Introduce another KeyValueStoreView

linera-execution/Cargo.toml

@@ -12,6 +12,7 @@ repository.workspace = true
 version.workspace = true
 
 [features]
+smallkeyvaluestoreview = []
 test = ["tokio/macros", "linera-base/test", "linera-views/test", "proptest"]
 revm = [
     "dep:revm",

linera-execution/src/execution.rs

@@ -13,7 +13,6 @@ use linera_base::{
 };
 use linera_views::{
     context::Context,
-    key_value_store_view::KeyValueStoreView,
     map_view::MapView,
     reentrant_collection_view::HashedReentrantCollectionView,
     views::{ClonableView, ReplaceContext, View},
@@ -44,7 +43,18 @@ pub struct ExecutionStateView<C> {
     /// System application.
     pub system: SystemExecutionStateView<C>,
     /// User applications.
-    pub users: HashedReentrantCollectionView<C, ApplicationId, KeyValueStoreView<C>>,
+    #[cfg(not(feature = "smallkeyvaluestoreview"))]
+    pub users: HashedReentrantCollectionView<
+        C,
+        ApplicationId,
+        linera_views::small_key_value_store_view::SmallKeyValueStoreView<C>,
+    >,
+    #[cfg(feature = "smallkeyvaluestoreview")]
+    pub users: HashedReentrantCollectionView<
+        C,
+        ApplicationId,
+        linera_views::key_value_store_view::KeyValueStoreView<C>,
+    >,
     /// The number of events in the streams that this chain is writing to.
     pub stream_event_counts: MapView<C, StreamId, u32>,
 }

linera-views/src/lib.rs

@@ -117,7 +117,7 @@ pub use backends::scylla_db;
 pub use backends::{journaling, lru_caching, memory, value_splitting};
 pub use views::{
     bucket_queue_view, collection_view, hashable_wrapper, key_value_store_view, log_view, map_view,
-    queue_view, reentrant_collection_view, register_view, set_view,
+    queue_view, reentrant_collection_view, register_view, set_view, small_key_value_store_view,
 };
 /// Re-exports used by the derive macros of this library.
 #[doc(hidden)]

linera-views/src/views/key_value_store_view.rs

@@ -396,12 +396,12 @@ impl<C: Context> KeyValueStoreView<C> {
     /// # use linera_views::views::View;
     /// # let context = MemoryContext::new_for_testing(());
     /// let mut view = KeyValueStoreView::load(context).await.unwrap();
-    /// let total_size = view.total_size();
+    /// let total_size = view.total_size().unwrap();
     /// assert_eq!(total_size, SizeData::default());
     /// # })
     /// ```
-    pub fn total_size(&self) -> SizeData {
-        self.total_size
+    pub fn total_size(&self) -> Result<SizeData, ViewError> {
+        Ok(self.total_size)
     }
 
     /// Applies the function f over all indices. If the function f returns

linera-views/src/views/mod.rs

@@ -42,6 +42,9 @@ pub mod reentrant_collection_view;
 /// The implementation of a key-value store view.
 pub mod key_value_store_view;
 
+/// The implementation of a key-value store view using a single BTreeMap.
+pub mod small_key_value_store_view;
+
 /// Wrapping a view to compute a hash.
 pub mod hashable_wrapper;