Trait DbCursorRO

pub trait DbCursorRO<T>
where
    T: Table,
{
    // Required methods
    fn first(
        &mut self,
    ) -> Result<Option<(<T as Table>::Key, <T as Table>::Value)>, DatabaseError>;
    fn seek_exact(
        &mut self,
        key: <T as Table>::Key,
    ) -> Result<Option<(<T as Table>::Key, <T as Table>::Value)>, DatabaseError>;
    fn seek(
        &mut self,
        key: <T as Table>::Key,
    ) -> Result<Option<(<T as Table>::Key, <T as Table>::Value)>, DatabaseError>;
    fn next(
        &mut self,
    ) -> Result<Option<(<T as Table>::Key, <T as Table>::Value)>, DatabaseError>;
    fn prev(
        &mut self,
    ) -> Result<Option<(<T as Table>::Key, <T as Table>::Value)>, DatabaseError>;
    fn last(
        &mut self,
    ) -> Result<Option<(<T as Table>::Key, <T as Table>::Value)>, DatabaseError>;
    fn current(
        &mut self,
    ) -> Result<Option<(<T as Table>::Key, <T as Table>::Value)>, DatabaseError>;
    fn walk(
        &mut self,
        start_key: Option<<T as Table>::Key>,
    ) -> Result<Walker<'_, T, Self>, DatabaseError>
       where Self: Sized;
    fn walk_range(
        &mut self,
        range: impl RangeBounds<<T as Table>::Key>,
    ) -> Result<RangeWalker<'_, T, Self>, DatabaseError>
       where Self: Sized;
    fn walk_back(
        &mut self,
        start_key: Option<<T as Table>::Key>,
    ) -> Result<ReverseWalker<'_, T, Self>, DatabaseError>
       where Self: Sized;
}

A read-only cursor over table T.

Required Methods

fn first( &mut self, ) -> Result<Option<(<T as Table>::Key, <T as Table>::Value)>, DatabaseError>

Positions the cursor at the first entry in the table, returning it.

fn seek_exact( &mut self, key: <T as Table>::Key, ) -> Result<Option<(<T as Table>::Key, <T as Table>::Value)>, DatabaseError>

Seeks to the KV pair exactly at key.

fn seek( &mut self, key: <T as Table>::Key, ) -> Result<Option<(<T as Table>::Key, <T as Table>::Value)>, DatabaseError>

Seeks to the KV pair whose key is greater than or equal to key.

fn next( &mut self, ) -> Result<Option<(<T as Table>::Key, <T as Table>::Value)>, DatabaseError>

Position the cursor at the next KV pair, returning it.

fn prev( &mut self, ) -> Result<Option<(<T as Table>::Key, <T as Table>::Value)>, DatabaseError>

Position the cursor at the previous KV pair, returning it.

fn last( &mut self, ) -> Result<Option<(<T as Table>::Key, <T as Table>::Value)>, DatabaseError>

Positions the cursor at the last entry in the table, returning it.

fn current( &mut self, ) -> Result<Option<(<T as Table>::Key, <T as Table>::Value)>, DatabaseError>

Get the KV pair at the cursor’s current position.

fn walk( &mut self, start_key: Option<<T as Table>::Key>, ) -> Result<Walker<'_, T, Self>, DatabaseError>

where Self: Sized,

Get an iterator that walks through the table.

If start_key is None, then the walker will start from the first entry of the table, otherwise it starts at the entry greater than or equal to the provided key.

fn walk_range( &mut self, range: impl RangeBounds<<T as Table>::Key>, ) -> Result<RangeWalker<'_, T, Self>, DatabaseError>

where Self: Sized,

Get an iterator that walks over a range of keys in the table.

fn walk_back( &mut self, start_key: Option<<T as Table>::Key>, ) -> Result<ReverseWalker<'_, T, Self>, DatabaseError>

where Self: Sized,

Get an iterator that walks through the table in reverse order.

If start_key is None, then the walker will start from the last entry of the table, otherwise it starts at the entry greater than or equal to the provided key.

Implementors

impl<K: TransactionKind, T: Table> DbCursorRO<T> for Cursor<K, T>

Available on crate feature mdbx only.

impl<T> DbCursorRO<T> for CursorMock

where T: Table,