diff --git a/substrate/frame/system/src/lib.rs b/substrate/frame/system/src/lib.rs index 9b30e7b452276b65ec409b9ec1a841f48c2b5355..0eefc23a6b5d6d6352fe50b91806c349fef0a21c 100644 --- a/substrate/frame/system/src/lib.rs +++ b/substrate/frame/system/src/lib.rs @@ -591,11 +591,14 @@ pub mod pallet { /// Events deposited for the current block. /// - /// NOTE: This storage item is explicitly unbounded since it is never intended to be read - /// from within the runtime. + /// NOTE: The item is unbound and should therefore never be read on chain. + /// It could otherwise inflate the PoV size of a block. + /// + /// Events have a large in-memory size. Box the events to not go out-of-memory + /// just in case someone still reads them from within the runtime. #[pallet::storage] pub(super) type Events<T: Config> = - StorageValue<_, Vec<EventRecord<T::Event, T::Hash>>, ValueQuery>; + StorageValue<_, Vec<Box<EventRecord<T::Event, T::Hash>>>, ValueQuery>; /// The number of events in the `Events<T>` list. #[pallet::storage] @@ -1213,7 +1216,7 @@ impl<T: Config> Pallet<T> { old_event_count }; - Events::<T>::append(&event); + Events::<T>::append(event); for topic in topics { <EventTopics<T>>::append(topic, &(block_number, event_idx)); @@ -1380,14 +1383,16 @@ impl<T: Config> Pallet<T> { /// items for any behavior like this. #[cfg(any(feature = "std", feature = "runtime-benchmarks", test))] pub fn events() -> Vec<EventRecord<T::Event, T::Hash>> { - Self::read_events_no_consensus() + // Dereferencing the events here is fine since we are not in the + // memory-restricted runtime. + Self::read_events_no_consensus().into_iter().map(|e| *e).collect() } /// Get the current events deposited by the runtime. /// /// Should only be called if you know what you are doing and outside of the runtime block /// execution else it can have a large impact on the PoV size of a block. - pub fn read_events_no_consensus() -> Vec<EventRecord<T::Event, T::Hash>> { + pub fn read_events_no_consensus() -> Vec<Box<EventRecord<T::Event, T::Hash>>> { Events::<T>::get() }