Struct Transactor

#[non_exhaustive]
pub struct Transactor { /* private fields */ }

A set of undoable updates and requests against a dataset.

Implementations

impl Transactor

pub async fn closed(&self) -> bool

Check if transaction is finished.

If the transaction has been cancelled or committed, then this function will return true, and any further calls to functions on this transaction will result in a Error::TxFinished error.

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

Cancel a transaction.

This reverses all changes made within the transaction.

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

Commit a transaction.

This attempts to commit all changes made within the transaction.

pub async fn exists<K>( &mut self, key: K, version: Option<u64>, ) -> Result<bool, Error>

where K: KeyEncode + Debug,

Check if a key exists in the datastore.

pub async fn get<K>( &mut self, key: K, version: Option<u64>, ) -> Result<Option<Val>, Error>

where K: KeyEncode + Debug,

Fetch a key from the datastore.

pub async fn getm<K>(&mut self, keys: Vec<K>) -> Result<Vec<Option<Val>>, Error>

where K: KeyEncode + Debug,

Fetch many keys from the datastore.

pub async fn getr<K>( &mut self, rng: Range<K>, version: Option<u64>, ) -> Result<Vec<(Key, Val)>, Error>

where K: KeyEncode + Debug,

Retrieve a specific range of keys from the datastore.

This function fetches all matching key-value pairs from the underlying datastore in grouped batches.

pub async fn getp<K>(&mut self, key: K) -> Result<Vec<(Key, Val)>, Error>

where K: KeyEncode + Debug,

Retrieve a specific prefixed range of keys from the datastore.

This function fetches all matching key-value pairs from the underlying datastore in grouped batches.

pub async fn set<K, V>( &mut self, key: K, val: V, version: Option<u64>, ) -> Result<(), Error>

where K: KeyEncode + Debug, V: Into<Val> + Debug,

Insert or update a key in the datastore.

pub async fn replace<K, V>(&mut self, key: K, val: V) -> Result<(), Error>

where K: KeyEncode + Debug, V: Into<Val> + Debug,

Insert or replace a key in the datastore.

pub async fn put<K, V>( &mut self, key: K, val: V, version: Option<u64>, ) -> Result<(), Error>

where K: KeyEncode + Debug, V: Into<Val> + Debug,

Insert a key if it doesn’t exist in the datastore.

pub async fn putc<K, V>( &mut self, key: K, val: V, chk: Option<V>, ) -> Result<(), Error>

where K: KeyEncode + Debug, V: Into<Val> + Debug,

Update a key in the datastore if the current value matches a condition.

pub async fn del<K>(&mut self, key: K) -> Result<(), Error>

where K: KeyEncode + Debug,

Delete a key from the datastore.

pub async fn delc<K, V>(&mut self, key: K, chk: Option<V>) -> Result<(), Error>

where K: KeyEncode + Debug, V: Into<Val> + Debug,

Delete a key from the datastore if the current value matches a condition.

pub async fn delr<K>(&mut self, rng: Range<K>) -> Result<(), Error>

where K: KeyEncode + Debug,

Delete a range of keys from the datastore.

This function deletes all matching key-value pairs from the underlying datastore in grouped batches.

pub async fn delp<K>(&mut self, key: K) -> Result<(), Error>

where K: KeyEncode + Debug,

Delete a prefixed range of keys from the datastore.

This function deletes all matching key-value pairs from the underlying datastore in grouped batches.

pub async fn clr<K>(&mut self, key: K) -> Result<(), Error>

where K: KeyEncode + Debug,

Delete all versions of a key from the datastore.

pub async fn clrc<K, V>(&mut self, key: K, chk: Option<V>) -> Result<(), Error>

where K: KeyEncode + Debug, V: Into<Val> + Debug,

Delete all versions of a key from the datastore if the current value matches a condition.

pub async fn clrr<K>(&mut self, rng: Range<K>) -> Result<(), Error>

where K: KeyEncode + Debug,

Delete all versions of a range of keys from the datastore.

This function deletes all matching key-value pairs from the underlying datastore in grouped batches.

pub async fn clrp<K>(&mut self, key: K) -> Result<(), Error>

where K: KeyEncode + Debug,

Delete all versions of a prefixed range of keys from the datastore.

This function deletes all matching key-value pairs from the underlying datastore in grouped batches.

pub async fn keys<K>( &mut self, rng: Range<K>, limit: u32, version: Option<u64>, ) -> Result<Vec<Key>, Error>

where K: KeyEncode + Debug,

Retrieve a specific range of keys from the datastore.

This function fetches the full range of keys without values, in a single request to the underlying datastore.

pub async fn scan<K>( &mut self, rng: Range<K>, limit: u32, version: Option<u64>, ) -> Result<Vec<(Key, Val)>, Error>

where K: KeyEncode + Debug,

Retrieve a specific range of keys from the datastore.

This function fetches the full range of key-value pairs, in a single request to the underlying datastore.

pub async fn batch_keys<K>( &mut self, rng: Range<K>, batch: u32, version: Option<u64>, ) -> Result<Batch<Key>, Error>

where K: KeyEncode + Debug,

Retrieve a batched scan over a specific range of keys in the datastore.

This function fetches keys, in batches, with multiple requests to the underlying datastore.

pub async fn count<K>(&mut self, rng: Range<K>) -> Result<usize, Error>

where K: KeyEncode + Debug,

Count the total number of keys within a range in the datastore.

This function fetches the total count, in batches, with multiple requests to the underlying datastore.

pub async fn batch_keys_vals<K>( &mut self, rng: Range<K>, batch: u32, version: Option<u64>, ) -> Result<Batch<(Key, Val)>, Error>

where K: KeyEncode + Debug,

Retrieve a batched scan over a specific range of keys in the datastore.

This function fetches key-value pairs, in batches, with multiple requests to the underlying datastore.

pub async fn batch_keys_vals_versions<K>( &mut self, rng: Range<K>, batch: u32, ) -> Result<Batch<(Key, Val, Version, bool)>, Error>

where K: KeyEncode + Debug,

Retrieve a batched scan of all versions over a specific range of keys in the datastore.

This function fetches key-value-version pairs, in batches, with multiple requests to the underlying datastore.

pub async fn get_timestamp<K>(&mut self, key: K) -> Result<VersionStamp, Error>

where K: KeyEncode + Debug,

Obtain a new change timestamp for a key which is replaced with the current timestamp when the transaction is committed. NOTE: This should be called when composing the change feed entries for this transaction, which should be done immediately before the transaction commit. That is to keep other transactions commit delay(pessimistic) or conflict(optimistic) as less as possible.

pub async fn set_versionstamped<K, V>( &mut self, ts_key: K, prefix: K, suffix: K, val: V, ) -> Result<(), Error>

where K: KeyEncode + Debug, V: Into<Val> + Debug,

Insert or update a key in the datastore.

pub async fn clock(&self) -> Timestamp

Clock retrieves the current timestamp, without guaranteeing monotonicity in all implementations.

It is used for unreliable ordering of events as well as handling of timeouts. Operations that are not guaranteed to be correct. But also allows for lexicographical ordering.

Public for tests, but not required for usage from a user perspective.

Trait Implementations

impl Display for Transactor

fn fmt(&self, f: &mut Formatter<'_>) -> Result

Formats the value using the given formatter.