migrations.rs

// This file is part of Substrate.

// Copyright (C) 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.

// Migrations for Multisig Pallet

use crate::*;
use frame::prelude::*;

pub mod v1 {
    use super::*;

    type OpaqueCall<T> = frame::traits::WrapperKeepOpaque<<T as Config>::RuntimeCall>;

    #[frame::storage_alias]
    type Calls<T: Config> = StorageMap<
        Pallet<T>,
        Identity,
        [u8; 32],
        (
            OpaqueCall<T>,
            <T as frame_system::Config>::AccountId,
            BalanceOf<T>,
        ),
    >;

    pub struct MigrateToV1<T>(core::marker::PhantomData<T>);
    impl<T: Config> OnRuntimeUpgrade for MigrateToV1<T> {
        #[cfg(feature = "try-runtime")]
        fn pre_upgrade() -> Result<Vec<u8>, frame::try_runtime::TryRuntimeError> {
            log!(
                info,
                "Number of calls to refund and delete: {}",
                Calls::<T>::iter().count()
            );

            Ok(Vec::new())
        }

        fn on_runtime_upgrade() -> Weight {
            use frame::traits::ReservableCurrency as _;
            let current = Pallet::<T>::in_code_storage_version();
            let onchain = Pallet::<T>::on_chain_storage_version();

            if onchain > 0 {
                log!(info, "MigrateToV1 should be removed");
                return T::DbWeight::get().reads(1);
            }

            let mut call_count = 0u64;
            Calls::<T>::drain().for_each(|(_call_hash, (_data, caller, deposit))| {
                T::Currency::unreserve(&caller, deposit);
                call_count.saturating_inc();
            });

            current.put::<Pallet<T>>();

            T::DbWeight::get().reads_writes(
                // Reads: Get Calls + Get Version
                call_count.saturating_add(1),
                // Writes: Drain Calls + Unreserves + Set version
                call_count.saturating_mul(2).saturating_add(1),
            )
        }

        #[cfg(feature = "try-runtime")]
        fn post_upgrade(_state: Vec<u8>) -> Result<(), frame::try_runtime::TryRuntimeError> {
            ensure!(
                Calls::<T>::iter().count() == 0,
                "there are some dangling calls that need to be destroyed and refunded"
            );
            Ok(())
        }
    }
}