Struct domain::base::serial::Serial

pub struct Serial(pub u32);

A serial number.

Serial numbers are used in DNS to track changes to resources. For instance, the [Soa] record type provides a serial number that expresses the version of the zone. Since these numbers are only 32 bits long, they can wrap. RFC 1982 defined the semantics for doing arithmetics in the face of these wrap-arounds. This type implements these semantics atop a native u32.

The RFC defines two operations: addition and comparison.

For addition, the amount added can only be a positive number of up to 2^31 - 1. Because of this, we decided to not implement the Add trait but rather have a dedicated method add so as to not cause surprise panics.

Serial numbers only implement a partial ordering. That is, there are pairs of values that are not equal but there still isn’t one value larger than the other. Since this is neatly implemented by the PartialOrd trait, the type implements that.

Implementations

impl Serial

pub fn now() -> Self

Returns a serial number for the current Unix time.

pub fn into_int(self) -> u32

Returns the serial number as a raw integer.

pub fn add(self, other: u32) -> Self

Add other to self.

Serial numbers only allow values of up to 2^31 - 1 to be added to them. Therefore, this method requires other to be a u32 instead of a Serial to indicate that you cannot simply add two serials together. This is also why we don’t implement the Add trait.

Panics

This method panics if other is greater than 2^31 - 1.

Trait Implementations

impl CanonicalOrd<Serial> for Serial

fn canonical_cmp(&self, other: &Self) -> Ordering

Returns the canonical ordering between self and other.

#[must_use]fn canonical_lt(&self, other: &Rhs) -> bool

Returns whether self is canonically less than other.

#[must_use]fn canonical_le(&self, other: &Rhs) -> bool

Returns whether self is canonically less than or equal to other.

#[must_use]fn canonical_gt(&self, other: &Rhs) -> bool

Returns whether self is canonically greater than other.

#[must_use]fn canonical_ge(&self, other: &Rhs) -> bool

Returns whether self is canonically greater than or equal to other.

impl Clone for Serial

fn clone(&self) -> Serial

Returns a copy of the value.

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

Performs copy-assignment from source.

impl Compose for Serial

fn compose<T: OctetsBuilder>(&self, target: &mut T) -> Result<(), ShortBuf>

Appends the concrete representation of the value to the target.

fn compose_canonical<T: OctetsBuilder>(
    &self,
    target: &mut T
) -> Result<(), ShortBuf>

Appends the canonical representation of the value to the target.

impl Copy for Serial

impl Debug for Serial

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

Formats the value using the given formatter.

impl Display for Serial

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

Formats the value using the given formatter.

impl Eq for Serial

impl From<Serial> for u32

fn from(serial: Serial) -> u32

Performs the conversion.

impl From<u32> for Serial

fn from(value: u32) -> Serial

Performs the conversion.

impl FromStr for Serial

type Err = <u32 as FromStr>::Err

The associated error which can be returned from parsing.

fn from_str(s: &str) -> Result<Self, Self::Err>

Parses a string s to return a value of this type.

impl Hash for Serial

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, 

Feeds a slice of this type into the given [Hasher].

impl<T: AsRef<[u8]>> Parse<T> for Serial

fn parse(parser: &mut Parser<T>) -> Result<Self, ParseError>

Extracts a value from the beginning of parser.

fn skip(parser: &mut Parser<T>) -> Result<(), ParseError>

Skips over a value of this type at the beginning of parser.

impl PartialEq<Serial> for Serial

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

This method tests for self and other values to be equal, and is used by ==.

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

This method tests for !=.

impl PartialOrd<Serial> for Serial

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

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

#[must_use]fn lt(&self, other: &Rhs) -> bool

This method tests less than (for self and other) and is used by the < operator.

#[must_use]fn le(&self, other: &Rhs) -> bool

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

#[must_use]fn gt(&self, other: &Rhs) -> bool

This method tests greater than (for self and other) and is used by the > operator.

#[must_use]fn ge(&self, other: &Rhs) -> bool

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

impl StructuralEq for Serial

impl StructuralPartialEq for Serial