Module state 

Pluggable state backend (StateBackend trait + impls). State backend abstraction. Two concrete backends: InProcessBackend for embedded single-process runs, and ObjectStoreBackend for anything durable (local filesystem via file://, or S3/GCS/Azure).

Re-exports

pub use backend::StateBackend;

pub use backend::StateBackendError;

pub use config::DiscoveryMode;

pub use config::StateBackendBuildError;

pub use config::StateBackendConfig;

pub use config::DEFAULT_VNODE_CAPACITY;

pub use in_process::InProcessBackend;

pub use object_store::ObjectStoreBackend;

pub use vnode::key_hash;

pub use vnode::owned_vnodes;

pub use vnode::round_robin_assignment;

pub use vnode::NodeId;

pub use vnode::VnodeRegistry;

Modules

backend

The StateBackend trait: the single contract between streaming operators and the storage tier. Backends persist per-(vnode, epoch) partial-state blobs and expose an epoch_complete durability gate.

config

StateBackendConfig: tagged enum selecting the runtime state backend. Three shapes: in_process, local (filesystem path), object_store (s3/gcs/file url).

in_process

InProcessBackend — non-durable StateBackend backed by an in-memory hashmap. Used for tests and embedded single-process runs.

object_store

ObjectStoreBackend — durable partial-state storage backed by any object_store implementation (S3, GCS, Azure, LocalFileSystem).

vnode

VnodeRegistry — runtime-configurable virtual node topology.