From 858b5455d7142a4df01a7d09d2ec2af769a0df0e Mon Sep 17 00:00:00 2001
From: Clement Rey <cr.rey.clement@gmail.com>
Date: Thu, 18 Apr 2024 15:18:58 +0200
Subject: [PATCH] introduce non-cacheable components

---
 crates/re_query/src/latest_at/query.rs | 19 +++++++++++-----
 crates/re_query/src/lib.rs             | 31 ++++++++++++++++++++++++++
 crates/re_query/src/range/query.rs     | 18 ++++++++++-----
 3 files changed, 56 insertions(+), 12 deletions(-)

diff --git a/crates/re_query/src/latest_at/query.rs b/crates/re_query/src/latest_at/query.rs
index b4ca7cdfe059..8107647fc3a1 100644
--- a/crates/re_query/src/latest_at/query.rs
+++ b/crates/re_query/src/latest_at/query.rs
@@ -33,12 +33,19 @@ impl Caches {
 
         for component_name in component_names {
             let key = CacheKey::new(entity_path.clone(), query.timeline(), component_name);
-            let cache = Arc::clone(
-                self.latest_at_per_cache_key
-                    .write()
-                    .entry(key.clone())
-                    .or_insert_with(|| Arc::new(RwLock::new(LatestAtCache::new(key.clone())))),
-            );
+
+            let cache = if crate::cacheable(component_name) {
+                Arc::clone(
+                    self.latest_at_per_cache_key
+                        .write()
+                        .entry(key.clone())
+                        .or_insert_with(|| Arc::new(RwLock::new(LatestAtCache::new(key.clone())))),
+                )
+            } else {
+                // If the component shouldn't be cached, simply instantiate a new cache for it.
+                // It will be dropped when the user is done with it.
+                Arc::new(RwLock::new(LatestAtCache::new(key.clone())))
+            };
 
             let mut cache = cache.write();
             cache.handle_pending_invalidation();
diff --git a/crates/re_query/src/lib.rs b/crates/re_query/src/lib.rs
index d75b866986dd..d9c9e5d26098 100644
--- a/crates/re_query/src/lib.rs
+++ b/crates/re_query/src/lib.rs
@@ -117,3 +117,34 @@ impl From<(RangeQuery, RangeResults)> for Results {
         Self::Range(query, results)
     }
 }
+
+// ---
+
+/// Returns `true` if the specified `component_name` can be cached.
+///
+/// Used internally to avoid unnecessarily caching components that are already cached in other
+/// places, for historical reasons.
+pub fn cacheable(component_name: re_types::ComponentName) -> bool {
+    use std::sync::OnceLock;
+    static NOT_CACHEABLE: OnceLock<re_types::ComponentNameSet> = OnceLock::new();
+
+    use re_types_core::Loggable as _;
+    let not_cacheable = NOT_CACHEABLE.get_or_init(|| {
+        [
+            // TODO(#5303): instance keys are on their way out anyhow.
+            re_types::components::InstanceKey::name(),
+            // TODO(#5974): tensors might already be cached in the ad-hoc JPEG cache, we don't
+            // want yet another copy.
+            re_types::components::TensorData::name(),
+            // TODO(#5974): meshes are already cached in the ad-hoc mesh cache, we don't
+            // want yet another copy.
+            re_types::components::MeshProperties::name(),
+            // TODO(#5974): blobs are used for assets, which are themselves already cached in
+            // the ad-hoc mesh cache -- we don't want yet another copy.
+            re_types::components::Blob::name(),
+        ]
+        .into()
+    });
+
+    !not_cacheable.contains(&component_name)
+}
diff --git a/crates/re_query/src/range/query.rs b/crates/re_query/src/range/query.rs
index 649aa7ef8700..28277cc16e94 100644
--- a/crates/re_query/src/range/query.rs
+++ b/crates/re_query/src/range/query.rs
@@ -33,12 +33,18 @@ impl Caches {
         for component_name in component_names {
             let key = CacheKey::new(entity_path.clone(), query.timeline(), component_name);
 
-            let cache = Arc::clone(
-                self.range_per_cache_key
-                    .write()
-                    .entry(key.clone())
-                    .or_insert_with(|| Arc::new(RwLock::new(RangeCache::new(key.clone())))),
-            );
+            let cache = if crate::cacheable(component_name) {
+                Arc::clone(
+                    self.range_per_cache_key
+                        .write()
+                        .entry(key.clone())
+                        .or_insert_with(|| Arc::new(RwLock::new(RangeCache::new(key.clone())))),
+                )
+            } else {
+                // If the component shouldn't be cached, simply instantiate a new cache for it.
+                // It will be dropped when the user is done with it.
+                Arc::new(RwLock::new(RangeCache::new(key.clone())))
+            };
 
             let mut cache = cache.write();
             cache.handle_pending_invalidation();