Struct PageSize 

pub struct PageSize(/* private fields */);

A validated page size.

A page size must be a power of two within MIN_PAGE_SIZE..=MAX_PAGE_SIZE. Validating once, here, means the rest of the crate can treat the size as a trusted invariant — buffer alignment, offset arithmetic, and the payload length all rely on it.

Examples

use page_db::PageSize;

assert!(PageSize::new(8192).is_ok());
assert!(PageSize::new(4096).is_ok());
assert!(PageSize::new(5000).is_err());   // not a power of two
assert!(PageSize::new(1024).is_err());   // below the 4 KiB floor

Implementations

impl PageSize

pub const fn new(size: usize) -> PageResult<Self>

Validate and wrap a page size in bytes.

Errors

Returns PageError::InvalidPageSize if size is not a power of two, or falls outside MIN_PAGE_SIZE..=MAX_PAGE_SIZE.

pub const fn get(self) -> usize

The page size in bytes.

pub const fn payload_len(self) -> usize

The usable payload length of a page of this size.

Trait Implementations

impl Clone for PageSize

fn clone(&self) -> PageSize

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Copy for PageSize

impl Debug for PageSize

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

Formats the value using the given formatter.

impl Default for PageSize

fn default() -> Self

Returns the “default value” for a type.

impl Eq for PageSize

impl Hash for PageSize

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 Ord for PageSize

fn cmp(&self, other: &PageSize) -> Ordering

This method returns an Ordering between self and other.

fn max(self, other: Self) -> Self

where Self: Sized,

Compares and returns the maximum of two values.

fn min(self, other: Self) -> Self

where Self: Sized,

Compares and returns the minimum of two values.

fn clamp(self, min: Self, max: Self) -> Self

where Self: Sized,

Restrict a value to a certain interval.

impl PartialEq for PageSize

fn eq(&self, other: &PageSize) -> 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 PartialOrd for PageSize

fn partial_cmp(&self, other: &PageSize) -> Option<Ordering>

This method returns an ordering between self and other values if one exists.

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

Tests less than (for self and other) and is used by the < operator.

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

Tests less than or equal to (for self and other) and is used by the <= operator.

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

Tests greater than (for self and other) and is used by the > operator.

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

Tests greater than or equal to (for self and other) and is used by the >= operator.

impl StructuralPartialEq for PageSize