hstreamdb-rust

Rust client library for HStreamDB.

compatibility

This library is experimental and work in progress, please use the latest released version on crates.io.

Example Usage

Write Data to Streams

use std::env;

use hstreamdb::client::Client;
use hstreamdb::producer::FlushSettings;
use hstreamdb::{CompressionType, Payload, Record, Stream};
use rand::distributions::Alphanumeric;
use rand::{thread_rng, Rng};

async fn produce_example() -> anyhow::Result<()> {
    let mut client = Client::new(env::var("TEST_SERVER_ADDR")?).await?;

    let stream_name = "test_stream";

    client
        .create_stream(Stream {
            stream_name: "test_stream".to_string(),
            replication_factor: 3,
            backlog_duration: 7 * 24 * 3600,
            shard_count: 12,
        })
        .await?;
    println!("{:?}", client.list_streams().await?);

    // `Appender` is cheap to clone
    let (appender, mut producer) = client
        .new_producer(
            stream_name.to_string(),
            hstreamdb_pb::CompressionType::Zstd,
            FlushSettings {
                len: 10,
                size: 4000 * 20,
            },
        )
        .await?;

    _ = tokio::spawn(async move {
        let mut appender = appender;

        for _ in 0..10 {
            for _ in 0..100 {
                let i: u32 = rand::random();
                let payload: Vec<u8> = thread_rng()
                    .sample_iter(&Alphanumeric)
                    .take(20)
                    .map(char::from)
                    .collect::<String>()
                    .into_bytes();
                appender
                    .append(Record {
                        partition_key: format!("test_partition_key_{i}"),
                        payload: Payload::RawRecord(payload),
                    })
                    .unwrap();
            }
        }
        drop(appender)
    });

    // when all `Appender`s for the corresponding `Producer` have been dropped,
    // the `Producer` will wait for all requests to be done and then stop
    producer.start().await;

    Ok(())
}

Read Data from Subscriptions

use std::env;

use hstreamdb::client::Client;
use hstreamdb::{SpecialOffset, Subscription};
use tokio_stream::StreamExt;

async fn consume_example() -> anyhow::Result<()> {
    let addr = env::var("TEST_SERVER_ADDR").unwrap();
    let mut client = Client::new(addr).await.unwrap();

    let stream_name = "test_stream";
    let subscription_id = "test_subscription";

    client
        .create_subscription(Subscription {
            subscription_id: subscription_id.to_string(),
            stream_name: stream_name.to_string(),
            ack_timeout_seconds: 60 * 60,
            max_unacked_records: 1000,
            offset: SpecialOffset::Earliest,
        })
        .await?;
    println!("{:?}", client.list_subscriptions().await?);

    let mut stream = client
        .streaming_fetch("test_consumer".to_string(), subscription_id.to_string())
        .await
        .unwrap();
    let mut records = Vec::new();
    while let Some((record, ack)) = stream.next().await {
        println!("{record:?}");
        records.push(record);
        ack().unwrap();
        if records.len() == 10 * 100 {
            println!("done");
            break;
        }
    }

    client
        .delete_subscription(subscription_id.to_string(), true)
        .await?;

    Ok(())
}