Struct RWTxGuard 

pub struct RWTxGuard<'a> { /* private fields */ }

Guard returned by DB.begin_rw_tx()

Statically guards against multiple mutable db borrows.

Implements Deref and DerefMut to Tx

Methods from Deref<Target = Tx>

pub fn writable(&self) -> bool

Returns whether the transaction can perform write operations.

pub fn on_commit(&mut self, handler: Box<dyn Fn()>)

Adds a handler function to be executed after the transaction successfully commits.

pub fn cursor(&self) -> Cursor<'_, RwLockWriteGuard<'_, Bucket>>

Creates a cursor associated with the root bucket. All items in the cursor will return a nil value because all items in root bucket are also buckets. The cursor is only valid as long as the transaction is open. Do not use a cursor after the transaction is closed.

pub fn stats(&self) -> TxStats

pub fn bucket( &self, key: &[u8], ) -> Result<MappedRwLockReadGuard<'_, Bucket>, Error>

Bucket retrieves a bucket by name. Returns None if the bucket does not exist. The bucket instance is only valid for the lifetime of the transaction.

pub fn bucket_mut( &mut self, key: &[u8], ) -> Result<MappedRwLockWriteGuard<'_, Bucket>, Error>

Bucket retrieves a mutable bucket by name. Returns None if the bucket does not exist. The bucket instance is only valid for the lifetime of the transaction.

pub fn buckets(&self) -> Vec<Vec<u8>>

returns bucket keys for db

pub fn create_bucket( &mut self, key: &[u8], ) -> Result<MappedRwLockWriteGuard<'_, Bucket>, Error>

Creates a new bucket. Returns an error if the bucket already exists, if the bucket name is blank, or if the bucket name is too long. The bucket instance is only valid for the lifetime of the transaction.

pub fn create_bucket_if_not_exists( &mut self, key: &[u8], ) -> Result<MappedRwLockWriteGuard<'_, Bucket>, Error>

Creates a new bucket if it doesn’t already exist. Returns an error if the bucket name is blank, or if the bucket name is too long. The bucket instance is only valid for the lifetime of the transaction.

pub fn delete_bucket(&mut self, key: &[u8]) -> Result<(), Error>

Deletes a bucket. Returns an error if the bucket cannot be found or if the key represents a non-bucket value.

pub fn for_each<'a, E: Into<Error>>( &self, handler: Box<dyn FnMut(&[u8], Option<&Bucket>) -> Result<(), E> + 'a>, ) -> Result<(), Error>

Executes a function for each bucket in the root. If the provided function returns an error then the iteration is stopped and the error is returned to the caller.

first argument of function is bucket’s key, second is bucket itself

pub fn write_to<W: Write>(&self, w: W) -> Result<i64, Error>

Writes the entire database to a writer. If err == nil then exactly tx.Size() bytes will be written into the writer.

pub fn copy_to(&self, path: &str, mode: OpenOptions) -> Result<(), Error>

Copies the entire database to file at the given path. A reader transaction is maintained during the copy so it is safe to continue using the database while a copy is in progress.

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

Writes all changes to disk and updates the meta page. Returns an error if a disk write error occurs, or if Commit is called on a read-only transaction.

pub fn rollback(&self) -> Result<(), Error>

Closes the transaction and ignores all previous updates. Read-only transactions must be rolled back and not committed.

pub fn check_sync(&self) -> Result<(), Error>

Sync version of check()

In case of checking thread panic will also return Error

pub fn check(&self) -> Receiver<String>

pub fn freed(&self) -> Result<HashMap<u64, bool>, Error>

pub fn page_info(&self, id: usize) -> Result<Option<PageInfo>, Error>

Returns page information for a given page number. This is only safe for concurrent use when used by a writable transaction.

Trait Implementations

impl<'a> Deref for RWTxGuard<'a>

type Target = Tx

The resulting type after dereferencing.

fn deref(&self) -> &Self::Target

Dereferences the value.

impl<'a> DerefMut for RWTxGuard<'a>

fn deref_mut(&mut self) -> &mut Self::Target

Mutably dereferences the value.