Struct PoolConfig 

pub struct PoolConfig {
    pub path: Option<PathBuf>,
    pub max_readers: usize,
    pub wal_mode: bool,
    pub busy_timeout: Duration,
    pub checkout_timeout: Duration,
    pub wal_autocheckpoint_pages: u32,
    pub journal_size_limit_bytes: i64,
    pub read_only: bool,
    pub write_queue_enabled: bool,
    pub write_queue_capacity: usize,
}

Configuration for the connection pool.

Fields

path: Option<PathBuf>

Database path. None = in-memory (pool degrades to single connection).

max_readers: usize

Number of reader connections (default: min(num_cpus, 8)).

wal_mode: bool

WAL mode (must be true for pooling to work; default: true).

busy_timeout: Duration

Busy timeout per connection (default: 30s).

Overridable via KHIVE_BUSY_TIMEOUT_SECS.

checkout_timeout: Duration

Time to wait for a reader connection before returning an error (default: 5s).

Overridable via KHIVE_CHECKOUT_TIMEOUT_SECS.

wal_autocheckpoint_pages: u32

Number of WAL pages that triggers an automatic checkpoint.

Maps to PRAGMA wal_autocheckpoint. The default (4000 pages, ~16 MiB at SQLite’s default 4 KiB page size) matches the pre-config behaviour.

Overridable via KHIVE_WAL_AUTOCHECKPOINT_PAGES.

journal_size_limit_bytes: i64

Maximum WAL journal size in bytes before SQLite resets the WAL.

Maps to PRAGMA journal_size_limit. Default: 64 MiB.

Overridable via KHIVE_JOURNAL_SIZE_LIMIT_BYTES.

read_only: bool

Open the database read-only (default: false).

When true, the pool’s writer connection is opened with SQLITE_OPEN_READ_ONLY (no SQLITE_OPEN_CREATE, so a missing path is rejected instead of created) and PRAGMA query_only = ON is set on every connection that can execute SQL. Reader connections are already opened read-only regardless of this flag.

write_queue_enabled: bool

Route migrated store write paths through the single-writer WriterTask channel (ADR-067 Component A) instead of the legacy per-call pool-mutex/standalone-connection path. Off by default.

Slice 1 wires exactly one path (SqlEntityStore::upsert_entities) behind this flag; enabling it does not yet claim ADR-067’s single-writer guarantee — other write paths still open their own writers until later slices migrate them.

Overridable via KHIVE_WRITE_QUEUE ("1" or "true", case-insensitive, enables it; anything else, or unset, leaves it off).

write_queue_capacity: usize

Bounded channel capacity for the WriterTask write queue.

Overridable via KHIVE_WRITE_QUEUE_CAPACITY. Default: 256 pending operations (ADR-067 Component A recommended default).

Trait Implementations

impl Clone for PoolConfig

fn clone(&self) -> PoolConfig

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Debug for PoolConfig

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

Formats the value using the given formatter.

impl Default for PoolConfig

fn default() -> Self

Returns the “default value” for a type.