Crate krabka_protocol 

Kafka wire-protocol codec.

krabka-protocol is a pure-Rust library that encodes and decodes every Apache Kafka request and response message, byte-equivalent to the upstream JVM implementation. It does no I/O and makes no async assumptions. The broker, client, and tooling crates in the Krabka project use it.

Two flavors

Every message has two generated types:

• owned::FooRequest owns its data as String, Bytes, and Vec<T>. It is easy to move across await points.
• borrowed::FooRequest<'a> references slices of the input buffer as &'a str and &'a [u8]. It decodes with zero copies.

Both implement Encode. The owned flavor implements Decode and the borrowed flavor implements DecodeBorrow.

Krabka-private messages

krabka holds the hand-written messages that Apache Kafka does not define. Their api keys sit at 1000 and above, so a later Kafka assignment cannot collide with them.

Versioning

krabka-protocol is pre-1.0. Breaking API changes are allowed per minor version. See CHANGELOG.md. crates/protocol/schemas/VERSION records the wire-protocol pin.

Encoding a generated request

use bytes::BytesMut;
use krabka_protocol::{Encode, owned::api_versions_request::ApiVersionsRequest};

let req = ApiVersionsRequest::default();
let version = 4;
let mut buf = BytesMut::with_capacity(req.encoded_len(version));
req.encode(&mut buf, version).unwrap();
assert_eq!(buf.len(), req.encoded_len(version));

Re-exports

pub use api_key::ApiKey;

pub use records::remote_log_metadata::RemoteLogMetadataRecord;

pub use tagged_fields::UnknownTaggedField;

pub use tagged_fields::UnknownTaggedFields;

Modules

api_key

borrowed

Borrowed-flavor generated message types.

kafka_3_6_2

krabka

Krabka-private wire messages that Apache Kafka does not define.

legacy_compat

Adapters between the canonical Produce and Fetch types and the kafka_3_6_2-namespaced flavors.

owned

Owned (heap-allocated) message types.

primitives

records

Typed v2 record batch decoder/encoder.

tagged_fields

KIP-482 flexible-version tagged fields.

Enums

ProtocolError

Errors that can occur during wire-protocol encoding or decoding.

Traits

Decode

Decode a Kafka wire-protocol value from a buffer at the given protocol version.

DecodeBorrow

Like Decode, but for the borrowed, zero-copy flavors.

Encode

Encode a Kafka wire-protocol value into a buffer at the given protocol version.

ProtocolRequest

Implemented by every generated Request struct in krabka-protocol.