Timestamp weights

frame/identity/src/lib.rs

@@ -548,7 +548,7 @@ mod weight_for {
 		subs: impl Into<Weight> + Copy,
 		extra_fields: impl Into<Weight>
 	) -> Weight {
-		db.reads_writes(3, subs.into() + 3) // 2 `take`s + S deletions
+		db.reads_writes(2, subs.into() + 2) // 2 `take`s + S deletions
 			+ db.reads_writes(1, 1) // balance ops
 			+ 170_000_000 // constant
 			+ 1_200_000 * judgements.into() // R

frame/timestamp/src/lib.rs

@@ -100,7 +100,7 @@ use frame_support::debug;
 use frame_support::{
 	Parameter, decl_storage, decl_module,
 	traits::{Time, UnixTime, Get},
-	weights::{DispatchClass},
+	weights::{DispatchClass, Weight},
 };
 use sp_runtime::{
 	RuntimeString,
@@ -150,15 +150,22 @@ decl_module! {
 		///
 		/// # <weight>
 		/// - `O(T)` where `T` complexity of `on_timestamp_set`
-		/// - 2 storage mutations (codec `O(1)`).
+		/// - 1 storage read and 1 storage mutation (codec `O(1)`). (because of `DidUpdate::take` in `on_finalize`)
 		/// - 1 event handler `on_timestamp_set` `O(T)`.
+		/// - Benchmark: 27.36 (median slopes analysis)
+		///   - NOTE: This benchmark was done for a runtime with insignificant `on_timestamp_set` handlers.
+		///     New benchmarking is needed when adding new handlers.
 		/// # </weight>
-		#[weight = (0, DispatchClass::Mandatory)]
+		#[weight = (
+			T::DbWeight::get().reads_writes(2, 1) + 28_000_000,
+			DispatchClass::Mandatory
+		)]
 		fn set(origin, #[compact] now: T::Moment) {
 			ensure_none(origin)?;
 			assert!(!<Self as Store>::DidUpdate::exists(), "Timestamp must be updated only once in the block");
+			let prev = Self::now();
 			assert!(
-				Self::now().is_zero() || now >= Self::now() + T::MinimumPeriod::get(),
+				prev.is_zero() || now >= prev + T::MinimumPeriod::get(),
 				"Timestamp must increment by at least <MinimumPeriod> between sequential blocks"
 			);
 			<Self as Store>::Now::put(now);
@@ -167,9 +174,16 @@ decl_module! {
 			<T::OnTimestampSet as OnTimestampSet<_>>::on_timestamp_set(now);
 		}
 
+		/// dummy `on_initialize` to return the weight used in `on_finalize`.
+		fn on_initialize() -> Weight {
+			// weight of `on_finalize`
+			19_000_000
+		}
+
 		/// # <weight>
 		/// - `O(1)`
 		/// - 1 storage deletion (codec `O(1)`).
+		/// - Benchmark: 18.7 µs (min squares analysis)
 		/// # </weight>
 		fn on_finalize() {
 			assert!(<Self as Store>::DidUpdate::take(), "Timestamp must be updated once in the block");