Struct HybridClock 

pub struct HybridClock {
    pub id: String,
    pub physical_ms: u64,
    pub logical: u32,
}

Hybrid Logical Clock for causal + real-time ordering across distributed nodes.

R-01: Combines wall-clock time (physical_ms) with a logical counter. The physical component captures when an event happened in real time. The logical component orders events that happen within the same millisecond.

Based on Kulkarni, Demirbas, Madeppa, Avva & Leone (2014). Used in production by CockroachDB for MVCC timestamps.

Rules:

• On local event: physical = max(old_physical, wall_clock). If physical advanced → logical = 0. Else → logical += 1.
• On merge: physical = max(local, remote, wall_clock). Logical follows the same advancement/increment rule.
• Total order: (physical, logical, id). Higher physical wins. Same physical → higher logical wins. Both equal → lower id wins.

Fields

id: String

Unique identifier of the instance that owns this clock

physical_ms: u64

Physical time in milliseconds since Unix epoch

logical: u32

Logical counter — incremented when physical time doesn’t advance

Implementations

impl HybridClock

pub fn new(id: impl Into<String>) -> Self

Create a new clock with the current wall-clock time.

pub fn with_values( id: impl Into<String>, physical_ms: u64, logical: u32, ) -> Self

Create a clock with explicit values (for tests and deserialization).

pub fn tick(&mut self) -> (u64, u32)

Increment the clock for a local event. Returns (physical_ms, logical) after advancement.

pub fn merge(&mut self, remote: &HybridClock) -> (u64, u32)

Merge with a remote clock. physical = max(local, remote, wall_clock). If physical advanced past both → logical = 0. If tied with one side → logical = max of tied sides + 1.

pub fn cmp_order(&self, other: &HybridClock) -> Ordering

Compare two clocks for total ordering. Higher physical wins. Same physical → higher logical wins. Both equal → lower id wins (deterministic tiebreaker).

pub fn as_tuple(&self) -> (u64, u32)

Compact representation for sorting: (physical_ms, logical).

Trait Implementations

impl Clone for HybridClock

fn clone(&self) -> HybridClock

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Debug for HybridClock

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

Formats the value using the given formatter.

impl<'de> Deserialize<'de> for HybridClock

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

where __D: Deserializer<'de>,

Deserialize this value from the given Serde deserializer.

impl PartialEq for HybridClock

fn eq(&self, other: &HybridClock) -> 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 Serialize for HybridClock

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

where __S: Serializer,

Serialize this value into the given Serde serializer.

impl Eq for HybridClock

impl StructuralPartialEq for HybridClock