git.delta.rocks / unique-network / refs/commits / 67ae8db02ffa

--- /dev/null
+++ b/pallets/scheduler-v2/Cargo.toml
@@ -0,0 +1,48 @@
+[package]
+name = "pallet-unique-scheduler-v2"
+version = "0.1.0"
+authors = ["Unique Network <support@uniquenetwork.io>"]
+edition = "2021"
+license = "GPLv3"
+homepage = "https://unique.network"
+repository = "https://github.com/UniqueNetwork/unique-chain"
+description = "Unique Scheduler pallet"
+readme = "README.md"
+
+[dependencies]
+codec = { package = "parity-scale-codec", version = "3.0.0", default-features = false, features = ["derive"] }
+log = { version = "0.4.17", default-features = false }
+scale-info = { version = "2.1.1", default-features = false, features = ["derive"] }
+frame-benchmarking = { default-features = false, optional = true, git = "https://github.com/paritytech/substrate", branch = "polkadot-v0.9.29" }
+frame-support = { default-features = false, git = "https://github.com/paritytech/substrate", branch = "polkadot-v0.9.29" }
+frame-system = { default-features = false, git = "https://github.com/paritytech/substrate", branch = "polkadot-v0.9.29" }
+sp-io = { version = "6.0.0", default-features = false, git = "https://github.com/paritytech/substrate", branch = "polkadot-v0.9.29" }
+sp-runtime = { version = "6.0.0", default-features = false, git = "https://github.com/paritytech/substrate", branch = "polkadot-v0.9.29" }
+sp-std = { version = "4.0.0", default-features = false, git = "https://github.com/paritytech/substrate", branch = "polkadot-v0.9.29" }
+sp-core = { version = "6.0.0", default-features = false, git = "https://github.com/paritytech/substrate", branch = "polkadot-v0.9.29" }
+
+[dev-dependencies]
+pallet-preimage = { git = "https://github.com/paritytech/substrate", branch = "polkadot-v0.9.29" }
+sp-core = { version = "6.0.0", default-features = false, git = "https://github.com/paritytech/substrate", branch = "polkadot-v0.9.29" }
+substrate-test-utils = { git = "https://github.com/paritytech/substrate", branch = "polkadot-v0.9.29" }
+
+[features]
+default = ["std"]
+runtime-benchmarks = [
+	"frame-benchmarking",
+	"frame-support/runtime-benchmarks",
+	"frame-system/runtime-benchmarks",
+]
+std = [
+	"codec/std",
+	"frame-benchmarking?/std",
+	"frame-support/std",
+	"frame-system/std",
+	"log/std",
+	"scale-info/std",
+	"sp-io/std",
+	"sp-runtime/std",
+	"sp-std/std",
+	"sp-core/std",
+]
+try-runtime = ["frame-support/try-runtime"]

--- /dev/null
+++ b/pallets/scheduler-v2/src/lib.rs
@@ -0,0 +1,894 @@
+// Copyright 2019-2022 Unique Network (Gibraltar) Ltd.
+// This file is part of Unique Network.
+
+// Unique Network is free software: you can redistribute it and/or modify
+// it under the terms of the GNU General Public License as published by
+// the Free Software Foundation, either version 3 of the License, or
+// (at your option) any later version.
+
+// Unique Network is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+// GNU General Public License for more details.
+
+// You should have received a copy of the GNU General Public License
+// along with Unique Network. If not, see <http://www.gnu.org/licenses/>.
+
+// Original license:
+// This file is part of Substrate.
+
+// Copyright (C) 2017-2022 Parity Technologies (UK) Ltd.
+// SPDX-License-Identifier: Apache-2.0
+
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+// 	http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+//! # Scheduler
+//! A Pallet for scheduling dispatches.
+//!
+//! - [`Config`]
+//! - [`Call`]
+//! - [`Pallet`]
+//!
+//! ## Overview
+//!
+//! This Pallet exposes capabilities for scheduling dispatches to occur at a
+//! specified block number or at a specified period. These scheduled dispatches
+//! may be named or anonymous and may be canceled.
+//!
+//! **NOTE:** The scheduled calls will be dispatched with the default filter
+//! for the origin: namely `frame_system::Config::BaseCallFilter` for all origin
+//! except root which will get no filter. And not the filter contained in origin
+//! use to call `fn schedule`.
+//!
+//! If a call is scheduled using proxy or whatever mecanism which adds filter,
+//! then those filter will not be used when dispatching the schedule call.
+//!
+//! ## Interface
+//!
+//! ### Dispatchable Functions
+//!
+//! * `schedule` - schedule a dispatch, which may be periodic, to occur at a specified block and
+//!   with a specified priority.
+//! * `cancel` - cancel a scheduled dispatch, specified by block number and index.
+//! * `schedule_named` - augments the `schedule` interface with an additional `Vec<u8>` parameter
+//!   that can be used for identification.
+//! * `cancel_named` - the named complement to the cancel function.
+
+// Ensure we're `no_std` when compiling for Wasm.
+#![cfg_attr(not(feature = "std"), no_std)]
+
+#[cfg(feature = "runtime-benchmarks")]
+mod benchmarking;
+#[cfg(test)]
+mod mock;
+#[cfg(test)]
+mod tests;
+pub mod weights;
+
+use codec::{Codec, Decode, Encode, MaxEncodedLen};
+use frame_support::{
+	dispatch::{
+		DispatchError, DispatchResult, Dispatchable, GetDispatchInfo, Parameter, RawOrigin,
+	},
+	ensure,
+	traits::{
+		schedule::{self, DispatchTime},
+		EnsureOrigin, Get, IsType, OriginTrait,
+		PalletInfoAccess, PrivilegeCmp, StorageVersion,
+        PreimageProvider, PreimageRecipient, ConstU32,
+	},
+	weights::Weight,
+};
+
+use frame_system::{self as system};
+use scale_info::TypeInfo;
+use sp_io::hashing::blake2_256;
+use sp_runtime::{
+	traits::{BadOrigin, One, Saturating, Zero, Hash},
+	BoundedVec, RuntimeDebug,
+};
+use sp_std::{borrow::Borrow, cmp::Ordering, marker::PhantomData, prelude::*};
+pub use weights::WeightInfo;
+
+pub use pallet::*;
+
+/// Just a simple index for naming period tasks.
+pub type PeriodicIndex = u32;
+/// The location of a scheduled task that can be used to remove it.
+pub type TaskAddress<BlockNumber> = (BlockNumber, u32);
+
+pub type EncodedCall = BoundedVec<u8, ConstU32<128>>;
+
+#[derive(Clone, Eq, PartialEq, Encode, Decode, RuntimeDebug, TypeInfo, MaxEncodedLen)]
+#[scale_info(skip_type_params(T))]
+pub enum ScheduledCall<T: Config> {
+    Inline(EncodedCall),
+    PreimageLookup {
+        hash: T::Hash,
+        unbounded_len: u32,
+    },
+}
+
+impl<T: Config> ScheduledCall<T> {
+	pub fn new(call: <T as Config>::Call) -> Result<Self, DispatchError> {
+		let encoded = call.encode();
+		let len = encoded.len();
+
+		match EncodedCall::try_from(encoded.clone()) {
+			Ok(bounded) => Ok(Self::Inline(bounded)),
+			Err(_) => {
+				let hash = <T as system::Config>::Hashing::hash_of(&encoded);
+				<T as Config>::Preimages::note_preimage(encoded.try_into().map_err(|_| <Error<T>>::TooBigScheduledCall)?);
+
+				Ok(Self::PreimageLookup { hash, unbounded_len: len as u32 })
+			}
+		}
+	}
+
+	/// The maximum length of the lookup that is needed to peek `Self`.
+	pub fn lookup_len(&self) -> Option<u32> {
+		match self {
+			Self::Inline(..) => None,
+			Self::PreimageLookup { unbounded_len, .. } => Some(*unbounded_len),
+		}
+	}
+
+	fn decode(mut data: &[u8]) -> Result<<T as Config>::Call, DispatchError> {
+		<T as Config>::Call::decode(&mut data)
+				.map_err(|_| <Error<T>>::ScheduledCallCorrupted.into())
+	}
+}
+
+pub trait SchedulerPreimages<T: Config>: PreimageRecipient<T::Hash> {
+    fn drop(call: &ScheduledCall<T>);
+
+	fn peek(call: &ScheduledCall<T>) -> Result<(<T as pallet::Config>::Call, Option<u32>), DispatchError>;
+}
+
+impl<T: Config, PP: PreimageRecipient<T::Hash>> SchedulerPreimages<T> for PP {
+    fn drop(call: &ScheduledCall<T>) {
+        match call {
+            ScheduledCall::Inline(_) => {},
+            ScheduledCall::PreimageLookup { hash, .. } => Self::unrequest_preimage(hash),
+        }
+    }
+
+	fn peek(call: &ScheduledCall<T>) -> Result<(<T as pallet::Config>::Call, Option<u32>), DispatchError> {
+		match call {
+			ScheduledCall::Inline(data) => Ok((ScheduledCall::<T>::decode(data)?, None)),
+			ScheduledCall::PreimageLookup { hash, unbounded_len } => {
+				let (preimage, len) = Self::get_preimage(hash)
+					.ok_or(<Error<T>>::PreimageNotFound)
+					.map(|preimage| (preimage, *unbounded_len))?;
+
+				Ok((ScheduledCall::<T>::decode(preimage.as_slice())?, Some(len)))
+			},
+		}
+	}
+}
+
+pub type TaskName = [u8; 32];
+
+/// Information regarding an item to be executed in the future.
+#[cfg_attr(any(feature = "std", test), derive(PartialEq, Eq))]
+#[derive(Clone, RuntimeDebug, Encode, Decode, MaxEncodedLen, TypeInfo)]
+pub struct Scheduled<Name, Call, BlockNumber, PalletsOrigin, AccountId> {
+	/// The unique identity for this task, if there is one.
+	maybe_id: Option<Name>,
+
+    /// This task's priority.
+	priority: schedule::Priority,
+
+    /// The call to be dispatched.
+	call: Call,
+
+    /// If the call is periodic, then this points to the information concerning that.
+	maybe_periodic: Option<schedule::Period<BlockNumber>>,
+
+    /// The origin with which to dispatch the call.
+	origin: PalletsOrigin,
+	_phantom: PhantomData<AccountId>,
+}
+
+pub type ScheduledOf<T> = Scheduled<
+	TaskName,
+	ScheduledCall<T>,
+	<T as frame_system::Config>::BlockNumber,
+	<T as Config>::PalletsOrigin,
+	<T as frame_system::Config>::AccountId,
+>;
+
+struct WeightCounter {
+	used: Weight,
+	limit: Weight,
+}
+
+impl WeightCounter {
+	fn check_accrue(&mut self, w: Weight) -> bool {
+		let test = self.used.saturating_add(w);
+		if test > self.limit {
+			false
+		} else {
+			self.used = test;
+			true
+		}
+	}
+
+	fn can_accrue(&mut self, w: Weight) -> bool {
+		self.used.saturating_add(w) <= self.limit
+	}
+}
+
+pub(crate) trait MarginalWeightInfo: WeightInfo {
+	fn service_task(maybe_lookup_len: Option<usize>, named: bool, periodic: bool) -> Weight {
+		let base = Self::service_task_base();
+		let mut total = match maybe_lookup_len {
+			None => base,
+			Some(l) => Self::service_task_fetched(l as u32),
+		};
+		if named {
+			total.saturating_accrue(Self::service_task_named().saturating_sub(base));
+		}
+		if periodic {
+			total.saturating_accrue(Self::service_task_periodic().saturating_sub(base));
+		}
+		total
+	}
+}
+
+impl<T: WeightInfo> MarginalWeightInfo for T {}
+
+#[frame_support::pallet]
+pub mod pallet {
+	use super::*;
+	use frame_support::{dispatch::PostDispatchInfo, pallet_prelude::*};
+	use system::pallet_prelude::*;
+
+	/// The current storage version.
+	const STORAGE_VERSION: StorageVersion = StorageVersion::new(0);
+
+    #[pallet::pallet]
+	#[pallet::generate_store(pub(super) trait Store)]
+	#[pallet::storage_version(STORAGE_VERSION)]
+	pub struct Pallet<T>(_);
+
+	#[pallet::config]
+	pub trait Config: frame_system::Config {
+        type Event: From<Event<Self>> + IsType<<Self as frame_system::Config>::Event>;
+
+        /// The aggregated origin which the dispatch will take.
+		type Origin: OriginTrait<PalletsOrigin = Self::PalletsOrigin>
+            + From<Self::PalletsOrigin>
+            + IsType<<Self as system::Config>::Origin>
+			+ Clone;
+
+        /// The caller origin, overarching type of all pallets origins.
+        type PalletsOrigin: From<system::RawOrigin<Self::AccountId>>
+            + Codec
+            + Clone
+            + Eq
+            + TypeInfo
+            + MaxEncodedLen;
+
+        /// The aggregated call type.
+        type Call: Parameter
+            + Dispatchable<
+                Origin = <Self as Config>::Origin,
+                PostInfo = PostDispatchInfo,
+            > + GetDispatchInfo
+            + From<system::Call<Self>>;
+
+        /// The maximum weight that may be scheduled per block for any dispatchables.
+        #[pallet::constant]
+        type MaximumWeight: Get<Weight>;
+
+        /// Required origin to schedule or cancel calls.
+        type ScheduleOrigin: EnsureOrigin<<Self as system::Config>::Origin>;
+
+        /// Compare the privileges of origins.
+        ///
+        /// This will be used when canceling a task, to ensure that the origin that tries
+        /// to cancel has greater or equal privileges as the origin that created the scheduled task.
+        ///
+        /// For simplicity the [`EqualPrivilegeOnly`](frame_support::traits::EqualPrivilegeOnly) can
+        /// be used. This will only check if two given origins are equal.
+        type OriginPrivilegeCmp: PrivilegeCmp<Self::PalletsOrigin>;
+
+        /// The maximum number of scheduled calls in the queue for a single block.
+        #[pallet::constant]
+        type MaxScheduledPerBlock: Get<u32>;
+
+        /// Weight information for extrinsics in this pallet.
+        type WeightInfo: WeightInfo;
+
+        /// The preimage provider with which we look up call hashes to get the call.
+		type Preimages: SchedulerPreimages<Self>;
+    }
+
+    #[pallet::storage]
+	pub type IncompleteSince<T: Config> = StorageValue<_, T::BlockNumber>;
+
+    /// Items to be executed, indexed by the block number that they should be executed on.
+	#[pallet::storage]
+	pub type Agenda<T: Config> = StorageMap<
+		_,
+		Twox64Concat,
+		T::BlockNumber,
+		BoundedVec<Option<ScheduledOf<T>>, T::MaxScheduledPerBlock>,
+		ValueQuery,
+	>;
+
+    /// Lookup from a name to the block number and index of the task.
+	#[pallet::storage]
+	pub(crate) type Lookup<T: Config> =
+		StorageMap<_, Twox64Concat, TaskName, TaskAddress<T::BlockNumber>>;
+
+    /// Events type.
+	#[pallet::event]
+	#[pallet::generate_deposit(pub(super) fn deposit_event)]
+	pub enum Event<T: Config> {
+		/// Scheduled some task.
+		Scheduled { when: T::BlockNumber, index: u32 },
+		/// Canceled some task.
+		Canceled { when: T::BlockNumber, index: u32 },
+		/// Dispatched some task.
+		Dispatched {
+			task: TaskAddress<T::BlockNumber>,
+			id: Option<[u8; 32]>,
+			result: DispatchResult,
+		},
+		/// The call for the provided hash was not found so the task has been aborted.
+		CallUnavailable { task: TaskAddress<T::BlockNumber>, id: Option<[u8; 32]> },
+		/// The given task was unable to be renewed since the agenda is full at that block.
+		PeriodicFailed { task: TaskAddress<T::BlockNumber>, id: Option<[u8; 32]> },
+		/// The given task can never be executed since it is overweight.
+		PermanentlyOverweight { task: TaskAddress<T::BlockNumber>, id: Option<[u8; 32]> },
+	}
+
+    #[pallet::error]
+	pub enum Error<T> {
+		/// Failed to schedule a call
+		FailedToSchedule,
+        /// There is no place for a new task in the agenda
+        AgendaIsExhausted,
+		/// Scheduled call is corrupted
+		ScheduledCallCorrupted,
+		/// Scheduled call preimage is not found
+		PreimageNotFound,
+		/// Scheduled call is too big
+		TooBigScheduledCall,
+		/// Cannot find the scheduled call.
+		NotFound,
+		/// Given target block number is in the past.
+		TargetBlockNumberInPast,
+		/// Reschedule failed because it does not change scheduled time.
+		RescheduleNoChange,
+		/// Attempt to use a non-named function on a named task.
+		Named,
+	}
+
+    #[pallet::hooks]
+	impl<T: Config> Hooks<BlockNumberFor<T>> for Pallet<T> {
+		/// Execute the scheduled calls
+		fn on_initialize(now: T::BlockNumber) -> Weight {
+			let mut weight_counter =
+				WeightCounter { used: Weight::zero(), limit: T::MaximumWeight::get() };
+			Self::service_agendas(&mut weight_counter, now, u32::max_value());
+			weight_counter.used
+		}
+	}
+
+    #[pallet::call]
+	impl<T: Config> Pallet<T> {
+        /// Anonymously schedule a task.
+		#[pallet::weight(<T as Config>::WeightInfo::schedule(T::MaxScheduledPerBlock::get()))]
+		pub fn schedule(
+			origin: OriginFor<T>,
+			when: T::BlockNumber,
+			maybe_periodic: Option<schedule::Period<T::BlockNumber>>,
+			priority: schedule::Priority,
+			call: Box<<T as Config>::Call>,
+		) -> DispatchResult {
+			T::ScheduleOrigin::ensure_origin(origin.clone())?;
+			let origin = <T as Config>::Origin::from(origin);
+			Self::do_schedule(
+				DispatchTime::At(when),
+				maybe_periodic,
+				priority,
+				origin.caller().clone(),
+				<ScheduledCall<T>>::new(*call)?,
+			)?;
+			Ok(())
+		}
+
+		/// Cancel an anonymously scheduled task.
+		#[pallet::weight(<T as Config>::WeightInfo::cancel(T::MaxScheduledPerBlock::get()))]
+		pub fn cancel(origin: OriginFor<T>, when: T::BlockNumber, index: u32) -> DispatchResult {
+			T::ScheduleOrigin::ensure_origin(origin.clone())?;
+			let origin = <T as Config>::Origin::from(origin);
+			Self::do_cancel(Some(origin.caller().clone()), (when, index))?;
+			Ok(())
+		}
+
+		/// Schedule a named task.
+		#[pallet::weight(<T as Config>::WeightInfo::schedule_named(T::MaxScheduledPerBlock::get()))]
+		pub fn schedule_named(
+			origin: OriginFor<T>,
+			id: TaskName,
+			when: T::BlockNumber,
+			maybe_periodic: Option<schedule::Period<T::BlockNumber>>,
+			priority: schedule::Priority,
+			call: Box<<T as Config>::Call>,
+		) -> DispatchResult {
+			T::ScheduleOrigin::ensure_origin(origin.clone())?;
+			let origin = <T as Config>::Origin::from(origin);
+			Self::do_schedule_named(
+				id,
+				DispatchTime::At(when),
+				maybe_periodic,
+				priority,
+				origin.caller().clone(),
+				<ScheduledCall<T>>::new(*call)?,
+			)?;
+			Ok(())
+		}
+
+		/// Cancel a named scheduled task.
+		#[pallet::weight(<T as Config>::WeightInfo::cancel_named(T::MaxScheduledPerBlock::get()))]
+		pub fn cancel_named(origin: OriginFor<T>, id: TaskName) -> DispatchResult {
+			T::ScheduleOrigin::ensure_origin(origin.clone())?;
+			let origin = <T as Config>::Origin::from(origin);
+			Self::do_cancel_named(Some(origin.caller().clone()), id)?;
+			Ok(())
+		}
+
+		/// Anonymously schedule a task after a delay.
+		///
+		/// # <weight>
+		/// Same as [`schedule`].
+		/// # </weight>
+		#[pallet::weight(<T as Config>::WeightInfo::schedule(T::MaxScheduledPerBlock::get()))]
+		pub fn schedule_after(
+			origin: OriginFor<T>,
+			after: T::BlockNumber,
+			maybe_periodic: Option<schedule::Period<T::BlockNumber>>,
+			priority: schedule::Priority,
+			call: Box<<T as Config>::Call>,
+		) -> DispatchResult {
+			T::ScheduleOrigin::ensure_origin(origin.clone())?;
+			let origin = <T as Config>::Origin::from(origin);
+			Self::do_schedule(
+				DispatchTime::After(after),
+				maybe_periodic,
+				priority,
+				origin.caller().clone(),
+				<ScheduledCall<T>>::new(*call)?,
+			)?;
+			Ok(())
+		}
+
+		/// Schedule a named task after a delay.
+		///
+		/// # <weight>
+		/// Same as [`schedule_named`](Self::schedule_named).
+		/// # </weight>
+		#[pallet::weight(<T as Config>::WeightInfo::schedule_named(T::MaxScheduledPerBlock::get()))]
+		pub fn schedule_named_after(
+			origin: OriginFor<T>,
+			id: TaskName,
+			after: T::BlockNumber,
+			maybe_periodic: Option<schedule::Period<T::BlockNumber>>,
+			priority: schedule::Priority,
+			call: Box<<T as Config>::Call>,
+		) -> DispatchResult {
+			T::ScheduleOrigin::ensure_origin(origin.clone())?;
+			let origin = <T as Config>::Origin::from(origin);
+			Self::do_schedule_named(
+				id,
+				DispatchTime::After(after),
+				maybe_periodic,
+				priority,
+				origin.caller().clone(),
+				<ScheduledCall<T>>::new(*call)?,
+			)?;
+			Ok(())
+		}
+    }
+}
+
+impl<T: Config> Pallet<T> {
+    fn resolve_time(when: DispatchTime<T::BlockNumber>) -> Result<T::BlockNumber, DispatchError> {
+		let now = frame_system::Pallet::<T>::block_number();
+
+		let when = match when {
+			DispatchTime::At(x) => x,
+			// The current block has already completed it's scheduled tasks, so
+			// Schedule the task at lest one block after this current block.
+			DispatchTime::After(x) => now.saturating_add(x).saturating_add(One::one()),
+		};
+
+		if when <= now {
+			return Err(Error::<T>::TargetBlockNumberInPast.into())
+		}
+
+		Ok(when)
+	}
+
+    fn place_task(
+		when: T::BlockNumber,
+		what: ScheduledOf<T>,
+	) -> Result<TaskAddress<T::BlockNumber>, (DispatchError, ScheduledOf<T>)> {
+		let maybe_name = what.maybe_id;
+		let index = Self::push_to_agenda(when, what)?;
+		let address = (when, index);
+		if let Some(name) = maybe_name {
+			Lookup::<T>::insert(name, address)
+		}
+		Self::deposit_event(Event::Scheduled { when: address.0, index: address.1 });
+		Ok(address)
+	}
+
+    fn push_to_agenda(
+		when: T::BlockNumber,
+		what: ScheduledOf<T>,
+	) -> Result<u32, (DispatchError, ScheduledOf<T>)> {
+		let mut agenda = Agenda::<T>::get(when);
+		let index = if (agenda.len() as u32) < T::MaxScheduledPerBlock::get() {
+			// will always succeed due to the above check.
+			let _ = agenda.try_push(Some(what));
+			agenda.len() as u32 - 1
+		} else {
+			if let Some(hole_index) = agenda.iter().position(|i| i.is_none()) {
+				agenda[hole_index] = Some(what);
+				hole_index as u32
+			} else {
+				return Err((<Error<T>>::AgendaIsExhausted.into(), what))
+			}
+		};
+		Agenda::<T>::insert(when, agenda);
+		Ok(index)
+	}
+
+    fn do_schedule(
+		when: DispatchTime<T::BlockNumber>,
+		maybe_periodic: Option<schedule::Period<T::BlockNumber>>,
+		priority: schedule::Priority,
+		origin: T::PalletsOrigin,
+		call: ScheduledCall<T>,
+	) -> Result<TaskAddress<T::BlockNumber>, DispatchError> {
+		let when = Self::resolve_time(when)?;
+
+		// sanitize maybe_periodic
+		let maybe_periodic = maybe_periodic
+			.filter(|p| p.1 > 1 && !p.0.is_zero())
+			// Remove one from the number of repetitions since we will schedule one now.
+			.map(|(p, c)| (p, c - 1));
+		let task = Scheduled {
+			maybe_id: None,
+			priority,
+			call,
+			maybe_periodic,
+			origin,
+			_phantom: PhantomData,
+		};
+		Self::place_task(when, task).map_err(|x| x.0)
+	}
+
+    fn do_cancel(
+		origin: Option<T::PalletsOrigin>,
+		(when, index): TaskAddress<T::BlockNumber>,
+	) -> Result<(), DispatchError> {
+		let scheduled = Agenda::<T>::try_mutate(when, |agenda| {
+			agenda.get_mut(index as usize).map_or(
+				Ok(None),
+				|s| -> Result<Option<Scheduled<_, _, _, _, _>>, DispatchError> {
+					if let (Some(ref o), Some(ref s)) = (origin, s.borrow()) {
+						if matches!(
+							T::OriginPrivilegeCmp::cmp_privilege(o, &s.origin),
+							Some(Ordering::Less) | None
+						) {
+							return Err(BadOrigin.into())
+						}
+					};
+					Ok(s.take())
+				},
+			)
+		})?;
+		if let Some(s) = scheduled {
+            T::Preimages::drop(&s.call);
+
+			if let Some(id) = s.maybe_id {
+				Lookup::<T>::remove(id);
+			}
+			Self::deposit_event(Event::Canceled { when, index });
+			Ok(())
+		} else {
+			return Err(Error::<T>::NotFound.into())
+		}
+	}
+
+    fn do_schedule_named(
+		id: TaskName,
+		when: DispatchTime<T::BlockNumber>,
+		maybe_periodic: Option<schedule::Period<T::BlockNumber>>,
+		priority: schedule::Priority,
+		origin: T::PalletsOrigin,
+		call: ScheduledCall<T>,
+	) -> Result<TaskAddress<T::BlockNumber>, DispatchError> {
+		// ensure id it is unique
+		if Lookup::<T>::contains_key(&id) {
+			return Err(Error::<T>::FailedToSchedule.into())
+		}
+
+		let when = Self::resolve_time(when)?;
+
+		// sanitize maybe_periodic
+		let maybe_periodic = maybe_periodic
+			.filter(|p| p.1 > 1 && !p.0.is_zero())
+			// Remove one from the number of repetitions since we will schedule one now.
+			.map(|(p, c)| (p, c - 1));
+
+		let task = Scheduled {
+			maybe_id: Some(id),
+			priority,
+			call,
+			maybe_periodic,
+			origin,
+			_phantom: Default::default(),
+		};
+		Self::place_task(when, task).map_err(|x| x.0)
+	}
+
+    fn do_cancel_named(origin: Option<T::PalletsOrigin>, id: TaskName) -> DispatchResult {
+		Lookup::<T>::try_mutate_exists(id, |lookup| -> DispatchResult {
+			if let Some((when, index)) = lookup.take() {
+				let i = index as usize;
+				Agenda::<T>::try_mutate(when, |agenda| -> DispatchResult {
+					if let Some(s) = agenda.get_mut(i) {
+						if let (Some(ref o), Some(ref s)) = (origin, s.borrow()) {
+							if matches!(
+								T::OriginPrivilegeCmp::cmp_privilege(o, &s.origin),
+								Some(Ordering::Less) | None
+							) {
+								return Err(BadOrigin.into())
+							}
+							T::Preimages::drop(&s.call);
+						}
+						*s = None;
+					}
+					Ok(())
+				})?;
+				Self::deposit_event(Event::Canceled { when, index });
+				Ok(())
+			} else {
+				return Err(Error::<T>::NotFound.into())
+			}
+		})
+	}
+}
+
+enum ServiceTaskError {
+	/// Could not be executed due to missing preimage.
+	Unavailable,
+	/// Could not be executed due to weight limitations.
+	Overweight,
+}
+use ServiceTaskError::*;
+
+impl<T: Config> Pallet<T> {
+	/// Service up to `max` agendas queue starting from earliest incompletely executed agenda.
+	fn service_agendas(weight: &mut WeightCounter, now: T::BlockNumber, max: u32) {
+		if !weight.check_accrue(T::WeightInfo::service_agendas_base()) {
+			return
+		}
+
+		let mut incomplete_since = now + One::one();
+		let mut when = IncompleteSince::<T>::take().unwrap_or(now);
+		let mut executed = 0;
+
+		let max_items = T::MaxScheduledPerBlock::get();
+		let mut count_down = max;
+		let service_agenda_base_weight = T::WeightInfo::service_agenda_base(max_items);
+		while count_down > 0 && when <= now && weight.can_accrue(service_agenda_base_weight) {
+			if !Self::service_agenda(weight, &mut executed, now, when, u32::max_value()) {
+				incomplete_since = incomplete_since.min(when);
+			}
+			when.saturating_inc();
+			count_down.saturating_dec();
+		}
+		incomplete_since = incomplete_since.min(when);
+		if incomplete_since <= now {
+			IncompleteSince::<T>::put(incomplete_since);
+		}
+	}
+
+	/// Returns `true` if the agenda was fully completed, `false` if it should be revisited at a
+	/// later block.
+	fn service_agenda(
+		weight: &mut WeightCounter,
+		executed: &mut u32,
+		now: T::BlockNumber,
+		when: T::BlockNumber,
+		max: u32,
+	) -> bool {
+		let mut agenda = Agenda::<T>::get(when);
+		let mut ordered = agenda
+			.iter()
+			.enumerate()
+			.filter_map(|(index, maybe_item)| {
+				maybe_item.as_ref().map(|item| (index as u32, item.priority))
+			})
+			.collect::<Vec<_>>();
+		ordered.sort_by_key(|k| k.1);
+		let within_limit =
+			weight.check_accrue(T::WeightInfo::service_agenda_base(ordered.len() as u32));
+		debug_assert!(within_limit, "weight limit should have been checked in advance");
+
+		// Items which we know can be executed and have postponed for execution in a later block.
+		let mut postponed = (ordered.len() as u32).saturating_sub(max);
+		// Items which we don't know can ever be executed.
+		let mut dropped = 0;
+
+		for (agenda_index, _) in ordered.into_iter().take(max as usize) {
+			let task = match agenda[agenda_index as usize].take() {
+				None => continue,
+				Some(t) => t,
+			};
+			let base_weight = T::WeightInfo::service_task(
+				task.call.lookup_len().map(|x| x as usize),
+				task.maybe_id.is_some(),
+				task.maybe_periodic.is_some(),
+			);
+			if !weight.can_accrue(base_weight) {
+				postponed += 1;
+				break
+			}
+			let result = Self::service_task(weight, now, when, agenda_index, *executed == 0, task);
+			agenda[agenda_index as usize] = match result {
+				Err((Unavailable, slot)) => {
+					dropped += 1;
+					slot
+				},
+				Err((Overweight, slot)) => {
+					postponed += 1;
+					slot
+				},
+				Ok(()) => {
+					*executed += 1;
+					None
+				},
+			};
+		}
+		if postponed > 0 || dropped > 0 {
+			Agenda::<T>::insert(when, agenda);
+		} else {
+			Agenda::<T>::remove(when);
+		}
+		postponed == 0
+	}
+
+	/// Service (i.e. execute) the given task, being careful not to overflow the `weight` counter.
+	///
+	/// This involves:
+	/// - removing and potentially replacing the `Lookup` entry for the task.
+	/// - realizing the task's call which can include a preimage lookup.
+	/// - Rescheduling the task for execution in a later agenda if periodic.
+	fn service_task(
+		weight: &mut WeightCounter,
+		now: T::BlockNumber,
+		when: T::BlockNumber,
+		agenda_index: u32,
+		is_first: bool,
+		mut task: ScheduledOf<T>,
+	) -> Result<(), (ServiceTaskError, Option<ScheduledOf<T>>)> {
+		if let Some(ref id) = task.maybe_id {
+			Lookup::<T>::remove(id);
+		}
+
+		let (call, lookup_len) = match T::Preimages::peek(&task.call) {
+			Ok(c) => c,
+			Err(_) => return Err((Unavailable, Some(task))),
+		};
+
+		weight.check_accrue(T::WeightInfo::service_task(
+			lookup_len.map(|x| x as usize),
+			task.maybe_id.is_some(),
+			task.maybe_periodic.is_some(),
+		));
+
+		match Self::execute_dispatch(weight, task.origin.clone(), call) {
+			Err(Unavailable) => {
+				debug_assert!(false, "Checked to exist with `peek`");
+				Self::deposit_event(Event::CallUnavailable {
+					task: (when, agenda_index),
+					id: task.maybe_id,
+				});
+				Err((Unavailable, Some(task)))
+			},
+			Err(Overweight) if is_first => {
+				T::Preimages::drop(&task.call);
+				Self::deposit_event(Event::PermanentlyOverweight {
+					task: (when, agenda_index),
+					id: task.maybe_id,
+				});
+				Err((Unavailable, Some(task)))
+			},
+			Err(Overweight) => Err((Overweight, Some(task))),
+			Ok(result) => {
+				Self::deposit_event(Event::Dispatched {
+					task: (when, agenda_index),
+					id: task.maybe_id,
+					result,
+				});
+				if let &Some((period, count)) = &task.maybe_periodic {
+					if count > 1 {
+						task.maybe_periodic = Some((period, count - 1));
+					} else {
+						task.maybe_periodic = None;
+					}
+					let wake = now.saturating_add(period);
+					match Self::place_task(wake, task) {
+						Ok(_) => {},
+						Err((_, task)) => {
+							// TODO: Leave task in storage somewhere for it to be rescheduled
+							// manually.
+							T::Preimages::drop(&task.call);
+							Self::deposit_event(Event::PeriodicFailed {
+								task: (when, agenda_index),
+								id: task.maybe_id,
+							});
+						},
+					}
+				} else {
+					T::Preimages::drop(&task.call);
+				}
+				Ok(())
+			},
+		}
+	}
+
+	/// Make a dispatch to the given `call` from the given `origin`, ensuring that the `weight`
+	/// counter does not exceed its limit and that it is counted accurately (e.g. accounted using
+	/// post info if available).
+	///
+	/// NOTE: Only the weight for this function will be counted (origin lookup, dispatch and the
+	/// call itself).
+	fn execute_dispatch(
+		weight: &mut WeightCounter,
+		origin: T::PalletsOrigin,
+		call: <T as Config>::Call,
+	) -> Result<DispatchResult, ServiceTaskError> {
+		let dispatch_origin: <T as Config>::Origin = origin.into();
+		let base_weight = match dispatch_origin.clone().as_signed() {
+			Some(_) => T::WeightInfo::execute_dispatch_signed(),
+			_ => T::WeightInfo::execute_dispatch_unsigned(),
+		};
+		let call_weight = call.get_dispatch_info().weight;
+		// We only allow a scheduled call if it cannot push the weight past the limit.
+		let max_weight = base_weight.saturating_add(call_weight);
+
+		if !weight.can_accrue(max_weight) {
+			return Err(Overweight)
+		}
+
+		let (maybe_actual_call_weight, result) = match call.dispatch(dispatch_origin) {
+			Ok(post_info) => (post_info.actual_weight, Ok(())),
+			Err(error_and_info) =>
+				(error_and_info.post_info.actual_weight, Err(error_and_info.error)),
+		};
+		let call_weight = maybe_actual_call_weight.unwrap_or(call_weight);
+		weight.check_accrue(base_weight);
+		weight.check_accrue(call_weight);
+		Ok(result)
+	}
+}