Struct SceneStore 

pub struct SceneStore { /* private fields */ }

Thread-safe scene storage shared across MCP, WebSocket, and HTTP.

Example

use canvas_core::store::SceneStore;
use canvas_core::{Element, ElementKind};

let store = SceneStore::new();

// Add an element to the default session
let element = Element::new(ElementKind::Text {
    content: "Hello".to_string(),
    font_size: 16.0,
    color: "#000000".to_string(),
});

let id = store.add_element("default", element).unwrap();

Implementations

impl SceneStore

pub fn new() -> Self

Create a new store with a default session (no persistence).

The default session is created with an 800x600 viewport.

pub fn with_data_dir(data_dir: impl Into<PathBuf>) -> Result<Self, StoreError>

Create a store with filesystem persistence.

Sessions are saved as JSON files in data_dir. The directory is created if it doesn’t exist.

Errors

Returns StoreError::Io if the directory cannot be created.

pub fn get_or_create(&self, session_id: &str) -> Scene

Get or create a scene for the given session ID.

If the session does not exist, a new scene with default viewport is created.

pub fn get(&self, session_id: &str) -> Option<Scene>

Get a scene by session ID if it exists.

pub fn replace(&self, session_id: &str, scene: Scene) -> Result<(), StoreError>

Replace the entire scene for a session.

Creates the session if it does not exist.

Errors

Returns StoreError::LockPoisoned if the lock is poisoned (currently recovered from, so this variant is reserved for future stricter modes).

pub fn update<F>(&self, session_id: &str, f: F) -> Result<(), StoreError>

where F: FnOnce(&mut Scene),

Update a scene using a closure.

The closure receives a mutable reference to the scene and can modify it.

Errors

Returns StoreError::SessionNotFound if the session does not exist.

pub fn add_element( &self, session_id: &str, element: Element, ) -> Result<ElementId, StoreError>

Add an element to a session’s scene.

Creates the session if it does not exist.

Errors

Currently infallible but returns Result for API consistency.

pub fn remove_element( &self, session_id: &str, id: ElementId, ) -> Result<(), StoreError>

Remove an element from a session’s scene.

Errors

Returns StoreError::SessionNotFound if the session does not exist. Returns StoreError::ElementNotFound if the element does not exist.

pub fn update_element<F>( &self, session_id: &str, id: ElementId, f: F, ) -> Result<(), StoreError>

where F: FnOnce(&mut Element),

Update an element using a closure.

Errors

Returns StoreError::SessionNotFound if the session does not exist. Returns StoreError::ElementNotFound if the element does not exist.

pub fn scene_document(&self, session_id: &str) -> SceneDocument

Get the canonical document representation of a scene.

If the session does not exist, returns a document for an empty scene.

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

Get a list of all session IDs.

pub fn load_session_from_disk(&self, session_id: &str) -> Result<(), StoreError>

Load a single session from disk into memory.

Errors

Returns an error if the file doesn’t exist or can’t be parsed.

pub fn load_all_sessions(&self) -> Result<Vec<String>, StoreError>

Discover and load all persisted sessions from the data directory.

Returns a list of session IDs that were found on disk.

Errors

Returns an error if the data directory can’t be read.

pub fn delete_session_file(&self, session_id: &str)

Remove a session’s persisted file from disk.

No-op if the store has no data directory or the file doesn’t exist.

pub fn clear(&self, session_id: &str) -> Result<(), StoreError>

Clear all elements from a session’s scene.

Errors

Returns StoreError::SessionNotFound if the session does not exist.

Trait Implementations

impl Clone for SceneStore

fn clone(&self) -> SceneStore

Returns a duplicate of the value.

fn clone_from(&mut self, source: &Self)

Performs copy-assignment from source.

impl Debug for SceneStore

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

Formats the value using the given formatter.

impl Default for SceneStore

fn default() -> SceneStore

Returns the “default value” for a type.