Struct StateRegistry 

pub struct StateRegistry { /* private fields */ }

Central registry for widget state persistence.

The registry maintains an in-memory cache of widget states and delegates to a StorageBackend for persistence. It provides the main API for save/restore operations.

Thread Safety

The registry is Send + Sync and uses internal locking for thread-safe access.

Example

use ftui_runtime::state_persistence::{StateRegistry, MemoryStorage};

// Create registry with memory storage
let registry = StateRegistry::new(Box::new(MemoryStorage::new()));

// Load state for a widget
if let Some(entry) = registry.get("ScrollView::main") {
    // Deserialize and restore...
}

// Save state
registry.set("ScrollView::main", 1, serialized_data);
registry.flush()?;

Implementations

impl StateRegistry

pub fn new(backend: Box<dyn StorageBackend>) -> Self

Create a new registry with the given storage backend.

Does not automatically load from storage; call load first.

pub fn in_memory() -> Self

Create a registry with memory storage (ephemeral, for testing).

pub fn load(&self) -> StorageResult<usize>

Load all state from the storage backend.

This replaces the in-memory cache with stored data. Safe to call multiple times; later calls refresh the cache.

pub fn flush(&self) -> StorageResult<bool>

Flush dirty state to the storage backend.

Only writes if changes have been made since last flush. Returns Ok(true) if data was written, Ok(false) if no changes.

pub fn get(&self, key: &str) -> Option<StoredEntry>

Get a stored state entry by canonical key.

Returns None if no state exists for the key.

pub fn set(&self, key: impl Into<String>, version: u32, data: Vec<u8>)

Set a state entry.

Marks the registry as dirty; call flush to persist.

pub fn remove(&self, key: &str) -> Option<StoredEntry>

Remove a state entry.

Returns the removed entry if it existed.

pub fn clear(&self) -> StorageResult<()>

Clear all state from both cache and storage.

pub fn len(&self) -> usize

Get the number of cached entries.

pub fn is_empty(&self) -> bool

Check if the cache is empty.

pub fn is_dirty(&self) -> bool

Check if there are unsaved changes.

pub fn backend_name(&self) -> &str

Get the backend name for logging.

pub fn is_available(&self) -> bool

Check if the storage backend is available.

pub fn keys(&self) -> Vec<String>

Get all cached keys.

impl StateRegistry

pub fn shared(self) -> Arc<Self>

Wrap in Arc for shared ownership.

impl StateRegistry

pub fn stats(&self) -> RegistryStats

Get statistics about the registry.

Trait Implementations

impl Debug for StateRegistry

fn fmt(&self, f: &mut Formatter<'_>) -> Result

Formats the value using the given formatter.