Struct RwTxn 

pub struct RwTxn<'p> { /* private fields */ }

A read-write transaction.

LMDB Limitations

Only one RwTxn may exist in the same environment at the same time. If two exist, the new one may wait on a mutex for RwTxn::commit or RwTxn::abort to be called for the first one.

OSX/Darwin Limitation

At least 10 transactions can be active at the same time in the same process, since only 10 POSIX semaphores can be active at the same time for a process. Threads are in the same process space.

If the process crashes in the POSIX semaphore locking section of the transaction, the semaphore will be kept locked.

Note: if your program already use POSIX semaphores, you will have less available for heed/LMDB!

You may increase the limit by editing it at your own risk: /Library/LaunchDaemons/sysctl.plist

Implementations

impl<'p> RwTxn<'p>

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

Commit all the operations of a transaction into the database. The transaction is reset.

pub fn abort(self)

Abandon all the operations of the transaction instead of saving them. The transaction is reset.

Methods from Deref<Target = RoTxn<'p>>

pub fn id(&self) -> usize

Return the LMDB transaction identifier for this read snapshot.

Read-only transactions with the same identifier observe the same coherent database snapshot. This is useful when independent cursors must scan one snapshot concurrently.

Trait Implementations

impl<'p> Deref for RwTxn<'p>

type Target = RoTxn<'p>

The resulting type after dereferencing.

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

Dereferences the value.