Struct OpenOptions 

pub struct OpenOptions {
    pub readonly: bool,
    pub lock: LockMode,
    pub snapshot_every: u64,
    pub compaction: Option<CatalogCompaction>,
    pub cypher: Option<CipherOptions>,
    pub follow: FollowOption,
    pub cache: CachePolicy,
    pub max_image_bytes: Option<u64>,
    pub password_hash: PasswordHashParams,
    pub layout: LayoutOptions,
}

How Database::open acquires the writer lock and whether it opens for writing at all.

Fields

readonly: bool

lock: LockMode

snapshot_every: u64

Ops applied to a table between periodic <table>.idx snapshots — see Table::snapshot. 0 disables periodic snapshotting; defaults to [DEFAULT_SNAPSHOT_EVERY].

compaction: Option<CatalogCompaction>

Overrides the automatic-compaction policy of every table for this handle — the TS compaction option, where Disabled is its false. None leaves the choice to the catalog: the table’s own options.compaction, then defaults.compaction, then [DEFAULT_COMPACTION].

cypher: Option<CipherOptions>

Keys for the fields a schema marks cypher. Without them such fields cannot be written.

follow: FollowOption

Whether reads catch up with what other processes appended, without an explicit refresh.

cache: CachePolicy

How many parsed documents each table of this handle keeps in memory in front of its log — see CachePolicy. Disabled by default, and named here rather than in the catalog on purpose: it costs memory in this process only, so it is the opener’s call and not a property of the database on disk.

max_image_bytes: Option<u64>

Refuses, at write time, an image field whose decoded bytes exceed this many. None accepts any size. Like cache, it is the opener’s call and not stored in the database; verify’s own max_image_bytes is the matching check on what is already on disk.

password_hash: PasswordHashParams

Argon2id cost of the hashes written to passwordHash fields by this handle (default 19 MiB, 2 passes, 1 lane). A hash already stored keeps its own cost and still verifies; verify_password reports needs_rehash for one made with another.

layout: LayoutOptions

Where in the directory the metadata document and the table files live. Left at its default, this is the flat arrangement every database used before layouts existed, under hayson.json — and an existing database is opened in the arrangement it is stored in, whether or not the caller names one.

Trait Implementations

impl Clone for OpenOptions

fn clone(&self) -> Self

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() -> Self

Returns the “default value” for a type.