Struct PoolConstraints

pub struct PoolConstraints { /* private fields */ }

Connection pool constraints.

This type stores min and max constraints for crate::Pool and ensures that min <= max.

Implementations

impl PoolConstraints

pub const fn new(min: usize, max: usize) -> Option<PoolConstraints>

Creates new PoolConstraints if constraints are valid (min <= max).

Connection URL

You can use pool_min and pool_max URL parameters to define pool constraints.

let opts = Opts::from_url("mysql://localhost/db?pool_min=0&pool_max=151")?;
assert_eq!(opts.pool_opts().constraints(), PoolConstraints::new(0, 151).unwrap());

pub fn min(&self) -> usize

Lower bound of this pool constraints.

pub fn max(&self) -> usize

Upper bound of this pool constraints.

Trait Implementations

impl Clone for PoolConstraints

fn clone(&self) -> PoolConstraints

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Debug for PoolConstraints

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

Formats the value using the given formatter.

impl Default for PoolConstraints

fn default() -> Self

Returns the “default value” for a type.

impl From<PoolConstraints> for (usize, usize)

fn from(_: PoolConstraints) -> Self

Transforms constraints to a pair of (min, max).

impl Hash for PoolConstraints

fn hash<__H: Hasher>(&self, state: &mut __H)

Feeds this value into the given Hasher.

fn hash_slice<H>(data: &[Self], state: &mut H)

where H: Hasher, Self: Sized,

Feeds a slice of this type into the given Hasher.

impl PartialEq for PoolConstraints

fn eq(&self, other: &PoolConstraints) -> bool

Tests for self and other values to be equal, and is used by ==.

fn ne(&self, other: &Rhs) -> bool

Tests for !=. The default implementation is almost always sufficient, and should not be overridden without very good reason.

impl Copy for PoolConstraints

impl Eq for PoolConstraints

impl StructuralPartialEq for PoolConstraints