Primary caching 12: barebone range support (#4784)

**Prefer on a per-commit basis, stuff has moved around**

Range queries are back!... in the most primitive form possible.

No invalidation, no bucketing, no optimization, no nothing. Just putting
everything in place.


https://github.com/rerun-io/rerun/assets/2910679/a65281e4-9843-4598-9547-ce7e45197995

---

Part of the primary caching series of PR (index search, joins,
deserialization):
- #4592
- #4593
- #4659
- #4680 
- #4681
- #4698
- #4711
- #4712
- #4721 
- #4726 
- #4773
- #4784
- #4785
- #4793
- #4800

crates/re_data_store/benches/arrow2.rs

@@ -5,7 +5,7 @@ static GLOBAL: mimalloc::MiMalloc = mimalloc::MiMalloc;
 
 use std::sync::Arc;
 
-use arrow2::array::{Array, PrimitiveArray, StructArray, UnionArray};
+use arrow2::array::{Array, FixedSizeListArray, PrimitiveArray, StructArray};
 use criterion::Criterion;
 use itertools::Itertools;
 
@@ -277,8 +277,8 @@ fn estimated_size_bytes(c: &mut Criterion) {
                 ArrayKind::Primitive => {
                     bench_downcast_first::<PrimitiveArray<u64>>(&mut group, kind);
                 }
-                ArrayKind::Struct => bench_downcast_first::<StructArray>(&mut group, kind),
-                ArrayKind::StructLarge => bench_downcast_first::<UnionArray>(&mut group, kind),
+                ArrayKind::Struct => bench_downcast_first::<FixedSizeListArray>(&mut group, kind),
+                ArrayKind::StructLarge => bench_downcast_first::<StructArray>(&mut group, kind),
             }
 
             fn bench_downcast_first<T: arrow2::array::Array + Clone>(

crates/re_log_types/src/example_components.rs

@@ -1,25 +1,35 @@
 //! Example components to be used for tests and docs
 
-use re_types_core::{Loggable, SizeBytes};
+use re_types_core::{components::InstanceKey, Loggable, SizeBytes};
 
 // ----------------------------------------------------------------------------
 
 #[derive(Debug)]
 pub struct MyPoints;
 
+impl MyPoints {
+    pub const NUM_COMPONENTS: usize = 5;
+}
+
 impl re_types_core::Archetype for MyPoints {
     type Indicator = re_types_core::GenericIndicatorComponent<Self>;
 
     fn name() -> re_types_core::ArchetypeName {
-        "test.MyPoints".into()
+        "example.MyPoints".into()
     }
 
     fn required_components() -> ::std::borrow::Cow<'static, [re_types_core::ComponentName]> {
         vec![MyPoint::name()].into()
     }
 
     fn recommended_components() -> std::borrow::Cow<'static, [re_types_core::ComponentName]> {
-        vec![MyColor::name(), MyLabel::name()].into()
+        vec![
+            re_types_core::LoggableBatch::name(&Self::Indicator::default()),
+            InstanceKey::name(),
+            MyColor::name(),
+            MyLabel::name(),
+        ]
+        .into()
     }
 }
 
@@ -32,6 +42,7 @@ pub struct MyPoint {
 }
 
 impl MyPoint {
+    #[inline]
     pub fn new(x: f32, y: f32) -> Self {
         Self { x, y }
     }
@@ -121,7 +132,15 @@ impl Loggable for MyPoint {
 #[repr(transparent)]
 pub struct MyColor(pub u32);
 
+impl MyColor {
+    #[inline]
+    pub fn from_rgb(r: u8, g: u8, b: u8) -> Self {
+        Self(u32::from_le_bytes([r, g, b, 255]))
+    }
+}
+
 impl From<u32> for MyColor {
+    #[inline]
     fn from(value: u32) -> Self {
         Self(value)
     }

crates/re_query_cache/src/cache.rs

@@ -18,7 +18,7 @@ use re_types_core::{
     components::InstanceKey, Archetype, ArchetypeName, Component, ComponentName, SizeBytes as _,
 };
 
-use crate::{ErasedFlatVecDeque, FlatVecDeque};
+use crate::{ErasedFlatVecDeque, FlatVecDeque, LatestAtCache, RangeCache};
 
 // ---
 
@@ -67,6 +67,17 @@ pub struct CachesPerArchetype {
     // than an `ArchetypeName`: the query system doesn't care about archetypes.
     pub(crate) latest_at_per_archetype: RwLock<HashMap<ArchetypeName, Arc<RwLock<LatestAtCache>>>>,
 
+    /// Which [`Archetype`] are we querying for?
+    ///
+    /// This is very important because of our data model: we not only query for components, but we
+    /// query for components from a specific point-of-view (the so-called primary component).
+    /// Different archetypes have different point-of-views, and therefore can end up with different
+    /// results, even from the same raw data.
+    //
+    // TODO(cmc): At some point we should probably just store the PoV and optional components rather
+    // than an `ArchetypeName`: the query system doesn't care about archetypes.
+    pub(crate) range_per_archetype: RwLock<HashMap<ArchetypeName, Arc<RwLock<RangeCache>>>>,
+
     /// Everything greater than or equal to this timestamp has been asynchronously invalidated.
     ///
     /// The next time this cache gets queried, it must remove any entry matching this criteria.
@@ -134,6 +145,42 @@ impl Caches {
         f(&mut cache)
     }
 
+    /// Gives write access to the appropriate `RangeCache` according to the specified
+    /// query parameters.
+    #[inline]
+    pub fn with_range<A, F, R>(
+        store_id: StoreId,
+        entity_path: EntityPath,
+        query: &RangeQuery,
+        mut f: F,
+    ) -> R
+    where
+        A: Archetype,
+        F: FnMut(&mut RangeCache) -> R,
+    {
+        let key = CacheKey::new(store_id, entity_path, query.timeline);
+
+        let cache =
+            re_data_store::DataStore::with_subscriber_once(*CACHES, move |caches: &Caches| {
+                let mut caches = caches.0.write();
+
+                let caches_per_archetype = caches.entry(key.clone()).or_default();
+                caches_per_archetype.handle_pending_invalidation(&key);
+
+                let mut range_per_archetype = caches_per_archetype.range_per_archetype.write();
+                let range_cache = range_per_archetype.entry(A::name()).or_default();
+
+                Arc::clone(range_cache)
+
+                // Implicitly releasing all intermediary locks.
+            })
+            // NOTE: downcasting cannot fail, this is our own private handle.
+            .unwrap();
+
+        let mut cache = cache.write();
+        f(&mut cache)
+    }
+
     #[inline]
     pub(crate) fn with<F: FnMut(&Caches) -> R, R>(f: F) -> R {
         // NOTE: downcasting cannot fail, this is our own private handle.
@@ -347,6 +394,9 @@ pub struct CacheBucket {
     ///
     /// This corresponds to the data time and `RowId` returned by `re_query::query_archetype`.
     ///
+    /// This is guaranteed to always be sorted and dense (i.e. there cannot be a hole in the cached
+    /// data, unless the raw data itself in the store has a hole at that particular point in time).
+    ///
     /// Reminder: within a single timestamp, rows are sorted according to their [`RowId`]s.
     pub(crate) data_times: VecDeque<(TimeInt, RowId)>,
 
@@ -375,6 +425,18 @@ impl CacheBucket {
         self.data_times.iter()
     }
 
+    #[inline]
+    pub fn contains_data_time(&self, data_time: TimeInt) -> bool {
+        let first_time = self.data_times.front().map_or(&TimeInt::MAX, |(t, _)| t);
+        let last_time = self.data_times.back().map_or(&TimeInt::MIN, |(t, _)| t);
+        *first_time <= data_time && data_time <= *last_time
+    }
+
+    #[inline]
+    pub fn contains_data_row(&self, data_time: TimeInt, row_id: RowId) -> bool {
+        self.data_times.binary_search(&(data_time, row_id)).is_ok()
+    }
+
     /// Iterate over the [`InstanceKey`] batches of the point-of-view components.
     #[inline]
     pub fn iter_pov_instance_keys(&self) -> impl Iterator<Item = &[InstanceKey]> {
@@ -554,42 +616,3 @@ impl CacheBucket {
         Ok(added_size_bytes)
     }
 }
-
-// ---
-
-// NOTE: Because we're working with deserialized data, everything has to be done with metaprogramming,
-// which is notoriously painful in Rust (i.e., macros).
-// For this reason we move as much of the code as possible into the already existing macros in `query.rs`.
-
-/// Caches the results of `LatestAt` archetype queries (`ArchetypeView`).
-///
-/// There is one `LatestAtCache` for each unique [`CacheKey`].
-///
-/// All query steps are cached: index search, cluster key joins and deserialization.
-#[derive(Default)]
-pub struct LatestAtCache {
-    /// Organized by _query_ time.
-    ///
-    /// If the data you're looking for isn't in here, try partially running the query (i.e. run the
-    /// index search in order to find a data time, but don't actually deserialize and join the data)
-    /// and check if there is any data available for the resulting _data_ time in [`Self::per_data_time`].
-    pub per_query_time: BTreeMap<TimeInt, Arc<RwLock<CacheBucket>>>,
-
-    /// Organized by _data_ time.
-    ///
-    /// Due to how our latest-at semantics work, any number of queries at time `T+n` where `n >= 0`
-    /// can result in a data time of `T`.
-    pub per_data_time: BTreeMap<TimeInt, Arc<RwLock<CacheBucket>>>,
-
-    /// Dedicated bucket for timeless data, if any.
-    ///
-    /// Query time and data time are one and the same in the timeless case, therefore we only need
-    /// this one bucket.
-    //
-    // NOTE: Lives separately so we don't pay the extra `Option` cost in the much more common
-    // timeful case.
-    pub timeless: Option<CacheBucket>,
-
-    /// Total size of the data stored in this cache in bytes.
-    pub total_size_bytes: u64,
-}