Implementation:Fede1024 Rust rdkafka ClientConfig Create With Context

Knowledge Sources	rust-rdkafka
Domains	Messaging, Configuration
Last Updated	2026-02-07 19:00 GMT

Overview

Concrete context-aware client creation method provided by rust-rdkafka's ClientConfig.

Description

ClientConfig::create_with_context delegates to the FromClientConfigAndContext trait implementation of the target type. For StreamConsumer, this is at src/consumer/stream_consumer.rs:L221-272. The construction process:

1. Creates a native config via create_native_config()
2. Extracts max.poll.interval.ms for the background wake loop
3. Creates a BaseConsumer with the native config and context
4. Sets up a WakerSlab for async waker management
5. Enables the queue nonempty callback for efficient wakeups
6. Spawns a background task that periodically wakes all streams

Usage

Call on a configured ClientConfig with the custom context instance and the desired consumer type as the type parameter.

Code Reference

Source Location

• Repository: rust-rdkafka
• File: src/config.rs (create_with_context method), src/consumer/stream_consumer.rs (FromClientConfigAndContext impl)
• Lines: config.rs:L310-316, stream_consumer.rs:L221-272

Signature

impl ClientConfig {
    pub fn create_with_context<C, T>(&self, context: C) -> KafkaResult<T>
    where
        C: ClientContext,
        T: FromClientConfigAndContext<C>;
}

// StreamConsumer's FromClientConfigAndContext impl
impl<C, R> FromClientConfigAndContext<C> for StreamConsumer<C, R>
where
    C: ConsumerContext + 'static,
    R: AsyncRuntime,
{
    fn from_config_and_context(config: &ClientConfig, context: C) -> KafkaResult<Self>;
}

Import

use rdkafka::config::ClientConfig;
use rdkafka::consumer::StreamConsumer;

I/O Contract

Inputs

Name	Type	Required	Description
&self	&ClientConfig	Yes	Configured ClientConfig
context	C: ClientContext	Yes	Custom context implementing ClientContext/ConsumerContext
T (type param)	FromClientConfigAndContext<C>	Yes	Target type (e.g., StreamConsumer<C>)

Outputs

Name	Type	Description
returns	KafkaResult<T>	Configured client with custom context or error

Usage Examples

Create StreamConsumer with Custom Context

use rdkafka::config::ClientConfig;
use rdkafka::consumer::StreamConsumer;

let consumer: StreamConsumer<MyContext> = ClientConfig::new()
    .set("bootstrap.servers", "localhost:9092")
    .set("group.id", "my-group")
    .create_with_context(MyContext::new())
    .expect("Consumer creation failed");

Related Pages

Implements Principle

• Principle:Fede1024_Rust_rdkafka_Consumer_Creation_With_Context

Requires Environment

• Environment:Fede1024_Rust_rdkafka_Rust_Librdkafka_Build_Environment