Struct Hlc 

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

A hybrid logical clock value, 64 bits: 48 bits of milliseconds since 1 January 2020 UTC in the high bits and a 16-bit logical counter in the low bits.

Commit timestamps, snapshots and page timestamps are Hlc values. The order of the u64 is the order of the clock.

Implementations

impl Hlc

pub const EPOCH_UNIX_MS: u64 = 1_577_836_800_000

The Unix time of the epoch, 2020-01-01 00:00:00 UTC, in milliseconds.

pub const MAX_PHYSICAL: u64

The largest physical part, 2^48 - 1 milliseconds, about 8,900 years.

pub const ZERO: Hlc

The zero value. No commit has it.

pub const MAX: Hlc

The largest value.

pub const fn new(physical: u64, logical: u16) -> Option<Hlc>

Makes a value from its two parts. Returns None if physical does not fit in 48 bits.

pub const fn from_bits(bits: u64) -> Hlc

The value with these stored bits.

pub const fn bits(self) -> u64

The stored bits.

pub const fn physical(self) -> u64

Milliseconds since the epoch of 2020.

pub const fn logical(self) -> u16

The logical counter.

pub const fn unix_ms(self) -> u64

The physical part as a Unix time in milliseconds.

pub const fn physical_from_unix_ms(unix_ms: u64) -> u64

Converts a Unix time in milliseconds to the physical part. Times before the epoch become 0.

pub fn tick(self, wall: u64) -> Hlc

The next local value after self, for a local event at wall time wall (milliseconds since the epoch).

This is the send rule of Kulkarni and others (2014). If the wall clock is ahead, the value takes it with logical 0. Otherwise the logical counter goes up by one, and when it overflows the physical part goes forward by one millisecond.

pub fn merge(self, remote: Hlc, wall: u64) -> Hlc

The next local value after self that is also above remote, a value received from another node or ring.

Trait Implementations

impl Clone for Hlc

fn clone(&self) -> Self

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Copy for Hlc

impl Debug for Hlc

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

Formats the value using the given formatter.

impl Default for Hlc

fn default() -> Self

Returns the “default value” for a type.

impl Display for Hlc

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

Formats the value using the given formatter.

impl Eq for Hlc

impl From<Hlc> for Lsn

fn from(hlc: Hlc) -> Lsn

Converts to this type from the input type.

impl FromStr for Hlc

type Err = Error

The associated error which can be returned from parsing.

fn from_str(s: &str) -> Result<Hlc, Error>

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

impl Hash for Hlc

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 Hlc

fn cmp(&self, other: &Self) -> 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.

fn clamp_to<R>(self, range: R) -> Self

where Self: Sized, R: ClampBounds<Self>,

🔬This is a nightly-only experimental API. (clamp_to)

Restrict a value to a certain range.

impl PartialEq for Hlc

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

Equality operator ==.

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

Inequality operator !=.

impl PartialOrd for Hlc

fn partial_cmp(&self, other: &Self) -> 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 Hlc