Struct Timestamp

pub struct Timestamp(pub i64);

A microsecond-precision UTC timestamp for use in Holochain’s actions.

It is assumed to be untrustworthy: it may contain times offset from the UNIX epoch with the full +/- i64 range. Most of these times are not representable by a chrono::DateTime<Utc> (which limits itself to a +/- i32 offset in days from Jan 1, 0AD and from 1970AD).

Also, most differences between two Timestamps are not representable by either a chrono::Duration (which limits itself to +/- i64 microseconds), nor by core::time::Duration (which limits itself to +’ve u64 seconds). Many constructions of these chrono and core::time types will panic!, so painful measures must be taken to avoid this outcome – it is not acceptable for our core Holochain algorithms to panic when accessing DHT Action information committed by other random Holochain nodes!

Timestamp implements Serialize and Display as rfc3339 time strings (if possible).

Supports +/- chrono::Duration directly. There is no Timestamp::now() method, since this is not supported by WASM; however, holochain_types provides a Timestamp::now() method.

Tuple Fields

0: i64

Microseconds from UNIX Epoch, positive or negative

Implementations

impl Timestamp

pub fn now() -> Timestamp

Returns the current system time as a Timestamp.

This is behind a feature because we need Timestamp to be WASM compatible, and chrono doesn’t have a now() implementation for WASM.

pub fn checked_difference_signed(&self, rhs: &Timestamp) -> Option<TimeDelta>

Compute signed difference between two Timestamp, returning None if overflow occurred, or Some(chrono::Duration). Produces Duration for differences of up to +/- i64::MIN/MAX microseconds.

pub fn checked_add_signed(&self, rhs: &TimeDelta) -> Option<Timestamp>

Add a signed chrono::Duration{ secs: i64, nanos: i32 } to a Timestamp.

pub fn checked_sub_signed(&self, rhs: &TimeDelta) -> Option<Timestamp>

Subtracts a chrono::Duration from a Timestamp

impl Timestamp

pub const ZERO: Timestamp

The Timestamp corresponding to the UNIX epoch

pub const MIN: Timestamp

The smallest possible Timestamp

pub const MAX: Timestamp

The largest possible Timestamp

pub const HOLOCHAIN_EPOCH: Timestamp

Jan 1, 2022, 12:00:00 AM UTC

pub fn max() -> Timestamp

Largest possible Timestamp.

pub fn from_micros(micros: i64) -> Timestamp

Construct from microseconds

pub fn as_micros(&self) -> i64

Access time as microseconds since UNIX epoch

pub fn as_millis(&self) -> i64

Access time as milliseconds since UNIX epoch

pub fn as_seconds_and_nanos(&self) -> (i64, u32)

Access seconds since UNIX epoch plus nanosecond offset

pub fn checked_add(&self, rhs: &Duration) -> Option<Timestamp>

Add unsigned core::time::Duration{ secs: u64, nanos: u32 } to a Timestamp. See: https://doc.rust-lang.org/src/core/time.rs.html#53-56

pub fn checked_sub(&self, rhs: &Duration) -> Option<Timestamp>

Sub unsigned core::time::Duration{ secs: u64, nanos: u32 } from a Timestamp.

pub fn saturating_add(&self, rhs: &Duration) -> Timestamp

Add a duration, clamping to MAX if overflow

pub fn saturating_sub(&self, rhs: &Duration) -> Timestamp

Subtract a duration, clamping to MIN if overflow

pub fn saturating_from_dur(duration: &Duration) -> Timestamp

Create a Timestamp from a core::time::Duration saturating at i64::MAX.

Trait Implementations

impl<D> Add<D> for &Timestamp

where D: Into<Duration>,

type Output = Result<Timestamp, TimestampError>

The resulting type after applying the + operator.

fn add(self, rhs: D) -> <&Timestamp as Add<D>>::Output

Performs the + operation.

impl<D> Add<D> for Timestamp

where D: Into<Duration>,

Timestamp +/- Intocore::time::Duration: Anything that can be converted into a core::time::Duration can be used as an overflow-checked offset (unsigned) for a Timestamp. A core::time::Duration allows only +’ve offsets

type Output = Result<Timestamp, TimestampError>

The resulting type after applying the + operator.

fn add(self, rhs: D) -> <Timestamp as Add<D>>::Output

Performs the + operation.

impl Clone for Timestamp

fn clone(&self) -> Timestamp

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Debug for Timestamp

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

Formats the value using the given formatter.

impl<'de> Deserialize<'de> for Timestamp

fn deserialize<__D>( __deserializer: __D, ) -> Result<Timestamp, <__D as Deserializer<'de>>::Error>

where __D: Deserializer<'de>,

Deserialize this value from the given Serde deserializer.

impl Display for Timestamp

Display as RFC3339 Date+Time for sane value ranges (0000-9999AD). Beyond that, format as (seconds, nanoseconds) tuple (output and parsing of large +/- years is unreliable).

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

Formats the value using the given formatter.

impl From<&DateTime<Utc>> for Timestamp

fn from(t: &DateTime<Utc>) -> Timestamp

Converts to this type from the input type.

impl From<&HumanTimestamp> for Timestamp

fn from(h: &HumanTimestamp) -> Timestamp

Converts to this type from the input type.

impl From<DateTime<Utc>> for Timestamp

fn from(t: DateTime<Utc>) -> Timestamp

Converts to this type from the input type.

impl From<HumanTimestamp> for Timestamp

fn from(h: HumanTimestamp) -> Timestamp

Converts to this type from the input type.

impl From<Timestamp> for HumanTimestamp

fn from(t: Timestamp) -> HumanTimestamp

Converts to this type from the input type.

impl FromStr for Timestamp

type Err = TimestampError

The associated error which can be returned from parsing.

fn from_str(t: &str) -> Result<Timestamp, <Timestamp as FromStr>::Err>

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

impl Hash for Timestamp

fn hash<__H>(&self, state: &mut __H)

where __H: Hasher,

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 Timestamp

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

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

fn partial_cmp(&self, other: &Timestamp) -> 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 Timestamp

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

where __S: Serializer,

Serialize this value into the given Serde serializer.

impl<D> Sub<D> for &Timestamp

where D: Into<Duration>,

type Output = Result<Timestamp, TimestampError>

The resulting type after applying the - operator.

fn sub(self, rhs: D) -> <&Timestamp as Sub<D>>::Output

Performs the - operation.

impl<D> Sub<D> for Timestamp

where D: Into<Duration>,

Timestamp - core::time::Duration.

type Output = Result<Timestamp, TimestampError>

The resulting type after applying the - operator.

fn sub(self, rhs: D) -> <Timestamp as Sub<D>>::Output

Performs the - operation.

impl Sub for Timestamp

Distance between two Timestamps as a chrono::Duration (subject to overflow). A Timestamp represents a signed distance from the UNIX Epoch (1970-01-01T00:00:00Z). A chrono::Duration is limited to +/- i64::MIN/MAX microseconds.

type Output = Result<TimeDelta, TimestampError>

The resulting type after applying the - operator.

fn sub(self, rhs: Timestamp) -> <Timestamp as Sub>::Output

Performs the - operation.

impl TryFrom<&String> for Timestamp

type Error = TimestampError

The type returned in the event of a conversion error.

fn try_from( t: &String, ) -> Result<Timestamp, <Timestamp as TryFrom<&String>>::Error>

Performs the conversion.

impl TryFrom<&Timestamp> for DateTime<Utc>

type Error = TimestampError

The type returned in the event of a conversion error.

fn try_from( t: &Timestamp, ) -> Result<DateTime<Utc>, <DateTime<Utc> as TryFrom<&Timestamp>>::Error>

Performs the conversion.

impl TryFrom<&str> for Timestamp

type Error = TimestampError

The type returned in the event of a conversion error.

fn try_from(t: &str) -> Result<Timestamp, <Timestamp as TryFrom<&str>>::Error>

Performs the conversion.

impl TryFrom<Duration> for Timestamp

type Error = TimestampError

The type returned in the event of a conversion error.

fn try_from( value: Duration, ) -> Result<Timestamp, <Timestamp as TryFrom<Duration>>::Error>

Performs the conversion.

impl TryFrom<String> for Timestamp

type Error = TimestampError

The type returned in the event of a conversion error.

fn try_from( t: String, ) -> Result<Timestamp, <Timestamp as TryFrom<String>>::Error>

Performs the conversion.

impl TryFrom<Timestamp> for DateTime<Utc>

type Error = TimestampError

The type returned in the event of a conversion error.

fn try_from( t: Timestamp, ) -> Result<DateTime<Utc>, <DateTime<Utc> as TryFrom<Timestamp>>::Error>

Performs the conversion.

impl Copy for Timestamp

impl Eq for Timestamp

impl StructuralPartialEq for Timestamp