Struct RequestSequencer 

pub struct RequestSequencer { /* private fields */ }

Available on crate feature core only.

Monotonic request id generator scoped to a single resource.

Each RequestSequencer produces a stream of RequestId values that are unique within the resource’s lifetime. The sequence counter increments from 1; when it would overflow u64::MAX, the scope advances to avoid producing duplicate ids.

Scope advancement

When the sequence counter reaches u64::MAX, next_request calls advance_scope, which increments scope_id and resets next_request_id to 1. This guarantees uniqueness across the entire lifetime of the sequencer.

Theoretical wrap-around

If scope_id itself overflows u64::MAX, it wraps back to 1 and next_request_id is reset to 1. This means a new RequestId(1, 1) could theoretically collide with a very old RequestId(1, 1) still held by a long-running future. In practice, reaching u64::MAX requests per scope is essentially impossible, so this is not a practical concern. For extremely long-lived processes (e.g., a server running for decades), the collision risk remains theoretical but documented here for completeness.

Implementations

impl RequestSequencer

pub fn new() -> Self

Create a new sequencer starting at scope 1, sequence 1.

pub fn next_request(&mut self) -> RequestId

Generate the next request id.

The sequence counter increments with each call. When it reaches u64::MAX, the scope advances automatically before the next call produces a duplicate.

pub fn advance_scope(&mut self)

Advance to a new scope when the sequence overflows.

Increments scope_id via checked addition. If scope_id itself overflows (astronomically unlikely), it wraps to 1 and the sequence resets, as documented on the struct.

pub fn is_current_scope(&self, request_id: RequestId) -> bool

Whether the given request id belongs to the current scope.

Trait Implementations

impl Clone for RequestSequencer

fn clone(&self) -> RequestSequencer

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Debug for RequestSequencer

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

Formats the value using the given formatter.

impl Default for RequestSequencer

fn default() -> Self

Returns the “default value” for a type.

impl<'de> Deserialize<'de> for RequestSequencer

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

where __D: Deserializer<'de>,

Deserialize this value from the given Serde deserializer.

impl Eq for RequestSequencer

impl PartialEq for RequestSequencer

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

Equality operator ==.

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

Inequality operator !=.

impl Serialize for RequestSequencer

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

where __S: Serializer,

Serialize this value into the given Serde serializer.

impl StructuralPartialEq for RequestSequencer