review

crates/re_query2/Cargo.toml

@@ -47,6 +47,7 @@ itertools = { workspace = true }
 nohash-hasher.workspace = true
 serde = { workspace = true, features = ["derive", "rc"], optional = true }
 smallvec.workspace = true
+static_assertions.workspace = true
 thiserror.workspace = true
 
 # Optional:

crates/re_query2/benches/latest_at.rs

@@ -283,7 +283,7 @@ fn query_and_visit_points(store: &DataStore, paths: &[EntityPath]) -> Vec<SavePo
         );
 
         let points = results.get_required::<Position2D>().unwrap();
-        let colors = results.get_optional::<Color>();
+        let colors = results.get_or_empty::<Color>();
 
         let points = points
             .iter_dense::<Position2D>(&resolver)
@@ -325,7 +325,7 @@ fn query_and_visit_strings(store: &DataStore, paths: &[EntityPath]) -> Vec<SaveS
         );
 
         let points = results.get_required::<Position2D>().unwrap();
-        let colors = results.get_optional::<Text>();
+        let colors = results.get_or_empty::<Text>();
 
         let points = points
             .iter_dense::<Position2D>(&resolver)

crates/re_query2/examples/latest_at.rs

@@ -38,11 +38,11 @@ fn main() -> anyhow::Result<()> {
     // _component batch_ itself (that says nothing about its _instances_!).
     //
     // * `get_required` returns an error if the component batch is missing
-    // * `get_optional` returns an empty set of results if the component if missing
+    // * `get_or_empty` returns an empty set of results if the component if missing
     // * `get` returns an option
     let points: &LatestAtComponentResults = results.get_required::<MyPoint>()?;
-    let colors: &LatestAtComponentResults = results.get_optional::<MyColor>();
-    let labels: &LatestAtComponentResults = results.get_optional::<MyLabel>();
+    let colors: &LatestAtComponentResults = results.get_or_empty::<MyColor>();
+    let labels: &LatestAtComponentResults = results.get_or_empty::<MyLabel>();
 
     // Then comes the time to resolve/convert and deserialize the data.
     // These steps have to be done together for efficiency reasons.

crates/re_query2/src/latest_at/results.rs

@@ -12,7 +12,7 @@ use crate::{Promise, PromiseResolver, PromiseResult};
 /// The data is neither deserialized, nor resolved/converted.
 /// It it the raw [`DataCell`]s, straight from our datastore.
 ///
-/// Use [`LatestAtResults::get`], [`LatestAtResults::get_required`] and [`LatestAtResults::get_optional`]
+/// Use [`LatestAtResults::get`], [`LatestAtResults::get_required`] and [`LatestAtResults::get_or_empty`]
 /// in order to access the raw results for each individual component.
 #[derive(Debug, Clone)]
 pub struct LatestAtResults {
@@ -69,11 +69,11 @@ impl LatestAtResults {
     ///
     /// Returns empty results if the component is not present.
     #[inline]
-    pub fn get_optional<C: Component>(&self) -> &LatestAtComponentResults {
+    pub fn get_or_empty<C: Component>(&self) -> &LatestAtComponentResults {
         if let Some(component) = self.components.get(&C::name()) {
             component
         } else {
-            static DEFAULT: LatestAtComponentResults = LatestAtComponentResults::empty();
+            static DEFAULT: LatestAtComponentResults = LatestAtComponentResults::EMPTY;
             &DEFAULT
         }
     }
@@ -120,18 +120,15 @@ pub struct LatestAtComponentResults {
 impl Default for LatestAtComponentResults {
     #[inline]
     fn default() -> Self {
-        Self::empty()
+        Self::EMPTY
     }
 }
 
 impl LatestAtComponentResults {
-    #[inline]
-    const fn empty() -> Self {
-        Self {
-            index: (TimeInt::STATIC, RowId::ZERO),
-            promise: None,
-        }
-    }
+    const EMPTY: Self = Self {
+        index: (TimeInt::STATIC, RowId::ZERO),
+        promise: None,
+    };
 }
 
 impl LatestAtComponentResults {
@@ -188,11 +185,6 @@ impl LatestAtComponentResults {
         &self,
         resolver: &PromiseResolver,
     ) -> PromiseResult<DeserializationResult<Vec<Option<C>>>> {
-        // Manufactured empty result.
-        if self.promise.is_none() {
-            return PromiseResult::Ready(Ok(vec![]));
-        }
-
         if let Some(cell) = self.promise.as_ref() {
             resolver.resolve(cell).map(|cell| {
                 cell.try_to_native_opt()

crates/re_query2/src/promise.rs

@@ -37,6 +37,8 @@ pub struct Promise {
     source: DataCell,
 }
 
+static_assertions::assert_eq_size!(Promise, Option<Promise>);
+
 impl Promise {
     #[inline]
     pub fn new(source: DataCell) -> Self {

crates/re_query2/tests/latest_at.rs

@@ -61,16 +61,10 @@ fn simple_query() -> anyhow::Result<()> {
         ];
 
         let points = results.get_required::<MyPoint>()?;
-        let point_data = points
-            .iter_dense::<MyPoint>(&resolver)
-            .flatten()
-            .unwrap();
-
-        let colors = results.get_optional::<MyColor>();
-        let color_data = colors
-            .iter_sparse::<MyColor>(&resolver)
-            .flatten()
-            .unwrap();
+        let point_data = points.iter_dense::<MyPoint>(&resolver).flatten().unwrap();
+
+        let colors = results.get_or_empty::<MyColor>();
+        let color_data = colors.iter_sparse::<MyColor>(&resolver).flatten().unwrap();
         let color_default_fn = || Some(MyColor::from(0xFF00FFFF));
 
         let (got_points, got_colors): (Vec<_>, Vec<_>) =
@@ -137,16 +131,10 @@ fn static_query() -> anyhow::Result<()> {
         ];
 
         let points = results.get_required::<MyPoint>()?;
-        let point_data = points
-            .iter_dense::<MyPoint>(&resolver)
-            .flatten()
-            .unwrap();
-
-        let colors = results.get_optional::<MyColor>();
-        let color_data = colors
-            .iter_sparse::<MyColor>(&resolver)
-            .flatten()
-            .unwrap();
+        let point_data = points.iter_dense::<MyPoint>(&resolver).flatten().unwrap();
+
+        let colors = results.get_or_empty::<MyColor>();
+        let color_data = colors.iter_sparse::<MyColor>(&resolver).flatten().unwrap();
         let color_default_fn = || Some(MyColor::from(0xFF00FFFF));
 
         let (got_points, got_colors): (Vec<_>, Vec<_>) =
@@ -212,16 +200,10 @@ fn no_instance_join_query() -> anyhow::Result<()> {
         ];
 
         let points = results.get_required::<MyPoint>()?;
-        let point_data = points
-            .iter_dense::<MyPoint>(&resolver)
-            .flatten()
-            .unwrap();
-
-        let colors = results.get_optional::<MyColor>();
-        let color_data = colors
-            .iter_sparse::<MyColor>(&resolver)
-            .flatten()
-            .unwrap();
+        let point_data = points.iter_dense::<MyPoint>(&resolver).flatten().unwrap();
+
+        let colors = results.get_or_empty::<MyColor>();
+        let color_data = colors.iter_sparse::<MyColor>(&resolver).flatten().unwrap();
         let color_default_fn = || Some(MyColor::from(0xFF00FFFF));
 
         let (got_points, got_colors): (Vec<_>, Vec<_>) =