Function create_backend 

pub async fn create_backend(
    backend_type: BackendType,
    config: BackendConfig,
) -> Result<Box<dyn StorageBackend>, IncrementalError>

Creates a storage backend based on the specified type and configuration.

This factory function provides runtime backend selection with compile-time feature gating. If a backend is requested but its feature flag is disabled, returns IncrementalError::UnsupportedBackend.

Arguments

• backend_type - The type of backend to instantiate.
• config - Configuration parameters for the backend.

Returns

A boxed trait object implementing StorageBackend, or an error if:

• The backend feature is disabled (IncrementalError::UnsupportedBackend)
• Backend initialization fails (IncrementalError::InitializationFailed)
• Configuration mismatch between backend_type and config

Examples

use thread_flow::incremental::backends::{BackendType, BackendConfig, create_backend};

// Create in-memory backend (always available)
let backend = create_backend(
    BackendType::InMemory,
    BackendConfig::InMemory,
).await?;

// Create Postgres backend (requires postgres-backend feature)
let backend = create_backend(
    BackendType::Postgres,
    BackendConfig::Postgres {
        database_url: "postgresql://localhost/thread".to_string(),
    },
).await?;

Errors

• IncrementalError::UnsupportedBackend: Feature flag disabled for requested backend
• IncrementalError::InitializationFailed: Connection failed, invalid config, or initialization error