diff --git a/substrate/frame/support/src/storage/bounded_btree_map.rs b/substrate/frame/support/src/storage/bounded_btree_map.rs index f2f32d890b..91196be9e8 100644 --- a/substrate/frame/support/src/storage/bounded_btree_map.rs +++ b/substrate/frame/support/src/storage/bounded_btree_map.rs @@ -79,5 +79,16 @@ pub mod test { assert!(FooDoubleMap::decode_len(1, 2).is_none()); assert!(FooDoubleMap::decode_len(2, 2).is_none()); }); + + TestExternalities::default().execute_with(|| { + let bounded = boundedmap_from_keys::>(&[1, 2, 3]); + FooDoubleMap::insert(1, 1, bounded.clone()); + FooDoubleMap::insert(2, 2, bounded); // duplicate value + + assert_eq!(FooDoubleMap::decode_len(1, 1).unwrap(), 3); + assert_eq!(FooDoubleMap::decode_len(2, 2).unwrap(), 3); + assert!(FooDoubleMap::decode_len(2, 1).is_none()); + assert!(FooDoubleMap::decode_len(1, 2).is_none()); + }); } } diff --git a/substrate/frame/support/src/storage/bounded_btree_set.rs b/substrate/frame/support/src/storage/bounded_btree_set.rs index 52be1bb99f..cf801eb478 100644 --- a/substrate/frame/support/src/storage/bounded_btree_set.rs +++ b/substrate/frame/support/src/storage/bounded_btree_set.rs @@ -17,10 +17,10 @@ //! Traits, types and structs to support a bounded `BTreeSet`. -use crate::storage::StorageDecodeLength; +use frame_support::storage::StorageDecodeNonDedupLength; pub use sp_runtime::BoundedBTreeSet; -impl StorageDecodeLength for BoundedBTreeSet {} +impl StorageDecodeNonDedupLength for BoundedBTreeSet {} #[cfg(test)] pub mod test { @@ -56,28 +56,28 @@ pub mod test { } #[test] - fn decode_len_works() { + fn decode_non_dedup_len_works() { TestExternalities::default().execute_with(|| { let bounded = boundedset_from_keys::>(&[1, 2, 3]); Foo::put(bounded); - assert_eq!(Foo::decode_len().unwrap(), 3); + assert_eq!(Foo::decode_non_dedup_len().unwrap(), 3); }); TestExternalities::default().execute_with(|| { let bounded = boundedset_from_keys::>(&[1, 2, 3]); FooMap::insert(1, bounded); - assert_eq!(FooMap::decode_len(1).unwrap(), 3); - assert!(FooMap::decode_len(0).is_none()); - assert!(FooMap::decode_len(2).is_none()); + assert_eq!(FooMap::decode_non_dedup_len(1).unwrap(), 3); + assert!(FooMap::decode_non_dedup_len(0).is_none()); + assert!(FooMap::decode_non_dedup_len(2).is_none()); }); TestExternalities::default().execute_with(|| { let bounded = boundedset_from_keys::>(&[1, 2, 3]); FooDoubleMap::insert(1, 1, bounded); - assert_eq!(FooDoubleMap::decode_len(1, 1).unwrap(), 3); - assert!(FooDoubleMap::decode_len(2, 1).is_none()); - assert!(FooDoubleMap::decode_len(1, 2).is_none()); - assert!(FooDoubleMap::decode_len(2, 2).is_none()); + assert_eq!(FooDoubleMap::decode_non_dedup_len(1, 1).unwrap(), 3); + assert!(FooDoubleMap::decode_non_dedup_len(2, 1).is_none()); + assert!(FooDoubleMap::decode_non_dedup_len(1, 2).is_none()); + assert!(FooDoubleMap::decode_non_dedup_len(2, 2).is_none()); }); } } diff --git a/substrate/frame/support/src/storage/mod.rs b/substrate/frame/support/src/storage/mod.rs index 851b0687bd..7f39a3fdad 100644 --- a/substrate/frame/support/src/storage/mod.rs +++ b/substrate/frame/support/src/storage/mod.rs @@ -167,6 +167,32 @@ pub trait StorageValue { { T::decode_len(&Self::hashed_key()) } + + /// Read the length of the storage value without decoding the entire value. + /// + /// `T` is required to implement [`StorageDecodeNonDedupLength`]. + /// + /// If the value does not exists or it fails to decode the length, `None` is returned. + /// Otherwise `Some(len)` is returned. + /// + /// # Warning + /// + /// - The value returned is the non-deduplicated length of the underlying Vector in storage.This + /// means that any duplicate items are included. + /// + /// - `None` does not mean that `get()` does not return a value. The default value is completely + /// ignored by this function. + /// + /// # Example + #[doc = docify::embed!("src/storage/mod.rs", btree_set_decode_non_dedup_len)] + /// This demonstrates how `decode_non_dedup_len` will count even the duplicate values in the + /// storage (in this case, the number `4` is counted twice). + fn decode_non_dedup_len() -> Option + where + T: StorageDecodeNonDedupLength, + { + T::decode_non_dedup_len(&Self::hashed_key()) + } } /// A non-continuous container type. @@ -346,6 +372,27 @@ pub trait StorageMap { V::decode_len(&Self::hashed_key_for(key)) } + /// Read the length of the storage value without decoding the entire value. + /// + /// `V` is required to implement [`StorageDecodeNonDedupLength`]. + /// + /// If the value does not exists or it fails to decode the length, `None` is returned. + /// Otherwise `Some(len)` is returned. + /// + /// # Warning + /// + /// - `None` does not mean that `get()` does not return a value. The default value is completly + /// ignored by this function. + /// + /// - The value returned is the non-deduplicated length of the underlying Vector in storage.This + /// means that any duplicate items are included. + fn decode_non_dedup_len>(key: KeyArg) -> Option + where + V: StorageDecodeNonDedupLength, + { + V::decode_non_dedup_len(&Self::hashed_key_for(key)) + } + /// Migrate an item with the given `key` from a defunct `OldHasher` to the current hasher. /// /// If the key doesn't exist, then it's a no-op. If it does, then it returns its value. @@ -741,6 +788,27 @@ pub trait StorageDoubleMap { V::decode_len(&Self::hashed_key_for(key1, key2)) } + /// Read the length of the storage value without decoding the entire value under the + /// given `key1` and `key2`. + /// + /// `V` is required to implement [`StorageDecodeNonDedupLength`]. + /// + /// If the value does not exists or it fails to decode the length, `None` is returned. + /// Otherwise `Some(len)` is returned. + /// + /// # Warning + /// + /// `None` does not mean that `get()` does not return a value. The default value is completly + /// ignored by this function. + fn decode_non_dedup_len(key1: KArg1, key2: KArg2) -> Option + where + KArg1: EncodeLike, + KArg2: EncodeLike, + V: StorageDecodeNonDedupLength, + { + V::decode_non_dedup_len(&Self::hashed_key_for(key1, key2)) + } + /// Migrate an item with the given `key1` and `key2` from defunct `OldHasher1` and /// `OldHasher2` to the current hashers. /// @@ -1400,8 +1468,7 @@ pub trait StoragePrefixedMap { /// This trait is sealed. pub trait StorageAppend: private::Sealed {} -/// Marker trait that will be implemented for types that support to decode their length in an -/// efficient way. It is expected that the length is at the beginning of the encoded object +/// It is expected that the length is at the beginning of the encoded object /// and that the length is a `Compact`. /// /// This trait is sealed. @@ -1421,6 +1488,29 @@ pub trait StorageDecodeLength: private::Sealed + codec::DecodeLength { } } +/// It is expected that the length is at the beginning of the encoded objectand that the length is a +/// `Compact`. +/// +/// # Note +/// The length returned by this trait is not deduplicated, i.e. it is the length of the underlying +/// stored Vec. +/// +/// This trait is sealed. +pub trait StorageDecodeNonDedupLength: private::Sealed + codec::DecodeLength { + /// Decode the length of the storage value at `key`. + /// + /// This function assumes that the length is at the beginning of the encoded object and is a + /// `Compact`. + /// + /// Returns `None` if the storage value does not exist or the decoding failed. + fn decode_non_dedup_len(key: &[u8]) -> Option { + let mut data = [0u8; 5]; + let len = sp_io::storage::read(key, &mut data, 0)?; + let len = data.len().min(len as usize); + ::len(&data[..len]).ok() + } +} + /// Provides `Sealed` trait to prevent implementing trait `StorageAppend` & `StorageDecodeLength` /// & `EncodeLikeTuple` outside of this crate. mod private { @@ -1471,7 +1561,14 @@ impl StorageAppend for Vec {} impl StorageDecodeLength for Vec {} impl StorageAppend for BTreeSet {} -impl StorageDecodeLength for BTreeSet {} +impl StorageDecodeNonDedupLength for BTreeSet {} + +// Blanket implementation StorageDecodeNonDedupLength for all types that are StorageDecodeLength. +impl StorageDecodeNonDedupLength for T { + fn decode_non_dedup_len(key: &[u8]) -> Option { + T::decode_len(key) + } +} /// We abuse the fact that SCALE does not put any marker into the encoding, i.e. we only encode the /// internal vec and we can append to this vec. We have a test that ensures that if the `Digest` @@ -2026,7 +2123,24 @@ mod test { FooSet::append(6); FooSet::append(7); - assert_eq!(FooSet::decode_len().unwrap(), 7); + assert_eq!(FooSet::decode_non_dedup_len().unwrap(), 7); + }); + } + + #[docify::export] + #[test] + fn btree_set_decode_non_dedup_len() { + #[crate::storage_alias] + type Store = StorageValue>; + + TestExternalities::default().execute_with(|| { + Store::append(4); + Store::append(4); // duplicate value + Store::append(5); + + let length_with_dup_items = 3; + + assert_eq!(Store::decode_non_dedup_len().unwrap(), length_with_dup_items); }); } } diff --git a/substrate/frame/support/src/storage/types/double_map.rs b/substrate/frame/support/src/storage/types/double_map.rs index 1002222a89..cb9479d491 100644 --- a/substrate/frame/support/src/storage/types/double_map.rs +++ b/substrate/frame/support/src/storage/types/double_map.rs @@ -27,6 +27,7 @@ use crate::{ StorageHasher, Twox128, }; use codec::{Decode, Encode, EncodeLike, FullCodec, MaxEncodedLen}; +use frame_support::storage::StorageDecodeNonDedupLength; use sp_arithmetic::traits::SaturatedConversion; use sp_metadata_ir::{StorageEntryMetadataIR, StorageEntryTypeIR}; use sp_std::prelude::*; @@ -455,6 +456,31 @@ where >::decode_len(key1, key2) } + /// Read the length of the storage value without decoding the entire value. + /// + /// `Value` is required to implement [`StorageDecodeNonDedupLength`]. + /// + /// If the value does not exists or it fails to decode the length, `None` is returned. + /// Otherwise `Some(len)` is returned. + /// + /// # Warning + /// + /// - `None` does not mean that `get()` does not return a value. The default value is completly + /// ignored by this function. + /// + /// - The value returned is the non-deduplicated length of the underlying Vector in storage.This + /// means that any duplicate items are included. + pub fn decode_non_dedup_len(key1: KArg1, key2: KArg2) -> Option + where + KArg1: EncodeLike, + KArg2: EncodeLike, + Value: StorageDecodeNonDedupLength, + { + >::decode_non_dedup_len( + key1, key2, + ) + } + /// Migrate an item with the given `key1` and `key2` from defunct `OldHasher1` and /// `OldHasher2` to the current hashers. /// diff --git a/substrate/frame/support/src/storage/types/map.rs b/substrate/frame/support/src/storage/types/map.rs index 75988220e3..d0149cf3fc 100644 --- a/substrate/frame/support/src/storage/types/map.rs +++ b/substrate/frame/support/src/storage/types/map.rs @@ -27,6 +27,7 @@ use crate::{ StorageHasher, Twox128, }; use codec::{Decode, Encode, EncodeLike, FullCodec, MaxEncodedLen}; +use frame_support::storage::StorageDecodeNonDedupLength; use sp_arithmetic::traits::SaturatedConversion; use sp_metadata_ir::{StorageEntryMetadataIR, StorageEntryTypeIR}; use sp_std::prelude::*; @@ -285,6 +286,27 @@ where >::decode_len(key) } + /// Read the length of the storage value without decoding the entire value. + /// + /// `Value` is required to implement [`StorageDecodeNonDedupLength`]. + /// + /// If the value does not exists or it fails to decode the length, `None` is returned. + /// Otherwise `Some(len)` is returned. + /// + /// # Warning + /// + /// - `None` does not mean that `get()` does not return a value. The default value is completly + /// ignored by this function. + /// + /// - The value returned is the non-deduplicated length of the underlying Vector in storage.This + /// means that any duplicate items are included. + pub fn decode_non_dedup_len>(key: KeyArg) -> Option + where + Value: StorageDecodeNonDedupLength, + { + >::decode_non_dedup_len(key) + } + /// Migrate an item with the given `key` from a defunct `OldHasher` to the current hasher. /// /// If the key doesn't exist, then it's a no-op. If it does, then it returns its value. diff --git a/substrate/frame/support/src/storage/types/value.rs b/substrate/frame/support/src/storage/types/value.rs index 9fff1774d7..34cc3e2495 100644 --- a/substrate/frame/support/src/storage/types/value.rs +++ b/substrate/frame/support/src/storage/types/value.rs @@ -26,6 +26,7 @@ use crate::{ traits::{GetDefault, StorageInfo, StorageInstance}, }; use codec::{Decode, Encode, EncodeLike, FullCodec, MaxEncodedLen}; +use frame_support::storage::StorageDecodeNonDedupLength; use sp_arithmetic::traits::SaturatedConversion; use sp_metadata_ir::{StorageEntryMetadataIR, StorageEntryTypeIR}; use sp_std::prelude::*; @@ -233,6 +234,27 @@ where >::decode_len() } + /// Read the length of the storage value without decoding the entire value. + /// + /// `Value` is required to implement [`StorageDecodeNonDedupLength`]. + /// + /// If the value does not exists or it fails to decode the length, `None` is returned. + /// Otherwise `Some(len)` is returned. + /// + /// # Warning + /// + /// - `None` does not mean that `get()` does not return a value. The default value is completly + /// ignored by this function. + /// + /// - The value returned is the non-deduplicated length of the underlying Vector in storage.This + /// means that any duplicate items are included. + pub fn decode_non_dedup_len() -> Option + where + Value: StorageDecodeNonDedupLength, + { + >::decode_non_dedup_len() + } + /// Try and append the given item to the value in the storage. /// /// Is only available if `Value` of the storage implements [`StorageTryAppend`].