diff --git a/substrate/frame/support/src/storage/generator/double_map.rs b/substrate/frame/support/src/storage/generator/double_map.rs index 6fb3abca5c..d8891a5ee6 100644 --- a/substrate/frame/support/src/storage/generator/double_map.rs +++ b/substrate/frame/support/src/storage/generator/double_map.rs @@ -153,6 +153,13 @@ impl storage::StorageDoubleMap for G where G::from_optional_value_to_query(unhashed::get(&Self::storage_double_map_final_key(k1, k2))) } + fn try_get(k1: KArg1, k2: KArg2) -> Result + where + KArg1: EncodeLike, + KArg2: EncodeLike { + unhashed::get(&Self::storage_double_map_final_key(k1, k2)).ok_or(()) + } + fn take(k1: KArg1, k2: KArg2) -> Self::Query where KArg1: EncodeLike, KArg2: EncodeLike, diff --git a/substrate/frame/support/src/storage/generator/map.rs b/substrate/frame/support/src/storage/generator/map.rs index 2c2390865d..11d895577f 100644 --- a/substrate/frame/support/src/storage/generator/map.rs +++ b/substrate/frame/support/src/storage/generator/map.rs @@ -226,6 +226,10 @@ impl> storage::StorageMap G::from_optional_value_to_query(unhashed::get(Self::storage_map_final_key(key).as_ref())) } + fn try_get>(key: KeyArg) -> Result { + unhashed::get(Self::storage_map_final_key(key).as_ref()).ok_or(()) + } + fn insert, ValArg: EncodeLike>(key: KeyArg, val: ValArg) { unhashed::put(Self::storage_map_final_key(key).as_ref(), &val) } diff --git a/substrate/frame/support/src/storage/mod.rs b/substrate/frame/support/src/storage/mod.rs index 302f176ef4..61ba147b09 100644 --- a/substrate/frame/support/src/storage/mod.rs +++ b/substrate/frame/support/src/storage/mod.rs @@ -107,8 +107,7 @@ pub fn with_transaction(f: impl FnOnce() -> TransactionOutcome) -> R { /// A trait for working with macro-generated storage values under the substrate storage API. /// -/// Details on implementation can be found at -/// [`generator::StorageValue`] +/// Details on implementation can be found at [`generator::StorageValue`]. pub trait StorageValue { /// The type that get/take return. type Query; @@ -122,8 +121,9 @@ pub trait StorageValue { /// Load the value from the provided storage instance. fn get() -> Self::Query; - /// Try to get the underlying value from the provided storage instance; `Ok` if it exists, - /// `Err` if not. + /// Try to get the underlying value from the provided storage instance. + /// + /// Returns `Ok` if it exists, `Err` if not. fn try_get() -> Result; /// Translate a value from some previous type (`O`) to the current type. @@ -200,8 +200,7 @@ pub trait StorageValue { /// A strongly-typed map in storage. /// -/// Details on implementation can be found at -/// [`generator::StorageMap`] +/// Details on implementation can be found at [`generator::StorageMap`]. pub trait StorageMap { /// The type that get/take return. type Query; @@ -215,6 +214,11 @@ pub trait StorageMap { /// Load the value associated with the given key from the map. fn get>(key: KeyArg) -> Self::Query; + /// Try to get the value for the given key from the map. + /// + /// Returns `Ok` if it exists, `Err` if not. + fn try_get>(key: KeyArg) -> Result; + /// Swap the values of two keys. fn swap, KeyArg2: EncodeLike>(key1: KeyArg1, key2: KeyArg2); @@ -233,7 +237,9 @@ pub trait StorageMap { f: F, ) -> Result; - /// Mutate the value under a key. Deletes the item if mutated to a `None`. + /// Mutate the value under a key. + /// + /// Deletes the item if mutated to a `None`. fn mutate_exists, R, F: FnOnce(&mut Option) -> R>(key: KeyArg, f: F) -> R; /// Mutate the item, only if an `Ok` value is returned. Deletes the item if mutated to a `None`. @@ -354,8 +360,7 @@ pub trait IterableStorageDoubleMap< /// It provides an important ability to efficiently remove all entries /// that have a common first key. /// -/// Details on implementation can be found at -/// [`generator::StorageDoubleMap`] +/// Details on implementation can be found at [`generator::StorageDoubleMap`]. pub trait StorageDoubleMap { /// The type that get/take returns. type Query; @@ -378,6 +383,14 @@ pub trait StorageDoubleMap { KArg1: EncodeLike, KArg2: EncodeLike; + /// Try to get the value for the given key from the double map. + /// + /// Returns `Ok` if it exists, `Err` if not. + fn try_get(k1: KArg1, k2: KArg2) -> Result + where + KArg1: EncodeLike, + KArg2: EncodeLike; + /// Take a value from storage, removing it afterwards. fn take(k1: KArg1, k2: KArg2) -> Self::Query where diff --git a/substrate/frame/support/src/storage/types/double_map.rs b/substrate/frame/support/src/storage/types/double_map.rs index 3e37c0522e..1133dbd84d 100644 --- a/substrate/frame/support/src/storage/types/double_map.rs +++ b/substrate/frame/support/src/storage/types/double_map.rs @@ -141,6 +141,16 @@ where >::get(k1, k2) } + /// Try to get the value for the given key from the double map. + /// + /// Returns `Ok` if it exists, `Err` if not. + pub fn try_get(k1: KArg1, k2: KArg2) -> Result + where + KArg1: EncodeLike, + KArg2: EncodeLike { + >::try_get(k1, k2) + } + /// Take a value from storage, removing it afterwards. pub fn take(k1: KArg1, k2: KArg2) -> QueryKind::Query where @@ -514,6 +524,7 @@ mod test { }); assert_eq!(A::contains_key(2, 20), true); assert_eq!(A::get(2, 20), Some(100)); + assert_eq!(A::try_get(2, 20), Ok(100)); let _: Result<(), ()> = AValueQueryWithAnOnEmpty::try_mutate_exists(2, 20, |v| { *v = Some(v.unwrap() * 10); Err(()) @@ -527,6 +538,7 @@ mod test { assert_eq!(A::contains_key(2, 20), false); assert_eq!(AValueQueryWithAnOnEmpty::take(2, 20), 97); assert_eq!(A::contains_key(2, 20), false); + assert_eq!(A::try_get(2, 20), Err(())); B::insert(2, 20, 10); assert_eq!(A::migrate_keys::(2, 20), Some(10)); diff --git a/substrate/frame/support/src/storage/types/map.rs b/substrate/frame/support/src/storage/types/map.rs index 64f9ff4b05..8fe11488b1 100644 --- a/substrate/frame/support/src/storage/types/map.rs +++ b/substrate/frame/support/src/storage/types/map.rs @@ -116,6 +116,13 @@ where >::get(key) } + /// Try to get the value for the given key from the map. + /// + /// Returns `Ok` if it exists, `Err` if not. + pub fn try_get>(key: KeyArg) -> Result { + >::try_get(key) + } + /// Swap the values of two keys. pub fn swap, KeyArg2: EncodeLike>(key1: KeyArg1, key2: KeyArg2) { >::swap(key1, key2) @@ -352,12 +359,14 @@ mod test { A::insert(3, 10); assert_eq!(A::contains_key(3), true); assert_eq!(A::get(3), Some(10)); + assert_eq!(A::try_get(3), Ok(10)); assert_eq!(AValueQueryWithAnOnEmpty::get(3), 10); A::swap(3, 2); assert_eq!(A::contains_key(3), false); assert_eq!(A::contains_key(2), true); assert_eq!(A::get(3), None); + assert_eq!(A::try_get(3), Err(())); assert_eq!(AValueQueryWithAnOnEmpty::get(3), 97); assert_eq!(A::get(2), Some(10)); assert_eq!(AValueQueryWithAnOnEmpty::get(2), 10);