Enum kv::Txn

pub enum Txn<'env> {
    ReadOnly(RoTransaction<'env>),
    ReadWrite(RwTransaction<'env>),
}

Access to the database

Variants

ReadOnly(RoTransaction<'env>)

Readonly access

ReadWrite(RwTransaction<'env>)

Read-write access

Methods

impl<'env> Txn<'env>

pub fn is_read_only(&self) -> bool

Returns true when the transaction is ReadOnly

pub fn commit(self) -> Result<(), Error>

Ends the transaction, saving all changes

pub fn abort(self)

Ends the transaction, discarding all changes

pub fn get<K: Key, V: Value<'env>>(
    &'env self,
    bucket: &Bucket<'env, K, V>,
    key: K
) -> Result<V, Error>

Gets the value associated with the given key

pub fn set<K: Key, V: Value<'env>, X: Into<V>>(
    &mut self,
    bucket: &Bucket<'env, K, V>,
    key: K,
    val: X
) -> Result<(), Error>

Sets the value associated with the given key

pub fn set_no_overwrite<K: Key, V: Value<'env>, X: Into<V>>(
    &mut self,
    bucket: &Bucket<'env, K, V>,
    key: K,
    val: X
) -> Result<(), Error>

Sets the value associated with the given key if it doesn't already exist

pub fn del<K: Key, V: Value<'env>>(
    &mut self,
    bucket: &Bucket<'env, K, V>,
    key: K
) -> Result<(), Error>

Deletes the key and value associated with key from the database

pub fn clear_db<K: Key, V: Value<'env>>(
    &mut self,
    bucket: &Bucket<'env, K, V>
) -> Result<(), Error>

Remove all items from the database

pub fn reserve<K: Key, V: Value<'env>>(
    &'env mut self,
    bucket: &Bucket<'env, K, V>,
    key: K,
    len: usize
) -> Result<ValueMut<'env>, Error>

Reserve a buffer

pub fn reserve_no_overwrite<K: Key, V: Value<'env>>(
    &'env mut self,
    bucket: &Bucket<'env, K, V>,
    key: K,
    len: usize
) -> Result<ValueMut<'env>, Error>

Reserve a buffer with a unique key

pub fn read_cursor<K: Key, V: Value<'env>>(
    &'env self,
    bucket: &Bucket<'env, K, V>
) -> Result<Cursor<'env, K, V>, Error>

Open a new readonly cursor

pub fn write_cursor<K: Key, V: Value<'env>>(
    &'env mut self,
    bucket: &Bucket<'env, K, V>
) -> Result<Cursor<'env, K, V>, Error>

Open a new writable cursor

pub fn txn(&mut self) -> Result<Txn, Error>

Open a nested transaction NOTE: you must alread be in a read/write transaction otherwise an error will be returned