Trait frame_support::storage::IterableStorageNMap

pub trait IterableStorageNMap<K: ReversibleKeyGenerator, V: FullCodec>: StorageNMap<K, V> {
    type KeyIterator: Iterator<Item = K::Key>;
    type Iterator: Iterator<Item = (K::Key, V)>;
    fn iter_prefix<KP>(
        kp: KP
    ) -> PrefixIterator<(<K as HasKeyPrefix<KP>>::Suffix, V)>
    where
        K: HasReversibleKeyPrefix<KP>;
    fn iter_prefix_from<KP>(
        kp: KP, 
        starting_raw_key: Vec<u8>
    ) -> PrefixIterator<(<K as HasKeyPrefix<KP>>::Suffix, V)>
    where
        K: HasReversibleKeyPrefix<KP>;
    fn iter_key_prefix<KP>(
        kp: KP
    ) -> KeyPrefixIterator<<K as HasKeyPrefix<KP>>::Suffix>
    where
        K: HasReversibleKeyPrefix<KP>;
    fn iter_key_prefix_from<KP>(
        kp: KP, 
        starting_raw_key: Vec<u8>
    ) -> KeyPrefixIterator<<K as HasKeyPrefix<KP>>::Suffix>
    where
        K: HasReversibleKeyPrefix<KP>;
    fn drain_prefix<KP>(
        kp: KP
    ) -> PrefixIterator<(<K as HasKeyPrefix<KP>>::Suffix, V)>
    where
        K: HasReversibleKeyPrefix<KP>;
    fn iter() -> Self::Iterator;
    fn iter_from(starting_raw_key: Vec<u8>) -> Self::Iterator;
    fn iter_keys() -> Self::KeyIterator;
    fn iter_keys_from(starting_raw_key: Vec<u8>) -> Self::KeyIterator;
    fn drain() -> Self::Iterator;
    fn translate<O: Decode, F: FnMut(K::Key, O) -> Option<V>>(f: F);
}

A strongly-typed map with arbitrary number of keys in storage whose keys and values can be iterated over.

Associated Types

type KeyIterator: Iterator<Item = K::Key>

The type that iterates over all (key1, key2, key3, ... keyN) tuples.

type Iterator: Iterator<Item = (K::Key, V)>

The type that iterates over all (key1, key2, key3, ... keyN), value) tuples.

Required methods

fn iter_prefix<KP>(
    kp: KP
) -> PrefixIterator<(<K as HasKeyPrefix<KP>>::Suffix, V)> where
    K: HasReversibleKeyPrefix<KP>, 

Enumerate all elements in the map with prefix key kp in lexicographical order of the encoded key. If you add or remove values whose prefix is kp to the map while doing this, you’ll get undefined results.

fn iter_prefix_from<KP>(
    kp: KP,
    starting_raw_key: Vec<u8>
) -> PrefixIterator<(<K as HasKeyPrefix<KP>>::Suffix, V)> where
    K: HasReversibleKeyPrefix<KP>, 

Enumerate all elements in the map with prefix key kp after a specified starting_raw_key in lexicographical order of the encoded key. If you add or remove values whose prefix is kp to the map while doing this, you’ll get undefined results.

fn iter_key_prefix<KP>(
    kp: KP
) -> KeyPrefixIterator<<K as HasKeyPrefix<KP>>::Suffix> where
    K: HasReversibleKeyPrefix<KP>, 

Enumerate all suffix keys in the map with prefix key kp in lexicographical order of the encoded key. If you add or remove values whose prefix is kp to the map while doing this, you’ll get undefined results.

fn iter_key_prefix_from<KP>(
    kp: KP,
    starting_raw_key: Vec<u8>
) -> KeyPrefixIterator<<K as HasKeyPrefix<KP>>::Suffix> where
    K: HasReversibleKeyPrefix<KP>, 

Enumerate all suffix keys in the map with prefix key kp after a specified starting_raw_key in lexicographical order of the encoded key. If you add or remove values whose prefix is kp to the map while doing this, you’ll get undefined results.

fn drain_prefix<KP>(
    kp: KP
) -> PrefixIterator<(<K as HasKeyPrefix<KP>>::Suffix, V)> where
    K: HasReversibleKeyPrefix<KP>, 

Remove all elements from the map with prefix key kp and iterate through them in lexicographical order of the encoded key. If you add elements with prefix key kp to the map while doing this, you’ll get undefined results.

fn iter() -> Self::Iterator

Enumerate all elements in the map in lexicographical order of the encoded key. If you add or remove values to the map while doing this, you’ll get undefined results.

fn iter_from(starting_raw_key: Vec<u8>) -> Self::Iterator

Enumerate all elements in the map after a specified starting_raw_key in lexicographical order of the encoded key. If you add or remove values to the map while doing this, you’ll get undefined results.

fn iter_keys() -> Self::KeyIterator

Enumerate all keys in the map in lexicographical order of the encoded key. If you add or remove values to the map while doing this, you’ll get undefined results.

fn iter_keys_from(starting_raw_key: Vec<u8>) -> Self::KeyIterator

Enumerate all keys in the map after starting_raw_key in lexicographical order of the encoded key. If you add or remove values to the map while doing this, you’ll get undefined results.

fn drain() -> Self::Iterator

Remove all elements from the map and iterate through them in lexicographical order of the encoded key. If you add elements to the map while doing this, you’ll get undefined results.

fn translate<O: Decode, F: FnMut(K::Key, O) -> Option<V>>(f: F)

Translate the values of all elements by a function f, in the map in lexicographical order of the encoded key. By returning None from f for an element, you’ll remove it from the map.

NOTE: If a value fail to decode because storage is corrupted then it is skipped.

Implementors

impl<K: ReversibleKeyGenerator, V: FullCodec, G: StorageNMap<K, V>> IterableStorageNMap<K, V> for G

type KeyIterator = KeyPrefixIterator<K::Key>

type Iterator = PrefixIterator<(K::Key, V)>