kagome::storage::face::MapCursor< K, V, KView > Struct Template Reference

An abstraction over generic map cursor. More...

#include <map_cursor.hpp>

Inheritance diagram for kagome::storage::face::MapCursor< K, V, KView >:

Collaboration diagram for kagome::storage::face::MapCursor< K, V, KView >:

Public Member Functions
virtual	~MapCursor ()=default
virtual outcome::result< bool >	seekFirst ()=0
	Same as std::begin(...);. More...
virtual outcome::result< bool >	seek (const KView &key)=0
	Find given key and seek iterator to this key. More...
virtual outcome::result< bool >	seekLast ()=0
	Same as std::rbegin(...);, e.g. points to the last valid element. More...
virtual bool	isValid () const =0
	Is the cursor in a valid state? More...
virtual outcome::result< void >	next ()=0
	Make step forward. More...
virtual std::optional< K >	key () const =0
	Getter for the key of the element currently pointed at. More...
virtual std::optional< V >	value () const =0
	Getter for value of the element currently pointed at. More...

Detailed Description

template<typename K, typename V, typename KView = K>
struct kagome::storage::face::MapCursor< K, V, KView >

An abstraction over generic map cursor.

Template Parameters

K	key type
V	value type
KView	key view type

Definition at line 22 of file map_cursor.hpp.

Constructor & Destructor Documentation

template<typename K, typename V, typename KView = K>

virtual kagome::storage::face::MapCursor< K, V, KView >::~MapCursor ( )

virtualdefault

Member Function Documentation

template<typename K, typename V, typename KView = K>

virtual bool kagome::storage::face::MapCursor< K, V, KView >::isValid ( ) const

pure virtual

Is the cursor in a valid state?

Returns

true if the cursor points to an element of the map, false otherwise

Implemented in kagome::storage::trie::PolkadotTrieCursorImpl, and kagome::storage::RocksDBCursor.

template<typename K, typename V, typename KView = K>

virtual std::optional<K> kagome::storage::face::MapCursor< K, V, KView >::key ( ) const

pure virtual

Getter for the key of the element currently pointed at.

Returns

key if isValid()

Implemented in kagome::storage::trie::PolkadotTrieCursorImpl, and kagome::storage::RocksDBCursor.

template<typename K, typename V, typename KView = K>

virtual outcome::result<void> kagome::storage::face::MapCursor< K, V, KView >::next ( )

pure virtual

Make step forward.

Implemented in kagome::storage::trie::PolkadotTrieCursorImpl, and kagome::storage::RocksDBCursor.

template<typename K, typename V, typename KView = K>

virtual outcome::result<bool> kagome::storage::face::MapCursor< K, V, KView >::seek ( const KView &  key )

pure virtual

Find given key and seek iterator to this key.

Returns

error if any, true if

• key found, false otherwise

Implemented in kagome::storage::trie::PolkadotTrieCursorImpl.

template<typename K, typename V, typename KView = K>

virtual outcome::result<bool> kagome::storage::face::MapCursor< K, V, KView >::seekFirst ( )

pure virtual

Same as std::begin(...);.

Returns

error if any, true if trie is not empty, false otherwise

Implemented in kagome::storage::trie::PolkadotTrieCursorImpl, and kagome::storage::RocksDBCursor.

template<typename K, typename V, typename KView = K>

virtual outcome::result<bool> kagome::storage::face::MapCursor< K, V, KView >::seekLast ( )

pure virtual

Same as std::rbegin(...);, e.g. points to the last valid element.

Returns

error if any, true if trie is not empty, false otherwise

Implemented in kagome::storage::trie::PolkadotTrieCursorImpl, and kagome::storage::RocksDBCursor.

template<typename K, typename V, typename KView = K>

virtual std::optional<V> kagome::storage::face::MapCursor< K, V, KView >::value ( ) const

pure virtual

Getter for value of the element currently pointed at.

Returns

value if isValid()

Implemented in kagome::storage::trie::PolkadotTrieCursorImpl, and kagome::storage::RocksDBCursor.

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The documentation for this struct was generated from the following file:

• core/storage/face/map_cursor.hpp