Struct async_nats::jetstream::message::Message

pub struct Message {
    pub message: Message,
    pub context: Context,
}

Fields

message: Message

context: Context

Implementations

impl Message

pub fn split(self) -> (Message, Acker)

Splits Message into Acker and crate::Message. This can help reduce memory footprint if Message can be dropped before acking, for example when it’s transformed into another structure and acked later

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

Acknowledges a message delivery by sending +ACK to the server.

If AckPolicy is set to All or Explicit, messages has to be acked. Otherwise redeliveries will occur and Consumer will not be able to advance.

Examples

use async_nats::jetstream::consumer::PullConsumer;
use futures::StreamExt;
let client = async_nats::connect("localhost:4222").await?;
let jetstream = async_nats::jetstream::new(client);

let consumer: PullConsumer = jetstream
    .get_stream("events")
    .await?
    .get_consumer("pull")
    .await?;

let mut messages = consumer.fetch().max_messages(100).messages().await?;

while let Some(message) = messages.next().await {
    message?.ack().await?;
}

pub async fn ack_with(&self, kind: AckKind) -> Result<(), Error>

Acknowledges a message delivery by sending a chosen AckKind variant to the server.

Examples

use async_nats::jetstream::consumer::PullConsumer;
use async_nats::jetstream::AckKind;
use futures::StreamExt;
let client = async_nats::connect("localhost:4222").await?;
let jetstream = async_nats::jetstream::new(client);

let consumer: PullConsumer = jetstream
    .get_stream("events")
    .await?
    .get_consumer("pull")
    .await?;

let mut messages = consumer.fetch().max_messages(100).messages().await?;

while let Some(message) = messages.next().await {
    message?.ack_with(AckKind::Nak(None)).await?;
}

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

Acknowledges a message delivery by sending +ACK to the server and awaits for confirmation for the server that it received the message. Useful if user wants to ensure exactly once semantics.

If AckPolicy is set to All or Explicit, messages has to be acked. Otherwise redeliveries will occur and Consumer will not be able to advance.

Examples

use futures::StreamExt;
let client = async_nats::connect("localhost:4222").await?;
let jetstream = async_nats::jetstream::new(client);

let consumer = jetstream
    .get_stream("events")
    .await?
    .get_consumer("pull")
    .await?;

let mut messages = consumer.fetch().max_messages(100).messages().await?;

while let Some(message) = messages.next().await {
    message?.double_ack().await?;
}

pub fn info(&self) -> Result<Info<'_>, Error>

Returns the JetStream message ID if this is a JetStream message.

Trait Implementations

impl Clone for Message

fn clone(&self) -> Message

Returns a copy of the value.

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

Performs copy-assignment from source.

impl Debug for Message

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

Formats the value using the given formatter.

impl Deref for Message

type Target = Message

The resulting type after dereferencing.

fn deref(&self) -> &Self::Target

Dereferences the value.

impl From<Message> for Message

fn from(source: Message) -> Message

Converts to this type from the input type.