Trait WorkspaceStoreAdapter 

pub trait WorkspaceStoreAdapter: Send + Sync {
    // Required methods
    fn load(&self, workspace_root: &Path) -> Result<Workspace, StoreError>;
    fn save_state(
        &self,
        workspace_root: &Path,
        workspace: &Workspace,
    ) -> Result<(), StoreError>;
    fn read_state_bytes(
        &self,
        workspace_root: &Path,
    ) -> Result<Option<Vec<u8>>, StoreError>;
    fn parse_state_bytes(
        &self,
        workspace_root: &Path,
        bytes: &[u8],
    ) -> Result<Vec<Mount>, StoreError>;
    fn save_state_cas(
        &self,
        workspace_root: &Path,
        workspace: &Workspace,
        expected: Option<&[u8]>,
    ) -> Result<bool, StoreError>;
}

Adapter trait — the seam between the engine and the persisted workspace state. Implementations decide where the mount list lives (two files under .memstead/, a SQLite database, a remote service, an in-memory test fixture); the engine consumes the produced Workspace uniformly.

Required Methods

fn load(&self, workspace_root: &Path) -> Result<Workspace, StoreError>

Load the workspace from workspace_root. Implementations resolve the adapter-specific files relative to this root (e.g. the file adapter reads <workspace_root>/.memstead/workspace.toml + <workspace_root>/.memstead/state/mounts.json).

fn save_state( &self, workspace_root: &Path, workspace: &Workspace, ) -> Result<(), StoreError>

Persist the engine-managed slice of state (today: the mount list). Operator-edited fields stay untouched — adapters that share one file with operator content must not overwrite it here. The two-layer file adapter writes only state/mounts.json.

Last-writer-wins. Prefer Self::save_state_cas whenever the caller can name what it read: a long-lived process that dumps its cached roster over this call drops every mount a sibling process registered since the dump was taken.

fn read_state_bytes( &self, workspace_root: &Path, ) -> Result<Option<Vec<u8>>, StoreError>

Raw bytes of the engine-managed state file, or None when it does not exist yet. The compare token for Self::save_state_cas.

fn parse_state_bytes( &self, workspace_root: &Path, bytes: &[u8], ) -> Result<Vec<Mount>, StoreError>

Parse state bytes previously returned by Self::read_state_bytes into the mount roster they carry.

fn save_state_cas( &self, workspace_root: &Path, workspace: &Workspace, expected: Option<&[u8]>, ) -> Result<bool, StoreError>

Compare-and-set counterpart of Self::save_state: write only when the on-disk state still equals expected, and report a mismatch as Ok(false) rather than an error so the caller can re-read, re-merge and retry. The check and the write are one step under the adapter’s own lock — a caller that reads, then compares, then writes leaves exactly the window this exists to close.

Dyn Compatibility

This trait is dyn compatible.

In older versions of Rust, dyn compatibility was called "object safety".

Implementors

impl WorkspaceStoreAdapter for FileWorkspaceStore