Trait ReadCursor 

pub trait ReadCursor<'txn, T: Table>: Clone {
    type IntoIter: Iterator<Item = Row<T>>;

    // Required methods
    fn first(&mut self) -> Option<Row<T>>;
    fn last(&mut self) -> Option<Row<T>>;
    fn next(&mut self) -> Option<Row<T>>;
    fn prev(&mut self) -> Option<Row<T>>;
    fn get_current(&mut self) -> Option<Row<T>>;
    fn set_key(&mut self, key: &T::Key) -> Option<T::Value>;
    fn set_lowerbound_key(&mut self, key: &T::Key) -> Option<Row<T>>;
    fn into_iter_start(self) -> Self::IntoIter;
    fn into_iter_from(self, key: &T::Key) -> Self::IntoIter;
}

A cursor is used for navigating the entries within a table. The read-only version cannot modify entries.

Closely follows libmdbx’s cursor API.

Required Associated Types

type IntoIter: Iterator<Item = Row<T>>

Required Methods

fn first(&mut self) -> Option<Row<T>>

Positions the cursor at the first entry in the table.

fn last(&mut self) -> Option<Row<T>>

Positions the cursor at the last entry in the table.

fn next(&mut self) -> Option<Row<T>>

Positions the cursor at the next entry in the table. For a DupTable, this can be either the next duplicate for the current key or the first duplicate for the next key.

fn prev(&mut self) -> Option<Row<T>>

Positions the cursor at the previous entry in the table. For a DupTable, this can be either the next duplicate for the current key or the first duplicate for the next key.

fn get_current(&mut self) -> Option<Row<T>>

Returns the current entry at the cursor position.

fn set_key(&mut self, key: &T::Key) -> Option<T::Value>

Positions the cursor at the entry that has a key == key. Previously seek_key.

fn set_lowerbound_key(&mut self, key: &T::Key) -> Option<Row<T>>

Positions the cursor at the first entry that has a key >= key. Previously seek_range_key.

fn into_iter_start(self) -> Self::IntoIter

Iterates over all entries in the table.

fn into_iter_from(self, key: &T::Key) -> Self::IntoIter

Iterates over all entries in the table starting from a given key.

Dyn Compatibility

This trait is not dyn compatible.

In older versions of Rust, dyn compatibility was called "object safety", so this trait is not object safe.

Implementors

impl<'txn, Kind: TransactionKind, T: Table> ReadCursor<'txn, T> for MdbxCursor<'txn, Kind, T>

type IntoIter = IntoIter<'txn, Kind, T>

impl<'txn, T: Table> ReadCursor<'txn, T> for CursorProxy<'txn, T>

type IntoIter = IntoIterProxy<'txn, T>