From 7a89ecbc3c7eb9958af4b8794f505b917d5da71a Mon Sep 17 00:00:00 2001
From: Ziyang Hu <hu.ziyang@cantab.net>
Date: Fri, 23 Dec 2022 17:04:13 +0800
Subject: [PATCH] time travel bench size

---
 cozo-core/benches/time_travel.rs | 24 +++++++++++++++++-
 cozo-core/src/data/aggr.rs       | 42 ++++++++++++++++++++++++++++++++
 2 files changed, 65 insertions(+), 1 deletion(-)

diff --git a/cozo-core/benches/time_travel.rs b/cozo-core/benches/time_travel.rs
index 01a15d9c..5aec2530 100644
--- a/cozo-core/benches/time_travel.rs
+++ b/cozo-core/benches/time_travel.rs
@@ -133,7 +133,19 @@ fn single_tt_read(k: usize) {
     TEST_DB
         .run_script(
             &format!(r#"
-            ?[min_cost(pack)] := *tt{}{{k: $id, vld, v}}, pack = [v, vld]
+            ?[smallest_by(pack)] := *tt{}{{k: $id, vld, v}}, pack = [v, vld]
+            "#, k),
+            BTreeMap::from([("id".to_string(), json!(i))]),
+        )
+        .unwrap();
+}
+
+fn single_tt_travel_read(k: usize) {
+    let i = rand::thread_rng().gen_range(0..10000);
+    TEST_DB
+        .run_script(
+            &format!(r#"
+            ?[v] := *tt{}{{k: $id v @ "NOW"}}
             "#, k),
             BTreeMap::from([("id".to_string(), json!(i))]),
         )
@@ -160,4 +172,14 @@ fn time_travel_init(_: &mut Bencher) {
         dbg!(k);
         dbg!((count as f64) / qps_single_tt_time.elapsed().as_secs_f64());
     }
+
+    for k in [1, 10, 100, 1000] {
+        let count = 100_000;
+        let qps_single_tt_travel_time = Instant::now();
+        (0..count).into_par_iter().for_each(|_| {
+            single_tt_travel_read(k);
+        });
+        dbg!(k);
+        dbg!((count as f64) / qps_single_tt_travel_time.elapsed().as_secs_f64());
+    }
 }
diff --git a/cozo-core/src/data/aggr.rs b/cozo-core/src/data/aggr.rs
index fe821ed6..c79b119f 100644
--- a/cozo-core/src/data/aggr.rs
+++ b/cozo-core/src/data/aggr.rs
@@ -756,6 +756,47 @@ impl NormalAggrObj for AggrLatestBy {
     }
 }
 
+define_aggr!(AGGR_SMALLEST_BY, false);
+
+pub(crate) struct AggrSmallestBy {
+    found: DataValue,
+    cost: DataValue,
+}
+
+impl Default for AggrSmallestBy {
+    fn default() -> Self {
+        Self {
+            found: DataValue::Null,
+            cost: DataValue::Null,
+        }
+    }
+}
+
+impl NormalAggrObj for AggrSmallestBy {
+    fn set(&mut self, value: &DataValue) -> Result<()> {
+        match value {
+            DataValue::List(l) => {
+                ensure!(
+                    l.len() == 2,
+                    "'smallest_by' requires a list of exactly two items as argument"
+                );
+                let c = &l[1];
+                if *c < self.cost {
+                    self.cost = c.clone();
+                    self.found = l[0].clone();
+                }
+                Ok(())
+            }
+            v => bail!("cannot compute 'smallest_by' on {:?}", v),
+        }
+    }
+
+    fn get(&self) -> Result<DataValue> {
+        Ok(self.found.clone())
+    }
+}
+
+
 define_aggr!(AGGR_MIN_COST, true);
 
 pub(crate) struct AggrMinCost {
@@ -1188,6 +1229,7 @@ impl Aggregation {
             name if name == AGGR_SHORTEST.name => Box::new(AggrShortest::default()),
             name if name == AGGR_MIN_COST.name => Box::new(AggrMinCost::default()),
             name if name == AGGR_LATEST_BY.name => Box::new(AggrLatestBy::default()),
+            name if name == AGGR_SMALLEST_BY.name => Box::new(AggrSmallestBy::default()),
             name if name == AGGR_CHOICE_RAND.name => Box::new(AggrChoiceRand::default()),
             name if name == AGGR_COLLECT.name => Box::new({
                 if args.is_empty() {