The Embedded
Event Store

Zero-copy event storage with sub-microsecond reads and 1M+ events/sec batch writes.

Get Started Read the Docs

$ cargo add varvedb

Built for Speed and Reliability

Zero-Copy Reads

Leverages rkyv to map data directly from disk. No deserialization means reads complete in nanoseconds.

Batch Writes

Achieve 700x throughput gains by batching events. Single transaction overhead amortized across thousands of events.

Append-Only Log

Immutable event stream ensures data integrity and simplifies replication. Perfect for Event Sourcing and CQRS.

Async Notifications

Optional runtime-agnostic notifications let async readers await new commits efficiently without polling (no Tokio required).

Architecture

Memory-mapped storage for maximum throughput. Built on LMDB for ACID guarantees.

User Application

⬇ Zero-Copy Read / Batch Append

VarveDB Engine

Stream Handler

Index Manager

Page Cache

⬇ mmap / fsync

LMDB / Disk

src/main.rs

use varvedb::{Varve, StreamId};

fn main() -> Result<(), Error> {
  // Initialize the event store
  let mut varve = Varve::new("./data")?;

  // Create a typed stream
  let mut stream = varve.stream::<Event, 256>("orders")?;

  // Append events (zero-copy on read)
  let (seq, _) = stream.append(StreamId(1), &event)?;

  // Read back instantly
  let bytes = stream.get_bytes(StreamId(1), seq)?;

  Ok(())
}