1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200 201 202 203 204 205 206 207 208 209 210 211 212 213 214 215 216 217 218 219 220 221 222 223 224 225 226 227 228 229 230 231 232 233 234 235 236 237 238 239 240 241 242 243 244 245 246 247 248 249 250 251 252 253 254 255 256 257 258 259 260 261 262 263 264 265 266 267 268 269 270 271 272 273 274 275 276 277 278 279 280 281 282 283 284 285 286 287 288 289 290 291 292 293 294 295 296 297 298 299 300 301 302 303 304 305 306 307 308 309 310 311 312 313 314 315 316 317 318 319 320 321 322 323 324 325 326 327 328 329 330 331 332 333 334 335 336 337 338 339 340 341 342 343 344 345 346 347 348 349 350 351 352 353 354 355 356 357 358 359 360 361 362 363 364 365 366 367 368 369 370 371 372 373 374 375 376 377 378 379 380 381 382 383 384 385 386 387 388 389 390 391 392 393 394 395 396 397 398 399 400 401 402 403 404 405 406 407 408 409 410 411 412 413 414 415 416 417 418 419 420 421 422 423 424 425 426 427 428 429 430 431 432 433 434 435 436 437 438 439 440 441 442 443 444 445 446 447 448 449 450 451 452 453 454 455 456 457 458 459 460 461 462 463 464 465 466 467 468 469 470 471 472 473 474 475 476 477 478 479 480 481 482 483 484 485 486 487 488 489 490 491 492 493 494 495 496 497 498 499 500 501 502 503 504 505 506 507 508 509 510 511 512 513 514 515 516 517 518 519 520 521 522 523 524 525 526 527 528 529 530 531 532 533 534 535 536 537 538 539 540 541 542 543 544 545 546 547 548 549 550 551 552 553 554 555 556 557 558 559 560 561 562 563 564 565 566 567 568 569 570 571 572 573 574 575 576 577 578 579 580 581 582 583 584 585 586 587 588 589 590 591 592 593 594 595 596 597 598 599 600 601 602 603 604 605 606 607 608 609 610 611 612 613 614 615 616 617 618 619 620 621 622 623 624 625 626 627 628 629 630 631 632 633 634 635 636 637 638 639 640 641 642 643 644 645 646 647 648 649 650 651 652 653 654 655 656 657 658 659 660 661 662 663 664 665 666 667 668 669 670 671 672 673 674 675 676 677 678 679 680 681 682 683 684 685 686 687 688 689 690 691 692 693 694 695 696 697 698 699 700 701 702 703 704 705 706 707 708 709 710 711 712 713 714 715 716 717 718 719 720 721 722 723 724 725 726 727 728 729 730 731 732 733 734 735 736 737 738 739 740 741 742 743 744 745 746 747 748 749 750 751 752 753 754 755 756 757 758 759 760 761 762 763 764 765 766 767 768 769 770 771 772 773 774 775 776 777 778 779 780 781 782 783 784 785 786 787 788 789 790 791 792 793 794 795 796 797 798 799 800 801 802 803 804 805 806 807 808 809 810 811 812 813 814 815 816 817 818 819 820 821 822 823 824 825 826 827 828 829 830 831 832 833 834 835 836 837 838 839 840 841 842 843 844 845 846 847 848 849 850 851 852 853 854 855 856 857 858 859 860 861 862 863 864 865 866 867 868 869 870 871 872 873 874 875 876 877 878 879 880 881 882 883 884 885 886 887 888 889 890 891 892 893 894 895 896 897 898 899 900 901 902 903 904 905 906 907 908 909 910 911 912 913 914 915 916 917 918 919 920 921 922 923 924 925 926 927 928 929 930 931 932 933 934 935 936 937 938 939 940 941 942 943 944 945 946 947 948 949 950 951 952 953 954 955 956 957 958 959 960 961 962 963 964 965 966 967 968 969 970 971 972 973 974 975 976 977 978 979 980 981 982 983 984 985 986 987 988 989 990 991 992 993 994 995 996 997 998 999 1000 1001 1002 1003 1004 1005 1006 1007 1008 1009 1010 1011 1012 1013 1014 1015 1016 1017 1018 1019 1020 1021 1022 1023 1024 1025 1026 1027 1028 1029 1030 1031 1032 1033 1034 1035 1036 1037 1038 1039 1040 1041 1042 1043 1044 1045 1046 1047 1048 1049 1050 1051 1052 1053 1054 1055 1056 1057 1058 1059 1060 1061 1062 1063 1064 1065 1066 1067 1068 1069 1070 1071 1072 1073 1074 1075 1076 1077 1078 1079 1080 1081 1082 1083 1084 1085 1086 1087 1088 1089 1090 1091 1092 1093 1094 1095 1096 1097 1098 1099 1100 1101 1102 1103 1104 1105 1106 1107 1108 1109 1110 1111 1112 1113 1114 1115 1116 1117 1118 1119 1120 1121 1122 1123 1124 1125 1126 1127 1128 1129 1130 1131 1132 1133 1134 1135 1136 1137 1138 1139 1140 1141 1142 1143 1144 1145 1146 1147 1148 1149 1150 1151 1152 1153 1154 1155 1156 1157 1158 1159 1160 1161 1162 1163 1164 1165 1166 1167 1168 1169 1170 1171 1172 1173 1174 1175 1176 1177 1178 1179 1180 1181 1182 1183 1184 1185 1186 1187 1188 1189 1190 1191 1192 1193 1194 1195 1196 1197 1198 1199 1200 1201 1202 1203 1204 1205 1206 1207
// 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.
use crate::{
defensive,
storage::{storage_prefix, transactional::with_transaction_opaque_err},
traits::{
Defensive, GetStorageVersion, NoStorageVersionSet, PalletInfoAccess, SafeMode,
StorageVersion,
},
weights::{RuntimeDbWeight, Weight, WeightMeter},
};
use alloc::vec::Vec;
use codec::{Decode, Encode, MaxEncodedLen};
use core::marker::PhantomData;
use impl_trait_for_tuples::impl_for_tuples;
use sp_arithmetic::traits::Bounded;
use sp_core::Get;
use sp_io::{hashing::twox_128, storage::clear_prefix, KillStorageResult};
use sp_runtime::traits::Zero;
/// Handles storage migration pallet versioning.
///
/// [`VersionedMigration`] allows developers to write migrations without worrying about checking and
/// setting storage versions. Instead, the developer wraps their migration in this struct which
/// takes care of version handling using best practices.
///
/// It takes 5 type parameters:
/// - `From`: The version being upgraded from.
/// - `To`: The version being upgraded to.
/// - `Inner`: An implementation of `UncheckedOnRuntimeUpgrade`.
/// - `Pallet`: The Pallet being upgraded.
/// - `Weight`: The runtime's RuntimeDbWeight implementation.
///
/// When a [`VersionedMigration`] `on_runtime_upgrade`, `pre_upgrade`, or `post_upgrade` method is
/// called, the on-chain version of the pallet is compared to `From`. If they match, the `Inner`
/// `UncheckedOnRuntimeUpgrade` is called and the pallets on-chain version is set to `To`
/// after the migration. Otherwise, a warning is logged notifying the developer that the upgrade was
/// a noop and should probably be removed.
///
/// By not bounding `Inner` with `OnRuntimeUpgrade`, we prevent developers from
/// accidentally using the unchecked version of the migration in a runtime upgrade instead of
/// [`VersionedMigration`].
///
/// ### Examples
/// ```ignore
/// // In file defining migrations
///
/// /// Private module containing *version unchecked* migration logic.
/// ///
/// /// Should only be used by the [`VersionedMigration`] type in this module to create something to
/// /// export.
/// ///
/// /// We keep this private so the unversioned migration cannot accidentally be used in any runtimes.
/// ///
/// /// For more about this pattern of keeping items private, see
/// /// - https://github.com/rust-lang/rust/issues/30905
/// /// - https://internals.rust-lang.org/t/lang-team-minutes-private-in-public-rules/4504/40
/// mod version_unchecked {
/// use super::*;
/// pub struct VersionUncheckedMigrateV5ToV6<T>(core::marker::PhantomData<T>);
/// impl<T: Config> UncheckedOnRuntimeUpgrade for VersionUncheckedMigrateV5ToV6<T> {
/// // `UncheckedOnRuntimeUpgrade` implementation...
/// }
/// }
///
/// pub type MigrateV5ToV6<T, I> =
/// VersionedMigration<
/// 5,
/// 6,
/// VersionUncheckedMigrateV5ToV6<T, I>,
/// crate::pallet::Pallet<T, I>,
/// <T as frame_system::Config>::DbWeight
/// >;
///
/// // Migrations tuple to pass to the Executive pallet:
/// pub type Migrations = (
/// // other migrations...
/// MigrateV5ToV6<T, ()>,
/// // other migrations...
/// );
/// ```
pub struct VersionedMigration<const FROM: u16, const TO: u16, Inner, Pallet, Weight> {
_marker: PhantomData<(Inner, Pallet, Weight)>,
}
/// A helper enum to wrap the pre_upgrade bytes like an Option before passing them to post_upgrade.
/// This enum is used rather than an Option to make the API clearer to the developer.
#[derive(Encode, Decode)]
pub enum VersionedPostUpgradeData {
/// The migration ran, inner vec contains pre_upgrade data.
MigrationExecuted(alloc::vec::Vec<u8>),
/// This migration is a noop, do not run post_upgrade checks.
Noop,
}
/// Implementation of the `OnRuntimeUpgrade` trait for `VersionedMigration`.
///
/// Its main function is to perform the runtime upgrade in `on_runtime_upgrade` only if the on-chain
/// version of the pallets storage matches `From`, and after the upgrade set the on-chain storage to
/// `To`. If the versions do not match, it writes a log notifying the developer that the migration
/// is a noop.
impl<
const FROM: u16,
const TO: u16,
Inner: crate::traits::UncheckedOnRuntimeUpgrade,
Pallet: GetStorageVersion<InCodeStorageVersion = StorageVersion> + PalletInfoAccess,
DbWeight: Get<RuntimeDbWeight>,
> crate::traits::OnRuntimeUpgrade for VersionedMigration<FROM, TO, Inner, Pallet, DbWeight>
{
/// Executes pre_upgrade if the migration will run, and wraps the pre_upgrade bytes in
/// [`VersionedPostUpgradeData`] before passing them to post_upgrade, so it knows whether the
/// migration ran or not.
#[cfg(feature = "try-runtime")]
fn pre_upgrade() -> Result<alloc::vec::Vec<u8>, sp_runtime::TryRuntimeError> {
let on_chain_version = Pallet::on_chain_storage_version();
if on_chain_version == FROM {
Ok(VersionedPostUpgradeData::MigrationExecuted(Inner::pre_upgrade()?).encode())
} else {
Ok(VersionedPostUpgradeData::Noop.encode())
}
}
/// Executes the versioned runtime upgrade.
///
/// First checks if the pallets on-chain storage version matches the version of this upgrade. If
/// it matches, it calls `Inner::on_runtime_upgrade`, updates the on-chain version, and returns
/// the weight. If it does not match, it writes a log notifying the developer that the migration
/// is a noop.
fn on_runtime_upgrade() -> Weight {
let on_chain_version = Pallet::on_chain_storage_version();
if on_chain_version == FROM {
log::info!(
"๐ Pallet {:?} VersionedMigration migrating storage version from {:?} to {:?}.",
Pallet::name(),
FROM,
TO
);
// Execute the migration
let weight = Inner::on_runtime_upgrade();
// Update the on-chain version
StorageVersion::new(TO).put::<Pallet>();
weight.saturating_add(DbWeight::get().reads_writes(1, 1))
} else {
log::warn!(
"๐ Pallet {:?} VersionedMigration migration {}->{} can be removed; on-chain is already at {:?}.",
Pallet::name(),
FROM,
TO,
on_chain_version
);
DbWeight::get().reads(1)
}
}
/// Executes `Inner::post_upgrade` if the migration just ran.
///
/// pre_upgrade passes [`VersionedPostUpgradeData::MigrationExecuted`] to post_upgrade if
/// the migration ran, and [`VersionedPostUpgradeData::Noop`] otherwise.
#[cfg(feature = "try-runtime")]
fn post_upgrade(
versioned_post_upgrade_data_bytes: alloc::vec::Vec<u8>,
) -> Result<(), sp_runtime::TryRuntimeError> {
use codec::DecodeAll;
match <VersionedPostUpgradeData>::decode_all(&mut &versioned_post_upgrade_data_bytes[..])
.map_err(|_| "VersionedMigration post_upgrade failed to decode PreUpgradeData")?
{
VersionedPostUpgradeData::MigrationExecuted(inner_bytes) =>
Inner::post_upgrade(inner_bytes),
VersionedPostUpgradeData::Noop => Ok(()),
}
}
}
/// Can store the in-code pallet version on-chain.
pub trait StoreInCodeStorageVersion<T: GetStorageVersion + PalletInfoAccess> {
/// Write the in-code storage version on-chain.
fn store_in_code_storage_version();
}
impl<T: GetStorageVersion<InCodeStorageVersion = StorageVersion> + PalletInfoAccess>
StoreInCodeStorageVersion<T> for StorageVersion
{
fn store_in_code_storage_version() {
let version = <T as GetStorageVersion>::in_code_storage_version();
version.put::<T>();
}
}
impl<T: GetStorageVersion<InCodeStorageVersion = NoStorageVersionSet> + PalletInfoAccess>
StoreInCodeStorageVersion<T> for NoStorageVersionSet
{
fn store_in_code_storage_version() {
StorageVersion::default().put::<T>();
}
}
/// Trait used by [`migrate_from_pallet_version_to_storage_version`] to do the actual migration.
pub trait PalletVersionToStorageVersionHelper {
fn migrate(db_weight: &RuntimeDbWeight) -> Weight;
}
impl<T: GetStorageVersion + PalletInfoAccess> PalletVersionToStorageVersionHelper for T
where
T::InCodeStorageVersion: StoreInCodeStorageVersion<T>,
{
fn migrate(db_weight: &RuntimeDbWeight) -> Weight {
const PALLET_VERSION_STORAGE_KEY_POSTFIX: &[u8] = b":__PALLET_VERSION__:";
fn pallet_version_key(name: &str) -> [u8; 32] {
crate::storage::storage_prefix(name.as_bytes(), PALLET_VERSION_STORAGE_KEY_POSTFIX)
}
sp_io::storage::clear(&pallet_version_key(<T as PalletInfoAccess>::name()));
<T::InCodeStorageVersion as StoreInCodeStorageVersion<T>>::store_in_code_storage_version();
db_weight.writes(2)
}
}
#[cfg_attr(all(not(feature = "tuples-96"), not(feature = "tuples-128")), impl_for_tuples(64))]
#[cfg_attr(all(feature = "tuples-96", not(feature = "tuples-128")), impl_for_tuples(96))]
#[cfg_attr(feature = "tuples-128", impl_for_tuples(128))]
impl PalletVersionToStorageVersionHelper for T {
fn migrate(db_weight: &RuntimeDbWeight) -> Weight {
let mut weight = Weight::zero();
for_tuples!( #( weight = weight.saturating_add(T::migrate(db_weight)); )* );
weight
}
}
/// Migrate from the `PalletVersion` struct to the new [`StorageVersion`] struct.
///
/// This will remove all `PalletVersion's` from the state and insert the in-code storage version.
pub fn migrate_from_pallet_version_to_storage_version<
Pallets: PalletVersionToStorageVersionHelper,
>(
db_weight: &RuntimeDbWeight,
) -> Weight {
Pallets::migrate(db_weight)
}
/// `RemovePallet` is a utility struct used to remove all storage items associated with a specific
/// pallet.
///
/// This struct is generic over two parameters:
/// - `P` is a type that implements the `Get` trait for a static string, representing the pallet's
/// name.
/// - `DbWeight` is a type that implements the `Get` trait for `RuntimeDbWeight`, providing the
/// weight for database operations.
///
/// On runtime upgrade, the `on_runtime_upgrade` function will clear all storage items associated
/// with the specified pallet, logging the number of keys removed. If the `try-runtime` feature is
/// enabled, the `pre_upgrade` and `post_upgrade` functions can be used to verify the storage
/// removal before and after the upgrade.
///
/// # Examples:
/// ```ignore
/// construct_runtime! {
/// pub enum Runtime
/// {
/// System: frame_system = 0,
///
/// SomePalletToRemove: pallet_something = 1,
/// AnotherPalletToRemove: pallet_something_else = 2,
///
/// YourOtherPallets...
/// }
/// };
///
/// parameter_types! {
/// pub const SomePalletToRemoveStr: &'static str = "SomePalletToRemove";
/// pub const AnotherPalletToRemoveStr: &'static str = "AnotherPalletToRemove";
/// }
///
/// pub type Migrations = (
/// RemovePallet<SomePalletToRemoveStr, RocksDbWeight>,
/// RemovePallet<AnotherPalletToRemoveStr, RocksDbWeight>,
/// AnyOtherMigrations...
/// );
///
/// pub type Executive = frame_executive::Executive<
/// Runtime,
/// Block,
/// frame_system::ChainContext<Runtime>,
/// Runtime,
/// Migrations
/// >;
/// ```
///
/// WARNING: `RemovePallet` has no guard rails preventing it from bricking the chain if the
/// operation of removing storage for the given pallet would exceed the block weight limit.
///
/// If your pallet has too many keys to be removed in a single block, it is advised to wait for
/// a multi-block scheduler currently under development which will allow for removal of storage
/// items (and performing other heavy migrations) over multiple blocks
/// (see <https://github.com/paritytech/substrate/issues/13690>).
pub struct RemovePallet<P: Get<&'static str>, DbWeight: Get<RuntimeDbWeight>>(
PhantomData<(P, DbWeight)>,
);
impl<P: Get<&'static str>, DbWeight: Get<RuntimeDbWeight>> frame_support::traits::OnRuntimeUpgrade
for RemovePallet<P, DbWeight>
{
fn on_runtime_upgrade() -> frame_support::weights::Weight {
let hashed_prefix = twox_128(P::get().as_bytes());
let keys_removed = match clear_prefix(&hashed_prefix, None) {
KillStorageResult::AllRemoved(value) => value,
KillStorageResult::SomeRemaining(value) => {
log::error!(
"`clear_prefix` failed to remove all keys for {}. THIS SHOULD NEVER HAPPEN! ๐จ",
P::get()
);
value
},
} as u64;
log::info!("Removed {} {} keys ๐งน", keys_removed, P::get());
DbWeight::get().reads_writes(keys_removed + 1, keys_removed)
}
#[cfg(feature = "try-runtime")]
fn pre_upgrade() -> Result<alloc::vec::Vec<u8>, sp_runtime::TryRuntimeError> {
use crate::storage::unhashed::contains_prefixed_key;
let hashed_prefix = twox_128(P::get().as_bytes());
match contains_prefixed_key(&hashed_prefix) {
true => log::info!("Found {} keys pre-removal ๐", P::get()),
false => log::warn!(
"Migration RemovePallet<{}> can be removed (no keys found pre-removal).",
P::get()
),
};
Ok(alloc::vec::Vec::new())
}
#[cfg(feature = "try-runtime")]
fn post_upgrade(_state: alloc::vec::Vec<u8>) -> Result<(), sp_runtime::TryRuntimeError> {
use crate::storage::unhashed::contains_prefixed_key;
let hashed_prefix = twox_128(P::get().as_bytes());
match contains_prefixed_key(&hashed_prefix) {
true => {
log::error!("{} has keys remaining post-removal โ", P::get());
return Err("Keys remaining post-removal, this should never happen ๐จ".into())
},
false => log::info!("No {} keys found post-removal ๐", P::get()),
};
Ok(())
}
}
/// `RemoveStorage` is a utility struct used to remove a storage item from a specific pallet.
///
/// This struct is generic over three parameters:
/// - `P` is a type that implements the [`Get`] trait for a static string, representing the pallet's
/// name.
/// - `S` is a type that implements the [`Get`] trait for a static string, representing the storage
/// name.
/// - `DbWeight` is a type that implements the [`Get`] trait for [`RuntimeDbWeight`], providing the
/// weight for database operations.
///
/// On runtime upgrade, the `on_runtime_upgrade` function will clear the storage from the specified
/// storage, logging the number of keys removed. If the `try-runtime` feature is enabled, the
/// `pre_upgrade` and `post_upgrade` functions can be used to verify the storage removal before and
/// after the upgrade.
///
/// # Examples:
/// ```ignore
/// construct_runtime! {
/// pub enum Runtime
/// {
/// System: frame_system = 0,
///
/// SomePallet: pallet_something = 1,
///
/// YourOtherPallets...
/// }
/// };
///
/// parameter_types! {
/// pub const SomePallet: &'static str = "SomePallet";
/// pub const StorageAccounts: &'static str = "Accounts";
/// pub const StorageAccountCount: &'static str = "AccountCount";
/// }
///
/// pub type Migrations = (
/// RemoveStorage<SomePallet, StorageAccounts, RocksDbWeight>,
/// RemoveStorage<SomePallet, StorageAccountCount, RocksDbWeight>,
/// AnyOtherMigrations...
/// );
///
/// pub type Executive = frame_executive::Executive<
/// Runtime,
/// Block,
/// frame_system::ChainContext<Runtime>,
/// Runtime,
/// Migrations
/// >;
/// ```
///
/// WARNING: `RemoveStorage` has no guard rails preventing it from bricking the chain if the
/// operation of removing storage for the given pallet would exceed the block weight limit.
///
/// If your storage has too many keys to be removed in a single block, it is advised to wait for
/// a multi-block scheduler currently under development which will allow for removal of storage
/// items (and performing other heavy migrations) over multiple blocks
/// (see <https://github.com/paritytech/substrate/issues/13690>).
pub struct RemoveStorage<P: Get<&'static str>, S: Get<&'static str>, DbWeight: Get<RuntimeDbWeight>>(
PhantomData<(P, S, DbWeight)>,
);
impl<P: Get<&'static str>, S: Get<&'static str>, DbWeight: Get<RuntimeDbWeight>>
frame_support::traits::OnRuntimeUpgrade for RemoveStorage<P, S, DbWeight>
{
fn on_runtime_upgrade() -> frame_support::weights::Weight {
let hashed_prefix = storage_prefix(P::get().as_bytes(), S::get().as_bytes());
let keys_removed = match clear_prefix(&hashed_prefix, None) {
KillStorageResult::AllRemoved(value) => value,
KillStorageResult::SomeRemaining(value) => {
log::error!(
"`clear_prefix` failed to remove all keys for storage `{}` from pallet `{}`. THIS SHOULD NEVER HAPPEN! ๐จ",
S::get(), P::get()
);
value
},
} as u64;
log::info!("Removed `{}` `{}` `{}` keys ๐งน", keys_removed, P::get(), S::get());
DbWeight::get().reads_writes(keys_removed + 1, keys_removed)
}
#[cfg(feature = "try-runtime")]
fn pre_upgrade() -> Result<alloc::vec::Vec<u8>, sp_runtime::TryRuntimeError> {
use crate::storage::unhashed::contains_prefixed_key;
let hashed_prefix = storage_prefix(P::get().as_bytes(), S::get().as_bytes());
match contains_prefixed_key(&hashed_prefix) {
true => log::info!("Found `{}` `{}` keys pre-removal ๐", P::get(), S::get()),
false => log::warn!(
"Migration RemoveStorage<{}, {}> can be removed (no keys found pre-removal).",
P::get(),
S::get()
),
};
Ok(Default::default())
}
#[cfg(feature = "try-runtime")]
fn post_upgrade(_state: alloc::vec::Vec<u8>) -> Result<(), sp_runtime::TryRuntimeError> {
use crate::storage::unhashed::contains_prefixed_key;
let hashed_prefix = storage_prefix(P::get().as_bytes(), S::get().as_bytes());
match contains_prefixed_key(&hashed_prefix) {
true => {
log::error!("`{}` `{}` has keys remaining post-removal โ", P::get(), S::get());
return Err("Keys remaining post-removal, this should never happen ๐จ".into())
},
false => log::info!("No `{}` `{}` keys found post-removal ๐", P::get(), S::get()),
};
Ok(())
}
}
/// A migration that can proceed in multiple steps.
pub trait SteppedMigration {
/// The cursor type that stores the progress (aka. state) of this migration.
type Cursor: codec::FullCodec + codec::MaxEncodedLen;
/// The unique identifier type of this migration.
type Identifier: codec::FullCodec + codec::MaxEncodedLen;
/// The unique identifier of this migration.
///
/// If two migrations have the same identifier, then they are assumed to be identical.
fn id() -> Self::Identifier;
/// The maximum number of steps that this migration can take.
///
/// This can be used to enforce progress and prevent migrations becoming stuck forever. A
/// migration that exceeds its max steps is treated as failed. `None` means that there is no
/// limit.
fn max_steps() -> Option<u32> {
None
}
/// Try to migrate as much as possible with the given weight.
///
/// **ANY STORAGE CHANGES MUST BE ROLLED-BACK BY THE CALLER UPON ERROR.** This is necessary
/// since the caller cannot return a cursor in the error case. [`Self::transactional_step`] is
/// provided as convenience for a caller. A cursor of `None` implies that the migration is at
/// its end. A migration that once returned `Nonce` is guaranteed to never be called again.
fn step(
cursor: Option<Self::Cursor>,
meter: &mut WeightMeter,
) -> Result<Option<Self::Cursor>, SteppedMigrationError>;
/// Same as [`Self::step`], but rolls back pending changes in the error case.
fn transactional_step(
mut cursor: Option<Self::Cursor>,
meter: &mut WeightMeter,
) -> Result<Option<Self::Cursor>, SteppedMigrationError> {
with_transaction_opaque_err(move || match Self::step(cursor, meter) {
Ok(new_cursor) => {
cursor = new_cursor;
sp_runtime::TransactionOutcome::Commit(Ok(cursor))
},
Err(err) => sp_runtime::TransactionOutcome::Rollback(Err(err)),
})
.map_err(|()| SteppedMigrationError::Failed)?
}
/// Hook for testing that is run before the migration is started.
///
/// Returns some bytes which are passed into `post_upgrade` after the migration is completed.
/// This is not run for the real migration, so panicking is not an issue here.
#[cfg(feature = "try-runtime")]
fn pre_upgrade() -> Result<Vec<u8>, sp_runtime::TryRuntimeError> {
Ok(Vec::new())
}
/// Hook for testing that is run after the migration is completed.
///
/// Should be used to verify the state of the chain after the migration. The `state` parameter
/// is the return value from `pre_upgrade`. This is not run for the real migration, so panicking
/// is not an issue here.
#[cfg(feature = "try-runtime")]
fn post_upgrade(_state: Vec<u8>) -> Result<(), sp_runtime::TryRuntimeError> {
Ok(())
}
}
/// Error that can occur during a [`SteppedMigration`].
#[derive(Debug, Encode, Decode, MaxEncodedLen, scale_info::TypeInfo)]
pub enum SteppedMigrationError {
// Transient errors:
/// The remaining weight is not enough to do anything.
///
/// Can be resolved by calling with at least `required` weight. Note that calling it with
/// exactly `required` weight could cause it to not make any progress.
InsufficientWeight {
/// Amount of weight required to make progress.
required: Weight,
},
// Permanent errors:
/// The migration cannot decode its cursor and therefore not proceed.
///
/// This should not happen unless (1) the migration itself returned an invalid cursor in a
/// previous iteration, (2) the storage got corrupted or (3) there is a bug in the caller's
/// code.
InvalidCursor,
/// The migration encountered a permanent error and cannot continue.
Failed,
}
/// A generic migration identifier that can be used by MBMs.
///
/// It is not required that migrations use this identifier type, but it can help.
#[derive(MaxEncodedLen, Encode, Decode)]
pub struct MigrationId<const N: usize> {
pub pallet_id: [u8; N],
pub version_from: u8,
pub version_to: u8,
}
/// Notification handler for status updates regarding Multi-Block-Migrations.
#[impl_trait_for_tuples::impl_for_tuples(8)]
pub trait MigrationStatusHandler {
/// Notifies of the start of a runtime migration.
fn started() {}
/// Notifies of the completion of a runtime migration.
fn completed() {}
}
/// Handles a failed runtime migration.
///
/// This should never happen, but is here for completeness.
pub trait FailedMigrationHandler {
/// Infallibly handle a failed runtime migration.
///
/// Gets passed in the optional index of the migration in the batch that caused the failure.
/// Returning `None` means that no automatic handling should take place and the callee decides
/// in the implementation what to do.
fn failed(migration: Option<u32>) -> FailedMigrationHandling;
}
/// Do now allow any transactions to be processed after a runtime upgrade failed.
///
/// This is **not a sane default**, since it prevents governance intervention.
pub struct FreezeChainOnFailedMigration;
impl FailedMigrationHandler for FreezeChainOnFailedMigration {
fn failed(_migration: Option<u32>) -> FailedMigrationHandling {
FailedMigrationHandling::KeepStuck
}
}
/// Enter safe mode on a failed runtime upgrade.
///
/// This can be very useful to manually intervene and fix the chain state. `Else` is used in case
/// that the safe mode could not be entered.
pub struct EnterSafeModeOnFailedMigration<SM, Else: FailedMigrationHandler>(
PhantomData<(SM, Else)>,
);
impl<Else: FailedMigrationHandler, SM: SafeMode> FailedMigrationHandler
for EnterSafeModeOnFailedMigration<SM, Else>
where
<SM as SafeMode>::BlockNumber: Bounded,
{
fn failed(migration: Option<u32>) -> FailedMigrationHandling {
let entered = if SM::is_entered() {
SM::extend(Bounded::max_value())
} else {
SM::enter(Bounded::max_value())
};
// If we could not enter or extend safe mode (for whatever reason), then we try the next.
if entered.is_err() {
Else::failed(migration)
} else {
FailedMigrationHandling::KeepStuck
}
}
}
/// How to proceed after a runtime upgrade failed.
///
/// There is NO SANE DEFAULT HERE. All options are very dangerous and should be used with care.
#[derive(Debug, Clone, Copy, PartialEq, Eq)]
pub enum FailedMigrationHandling {
/// Resume extrinsic processing of the chain. This will not resume the upgrade.
///
/// This should be supplemented with additional measures to ensure that the broken chain state
/// does not get further messed up by user extrinsics.
ForceUnstuck,
/// Set the cursor to `Stuck` and keep blocking extrinsics.
KeepStuck,
/// Don't do anything with the cursor and let the handler decide.
///
/// This can be useful in cases where the other two options would overwrite any changes that
/// were done by the handler to the cursor.
Ignore,
}
/// Something that can do multi step migrations.
pub trait MultiStepMigrator {
/// Hint for whether [`Self::step`] should be called.
fn ongoing() -> bool;
/// Do the next step in the MBM process.
///
/// Must gracefully handle the case that it is currently not upgrading.
fn step() -> Weight;
}
impl MultiStepMigrator for () {
fn ongoing() -> bool {
false
}
fn step() -> Weight {
Weight::zero()
}
}
/// Multiple [`SteppedMigration`].
pub trait SteppedMigrations {
/// The number of migrations that `Self` aggregates.
fn len() -> u32;
/// The `n`th [`SteppedMigration::id`].
///
/// Is guaranteed to return `Some` if `n < Self::len()`. Calling this with any index larger or
/// equal to `Self::len()` MUST return `None`.
fn nth_id(n: u32) -> Option<Vec<u8>>;
/// The [`SteppedMigration::max_steps`] of the `n`th migration.
///
/// Is guaranteed to return `Some` if `n < Self::len()`.
fn nth_max_steps(n: u32) -> Option<Option<u32>>;
/// Do a [`SteppedMigration::step`] on the `n`th migration.
///
/// Is guaranteed to return `Some` if `n < Self::len()`.
fn nth_step(
n: u32,
cursor: Option<Vec<u8>>,
meter: &mut WeightMeter,
) -> Option<Result<Option<Vec<u8>>, SteppedMigrationError>>;
/// Do a [`SteppedMigration::transactional_step`] on the `n`th migration.
///
/// Is guaranteed to return `Some` if `n < Self::len()`.
fn nth_transactional_step(
n: u32,
cursor: Option<Vec<u8>>,
meter: &mut WeightMeter,
) -> Option<Result<Option<Vec<u8>>, SteppedMigrationError>>;
/// Call the pre-upgrade hooks of the `n`th migration.
///
/// Returns `None` if the index is out of bounds.
#[cfg(feature = "try-runtime")]
fn nth_pre_upgrade(n: u32) -> Option<Result<Vec<u8>, sp_runtime::TryRuntimeError>>;
/// Call the post-upgrade hooks of the `n`th migration.
///
/// Returns `None` if the index is out of bounds.
#[cfg(feature = "try-runtime")]
fn nth_post_upgrade(n: u32, _state: Vec<u8>)
-> Option<Result<(), sp_runtime::TryRuntimeError>>;
/// The maximal encoded length across all cursors.
fn cursor_max_encoded_len() -> usize;
/// The maximal encoded length across all identifiers.
fn identifier_max_encoded_len() -> usize;
/// Assert the integrity of the migrations.
///
/// Should be executed as part of a test prior to runtime usage. May or may not need
/// externalities.
#[cfg(feature = "std")]
fn integrity_test() -> Result<(), &'static str> {
use crate::ensure;
let l = Self::len();
for n in 0..l {
ensure!(Self::nth_id(n).is_some(), "id is None");
ensure!(Self::nth_max_steps(n).is_some(), "steps is None");
// The cursor that we use does not matter. Hence use empty.
ensure!(
Self::nth_step(n, Some(vec![]), &mut WeightMeter::new()).is_some(),
"steps is None"
);
ensure!(
Self::nth_transactional_step(n, Some(vec![]), &mut WeightMeter::new()).is_some(),
"steps is None"
);
}
Ok(())
}
}
impl SteppedMigrations for () {
fn len() -> u32 {
0
}
fn nth_id(_n: u32) -> Option<Vec<u8>> {
None
}
fn nth_max_steps(_n: u32) -> Option<Option<u32>> {
None
}
fn nth_step(
_n: u32,
_cursor: Option<Vec<u8>>,
_meter: &mut WeightMeter,
) -> Option<Result<Option<Vec<u8>>, SteppedMigrationError>> {
None
}
fn nth_transactional_step(
_n: u32,
_cursor: Option<Vec<u8>>,
_meter: &mut WeightMeter,
) -> Option<Result<Option<Vec<u8>>, SteppedMigrationError>> {
None
}
#[cfg(feature = "try-runtime")]
fn nth_pre_upgrade(_n: u32) -> Option<Result<Vec<u8>, sp_runtime::TryRuntimeError>> {
Some(Ok(Vec::new()))
}
#[cfg(feature = "try-runtime")]
fn nth_post_upgrade(
_n: u32,
_state: Vec<u8>,
) -> Option<Result<(), sp_runtime::TryRuntimeError>> {
Some(Ok(()))
}
fn cursor_max_encoded_len() -> usize {
0
}
fn identifier_max_encoded_len() -> usize {
0
}
}
// A collection consisting of only a single migration.
impl<T: SteppedMigration> SteppedMigrations for T {
fn len() -> u32 {
1
}
fn nth_id(n: u32) -> Option<Vec<u8>> {
n.is_zero()
.then_some(T::id().encode())
.defensive_proof("nth_id should only be called with n==0")
}
fn nth_max_steps(n: u32) -> Option<Option<u32>> {
// It should be generally fine to call with n>0, but the code should not attempt to.
n.is_zero()
.then_some(T::max_steps())
.defensive_proof("nth_max_steps should only be called with n==0")
}
fn nth_step(
n: u32,
cursor: Option<Vec<u8>>,
meter: &mut WeightMeter,
) -> Option<Result<Option<Vec<u8>>, SteppedMigrationError>> {
if !n.is_zero() {
defensive!("nth_step should only be called with n==0");
return None
}
let cursor = match cursor {
Some(cursor) => match T::Cursor::decode(&mut &cursor[..]) {
Ok(cursor) => Some(cursor),
Err(_) => return Some(Err(SteppedMigrationError::InvalidCursor)),
},
None => None,
};
Some(T::step(cursor, meter).map(|cursor| cursor.map(|cursor| cursor.encode())))
}
fn nth_transactional_step(
n: u32,
cursor: Option<Vec<u8>>,
meter: &mut WeightMeter,
) -> Option<Result<Option<Vec<u8>>, SteppedMigrationError>> {
if n != 0 {
defensive!("nth_transactional_step should only be called with n==0");
return None
}
let cursor = match cursor {
Some(cursor) => match T::Cursor::decode(&mut &cursor[..]) {
Ok(cursor) => Some(cursor),
Err(_) => return Some(Err(SteppedMigrationError::InvalidCursor)),
},
None => None,
};
Some(
T::transactional_step(cursor, meter).map(|cursor| cursor.map(|cursor| cursor.encode())),
)
}
#[cfg(feature = "try-runtime")]
fn nth_pre_upgrade(n: u32) -> Option<Result<Vec<u8>, sp_runtime::TryRuntimeError>> {
if n != 0 {
defensive!("nth_pre_upgrade should only be called with n==0");
}
Some(T::pre_upgrade())
}
#[cfg(feature = "try-runtime")]
fn nth_post_upgrade(n: u32, state: Vec<u8>) -> Option<Result<(), sp_runtime::TryRuntimeError>> {
if n != 0 {
defensive!("nth_post_upgrade should only be called with n==0");
}
Some(T::post_upgrade(state))
}
fn cursor_max_encoded_len() -> usize {
T::Cursor::max_encoded_len()
}
fn identifier_max_encoded_len() -> usize {
T::Identifier::max_encoded_len()
}
}
#[impl_trait_for_tuples::impl_for_tuples(1, 30)]
impl SteppedMigrations for Tuple {
fn len() -> u32 {
for_tuples!( #( Tuple::len() )+* )
}
fn nth_id(n: u32) -> Option<Vec<u8>> {
let mut i = 0;
for_tuples!( #(
if (i + Tuple::len()) > n {
return Tuple::nth_id(n - i)
}
i += Tuple::len();
)* );
None
}
fn nth_step(
n: u32,
cursor: Option<Vec<u8>>,
meter: &mut WeightMeter,
) -> Option<Result<Option<Vec<u8>>, SteppedMigrationError>> {
let mut i = 0;
for_tuples!( #(
if (i + Tuple::len()) > n {
return Tuple::nth_step(n - i, cursor, meter)
}
i += Tuple::len();
)* );
None
}
fn nth_transactional_step(
n: u32,
cursor: Option<Vec<u8>>,
meter: &mut WeightMeter,
) -> Option<Result<Option<Vec<u8>>, SteppedMigrationError>> {
let mut i = 0;
for_tuples! ( #(
if (i + Tuple::len()) > n {
return Tuple::nth_transactional_step(n - i, cursor, meter)
}
i += Tuple::len();
)* );
None
}
#[cfg(feature = "try-runtime")]
fn nth_pre_upgrade(n: u32) -> Option<Result<Vec<u8>, sp_runtime::TryRuntimeError>> {
let mut i = 0;
for_tuples! ( #(
if (i + Tuple::len()) > n {
return Tuple::nth_pre_upgrade(n - i)
}
i += Tuple::len();
)* );
None
}
#[cfg(feature = "try-runtime")]
fn nth_post_upgrade(n: u32, state: Vec<u8>) -> Option<Result<(), sp_runtime::TryRuntimeError>> {
let mut i = 0;
for_tuples! ( #(
if (i + Tuple::len()) > n {
return Tuple::nth_post_upgrade(n - i, state)
}
i += Tuple::len();
)* );
None
}
fn nth_max_steps(n: u32) -> Option<Option<u32>> {
let mut i = 0;
for_tuples!( #(
if (i + Tuple::len()) > n {
return Tuple::nth_max_steps(n - i)
}
i += Tuple::len();
)* );
None
}
fn cursor_max_encoded_len() -> usize {
let mut max_len = 0;
for_tuples!( #(
max_len = max_len.max(Tuple::cursor_max_encoded_len());
)* );
max_len
}
fn identifier_max_encoded_len() -> usize {
let mut max_len = 0;
for_tuples!( #(
max_len = max_len.max(Tuple::identifier_max_encoded_len());
)* );
max_len
}
}
#[cfg(test)]
mod tests {
use super::*;
use crate::{assert_ok, storage::unhashed};
#[derive(Decode, Encode, MaxEncodedLen, Eq, PartialEq)]
pub enum Either<L, R> {
Left(L),
Right(R),
}
pub struct M0;
impl SteppedMigration for M0 {
type Cursor = ();
type Identifier = u8;
fn id() -> Self::Identifier {
0
}
fn step(
_cursor: Option<Self::Cursor>,
_meter: &mut WeightMeter,
) -> Result<Option<Self::Cursor>, SteppedMigrationError> {
log::info!("M0");
unhashed::put(&[0], &());
Ok(None)
}
}
pub struct M1;
impl SteppedMigration for M1 {
type Cursor = ();
type Identifier = u8;
fn id() -> Self::Identifier {
1
}
fn step(
_cursor: Option<Self::Cursor>,
_meter: &mut WeightMeter,
) -> Result<Option<Self::Cursor>, SteppedMigrationError> {
log::info!("M1");
unhashed::put(&[1], &());
Ok(None)
}
fn max_steps() -> Option<u32> {
Some(1)
}
}
pub struct M2;
impl SteppedMigration for M2 {
type Cursor = ();
type Identifier = u8;
fn id() -> Self::Identifier {
2
}
fn step(
_cursor: Option<Self::Cursor>,
_meter: &mut WeightMeter,
) -> Result<Option<Self::Cursor>, SteppedMigrationError> {
log::info!("M2");
unhashed::put(&[2], &());
Ok(None)
}
fn max_steps() -> Option<u32> {
Some(2)
}
}
pub struct F0;
impl SteppedMigration for F0 {
type Cursor = ();
type Identifier = u8;
fn id() -> Self::Identifier {
3
}
fn step(
_cursor: Option<Self::Cursor>,
_meter: &mut WeightMeter,
) -> Result<Option<Self::Cursor>, SteppedMigrationError> {
log::info!("F0");
unhashed::put(&[3], &());
Err(SteppedMigrationError::Failed)
}
}
// Three migrations combined to execute in order:
type Triple = (M0, (M1, M2));
// Six migrations, just concatenating the ones from before:
type Hextuple = (Triple, Triple);
#[test]
fn singular_migrations_work() {
assert_eq!(M0::max_steps(), None);
assert_eq!(M1::max_steps(), Some(1));
assert_eq!(M2::max_steps(), Some(2));
assert_eq!(<(M0, M1)>::nth_max_steps(0), Some(None));
assert_eq!(<(M0, M1)>::nth_max_steps(1), Some(Some(1)));
assert_eq!(<(M0, M1, M2)>::nth_max_steps(2), Some(Some(2)));
assert_eq!(<(M0, M1)>::nth_max_steps(2), None);
}
#[test]
fn tuple_migrations_work() {
assert_eq!(<() as SteppedMigrations>::len(), 0);
assert_eq!(<((), ((), ())) as SteppedMigrations>::len(), 0);
assert_eq!(<Triple as SteppedMigrations>::len(), 3);
assert_eq!(<Hextuple as SteppedMigrations>::len(), 6);
// Check the IDs. The index specific functions all return an Option,
// to account for the out-of-range case.
assert_eq!(<Triple as SteppedMigrations>::nth_id(0), Some(0u8.encode()));
assert_eq!(<Triple as SteppedMigrations>::nth_id(1), Some(1u8.encode()));
assert_eq!(<Triple as SteppedMigrations>::nth_id(2), Some(2u8.encode()));
sp_io::TestExternalities::default().execute_with(|| {
for n in 0..3 {
<Triple as SteppedMigrations>::nth_step(
n,
Default::default(),
&mut WeightMeter::new(),
);
}
});
}
#[test]
fn integrity_test_works() {
sp_io::TestExternalities::default().execute_with(|| {
assert_ok!(<() as SteppedMigrations>::integrity_test());
assert_ok!(<M0 as SteppedMigrations>::integrity_test());
assert_ok!(<M1 as SteppedMigrations>::integrity_test());
assert_ok!(<M2 as SteppedMigrations>::integrity_test());
assert_ok!(<Triple as SteppedMigrations>::integrity_test());
assert_ok!(<Hextuple as SteppedMigrations>::integrity_test());
});
}
#[test]
fn transactional_rollback_works() {
sp_io::TestExternalities::default().execute_with(|| {
assert_ok!(<(M0, F0) as SteppedMigrations>::nth_transactional_step(
0,
Default::default(),
&mut WeightMeter::new()
)
.unwrap());
assert!(unhashed::exists(&[0]));
let _g = crate::StorageNoopGuard::new();
assert!(<(M0, F0) as SteppedMigrations>::nth_transactional_step(
1,
Default::default(),
&mut WeightMeter::new()
)
.unwrap()
.is_err());
assert!(<(F0, M1) as SteppedMigrations>::nth_transactional_step(
0,
Default::default(),
&mut WeightMeter::new()
)
.unwrap()
.is_err());
});
}
}