Struct KafkaHttpClient

Source

pub struct KafkaHttpClient { /* private fields */ }

Expand description

A client for interacting with Kafka REST Proxy over HTTP.

This client provides methods for creating consumers, subscribing to topics, polling for records, producing messages, and committing offsets using the Kafka REST API.

§Examples

use kafka_http::KafkaHttpClient;

let mut client = KafkaHttpClient::new("http://localhost:8082");
client.set_timeout_ms(5000);

Implementations§

Source §

impl KafkaHttpClient

Source

pub fn new(base_uri: &str) -> Self

Creates a new KafkaHttpClient instance.

§Arguments

base_uri - The base URI of the Kafka REST Proxy (e.g., “http://localhost:8082”)

§Returns

A new KafkaHttpClient with default timeout of 1000ms

§Examples

use kafka_http::KafkaHttpClient;

let client = KafkaHttpClient::new("http://localhost:8082");

Source

pub fn set_consumer_uri(&mut self, uri: &String)

Sets the consumer URI for this client.

This is typically called internally after creating a consumer, but can be used to manually set a consumer URI if needed.

§Arguments

uri - The consumer instance URI to set

Source

pub fn set_timeout_ms(&mut self, timeout_ms: u64)

Sets the timeout duration for polling operations.

§Arguments

timeout_ms - The timeout duration in milliseconds

§Examples

use kafka_http::KafkaHttpClient;

let mut client = KafkaHttpClient::new("http://localhost:8082");
client.set_timeout_ms(5000);  // Set 5 second timeout

Source

pub async fn create_consumer( &mut self, group: &str, params: &CreateConsumerParams, ) -> Result<String, Error>

Creates a new consumer in the specified consumer group.

This method will fail if the consumer already exists. Use try_create_consumer if you want to handle existing consumers gracefully.

§Arguments

group - The consumer group name
params - Parameters for creating the consumer (name, format, etc.)

§Returns

Ok(String) - The consumer instance URI on success
Err(Error) - An error if the consumer creation fails or URI is not returned

§Examples

use kafka_http::{KafkaHttpClient, types::CreateConsumerParams};

let mut client = KafkaHttpClient::new("http://localhost:8082");
let params = CreateConsumerParams {
    name: "consumer-1".to_string(),
    format: "json".to_string(),
    ..Default::default()
};
let consumer_uri = client.create_consumer("my-group", &params).await?;

Source

pub async fn try_create_consumer( &mut self, group: &str, params: &CreateConsumerParams, ) -> Result<Option<String>, Error>

Attempts to create a new consumer, handling the case where the consumer already exists.

If the consumer already exists, this method will reconstruct the consumer URI based on the group and consumer name, and return it wrapped in Some. This allows reconnecting to existing consumers.

§Arguments

group - The consumer group name
params - Parameters for creating the consumer (name, format, etc.)

§Returns

Ok(Some(String)) - The consumer instance URI (new or reconstructed)
Ok(None) - Should not occur in current implementation
Err(Error) - An error if the operation fails

§Examples

use kafka_http::{KafkaHttpClient, types::CreateConsumerParams};

let mut client = KafkaHttpClient::new("http://localhost:8082");
let params = CreateConsumerParams {
    name: "consumer-1".to_string(),
    format: "json".to_string(),
    ..Default::default()
};
// This won't fail if consumer already exists
let consumer_uri = client.try_create_consumer("my-group", &params).await?;

Subscribes the consumer to one or more topics.

A consumer must be created before calling this method. The consumer URI must be set (either by creating a consumer or manually setting it).

§Arguments

group - The consumer group name (used for logging)
params - Subscription parameters including topics to subscribe to

§Returns

Ok(()) - Subscription was successful
Err(Error) - An error if consumer URI is not set or subscription fails

§Examples /// Polls for new records from subscribed topics.

This method uses the timeout configured via set_timeout_ms(). A consumer must be created and subscribed to topics before polling.

§Returns

Ok(Vec<Record>) - A vector of records (may be empty if no records available)
Err(Error) - An error if consumer URI is not set or polling fails

§Examples

use kafka_http_client::KafkaHttpClient;

let mut client = KafkaHttpClient::new("http://localhost:8082");
// ... create consumer and subscribe ...
let records = client.poll().await?;
for record in records {
    println!("Received: {:?}", record);
}

use kafka_http::{KafkaHttpClient, types::{CreateConsumerParams, SubscribeParams}};

let mut client = KafkaHttpClient::new("http://localhost:8082");
// ... create consumer first ...
let subscribe_params = SubscribeParams {
    topics: vec!["my-topic".to_string()],
    ..Default::default()
};
client.subscribe("my-group", &subscribe_params).await?;

Source

pub async fn poll(&self) -> Result<Vec<Record>, Error>

Polls for new records from subscribed topics.

This method uses the timeout configured via set_timeout_ms(). A consumer must be created and subscribed to topics before polling.

§Returns

Ok(Vec<Record>) - A vector of records (may be empty if no records available)
Err(Error) - An error if consumer URI is not set or polling fails

§Examples

use kafka_http::KafkaHttpClient;

let mut client = KafkaHttpClient::new("http://localhost:8082");
// ... create consumer and subscribe ...
let records = client.poll().awaait?;
for record in records {
    println!("Received: {:?}", record);
}

Source

pub async fn produce( &self, topic: &str, params: &ProduceParams, ) -> Result<(), Error>

Produces records to a Kafka topic.

§Arguments

topic - The name of the topic to produce to
params - Parameters containing the records to produce

§Returns

Ok(()) - Records were successfully produced
Err(Error) - An error if production fails

§Examples

use kafka_http::{KafkaHttpClient, types::ProduceParams};

let client = KafkaHttpClient::new("http://localhost:8082");
let params = ProduceParams {
    records: vec![/* records */],
    ..Default::default()
};
client.produce("my-topic", &params).await?;

Source

pub async fn commit( &self, params: &PartitionOffsetCommitParams, ) -> Result<(), Error>

Commits offsets for consumed messages.

A consumer must be created before calling this method. The consumer URI must be set.

§Arguments

params - Parameters specifying which partition offsets to commit

§Returns

Ok(()) - Offsets were successfully committed
Err(Error) - An error if consumer URI is not set or commit fails

§Examples

use kafka_http::{KafkaHttpClient, types::PartitionOffsetCommitParams};

let mut client = KafkaHttpClient::new("http://localhost:8082");
// ... create consumer, subscribe, and poll ...
let params = PartitionOffsetCommitParams {
    partitions: vec![/* partition offsets */],
    ..Default::default()
};
client.commit(&params).await?;