Struct Clock 

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

A hybrid logical clock (HLC) timestamp, consisting of a modified NTP timestamp rounded to 48 bits and a 16 bit counter value. Instead of the NTP epoch (1900-01-01), this uses the Unix epoch (1970-01-01).

The NTP timestamp is an unsigned 64b fixed point number

• upper 32b are seconds since 1900 (here: 1970)
• lower 32b are fractional seconds

The HLC Timestamp is the same as an NTP timestamp, except for the 16 least significant bits. These represent the “counter” value for correctly ordering events where the system clock has not increased since the last timestamp (this includes “simultaneous” events and events occuring after the system clock is set backwards).

To illustrate:

0000000000000000000000000000000000000000000000000000000000000000 | bits
[------------seconds-----------][-----fractional seconds-------] | NTP
[--------------rounded timestamp---------------][---counter----] | HLC

Taken from “Logical Physical Clocks and Consistent Snapshots in Globally Distributed Databases” by Kulkarni, Demirbas, Madeppa, Avva, and Leone. However, unlike the implementation described there, this one is not backwards compatible with NTP because it uses the Unix epoch instead of the NTP epoch.

Implementations

impl Clock

pub fn null_clock() -> Self

Generate the first ever HLC

pub fn get_time(self) -> SystemTime

Convert the time component to a SystemTime

Trait Implementations

impl Bind for Clock

const COLUMNS: usize = 1usize

fn bind(&self, binder: &mut Binder<'_, '_>) -> SqlResult<()>

fn bind_to(&self, stmt: &mut Statement<'_>) -> Result<(), Error>

Bind to the Statement’s parameters starting from the beginning

impl Clone for Clock

fn clone(&self) -> Clock

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Debug for Clock

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

Formats the value using the given formatter.

impl<'de> Deserialize<'de> for Clock

fn deserialize<__D>(__deserializer: __D) -> Result<Self, __D::Error>

where __D: Deserializer<'de>,

Deserialize this value from the given Serde deserializer.

impl Display for Clock

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

Formats the value using the given formatter.

impl Fetch for Clock

fn fetch(fetcher: &mut Fetcher<'_>) -> SqlResult<Self>

fn try_fetch(fetcher: &mut Fetcher<'_>) -> SqlResult<Option<Self>>

fn from_row(row: &Row<'_>) -> Result<Self, Error>

impl Ord for Clock

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

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

fn partial_cmp(&self, other: &Clock) -> 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 Serialize for Clock

fn serialize<__S>(&self, __serializer: __S) -> Result<__S::Ok, __S::Error>

where __S: Serializer,

Serialize this value into the given Serde serializer.

impl Value for Clock

const DEFINITION: ValueDef

type References = <(<u64 as Value>::References,) as Filter>::F

const COLUMN_COUNT: usize = _

impl Copy for Clock

impl Eq for Clock

impl StructuralPartialEq for Clock