Free TX - council can update free tx per era, fixed benchmarks

pallets/free-tx/src/benchmarking.rs

@@ -2,8 +2,8 @@
 #![cfg(feature = "runtime-benchmarks")]
 
 use frame_benchmarking::{benchmarks, whitelisted_caller};
+use frame_support::{assert_ok, traits::EnsureOrigin};
 use frame_system::RawOrigin;
-use sp_staking::EraIndex;
 use sp_std::prelude::Box;
 
 use super::*;
@@ -12,7 +12,7 @@ use super::*;
 benchmarks! {
   try_free_call {
     let caller: T::AccountId = whitelisted_caller();
-    FreeCallsRemaining::<T>::insert(&caller, FreeCallInfo { free_calls_remaining: 2 as FreeCallCount, era_index: 1 as EraIndex});
+    FreeCallsPerEra::<T>::set(Some(2));
 
     let call: <T as Config>::Call = frame_system::Call::<T>::remark { remark: b"entropy rocks".to_vec() }.into();
   }: _(RawOrigin::Signed(caller.clone()), Box::new(call))
@@ -21,9 +21,13 @@ benchmarks! {
     assert_eq!(free_calls_remaining, 1 as FreeCallCount);
   }
   set_free_calls_per_era {
-    let caller: T::AccountId = whitelisted_caller();
+    let origin = T::UpdateOrigin::successful_origin();
     let free_calls = 1 as FreeCallCount;
-  }: _(RawOrigin::Root, free_calls as FreeCallCount)
+  }: {
+    assert_ok!(
+      <FreeTx<T>>::set_free_calls_per_era(origin, free_calls)
+    );
+  }
   verify {
     assert_eq!(FreeCallsPerEra::<T>::get().unwrap(), free_calls as FreeCallCount);
   }

pallets/free-tx/src/lib.rs

@@ -2,18 +2,6 @@
 
 //! TODO JH: This is NOT SAFE for production yet. This is an MVP and likely DoS-able.
 
-//! TODO JH: Free Transactions per Era
-//! [x] FreeTxPerEra StorageValue - Enable pallet by setting it to Some(u16)
-//! [x] FreeTxLeft StorageMap(AccountId, u16) - store the number of free transactions left for each
-//!   account
-//! [x] try_free_tx modification
-//! [x] SignedExtension modification
-//! [] on_idle hook (optional/future) - prunes FreeCallsRemaining
-//! [x] reset_free_tx - root function clears FreeTxLeft
-//!
-//! [] Remove GenesisConfig and fix tests - remove genesis config
-//! [] new tests
-
 /// Edit this file to define custom logic or remove it if it is not needed.
 /// Learn more about FRAME and the core library of Substrate FRAME pallets:
 /// <https://docs.substrate.io/reference/frame-pallets/>
@@ -33,6 +21,7 @@ pub mod pallet {
     dispatch::Dispatchable,
     pallet_prelude::*,
     traits::IsSubType,
+    transactional,
     weights::{GetDispatchInfo, PostDispatchInfo},
   };
   use frame_system::{pallet_prelude::*, RawOrigin};
@@ -44,6 +33,7 @@ pub mod pallet {
   use sp_staking::EraIndex;
   use sp_std::{fmt::Debug, prelude::*};
 
+  // use super::*;
   pub use crate::weights::WeightInfo;
 
   #[pallet::config]
@@ -57,6 +47,9 @@ pub mod pallet {
       + GetDispatchInfo
       + From<frame_system::Call<Self>>;
 
+    // Counsil (or another) can update the number of free transactions per era
+    type UpdateOrigin: EnsureOrigin<Self::Origin>;
+
     // The weight information of this pallet.
     type WeightInfo: WeightInfo;
   }
@@ -162,12 +155,13 @@ pub mod pallet {
     /// Sets the number of free calls each account gets per era.
     /// To disable free calls, set this to `0`.
     /// TODO: weight
-    #[pallet::weight(10_000)]
+    #[pallet::weight(<T as crate::Config>::WeightInfo::set_free_calls_per_era())]
+    #[transactional]
     pub fn set_free_calls_per_era(
       origin: OriginFor<T>,
       free_calls_per_era: FreeCallCount,
     ) -> DispatchResult {
-      ensure_root(origin)?;
+      T::UpdateOrigin::ensure_origin(origin)?;
       if free_calls_per_era == 0 {
         // make sure that <FreeCallsPerEra<T>>::get() returns None instead of Some(0)
         <FreeCallsPerEra<T>>::kill();

pallets/free-tx/src/mock.rs

@@ -2,10 +2,11 @@ use core::convert::{TryFrom, TryInto};
 
 use frame_election_provider_support::{onchain, SequentialPhragmen, VoteWeight};
 use frame_support::{
-  parameter_types,
+  ord_parameter_types, parameter_types,
   traits::{ConstU32, GenesisBuild, Get, Hooks, OneSessionHandler},
 };
 use frame_system as system;
+use frame_system::EnsureSignedBy;
 use pallet_session::historical as pallet_session_historical;
 use pallet_staking::StakerStatus;
 use sp_core::H256;
@@ -258,9 +259,14 @@ impl pallet_staking_extension::Config for Test {
   type WeightInfo = ();
 }
 
+ord_parameter_types! {
+  pub const One: AccountId = 1;
+}
+
 impl pallet_free_tx::Config for Test {
   type Call = Call;
   type Event = Event;
+  type UpdateOrigin = EnsureSignedBy<One, AccountId>;
   type WeightInfo = ();
 }
 
@@ -462,7 +468,7 @@ pub(crate) fn current_era() -> EraIndex { FrameStaking::current_era().unwrap() }
 
 /// Progress until the given era.
 pub(crate) fn start_active_era(era_index: EraIndex) {
-  start_session((era_index * <SessionsPerEra as Get<u32>>::get()));
+  start_session(era_index * <SessionsPerEra as Get<u32>>::get());
   assert_eq!(active_era(), era_index);
   // One way or another, current_era must have changed before the active era, so they must match
   // at this point.

pallets/free-tx/src/tests.rs

@@ -105,7 +105,7 @@ fn free_calls_refresh_every_era() {
     start_active_era(1);
 
     // enable free calls via extrinsic
-    let _ = FreeTx::set_free_calls_per_era(Origin::root(), 5);
+    let _ = FreeTx::set_free_calls_per_era(Origin::signed(1), 5);
     assert_eq!(FreeTx::free_calls_remaining(&1u64), 5 as FreeCallCount);
 
     // make a call that works, check call is used

pallets/free-tx/src/weights.rs

@@ -33,6 +33,7 @@ use sp_std::marker::PhantomData;
 
 pub trait WeightInfo {
 	fn try_free_call() -> Weight;
+	fn set_free_calls_per_era() -> Weight;
 }
 
 /// Weight functions for `pallet_free_tx`.
@@ -44,6 +45,12 @@ impl<T: frame_system::Config> WeightInfo for SubstrateWeight<T> {
 			.saturating_add(T::DbWeight::get().reads(1 as Weight))
 			.saturating_add(T::DbWeight::get().writes(1 as Weight))
 	}
+
+	fn set_free_calls_per_era() -> Weight {
+		(14_000_000 as Weight)
+			.saturating_add(T::DbWeight::get().reads(1 as Weight))
+			.saturating_add(T::DbWeight::get().writes(1 as Weight))
+	}
 }
 
 // For backwards compatibility and tests
@@ -55,4 +62,10 @@ impl WeightInfo for () {
 			.saturating_add(RocksDbWeight::get().reads(1 as Weight))
 			.saturating_add(RocksDbWeight::get().writes(1 as Weight))
 	}
+
+	fn set_free_calls_per_era() -> Weight {
+		(14_000_000 as Weight)
+			.saturating_add(RocksDbWeight::get().reads(1 as Weight))
+			.saturating_add(RocksDbWeight::get().writes(1 as Weight))
+	}
 }

runtime/src/lib.rs

@@ -1205,6 +1205,10 @@ impl pallet_bags_list::Config for Runtime {
 impl pallet_free_tx::Config for Runtime {
   type Call = Call;
   type Event = Event;
+  type UpdateOrigin = EnsureOneOf<
+    EnsureRoot<AccountId>,
+    pallet_collective::EnsureProportionAtLeast<AccountId, CouncilCollective, 2, 3>,
+  >;
   type WeightInfo = weights::pallet_free_tx::WeightInfo<Runtime>;
 }
 

runtime/src/weights/pallet_free_tx.rs

@@ -2,26 +2,20 @@
 //! Autogenerated weights for `pallet_free_tx`
 //!
 //! THIS FILE WAS AUTO-GENERATED USING THE SUBSTRATE BENCHMARK CLI VERSION 4.0.0-dev
-//! DATE: 2022-08-12, STEPS: `50`, REPEAT: 20, LOW RANGE: `[]`, HIGH RANGE: `[]`
+//! DATE: 2022-09-07, STEPS: `50`, REPEAT: 20, LOW RANGE: `[]`, HIGH RANGE: `[]`
 //! EXECUTION: Some(Wasm), WASM-EXECUTION: Compiled, CHAIN: Some("dev"), DB CACHE: 1024
 
 // Executed Command:
 // ./target/release/entropy
 // benchmark
-// --chain
-// dev
+// --chain=dev
 // --execution=wasm
 // --wasm-execution=compiled
-// --pallet
-// pallet_free_tx
-// --extrinsic
-// *
-// --steps
-// 50
-// --repeat
-// 20
-// --output
-// ./weights.rs
+// --pallet=pallet_free_tx
+// --extrinsic=*
+// --steps=50
+// --repeat=20
+// --output=./runtime/src/weights/
 
 #![cfg_attr(rustfmt, rustfmt_skip)]
 #![allow(unused_parens)]
@@ -33,10 +27,19 @@ use sp_std::marker::PhantomData;
 /// Weight functions for `pallet_free_tx`.
 pub struct WeightInfo<T>(PhantomData<T>);
 impl<T: frame_system::Config> pallet_free_tx::WeightInfo for WeightInfo<T> {
-	// Storage: FreeTx FreeCallsLeft (r:1 w:1)
+	// Storage: FreeTx FreeCallsPerEra (r:1 w:0)
+	// Storage: FreeTx FreeCallsRemaining (r:1 w:1)
+	// Storage: Staking CurrentEra (r:1 w:0)
 	fn try_free_call() -> Weight {
-		(14_000_000 as Weight)
-			.saturating_add(T::DbWeight::get().reads(1 as Weight))
+		(18_000_000 as Weight)
+			.saturating_add(T::DbWeight::get().reads(3 as Weight))
 			.saturating_add(T::DbWeight::get().writes(1 as Weight))
 	}
+	// Storage: unknown [0x3a7472616e73616374696f6e5f6c6576656c3a] (r:1 w:1)
+	// Storage: FreeTx FreeCallsPerEra (r:0 w:1)
+	fn set_free_calls_per_era() -> Weight {
+		(4_000_000 as Weight)
+			.saturating_add(T::DbWeight::get().reads(1 as Weight))
+			.saturating_add(T::DbWeight::get().writes(2 as Weight))
+	}
 }

scripts/benchmarks.sh

@@ -9,6 +9,7 @@ pallets=(
   pallet_staking_extension
   pallet_constraints
   pallet_transaction_pause
+  pallet_free_tx
 )
 
 for p in ${pallets[@]}