Struct LifecycleHooks 

#[non_exhaustive]
pub struct LifecycleHooks<C> {
    pub on_create: Option<Box<dyn Fn(&C) + Send + Sync>>,
    pub before_acquire: Option<Box<dyn Fn() + Send + Sync>>,
    pub on_checkout: Option<Box<dyn Fn(&C) + Send + Sync>>,
    pub on_checkin: Option<Box<dyn Fn(&C) + Send + Sync>>,
    pub after_release: Option<Box<dyn Fn() + Send + Sync>>,
    pub on_destroy: Option<Box<dyn Fn() + Send + Sync>>,
}

Lifecycle hook callbacks. All hooks are optional.

Connection-aware hooks (on_create, on_checkout, on_checkin) receive a &C reference to the connection. Non-connection hooks (before_acquire, after_release, on_destroy) take no parameters — on_destroy because the connection may be invalid, and before_acquire/after_release because no specific connection is involved yet.

Marked #[non_exhaustive] so additional hooks can be introduced in future minor releases without breaking downstream construction.

Fields (Non-exhaustive)

Non-exhaustive structs could have additional fields added in future. Therefore, non-exhaustive structs cannot be constructed in external crates using the traditional Struct { .. } syntax; cannot be matched against without a wildcard ..; and struct update syntax will not work.

on_create: Option<Box<dyn Fn(&C) + Send + Sync>>

Called after a new connection is created.

before_acquire: Option<Box<dyn Fn() + Send + Sync>>

Called before attempting to acquire a connection (checkout starts).

on_checkout: Option<Box<dyn Fn(&C) + Send + Sync>>

Called when a connection is checked out and ready to use.

on_checkin: Option<Box<dyn Fn(&C) + Send + Sync>>

Called when a connection passes health checks and is about to return to the pool.

after_release: Option<Box<dyn Fn() + Send + Sync>>

Called after a connection is fully released (all exit paths from return).

on_destroy: Option<Box<dyn Fn() + Send + Sync>>

Called when a connection is destroyed (expired, invalid, or during drain).

Trait Implementations

impl<C> Debug for LifecycleHooks<C>

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

Formats the value using the given formatter.

impl<C> Default for LifecycleHooks<C>

fn default() -> Self

Returns the “default value” for a type.