Trait WriteTransaction 

pub trait WriteTransaction<'db>: ReadTransaction<'db> + Sized {
    type WriteCursor<'txn, T: Table>: WriteCursor<'txn, T>
       where Self: 'txn;
    type DupWriteCursor<'txn, T: DupTable>: DupWriteCursor<'txn, T>
       where Self: 'txn;

    // Required methods
    fn put_reserve<T: RegularTable>(
        &mut self,
        table: &T,
        key: &T::Key,
        value: &T::Value,
    )
       where T::Value: IntoDatabaseValue;
    fn put<T: Table>(&mut self, table: &T, key: &T::Key, value: &T::Value);
    fn append<T: Table>(&mut self, table: &T, key: &T::Key, value: &T::Value);
    fn remove<T: Table>(&mut self, table: &T, key: &T::Key);
    fn remove_item<T: Table>(
        &mut self,
        table: &T,
        key: &T::Key,
        value: &T::Value,
    );
    fn commit(self);
    fn cursor<'txn, T: RegularTable>(
        &'txn self,
        table: &T,
    ) -> Self::WriteCursor<'txn, T>;
    fn dup_cursor<'txn, T: DupTable>(
        &'txn self,
        table: &T,
    ) -> Self::DupWriteCursor<'txn, T>;
    fn clear_table<T: Table>(&mut self, table: &T);

    // Provided method
    fn abort(self) { ... }
}

Write-transactions can perform read and write operations on a database.

Required Associated Types

type WriteCursor<'txn, T: Table>: WriteCursor<'txn, T> where Self: 'txn

type DupWriteCursor<'txn, T: DupTable>: DupWriteCursor<'txn, T> where Self: 'txn

Required Methods

fn put_reserve<T: RegularTable>( &mut self, table: &T, key: &T::Key, value: &T::Value, )

where T::Value: IntoDatabaseValue,

Puts a key/value pair into the database by copying it into a reserved space in the database. This works best for values that need to be serialized into the reserved space. This method will panic when called on a database with duplicate keys!

fn put<T: Table>(&mut self, table: &T, key: &T::Key, value: &T::Value)

Puts a key/value pair into the database by passing a reference to a byte slice. This is more efficient than put_reserve if no serialization is needed, and the existing value can be immediately written into the database.

fn append<T: Table>(&mut self, table: &T, key: &T::Key, value: &T::Value)

Appends a key/value pair to the end of the database. This method is more efficient than put. This operation fails if the key is less than the last key.

fn remove<T: Table>(&mut self, table: &T, key: &T::Key)

Removes the entry with this key from the database. In dup tables, it removes all entries with this key.

fn remove_item<T: Table>(&mut self, table: &T, key: &T::Key, value: &T::Value)

Removes the entry with this key and value from the database. Only matching entries will be deleted.

fn commit(self)

Commits the changes to the database.

fn cursor<'txn, T: RegularTable>( &'txn self, table: &T, ) -> Self::WriteCursor<'txn, T>

Creates a write cursor for the given table.

fn dup_cursor<'txn, T: DupTable>( &'txn self, table: &T, ) -> Self::DupWriteCursor<'txn, T>

Creates a write cursor for the given duplicate table.

fn clear_table<T: Table>(&mut self, table: &T)

Clears the table of all entries.

Provided Methods

fn abort(self)

Aborts the transaction and discards all changes.

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<'db> WriteTransaction<'db> for MdbxTransaction<'db, RW>

type WriteCursor<'txn, T: Table> = MdbxCursor<'txn, RW, T> where 'db: 'txn

type DupWriteCursor<'txn, T: DupTable> = MdbxCursor<'txn, RW, T> where 'db: 'txn

impl<'db> WriteTransaction<'db> for MdbxWriteTransaction<'db>

type WriteCursor<'txn, T: Table> = MdbxCursor<'txn, RW, T> where Self: 'txn

type DupWriteCursor<'txn, T: DupTable> = MdbxCursor<'txn, RW, T> where Self: 'txn