Struct uhlc::HLC

pub struct HLC { /* private fields */ }

An Hybric Logical Clock generating Timestamps

Implementations

impl HLC

pub fn new_timestamp(&self) -> Timestamp

Generate a new Timestamp.

This timestamp is unique in the system and is always greater than the latest timestamp generated by the HLC and than the latest incoming timestamp that was used to update this HLC (using HLC::update_with_timestamp()).

Examples

use uhlc::HLC;

let hlc = HLC::default();
let ts1 =  hlc.new_timestamp();
let ts2 =  hlc.new_timestamp();
assert!(ts2 > ts1);

pub fn get_id(&self) -> &ID

Returns the HLC ID.

This ID is the specific identifier for this HLC instance.

pub fn get_delta(&self) -> &NTP64

Returns the HLC delta as NTP64.

The maximum delta accepted by an HLC when updating it’s logical clock calling HLC::update_with_timestamp().

pub fn update_with_timestamp(&self, timestamp: &Timestamp) -> Result<(), String>

Update this HLC with a Timestamp.

Typically, this timestamp should have been generated by another HLC. If the timestamp exceeds the current time of this HLC by more than the configured maximum delta (see HLCBuilder::with_max_delta()) an Err is returned.

Examples

use uhlc::HLC;

let hlc1 = HLC::default();

// update the HLC with a timestamp incoming from another HLC
// (typically remote, but not in this example...)
let hlc2 = HLC::default();
let other_ts = hlc2.new_timestamp();
if ! hlc1.update_with_timestamp(&other_ts).is_ok() {
    println!(r#"The incoming timestamp would make this HLC
             to drift too much. You should refuse it!"#);
}

let ts = hlc1.new_timestamp();
assert!(ts > other_ts);

Trait Implementations

impl Default for HLC

fn default() -> Self

Create a new HLC with a generated UUID and using system_time_clock() as physical clock. This is equivalent to HLCBuilder::default().build()