {
+            if !has_pending {
+                let e = Error::from(format!("missing but no pending"));
+                Break(Ready(Some(Err(e))))
+            } else {
+                Break(Pending)
+            }
+        } else {
+            match Self::process(Pin::new(&mut self), cx) {
+                Ok(Break(item)) => Break(Ready(Some(Ok(item)))),
+                Ok(Continue(())) => Continue(()),
+                Err(e) => Break(Ready(Some(Err(e)))),
+            }
+        }
+    }
+}
+
+impl Stream for ChannelEventsMerger {
+    type Item = Sitemty<ChannelEvents>;
+
+    fn poll_next(mut self: Pin<&mut Self>, cx: &mut Context) -> Poll<Option<Self::Item>> {
+        use Poll::*;
+        const NAME: &str = "ChannelEventsMerger";
+        let span = span!(Level::TRACE, NAME);
+        let _spanguard = span.enter();
+        loop {
+            break if self.complete {
+                panic!("poll after complete");
+            } else if self.done2 {
+                self.complete = true;
+                Ready(None)
+            } else if self.done {
+                self.done2 = true;
+                if self.range_complete {
+                    trace!("MERGER EMITTING ChannelEvents::RangeComplete");
+                    Ready(Some(Ok(StreamItem::DataItem(RangeCompletableItem::RangeComplete))))
+                } else {
+                    continue;
+                }
+            } else {
+                match Self::poll2(self.as_mut(), cx) {
+                    ControlFlow::Continue(()) => continue,
+                    ControlFlow::Break(k) => match k {
+                        Ready(Some(Ok(ChannelEvents::Events(item)))) => {
+                            trace!("\n\nMERGER EMITTING\n{:?}\n\n", item);
+                            Ready(Some(Ok(StreamItem::DataItem(RangeCompletableItem::Data(
+                                ChannelEvents::Events(item),
+                            )))))
+                        }
+                        Ready(Some(Ok(ChannelEvents::Status(item)))) => {
+                            trace!("\n\nMERGER EMITTING\n{:?}\n\n", item);
+                            Ready(Some(Ok(StreamItem::DataItem(RangeCompletableItem::Data(
+                                ChannelEvents::Status(item),
+                            )))))
+                        }
+                        Ready(Some(Err(e))) => {
+                            self.done = true;
+                            Ready(Some(Err(e.into())))
+                        }
+                        Ready(None) => {
+                            self.done = true;
+                            continue;
+                        }
+                        Pending => Pending,
+                    },
+                }
+            };
+        }
+    }
+}

items_2/src/test.rs

@@ -1,16 +1,128 @@
 use crate::binsdim0::BinsDim0CollectedResult;
 use crate::eventsdim0::EventsDim0;
-use crate::merger::ChannelEventsMerger;
+use crate::merger::{Mergeable, Merger};
+use crate::merger_cev::ChannelEventsMerger;
+use crate::testgen::make_some_boxed_d0_f32;
 use crate::{binned_collected, runfut, ChannelEvents, Empty, Events, IsoDateTime};
 use crate::{ConnStatus, ConnStatusEvent, Error};
 use chrono::{TimeZone, Utc};
-use futures_util::StreamExt;
-use items::{RangeCompletableItem, Sitemty, StreamItem};
+use futures_util::{stream, StreamExt};
+use items::{sitem_data, RangeCompletableItem, Sitemty, StreamItem};
 use netpod::log::*;
 use netpod::timeunits::*;
 use netpod::{AggKind, BinnedRange, NanoRange, ScalarType, Shape};
 use std::time::Duration;
 
+#[test]
+fn items_move_events() {
+    let evs = make_some_boxed_d0_f32(10, SEC, SEC, 0, 1846713782);
+    let v0 = ChannelEvents::Events(evs);
+    let mut v1 = v0.clone();
+    eprintln!("{v1:?}");
+    eprintln!("{}", v1.len());
+    let mut v2 = v1.move_into_fresh(4);
+    eprintln!("{}", v1.len());
+    eprintln!("{}", v2.len());
+    v1.move_into_existing(&mut v2, u64::MAX).unwrap();
+    eprintln!("{}", v1.len());
+    eprintln!("{}", v2.len());
+    eprintln!("{v1:?}");
+    eprintln!("{v2:?}");
+    assert_eq!(v1.len(), 0);
+    assert_eq!(v2.len(), 10);
+    assert_eq!(v2, v0);
+}
+
+#[test]
+fn items_merge_00() {
+    let fut = async {
+        use crate::merger::Merger;
+        let evs0 = make_some_boxed_d0_f32(10, SEC * 1, SEC * 2, 0, 1846713782);
+        let evs1 = make_some_boxed_d0_f32(10, SEC * 2, SEC * 2, 0, 828764893);
+        let v0 = ChannelEvents::Events(evs0);
+        let v1 = ChannelEvents::Events(evs1);
+        let stream0 = Box::pin(stream::iter(vec![sitem_data(v0)]));
+        let stream1 = Box::pin(stream::iter(vec![sitem_data(v1)]));
+        let mut merger = Merger::new(vec![stream0, stream1], 8);
+        while let Some(item) = merger.next().await {
+            eprintln!("{item:?}");
+        }
+        Ok(())
+    };
+    runfut(fut).unwrap();
+}
+
+#[test]
+fn items_merge_01() {
+    let fut = async {
+        use crate::merger::Merger;
+        let evs0 = make_some_boxed_d0_f32(10, SEC * 1, SEC * 2, 0, 1846713782);
+        let evs1 = make_some_boxed_d0_f32(10, SEC * 2, SEC * 2, 0, 828764893);
+        let v0 = ChannelEvents::Events(evs0);
+        let v1 = ChannelEvents::Events(evs1);
+        let v2 = ChannelEvents::Status(ConnStatusEvent::new(MS * 100, ConnStatus::Connect));
+        let v3 = ChannelEvents::Status(ConnStatusEvent::new(MS * 2300, ConnStatus::Disconnect));
+        let v4 = ChannelEvents::Status(ConnStatusEvent::new(MS * 2800, ConnStatus::Connect));
+        let stream0 = Box::pin(stream::iter(vec![sitem_data(v0)]));
+        let stream1 = Box::pin(stream::iter(vec![sitem_data(v1)]));
+        let stream2 = Box::pin(stream::iter(vec![sitem_data(v2), sitem_data(v3), sitem_data(v4)]));
+        let mut merger = Merger::new(vec![stream0, stream1, stream2], 8);
+        let mut total_event_count = 0;
+        while let Some(item) = merger.next().await {
+            eprintln!("{item:?}");
+            let item = item?;
+            match item {
+                StreamItem::DataItem(item) => match item {
+                    RangeCompletableItem::RangeComplete => {}
+                    RangeCompletableItem::Data(item) => {
+                        total_event_count += item.len();
+                    }
+                },
+                StreamItem::Log(_) => {}
+                StreamItem::Stats(_) => {}
+            }
+        }
+        assert_eq!(total_event_count, 23);
+        Ok(())
+    };
+    runfut(fut).unwrap();
+}
+
+#[test]
+fn items_merge_02() {
+    let fut = async {
+        let evs0 = make_some_boxed_d0_f32(100, SEC * 1, SEC * 2, 0, 1846713782);
+        let evs1 = make_some_boxed_d0_f32(100, SEC * 2, SEC * 2, 0, 828764893);
+        let v0 = ChannelEvents::Events(evs0);
+        let v1 = ChannelEvents::Events(evs1);
+        let v2 = ChannelEvents::Status(ConnStatusEvent::new(MS * 100, ConnStatus::Connect));
+        let v3 = ChannelEvents::Status(ConnStatusEvent::new(MS * 2300, ConnStatus::Disconnect));
+        let v4 = ChannelEvents::Status(ConnStatusEvent::new(MS * 2800, ConnStatus::Connect));
+        let stream0 = Box::pin(stream::iter(vec![sitem_data(v0)]));
+        let stream1 = Box::pin(stream::iter(vec![sitem_data(v1)]));
+        let stream2 = Box::pin(stream::iter(vec![sitem_data(v2), sitem_data(v3), sitem_data(v4)]));
+        let mut merger = Merger::new(vec![stream0, stream1, stream2], 8);
+        let mut total_event_count = 0;
+        while let Some(item) = merger.next().await {
+            eprintln!("{item:?}");
+            let item = item.unwrap();
+            match item {
+                StreamItem::DataItem(item) => match item {
+                    RangeCompletableItem::RangeComplete => {}
+                    RangeCompletableItem::Data(item) => {
+                        total_event_count += item.len();
+                    }
+                },
+                StreamItem::Log(_) => {}
+                StreamItem::Stats(_) => {}
+            }
+        }
+        assert_eq!(total_event_count, 203);
+        Ok(())
+    };
+    runfut(fut).unwrap();
+}
+
 #[test]
 fn merge01() {
     let fut = async {

items_2/src/testgen.rs

@@ -0,0 +1,23 @@
+use crate::eventsdim0::EventsDim0;
+use crate::{Empty, Events};
+
+#[allow(unused)]
+fn xorshift32(state: u32) -> u32 {
+    let mut x = state;
+    x ^= x << 13;
+    x ^= x >> 17;
+    x ^= x << 5;
+    x
+}
+
+pub fn make_some_boxed_d0_f32(n: usize, t0: u64, tstep: u64, tmask: u64, seed: u32) -> Box<dyn Events> {
+    let mut vstate = seed;
+    let mut events = EventsDim0::empty();
+    for i in 0..n {
+        vstate = xorshift32(vstate);
+        let ts = t0 + i as u64 * tstep + (vstate as u64 & tmask);
+        let value = i as f32 * 100. + vstate as f32 / u32::MAX as f32 / 10.;
+        events.push(ts, ts, value);
+    }
+    Box::new(events.clone())
+}

items_2/src/timebin.rs

@@ -0,0 +1,29 @@
+use std::fmt;
+
+pub trait TimeBinner: fmt::Debug + Unpin {
+    type Input;
+    type Output;
+
+    fn ingest(&mut self, item: &mut Self::Input);
+
+    fn set_range_complete(&mut self);
+
+    fn bins_ready_count(&self) -> usize;
+
+    fn bins_ready(&mut self) -> Option<Self::Output>;
+
+    /// If there is a bin in progress with non-zero count, push it to the result set.
+    /// With push_empty == true, a bin in progress is pushed even if it contains no counts.
+    fn push_in_progress(&mut self, push_empty: bool);
+
+    /// Implies `Self::push_in_progress` but in addition, pushes a zero-count bin if the call
+    /// to `push_in_progress` did not change the result count, as long as edges are left.
+    /// The next call to `Self::bins_ready_count` must return one higher count than before.
+    fn cycle(&mut self);
+}
+
+pub trait TimeBinnable: fmt::Debug + Sized {
+    type TimeBinner: TimeBinner<Input = Self>;
+
+    fn time_binner_new(&self, edges: Vec<u64>, do_time_weight: bool) -> Self::TimeBinner;
+}