Struct OpenOptions 

pub struct OpenOptions {
    pub lock_timeout_ms: u32,
    pub memory_budget_bytes: Option<u64>,
    pub temp_disk_budget_bytes: Option<u64>,
    pub offline_validation: bool,
}

Knobs for Database::open_with_options.

All fields default to the same values the convenience Database::open / [Database::open_encrypted] / etc. constructors use, so OpenOptions::default() round-trips the historical behavior exactly.

Fields

lock_timeout_ms: u32

Maximum time, in milliseconds, to wait for the cross-process database lock (_meta/.lock) before failing with MongrelError::DatabaseLocked.

0 (the default) preserves the historical fail-fast semantics: a single try_lock_exclusive call, no retry, no sleep. SQLite-style busy_timeout semantics kick in once this is non-zero — the open sleeps with progressively wider backoff (1ms → 10ms → 50ms) until either the lock is acquired or lock_timeout_ms elapses, at which point the open returns the same typed lock error as the fail-fast path.

Only the cross-process lock is affected. Mounted tables, page-cache misses, and WAL appends already serialize through in-process locks that handle their own contention. A second independent open in the same process always returns DatabaseLocked immediately; share the existing Arc<Database> instead.

memory_budget_bytes: Option<u64>

Total bytes the storage core’s crate::memory::MemoryGovernor may hand out across every memory class (S1E-003). None (the default) uses DEFAULT_MEMORY_BUDGET_BYTES. The governor is a reservation accounting layer, not an allocation: this is a cap, not a preallocation.

temp_disk_budget_bytes: Option<u64>

Total bytes of live spill files the core’s crate::spill::SpillManager allows across every query (S1E-004). None (the default) uses DEFAULT_TEMP_DISK_BUDGET_BYTES. Again a cap, not a preallocation.

offline_validation: bool

Open the database through the special offline-validation API (spec section 5.3): any crate::storage_mode::StorageMode — including ClusterReplica, which every normal open path rejects — is opened read-only so a backup validator can inspect it. The opened core rejects every write with MongrelError::ReadOnlyReplica. This is the only way to open a cluster replica outside the cluster node runtime.

Implementations

impl OpenOptions

pub fn with_lock_timeout_ms(self, ms: u32) -> Self

Set OpenOptions::lock_timeout_ms. 0 keeps the fail-fast default; SQLite-style applications typically pick 1_000 – 5_000ms.

pub fn with_memory_budget_bytes(self, bytes: u64) -> Self

Set OpenOptions::memory_budget_bytes.

pub fn with_temp_disk_budget_bytes(self, bytes: u64) -> Self

Set OpenOptions::temp_disk_budget_bytes.

pub fn with_offline_validation(self, offline_validation: bool) -> Self

Set OpenOptions::offline_validation. true opens any storage mode read-only (the offline backup-validator API of spec section 5.3).

Trait Implementations

impl Clone for OpenOptions

fn clone(&self) -> OpenOptions

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Debug for OpenOptions

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

Formats the value using the given formatter.

impl Default for OpenOptions

fn default() -> OpenOptions

Returns the “default value” for a type.