Struct VarLenRef 

#[repr(C)]
pub struct VarLenRef {
    pub length_in_bytes: u16,
    pub first_granule: PageOffset,
}

Reference to var-len object within a page.

Fields

length_in_bytes: u16

The length of the var-len object in bytes. When self.is_large_blob() returns true, this is not the proper length of the object. Rather, the blob store must be consulted for the true length.

first_granule: PageOffset

The offset to the first granule containing some of the object’s data as well a pointer to the next granule.

Implementations

impl VarLenRef

pub const LARGE_BLOB_SENTINEL: u16 = 65_535u16

The sentinel for a var-len ref to a large blob.

pub const NULL: Self

The NULL var-len reference for empty variable components.

A null VarLenRef can occur when a row has no var-len component or needs to point to one that is empty.

pub const fn is_large_blob(self) -> bool

Does this refer to a large blob object where self.first_granule is a blob hash?

pub const fn large_blob(first_granule: PageOffset) -> Self

Returns a var-len ref for a large blob object.

pub const fn granules_used(&self) -> usize

Returns the number of granules this var-len ref uses in it page.

pub const fn is_null(self) -> bool

Is this reference NULL, i.e. empty?

Trait Implementations

impl Clone for VarLenRef

fn clone(&self) -> VarLenRef

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Debug for VarLenRef

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

Formats the value using the given formatter.

impl Hash for VarLenRef

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 VarLenRef

fn cmp(&self, other: &VarLenRef) -> 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 VarLenRef

fn eq(&self, other: &VarLenRef) -> 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 VarLenRef

fn partial_cmp(&self, other: &VarLenRef) -> 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 Copy for VarLenRef

impl Eq for VarLenRef

impl StructuralPartialEq for VarLenRef