Generalised proxies (#6156)

* Initial work * It should work * Fix node * Fix tests * Initial test * Tests * Expunge proxy functionality from democracy and elections * Allow different proxy types * Repotted * Build * Build * Making a start on weights * Undo breaking change * Line widths. * Fix * fix tests * finish benchmarks? * Storage name! * Utility -> Proxy * proxy weight * add proxy weight * remove weights * Update transfer constraint * Again, fix constraints * Fix negation * Update frame/proxy/Cargo.toml Co-authored-by: Kian Paimani <5588131+kianenigma@users.noreply.github.com> * Remove unneeded event. * Grumbles * Apply suggestions from code review Co-authored-by: Kian Paimani <5588131+kianenigma@users.noreply.github.com> Co-authored-by: Shawn Tabrizi <shawntabrizi@gmail.com> Co-authored-by: Kian Paimani <5588131+kianenigma@users.noreply.github.com>
2026-06-13 22:11:06 +00:00 · 2020-06-02 18:15:15 +02:00
parent ffea161765
commit 4adac40c07
20 changed files with 724 additions and 738 deletions
@@ -0,0 +1,271 @@
+// This file is part of Substrate.
+
+// Copyright (C) 2019-2020 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.
+
+//! # Proxy Module
+//! A module allowing accounts to give permission to other accounts to dispatch types of calls from
+//! their signed origin.
+//!
+//! - [`proxy::Trait`](./trait.Trait.html)
+//! - [`Call`](./enum.Call.html)
+//!
+//! ## Overview
+//!
+//! ## Interface
+//!
+//! ### Dispatchable Functions
+//!
+//! [`Call`]: ./enum.Call.html
+//! [`Trait`]: ./trait.Trait.html
+
+// Ensure we're `no_std` when compiling for Wasm.
+#![cfg_attr(not(feature = "std"), no_std)]
+
+use sp_std::prelude::*;
+use frame_support::{decl_module, decl_event, decl_error, decl_storage, Parameter, ensure};
+use frame_support::{
+	traits::{Get, ReservableCurrency, Currency, Filter, InstanceFilter},
+	weights::{GetDispatchInfo, constants::{WEIGHT_PER_MICROS, WEIGHT_PER_NANOS}},
+	dispatch::{PostDispatchInfo, IsSubType},
+};
+use frame_system::{self as system, ensure_signed};
+use sp_runtime::{DispatchResult, traits::{Dispatchable, Zero}};
+use sp_runtime::traits::Member;
+
+mod tests;
+mod benchmarking;
+
+type BalanceOf<T> = <<T as Trait>::Currency as Currency<<T as frame_system::Trait>::AccountId>>::Balance;
+
+/// Configuration trait.
+pub trait Trait: frame_system::Trait {
+	/// The overarching event type.
+	type Event: From<Event> + Into<<Self as frame_system::Trait>::Event>;
+
+	/// The overarching call type.
+	type Call: Parameter + Dispatchable<Origin=Self::Origin, PostInfo=PostDispatchInfo>
+		+ GetDispatchInfo + From<frame_system::Call<Self>> + IsSubType<Module<Self>, Self>;
+
+	/// The currency mechanism.
+	type Currency: ReservableCurrency<Self::AccountId>;
+
+	/// Is a given call compatible with the proxying subsystem?
+	type IsCallable: Filter<<Self as Trait>::Call>;
+
+	/// A kind of proxy; specified with the proxy and passed in to the `IsProxyable` fitler.
+	/// The instance filter determines whether a given call may be proxied under this type.
+	type ProxyType: Parameter + Member + Ord + PartialOrd + InstanceFilter<<Self as Trait>::Call>
+		+ Default;
+
+	/// The base amount of currency needed to reserve for creating a proxy.
+	///
+	/// This is held for an additional storage item whose value size is
+	/// `sizeof(Balance)` bytes and whose key size is `sizeof(AccountId)` bytes.
+	type ProxyDepositBase: Get<BalanceOf<Self>>;
+
+	/// The amount of currency needed per proxy added.
+	///
+	/// This is held for adding 32 bytes plus an instance of `ProxyType` more into a pre-existing
+	/// storage value.
+	type ProxyDepositFactor: Get<BalanceOf<Self>>;
+
+	/// The maximum amount of proxies allowed for a single account.
+	type MaxProxies: Get<u16>;
+}
+
+decl_storage! {
+	trait Store for Module<T: Trait> as Proxy {
+		/// The set of account proxies. Maps the account which has delegated to the accounts
+		/// which are being delegated to, together with the amount held on deposit.
+		pub Proxies: map hasher(twox_64_concat) T::AccountId => (Vec<(T::AccountId, T::ProxyType)>, BalanceOf<T>);
+	}
+}
+
+decl_error! {
+	pub enum Error for Module<T: Trait> {
+		/// There are too many proxies registered.
+		TooMany,
+		/// Proxy registration not found.
+		NotFound,
+		/// Sender is not a proxy of the account to be proxied.
+		NotProxy,
+		/// A call with a `false` `IsCallable` filter was attempted.
+		Uncallable,
+		/// A call which is incompatible with the proxy type's filter was attempted.
+		Unproxyable,
+		/// Account is already a proxy.
+		Duplicate,
+		/// Call may not be made by proxy because it may escalate its privileges.
+		NoPermission,
+	}
+}
+
+decl_event! {
+	/// Events type.
+	pub enum Event {
+		/// A proxy was executed correctly, with the given result.
+		ProxyExecuted(DispatchResult),
+	}
+}
+
+decl_module! {
+	pub struct Module<T: Trait> for enum Call where origin: T::Origin {
+		type Error = Error<T>;
+
+		/// Deposit one of this module's events by using the default implementation.
+		fn deposit_event() = default;
+
+		/// Dispatch the given `call` from an account that the sender is authorised for through
+		/// `add_proxy`.
+		///
+		/// The dispatch origin for this call must be _Signed_.
+		///
+		/// Parameters:
+		/// - `real`: The account that the proxy will make a call on behalf of.
+		/// - `force_proxy_type`: Specify the exact proxy type to be used and checked for this call.
+		/// - `call`: The call to be made by the `real` account.
+		///
+		/// # <weight>
+		/// P is the number of proxies the user has
+		/// - Base weight: 19.87 + .141 * P µs
+		/// - DB weight: 1 storage read.
+		/// - Plus the weight of the `call`
+		/// # </weight>
+		#[weight = {
+			let di = call.get_dispatch_info();
+			(T::DbWeight::get().reads(1)
+				.saturating_add(di.weight)
+				.saturating_add(20 * WEIGHT_PER_MICROS)
+				.saturating_add((140 * WEIGHT_PER_NANOS).saturating_mul(T::MaxProxies::get().into())),
+			di.class)
+		}]
+		fn proxy(origin,
+			real: T::AccountId,
+			force_proxy_type: Option<T::ProxyType>,
+			call: Box<<T as Trait>::Call>
+		) {
+			let who = ensure_signed(origin)?;
+			ensure!(T::IsCallable::filter(&call), Error::<T>::Uncallable);
+			let (_, proxy_type) = Proxies::<T>::get(&real).0.into_iter()
+				.find(|x| &x.0 == &who && force_proxy_type.as_ref().map_or(true, |y| &x.1 == y))
+				.ok_or(Error::<T>::NotProxy)?;
+			match call.is_sub_type() {
+				Some(Call::add_proxy(_, ref pt)) | Some(Call::remove_proxy(_, ref pt)) =>
+					ensure!(&proxy_type == pt, Error::<T>::NoPermission),
+				_ => (),
+			}
+			ensure!(proxy_type.filter(&call), Error::<T>::Unproxyable);
+			let e = call.dispatch(frame_system::RawOrigin::Signed(real).into());
+			Self::deposit_event(Event::ProxyExecuted(e.map(|_| ()).map_err(|e| e.error)));
+		}
+
+		/// Register a proxy account for the sender that is able to make calls on its behalf.
+		///
+		/// The dispatch origin for this call must be _Signed_.
+		///
+		/// Parameters:
+		/// - `proxy`: The account that the `caller` would like to make a proxy.
+		/// - `proxy_type`: The permissions allowed for this proxy account.
+		///
+		/// # <weight>
+		/// P is the number of proxies the user has
+		/// - Base weight: 17.48 + .176 * P µs
+		/// - DB weight: 1 storage read and write.
+		/// # </weight>
+		#[weight = T::DbWeight::get().reads_writes(1, 1)
+				.saturating_add(18 * WEIGHT_PER_MICROS)
+				.saturating_add((200 * WEIGHT_PER_NANOS).saturating_mul(T::MaxProxies::get().into()))
+		]
+		fn add_proxy(origin, proxy: T::AccountId, proxy_type: T::ProxyType) -> DispatchResult {
+			let who = ensure_signed(origin)?;
+			Proxies::<T>::try_mutate(&who, |(ref mut proxies, ref mut deposit)| {
+				ensure!(proxies.len() < T::MaxProxies::get() as usize, Error::<T>::TooMany);
+				let typed_proxy = (proxy, proxy_type);
+				let i = proxies.binary_search(&typed_proxy).err().ok_or(Error::<T>::Duplicate)?;
+				proxies.insert(i, typed_proxy);
+				let new_deposit = T::ProxyDepositBase::get()
+					+ T::ProxyDepositFactor::get() * (proxies.len() as u32).into();
+				if new_deposit > *deposit {
+					T::Currency::reserve(&who, new_deposit - *deposit)?;
+				} else if new_deposit < *deposit {
+					T::Currency::unreserve(&who, *deposit - new_deposit);
+				}
+				*deposit = new_deposit;
+				Ok(())
+			})
+		}
+
+		/// Unregister a proxy account for the sender.
+		///
+		/// The dispatch origin for this call must be _Signed_.
+		///
+		/// Parameters:
+		/// - `proxy`: The account that the `caller` would like to remove as a proxy.
+		/// - `proxy_type`: The permissions currently enabled for the removed proxy account.
+		///
+		/// # <weight>
+		/// P is the number of proxies the user has
+		/// - Base weight: 14.37 + .164 * P µs
+		/// - DB weight: 1 storage read and write.
+		/// # </weight>
+		#[weight = T::DbWeight::get().reads_writes(1, 1)
+				.saturating_add(14 * WEIGHT_PER_MICROS)
+				.saturating_add((160 * WEIGHT_PER_NANOS).saturating_mul(T::MaxProxies::get().into()))
+		]
+		fn remove_proxy(origin, proxy: T::AccountId, proxy_type: T::ProxyType) -> DispatchResult {
+			let who = ensure_signed(origin)?;
+			Proxies::<T>::try_mutate_exists(&who, |x| {
+				let (mut proxies, old_deposit) = x.take().ok_or(Error::<T>::NotFound)?;
+				let typed_proxy = (proxy, proxy_type);
+				let i = proxies.binary_search(&typed_proxy).ok().ok_or(Error::<T>::NotFound)?;
+				proxies.remove(i);
+				let new_deposit = if proxies.is_empty() {
+					BalanceOf::<T>::zero()
+				} else {
+					T::ProxyDepositBase::get() + T::ProxyDepositFactor::get() * (proxies.len() as u32).into()
+				};
+				if new_deposit > old_deposit {
+					T::Currency::reserve(&who, new_deposit - old_deposit)?;
+				} else if new_deposit < old_deposit {
+					T::Currency::unreserve(&who, old_deposit - new_deposit);
+				}
+				if !proxies.is_empty() {
+					*x = Some((proxies, new_deposit))
+				}
+				Ok(())
+			})
+		}
+
+		/// Unregister all proxy accounts for the sender.
+		///
+		/// The dispatch origin for this call must be _Signed_.
+		///
+		/// # <weight>
+		/// P is the number of proxies the user has
+		/// - Base weight: 13.73 + .129 * P µs
+		/// - DB weight: 1 storage read and write.
+		/// # </weight>
+		#[weight = T::DbWeight::get().reads_writes(1, 1)
+				.saturating_add(14 * WEIGHT_PER_MICROS)
+				.saturating_add((130 * WEIGHT_PER_NANOS).saturating_mul(T::MaxProxies::get().into()))
+		]
+		fn remove_proxies(origin) {
+			let who = ensure_signed(origin)?;
+			let (_, old_deposit) = Proxies::<T>::take(&who);
+			T::Currency::unreserve(&who, old_deposit);
+		}
+	}
+}