Struct Settings 

pub struct Settings {
    pub database_path: Option<PathBuf>,
    pub config: Config,
    pub embedder: Option<Box<dyn Embedder>>,
    pub snapshot_every_ops: Option<u64>,
    pub snapshot_journal_bytes: Option<u64>,
    pub maintain_every_forgets: Option<u64>,
    pub fsync: Option<FsyncPolicy>,
    pub workspace: WorkspaceSettings,
    pub warnings: Vec<SettingWarning>,
}

Resolved runtime settings: the engine config, an optional embedder, and the maintenance policy. The wrapper-specific knobs (import batch size, server workers) are read separately from the same read_config table.

Fields

database_path: Option<PathBuf>

[database].path, if set. Wrapper-specific explicit paths take precedence over this value; otherwise the platform default is used.

config: Config

The engine configuration (size-bearing fields from [engine]).

embedder: Option<Box<dyn Embedder>>

The embedder built from [embedder], or None (lexical/graph/time recall still work without one).

snapshot_every_ops: Option<u64>

[maintenance].snapshot_every_ops, if set.

snapshot_journal_bytes: Option<u64>

[maintenance].snapshot_journal_bytes, if set.

maintain_every_forgets: Option<u64>

[maintenance].maintain_every_forgets, if set.

fsync: Option<FsyncPolicy>

[maintenance].fsync, if set. None leaves the engine default (FsyncPolicy::EachOp) — every acknowledged write survives a power cut. This is the largest single lever on write throughput, which is why changing it is a deliberate config edit and not a per-call flag.

workspace: WorkspaceSettings

The [workspace] section. Its dir is None unless the file names one — the default is a single database, and nothing turns a workspace on by itself.

warnings: Vec<SettingWarning>

Sections and keys in the file that nothing claimed, in file order.

Empty for a clean config, which is why this is a field rather than an error: a typo must not stop a program that was configured correctly enough to run. Show them. A surface that drops these is back to the silence this exists to end — see SettingWarning.

Implementations

impl Settings

pub fn load(flag: Option<&Path>) -> Result<Settings, SettingsError>

Loads settings from the config file resolved by read_config (an explicit flag path, else $PLUGMEM_CONFIG, else the platform config path from crate::default_config_path). Missing config → defaults.

pub fn from_table(table: Option<&Table>) -> Result<Settings, SettingsError>

Builds settings from an already-parsed config table (or None for all defaults). $PLUGMEM_EMBEDDER_ENABLED overrides [embedder].enabled. Use this when the caller also needs its own keys from the same table (read once via read_config, then passed here).

pub fn open(self, path: &Path) -> Result<Database, HostError>

Opens a read-write Database, applying the maintenance policy and embedder to the builder. Consumes self (the embedder moves into the database). For a read-only handle, take Settings::embedder out first, then call Database::open_readonly with Settings::config.

pub fn open_workspace(self, root: &Path) -> Result<Workspace, WorkspaceError>

Opens a Workspace rooted at root: many named databases, each built with these same settings.

The embedder is shared rather than duplicated — a hundred chats pointed at one endpoint want one client, not a hundred (see SharedEmbedder).

root is passed rather than read from WorkspaceSettings::dir so a wrapper keeps its own precedence (flag, then environment, then config), the same way it already does for the database path.

Errors

Nothing yet — the databases open lazily, so a bad root is reported by the first Workspace::get rather than here. The signature is fallible because that is where the failure will move if the root ever needs validating up front.