Struct ReadLimits 

#[non_exhaustive]
pub struct ReadLimits {
    pub count: Option<usize>,
    pub bytes: Option<usize>,
}

Limits on how much to read.

Fields (Non-exhaustive)

Non-exhaustive structs could have additional fields added in future. Therefore, non-exhaustive structs cannot be constructed in external crates using the traditional Struct { .. } syntax; cannot be matched against without a wildcard ..; and struct update syntax will not work.

count: Option<usize>

Limit on number of records.

Defaults to 1000 for non-streaming read.

bytes: Option<usize>

Limit on total metered bytes of records.

Defaults to 1MiB for non-streaming read.

Implementations

impl ReadLimits

pub fn new() -> Self

Create a new ReadLimits with default values.

Examples found in repository

examples/get_latest_record.rs (line 24)

async fn main() -> Result<(), Box<dyn std::error::Error>> {
    let access_token =
        std::env::var("S2_ACCESS_TOKEN").map_err(|_| "S2_ACCESS_TOKEN env var not set")?;
    let basin_name: BasinName = std::env::var("S2_BASIN")
        .map_err(|_| "S2_BASIN env var not set")?
        .parse()?;
    let stream_name: StreamName = std::env::var("S2_STREAM")
        .map_err(|_| "S2_STREAM env var not set")?
        .parse()?;

    let s2 = S2::new(S2Config::new(access_token))?;
    let stream = s2.basin(basin_name).stream(stream_name);

    let input = ReadInput::new()
        .with_start(ReadStart::new().with_from(ReadFrom::TailOffset(1)))
        .with_stop(ReadStop::new().with_limits(ReadLimits::new().with_count(1)));
    let batch = stream.read(input).await?;
    println!("{batch:#?}");

    Ok(())
}

examples/docs_encryption.rs (line 64)

async fn main() -> Result<(), Box<dyn std::error::Error>> {
    let access_token = std::env::var("S2_ACCESS_TOKEN")?;
    let basin_name: BasinName = std::env::var("S2_BASIN")?.parse()?;
    let stream_name: StreamName = format!(
        "docs-encryption-{}",
        std::time::SystemTime::now()
            .duration_since(std::time::UNIX_EPOCH)?
            .as_millis()
    )
    .parse()?;

    let client = S2::new(S2Config::new(access_token))?;

    // ANCHOR: basin-cipher
    client
        .create_basin(
            CreateBasinInput::new(basin_name.clone())
                .with_config(BasinConfig::new().with_stream_cipher(EncryptionAlgorithm::Aegis256)),
        )
        .await?;

    client
        .reconfigure_basin(ReconfigureBasinInput::new(
            basin_name.clone(),
            BasinReconfiguration::new().with_stream_cipher(EncryptionAlgorithm::Aes256Gcm),
        ))
        .await?;
    // ANCHOR_END: basin-cipher

    let basin = client.basin(basin_name.clone());
    basin
        .create_stream(CreateStreamInput::new(stream_name.clone()))
        .await?;

    // ANCHOR: append-read
    let stream = basin
        .stream(stream_name.clone())
        .with_encryption_key(std::env::var("S2_ENCRYPTION_KEY")?.parse()?);

    stream
        .append(AppendInput::new(AppendRecordBatch::try_from_iter([
            AppendRecord::new("top secret")?,
        ])?))
        .await?;

    let batch = stream
        .read(
            ReadInput::new()
                .with_start(ReadStart::new().with_from(ReadFrom::SeqNum(0)))
                .with_stop(ReadStop::new().with_limits(ReadLimits::new().with_count(10))),
        )
        .await?;
    // ANCHOR_END: append-read

    println!("Read {} encrypted record(s)", batch.records.len());

    basin
        .delete_stream(DeleteStreamInput::new(stream_name))
        .await?;

    Ok(())
}

examples/docs_streams.rs (line 62)

async fn main() -> Result<(), Box<dyn std::error::Error>> {
    let access_token = std::env::var("S2_ACCESS_TOKEN")?;
    let basin_name: BasinName = std::env::var("S2_BASIN")?.parse()?;

    let client = S2::new(S2Config::new(access_token))?;
    let basin = client.basin(basin_name);

    // Create a temporary stream for examples
    let stream_name: StreamName = format!(
        "docs-streams-{}",
        std::time::SystemTime::now()
            .duration_since(std::time::UNIX_EPOCH)?
            .as_millis()
    )
    .parse()?;
    basin
        .create_stream(s2_sdk::types::CreateStreamInput::new(stream_name.clone()))
        .await?;

    // ANCHOR: simple-append
    let stream = basin.stream(stream_name.clone());

    let ack = stream
        .append(AppendInput::new(AppendRecordBatch::try_from_iter([
            AppendRecord::new("first event")?,
            AppendRecord::new("second event")?,
        ])?))
        .await?;

    // ack tells us where the records landed
    println!(
        "Wrote records {} through {}",
        ack.start.seq_num,
        ack.end.seq_num - 1
    );
    // ANCHOR_END: simple-append

    // ANCHOR: simple-read
    let batch = stream
        .read(
            ReadInput::new()
                .with_start(ReadStart::new().with_from(ReadFrom::SeqNum(0)))
                .with_stop(ReadStop::new().with_limits(ReadLimits::new().with_count(100))),
        )
        .await?;

    for record in batch.records {
        println!("[{}] {:?}", record.seq_num, record.body);
    }
    // ANCHOR_END: simple-read

    // ANCHOR: append-session
    let session = stream.append_session(AppendSessionConfig::new());

    // Submit a batch - this enqueues it and returns a ticket
    let records = AppendRecordBatch::try_from_iter([
        AppendRecord::new("event-1")?,
        AppendRecord::new("event-2")?,
    ])?;
    let ticket = session.submit(AppendInput::new(records)).await?;

    // Wait for durability
    let ack = ticket.await?;
    println!("Durable at seqNum {}", ack.start.seq_num);

    session.close().await?;
    // ANCHOR_END: append-session

    // ANCHOR: producer
    let producer = stream.producer(
        ProducerConfig::new()
            .with_batching(BatchingConfig::new().with_linger(Duration::from_millis(5))),
    );

    // Submit individual records
    let ticket = producer.submit(AppendRecord::new("my event")?).await?;

    // Get the exact sequence number
    let ack = ticket.await?;
    println!("Record durable at seqNum {}", ack.seq_num);

    producer.close().await?;
    // ANCHOR_END: producer

    // ANCHOR: check-tail
    let tail = stream.check_tail().await?;
    println!("Stream has {} records", tail.seq_num);
    // ANCHOR_END: check-tail

    // Cleanup
    basin
        .delete_stream(s2_sdk::types::DeleteStreamInput::new(stream_name))
        .await?;

    println!("Streams examples completed");

    // The following read session examples are for documentation snippets only.
    // They are not executed because they would block waiting for new records.
    if std::env::var("RUN_READ_SESSIONS").is_err() {
        return Ok(());
    }

    // ANCHOR: read-session
    let mut session = stream
        .read_session(
            ReadInput::new().with_start(ReadStart::new().with_from(ReadFrom::SeqNum(0))),
            ReadSessionConfig::default(),
        )
        .await?;

    while let Some(batch) = session.next().await {
        let batch = batch?;
        for record in batch.records {
            println!("[{}] {:?}", record.seq_num, record.body);
        }
    }
    // ANCHOR_END: read-session

    // ANCHOR: read-session-tail-offset
    // Start reading from 10 records before the current tail
    let mut session = stream
        .read_session(
            ReadInput::new().with_start(ReadStart::new().with_from(ReadFrom::TailOffset(10))),
            ReadSessionConfig::default(),
        )
        .await?;

    while let Some(batch) = session.next().await {
        let batch = batch?;
        for record in batch.records {
            println!("[{}] {:?}", record.seq_num, record.body);
        }
    }
    // ANCHOR_END: read-session-tail-offset

    // ANCHOR: read-session-timestamp
    // Start reading from a specific timestamp
    let one_hour_ago = std::time::SystemTime::now()
        .duration_since(std::time::UNIX_EPOCH)?
        .as_millis() as u64
        - 3600 * 1000;
    let mut session = stream
        .read_session(
            ReadInput::new()
                .with_start(ReadStart::new().with_from(ReadFrom::Timestamp(one_hour_ago))),
            ReadSessionConfig::default(),
        )
        .await?;

    while let Some(batch) = session.next().await {
        let batch = batch?;
        for record in batch.records {
            println!("[{}] {:?}", record.seq_num, record.body);
        }
    }
    // ANCHOR_END: read-session-timestamp

    // ANCHOR: read-session-until
    // Read records until a specific timestamp
    let one_hour_ago = std::time::SystemTime::now()
        .duration_since(std::time::UNIX_EPOCH)?
        .as_millis() as u64
        - 3600 * 1000;
    let mut session = stream
        .read_session(
            ReadInput::new()
                .with_start(ReadStart::new().with_from(ReadFrom::SeqNum(0)))
                .with_stop(ReadStop::new().with_until(..one_hour_ago)),
            ReadSessionConfig::default(),
        )
        .await?;

    while let Some(batch) = session.next().await {
        let batch = batch?;
        for record in batch.records {
            println!("[{}] {:?}", record.seq_num, record.body);
        }
    }
    // ANCHOR_END: read-session-until

    // ANCHOR: read-session-wait
    // Read all available records, and once reaching the current tail, wait an additional 30 seconds
    // for new ones
    let mut session = stream
        .read_session(
            ReadInput::new()
                .with_start(ReadStart::new().with_from(ReadFrom::SeqNum(0)))
                .with_stop(ReadStop::new().with_wait(30)),
            ReadSessionConfig::default(),
        )
        .await?;

    while let Some(batch) = session.next().await {
        let batch = batch?;
        for record in batch.records {
            println!("[{}] {:?}", record.seq_num, record.body);
        }
    }
    // ANCHOR_END: read-session-wait

    Ok(())
}

pub fn with_count(self, count: usize) -> Self

Set the limit on number of records.

Examples found in repository

examples/get_latest_record.rs (line 24)

async fn main() -> Result<(), Box<dyn std::error::Error>> {
    let access_token =
        std::env::var("S2_ACCESS_TOKEN").map_err(|_| "S2_ACCESS_TOKEN env var not set")?;
    let basin_name: BasinName = std::env::var("S2_BASIN")
        .map_err(|_| "S2_BASIN env var not set")?
        .parse()?;
    let stream_name: StreamName = std::env::var("S2_STREAM")
        .map_err(|_| "S2_STREAM env var not set")?
        .parse()?;

    let s2 = S2::new(S2Config::new(access_token))?;
    let stream = s2.basin(basin_name).stream(stream_name);

    let input = ReadInput::new()
        .with_start(ReadStart::new().with_from(ReadFrom::TailOffset(1)))
        .with_stop(ReadStop::new().with_limits(ReadLimits::new().with_count(1)));
    let batch = stream.read(input).await?;
    println!("{batch:#?}");

    Ok(())
}

examples/docs_encryption.rs (line 64)

async fn main() -> Result<(), Box<dyn std::error::Error>> {
    let access_token = std::env::var("S2_ACCESS_TOKEN")?;
    let basin_name: BasinName = std::env::var("S2_BASIN")?.parse()?;
    let stream_name: StreamName = format!(
        "docs-encryption-{}",
        std::time::SystemTime::now()
            .duration_since(std::time::UNIX_EPOCH)?
            .as_millis()
    )
    .parse()?;

    let client = S2::new(S2Config::new(access_token))?;

    // ANCHOR: basin-cipher
    client
        .create_basin(
            CreateBasinInput::new(basin_name.clone())
                .with_config(BasinConfig::new().with_stream_cipher(EncryptionAlgorithm::Aegis256)),
        )
        .await?;

    client
        .reconfigure_basin(ReconfigureBasinInput::new(
            basin_name.clone(),
            BasinReconfiguration::new().with_stream_cipher(EncryptionAlgorithm::Aes256Gcm),
        ))
        .await?;
    // ANCHOR_END: basin-cipher

    let basin = client.basin(basin_name.clone());
    basin
        .create_stream(CreateStreamInput::new(stream_name.clone()))
        .await?;

    // ANCHOR: append-read
    let stream = basin
        .stream(stream_name.clone())
        .with_encryption_key(std::env::var("S2_ENCRYPTION_KEY")?.parse()?);

    stream
        .append(AppendInput::new(AppendRecordBatch::try_from_iter([
            AppendRecord::new("top secret")?,
        ])?))
        .await?;

    let batch = stream
        .read(
            ReadInput::new()
                .with_start(ReadStart::new().with_from(ReadFrom::SeqNum(0)))
                .with_stop(ReadStop::new().with_limits(ReadLimits::new().with_count(10))),
        )
        .await?;
    // ANCHOR_END: append-read

    println!("Read {} encrypted record(s)", batch.records.len());

    basin
        .delete_stream(DeleteStreamInput::new(stream_name))
        .await?;

    Ok(())
}

examples/docs_streams.rs (line 62)

async fn main() -> Result<(), Box<dyn std::error::Error>> {
    let access_token = std::env::var("S2_ACCESS_TOKEN")?;
    let basin_name: BasinName = std::env::var("S2_BASIN")?.parse()?;

    let client = S2::new(S2Config::new(access_token))?;
    let basin = client.basin(basin_name);

    // Create a temporary stream for examples
    let stream_name: StreamName = format!(
        "docs-streams-{}",
        std::time::SystemTime::now()
            .duration_since(std::time::UNIX_EPOCH)?
            .as_millis()
    )
    .parse()?;
    basin
        .create_stream(s2_sdk::types::CreateStreamInput::new(stream_name.clone()))
        .await?;

    // ANCHOR: simple-append
    let stream = basin.stream(stream_name.clone());

    let ack = stream
        .append(AppendInput::new(AppendRecordBatch::try_from_iter([
            AppendRecord::new("first event")?,
            AppendRecord::new("second event")?,
        ])?))
        .await?;

    // ack tells us where the records landed
    println!(
        "Wrote records {} through {}",
        ack.start.seq_num,
        ack.end.seq_num - 1
    );
    // ANCHOR_END: simple-append

    // ANCHOR: simple-read
    let batch = stream
        .read(
            ReadInput::new()
                .with_start(ReadStart::new().with_from(ReadFrom::SeqNum(0)))
                .with_stop(ReadStop::new().with_limits(ReadLimits::new().with_count(100))),
        )
        .await?;

    for record in batch.records {
        println!("[{}] {:?}", record.seq_num, record.body);
    }
    // ANCHOR_END: simple-read

    // ANCHOR: append-session
    let session = stream.append_session(AppendSessionConfig::new());

    // Submit a batch - this enqueues it and returns a ticket
    let records = AppendRecordBatch::try_from_iter([
        AppendRecord::new("event-1")?,
        AppendRecord::new("event-2")?,
    ])?;
    let ticket = session.submit(AppendInput::new(records)).await?;

    // Wait for durability
    let ack = ticket.await?;
    println!("Durable at seqNum {}", ack.start.seq_num);

    session.close().await?;
    // ANCHOR_END: append-session

    // ANCHOR: producer
    let producer = stream.producer(
        ProducerConfig::new()
            .with_batching(BatchingConfig::new().with_linger(Duration::from_millis(5))),
    );

    // Submit individual records
    let ticket = producer.submit(AppendRecord::new("my event")?).await?;

    // Get the exact sequence number
    let ack = ticket.await?;
    println!("Record durable at seqNum {}", ack.seq_num);

    producer.close().await?;
    // ANCHOR_END: producer

    // ANCHOR: check-tail
    let tail = stream.check_tail().await?;
    println!("Stream has {} records", tail.seq_num);
    // ANCHOR_END: check-tail

    // Cleanup
    basin
        .delete_stream(s2_sdk::types::DeleteStreamInput::new(stream_name))
        .await?;

    println!("Streams examples completed");

    // The following read session examples are for documentation snippets only.
    // They are not executed because they would block waiting for new records.
    if std::env::var("RUN_READ_SESSIONS").is_err() {
        return Ok(());
    }

    // ANCHOR: read-session
    let mut session = stream
        .read_session(
            ReadInput::new().with_start(ReadStart::new().with_from(ReadFrom::SeqNum(0))),
            ReadSessionConfig::default(),
        )
        .await?;

    while let Some(batch) = session.next().await {
        let batch = batch?;
        for record in batch.records {
            println!("[{}] {:?}", record.seq_num, record.body);
        }
    }
    // ANCHOR_END: read-session

    // ANCHOR: read-session-tail-offset
    // Start reading from 10 records before the current tail
    let mut session = stream
        .read_session(
            ReadInput::new().with_start(ReadStart::new().with_from(ReadFrom::TailOffset(10))),
            ReadSessionConfig::default(),
        )
        .await?;

    while let Some(batch) = session.next().await {
        let batch = batch?;
        for record in batch.records {
            println!("[{}] {:?}", record.seq_num, record.body);
        }
    }
    // ANCHOR_END: read-session-tail-offset

    // ANCHOR: read-session-timestamp
    // Start reading from a specific timestamp
    let one_hour_ago = std::time::SystemTime::now()
        .duration_since(std::time::UNIX_EPOCH)?
        .as_millis() as u64
        - 3600 * 1000;
    let mut session = stream
        .read_session(
            ReadInput::new()
                .with_start(ReadStart::new().with_from(ReadFrom::Timestamp(one_hour_ago))),
            ReadSessionConfig::default(),
        )
        .await?;

    while let Some(batch) = session.next().await {
        let batch = batch?;
        for record in batch.records {
            println!("[{}] {:?}", record.seq_num, record.body);
        }
    }
    // ANCHOR_END: read-session-timestamp

    // ANCHOR: read-session-until
    // Read records until a specific timestamp
    let one_hour_ago = std::time::SystemTime::now()
        .duration_since(std::time::UNIX_EPOCH)?
        .as_millis() as u64
        - 3600 * 1000;
    let mut session = stream
        .read_session(
            ReadInput::new()
                .with_start(ReadStart::new().with_from(ReadFrom::SeqNum(0)))
                .with_stop(ReadStop::new().with_until(..one_hour_ago)),
            ReadSessionConfig::default(),
        )
        .await?;

    while let Some(batch) = session.next().await {
        let batch = batch?;
        for record in batch.records {
            println!("[{}] {:?}", record.seq_num, record.body);
        }
    }
    // ANCHOR_END: read-session-until

    // ANCHOR: read-session-wait
    // Read all available records, and once reaching the current tail, wait an additional 30 seconds
    // for new ones
    let mut session = stream
        .read_session(
            ReadInput::new()
                .with_start(ReadStart::new().with_from(ReadFrom::SeqNum(0)))
                .with_stop(ReadStop::new().with_wait(30)),
            ReadSessionConfig::default(),
        )
        .await?;

    while let Some(batch) = session.next().await {
        let batch = batch?;
        for record in batch.records {
            println!("[{}] {:?}", record.seq_num, record.body);
        }
    }
    // ANCHOR_END: read-session-wait

    Ok(())
}

pub fn with_bytes(self, bytes: usize) -> Self

Set the limit on total metered bytes of records.

Trait Implementations

impl Clone for ReadLimits

fn clone(&self) -> ReadLimits

Returns a duplicate of the value.

fn clone_from(&mut self, source: &Self)

Performs copy-assignment from source.

impl Debug for ReadLimits

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

Formats the value using the given formatter.

impl Default for ReadLimits

fn default() -> ReadLimits

Returns the “default value” for a type.