Struct OpenOptions 

pub struct OpenOptions {
    pub auto_migrate: bool,
    pub repair_wal: bool,
    pub read_only: bool,
}

Options for GraphDb::open_with_options.

Fields

auto_migrate: bool

Rewrite an old-format snapshot to the current VERSION after a successful load (default true). The old snapshot is kept as snapshot.bin.bak until the next clean open at the current version, at which point the .bak is deleted.

Set to false to open a store without touching any on-disk files (useful for read-only inspection of a store at an older format).

repair_wal: bool

Write the valid WAL prefix back over a torn tail on open (default true). Truncating a genuinely torn tail is correct crash recovery.

Set to false for an unattended reader. The valid prefix is still decoded and replayed in memory, but nothing is written: a reader that opens while another process is mid-append would otherwise discard a frame that writer believes durable. mushroomdb recall, which runs on every prompt, passes false for exactly this reason.

read_only: bool

Open without ever writing to the store (default false).

A read-only handle:

• returns GraphError::ReadOnly from every mutation and from snapshot();
• performs no disk write at open — no WAL repair write-back and no auto-migration rewrite, whatever the other two flags say;
• never takes the cross-process write lock, so it opens immediately even while another process is writing, and never makes a writer wait.

refresh and is_stale work normally, so a read-only handle can follow another process’s commits.

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 Copy for OpenOptions

impl Debug for OpenOptions

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

Formats the value using the given formatter.

impl Default for OpenOptions

fn default() -> Self

Returns the “default value” for a type.