event-store-adapter-rs

This library is designed to turn DynamoDB into an Event Store for Event Sourcing.

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Usage

You can easily implement an Event Sourcing-enabled repository using EventStore.

```rust pub struct UserAccountRepository { event_store: EventStore, }

impl UserAccountRepository { pub fn new(eventstore: EventStore) -> Self { Self { eventstore } }

pub async fn store( &mut self, event: &UserAccountEvent, version: usize, snapshotopt: Option<&UserAccount>, ) -> Result<()> { match (event.iscreated(), snapshotopt) { (false, None) => { self.eventstore.persistevent(event, version).await?; } (true, None) => { panic!("Invalid state") } (, Some(snapshot)) => { self.eventstore.persisteventandsnapshot(event, snapshot).await?; } } Ok(()) }

pub async fn findbyid(&self, id: &UserAccountId) -> Result { let snapshot = self.eventstore.getlatestsnapshotbyid(id).await?; match snapshot { Some((snapshot, version)) => { let events = self.eventstore .geteventsbyidsinceseqnr(id, snapshot.seq_nr) .await?; let result = UserAccount::replay(events, snapshot, version); Ok(Some(result)) } None => Ok(None), } }

} ```

The following is an example of the repository usage

```rust let eventstore = EventStore::new( awsdynamodbclient.clone(), journaltablename.tostring(), journalaidindexname.tostring(), snapshottablename.tostring(), snapshotaidindexname.to_string(), 64, );

let mut repository = UserAccountRepository::new(event_store);

// Replay the aggregate from the event store let mut useraccount = repository.findbyid(useraccount_id).await.unwrap();

// Execute a command on the aggregate let useraccountevent = user_account.rename(name).unwrap();

// Store the new event without a snapshot repository .store(&useraccountevent, useraccount.version(), None) .await // Store the new event with a snapshot // repository // .store(&useraccountevent, useraccount.version(), Some(&user_account)) // .await ```

Table Specifications

See docs/DATABASE_SCHEMA.md.