Convert timestamp to unit type wrapper (#8333)

The timestamp inherent type was up to now just a simple `u64`. This
worked, but doesn't give you that much guarantees at compile time about
the type. This pr changes that by converting this type to a unit type
wrapper, similar to what we have done for `Slot`.

This is required for some future pr that touches quite a lot of the
inherents stuff :)

Besides this unit wrapper type, this pr also moves the `OnTimestampSet`
trait to `frame_support::traits`.

substrate/frame/aura/Cargo.toml

@@ -22,7 +22,6 @@ sp-runtime = { version = "3.0.0", default-features = false, path = "../../primit
 frame-support = { version = "3.0.0", default-features = false, path = "../support" }
 sp-consensus-aura = { version = "0.9.0", path = "../../primitives/consensus/aura", default-features = false }
 frame-system = { version = "3.0.0", default-features = false, path = "../system" }
-sp-timestamp = { version = "3.0.0", default-features = false, path = "../../primitives/timestamp" }
 pallet-timestamp = { version = "3.0.0", default-features = false, path = "../timestamp" }
 
 [dev-dependencies]
@@ -42,7 +41,6 @@ std = [
 	"frame-support/std",
 	"sp-consensus-aura/std",
 	"frame-system/std",
-	"sp-timestamp/std",
 	"pallet-timestamp/std",
 ]
 try-runtime = ["frame-support/try-runtime"]

substrate/frame/aura/src/lib.rs

@@ -39,12 +39,13 @@
 
 use sp_std::prelude::*;
 use codec::{Encode, Decode};
-use frame_support::{Parameter, traits::{Get, FindAuthor, OneSessionHandler}, ConsensusEngineId};
+use frame_support::{
+	Parameter, traits::{Get, FindAuthor, OneSessionHandler, OnTimestampSet}, ConsensusEngineId,
+};
 use sp_runtime::{
 	RuntimeAppPublic,
 	traits::{SaturatedConversion, Saturating, Zero, Member, IsMember}, generic::DigestItem,
 };
-use sp_timestamp::OnTimestampSet;
 use sp_consensus_aura::{AURA_ENGINE_ID, ConsensusLog, AuthorityIndex, Slot};
 
 mod mock;

substrate/frame/babe/Cargo.toml

@@ -29,7 +29,6 @@ sp-runtime = { version = "3.0.0", default-features = false, path = "../../primit
 sp-session = { version = "3.0.0", default-features = false, path = "../../primitives/session" }
 sp-staking = { version = "3.0.0", default-features = false, path = "../../primitives/staking" }
 sp-std = { version = "3.0.0", default-features = false, path = "../../primitives/std" }
-sp-timestamp = { version = "3.0.0", default-features = false, path = "../../primitives/timestamp" }
 log = { version = "0.4.14", default-features = false }
 
 [dev-dependencies]
@@ -59,7 +58,6 @@ std = [
 	"sp-session/std",
 	"sp-staking/std",
 	"sp-std/std",
-	"sp-timestamp/std",
 	"log/std",
 ]
 runtime-benchmarks = ["frame-benchmarking"]

substrate/frame/babe/src/lib.rs

@@ -25,7 +25,7 @@ use codec::{Decode, Encode};
 use frame_support::{
 	decl_error, decl_module, decl_storage,
 	dispatch::DispatchResultWithPostInfo,
-	traits::{FindAuthor, Get, KeyOwnerProofSystem, OneSessionHandler},
+	traits::{FindAuthor, Get, KeyOwnerProofSystem, OneSessionHandler, OnTimestampSet},
 	weights::{Pays, Weight},
 	Parameter,
 };
@@ -38,7 +38,6 @@ use sp_runtime::{
 };
 use sp_session::{GetSessionNumber, GetValidatorCount};
 use sp_std::prelude::*;
-use sp_timestamp::OnTimestampSet;
 
 use sp_consensus_babe::{
 	digests::{NextConfigDescriptor, NextEpochDescriptor, PreDigest},

substrate/frame/support/src/traits.rs

@@ -2291,6 +2291,13 @@ pub trait ExecuteBlock<Block: BlockT> {
 	fn execute_block(block: Block);
 }
 
+/// A trait which is called when the timestamp is set in the runtime.
+#[impl_trait_for_tuples::impl_for_tuples(30)]
+pub trait OnTimestampSet<Moment> {
+	/// Called when the timestamp is set.
+	fn on_timestamp_set(moment: Moment);
+}
+
 #[cfg(test)]
 mod tests {
 	use super::*;

substrate/frame/timestamp/src/lib.rs

@@ -97,7 +97,7 @@ pub mod weights;
 
 use sp_std::{result, cmp};
 use sp_inherents::InherentData;
-use frame_support::traits::{Time, UnixTime};
+use frame_support::traits::{Time, UnixTime, OnTimestampSet};
 use sp_runtime::{
 	RuntimeString,
 	traits::{
@@ -106,7 +106,6 @@ use sp_runtime::{
 };
 use sp_timestamp::{
 	InherentError, INHERENT_IDENTIFIER, InherentType,
-	OnTimestampSet,
 };
 pub use weights::WeightInfo;
 
@@ -214,16 +213,17 @@ pub mod pallet {
 		const INHERENT_IDENTIFIER: InherentIdentifier = INHERENT_IDENTIFIER;
 
 		fn create_inherent(data: &InherentData) -> Option<Self::Call> {
-			let data: T::Moment = extract_inherent_data(data)
-				.expect("Gets and decodes timestamp inherent data")
-				.saturated_into();
+			let inherent_data = extract_inherent_data(data)
+				.expect("Gets and decodes timestamp inherent data");
+			let data = (*inherent_data).saturated_into::<T::Moment>();
 
 			let next_time = cmp::max(data, Self::now() + T::MinimumPeriod::get());
 			Some(Call::set(next_time.into()))
 		}
 
 		fn check_inherent(call: &Self::Call, data: &InherentData) -> result::Result<(), Self::Error> {
-			const MAX_TIMESTAMP_DRIFT_MILLIS: u64 = 30 * 1000;
+			const MAX_TIMESTAMP_DRIFT_MILLIS: sp_timestamp::Timestamp =
+				sp_timestamp::Timestamp::new(30 * 1000);
 
 			let t: u64 = match call {
 				Call::set(ref t) => t.clone().saturated_into::<u64>(),
@@ -233,10 +233,10 @@ pub mod pallet {
 			let data = extract_inherent_data(data).map_err(|e| InherentError::Other(e))?;
 
 			let minimum = (Self::now() + T::MinimumPeriod::get()).saturated_into::<u64>();
-			if t > data + MAX_TIMESTAMP_DRIFT_MILLIS {
+			if t > *(data + MAX_TIMESTAMP_DRIFT_MILLIS) {
 				Err(InherentError::Other("Timestamp too far in future to accept".into()))
 			} else if t < minimum {
-				Err(InherentError::ValidAtTimestamp(minimum))
+				Err(InherentError::ValidAtTimestamp(minimum.into()))
 			} else {
 				Ok(())
 			}