Struct Transaction

pub struct Transaction {
    preconditions: Vec<Precondition>,
    operations: Vec<Operation>,
}

A Transaction executes several writes(aka. operations) to meta store atomically with optional preconditions checked. It executes as follows:

1. If all preconditions are valid, all operations are executed; Otherwise no operation is executed.
2. Upon commit the transaction, the TransactionAbort error will be returned if any precondition was not met in previous step.

Fields

preconditions: Vec<Precondition>

operations: Vec<Operation>

Implementations

impl Transaction

pub fn check_exists(&mut self, cf: ColumnFamily, key: Key)

Check whether the key exists.

The check call will never fail, instead, it will only fail on commit.

pub fn check_equal(&mut self, cf: ColumnFamily, key: Key, value: Value)

Check whether the key exists.

The check call will never fail, instead, it will only fail on commit.

pub fn put(&mut self, cf: ColumnFamily, key: Key, value: Value)

Put the key/value pair if the preconditions satisfied.

pub fn delete(&mut self, cf: ColumnFamily, key: Key)

Delete the key if the preconditions satisfied.

fn add_precondition(&mut self, precondition: Precondition)

fn add_operation(&mut self, operation: Operation)

pub fn add_preconditions( &mut self, preconditions: impl AsMut<Vec<Precondition>>, )

Add a batch of preconditions.

pub fn add_operations(&mut self, operations: impl AsMut<Vec<Operation>>)

Add a batch of operations.

Trait Implementations

impl Default for Transaction

fn default() -> Transaction

Returns the “default value” for a type.