Struct ConnectionId 

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

Which connection an event is about.

Process-wide and monotonic, so a Closed can be matched to the Connected that opened the same socket — which is the only reason it exists. Without it a close event says “a connection ended” and a caller holding several has no way to learn which.

ConnectionId::UNWATCHED is what an event carries when there was no id to mint for it — because nobody is watching, or because there is no connection. See that constant.

Implementations

impl ConnectionId

pub const UNWATCHED: ConnectionId

The id an event carries when no id was minted for it.

Two things produce it, and a reader can only ever meet the second:

• Nobody is watching. Hooks::WATCHING is false, so a transport that owns connections leaves the counter alone rather than paying an atomic per connection for nobody. That const’s own question is whether anything reads these events, so a build producing this value for this reason has, by its own declaration, no reader for the event carrying it.
• There is no connection to name. hclient-fetch and hclient-wasi own none — the Fetch Standard exposes no connection object, and there is no connection resource anywhere in wasi:http@0.3.0 — so their one event, Head, carries this.

To a hook that reads events it therefore means exactly one thing, this event names no connection, and that is something a portable hook can act on rather than a gap it has to guess at: it is the only id ConnectionId::next never returns, so looking it up in a table of live connections cannot hit one.

The name is a producer, not the meaning

There is deliberately no second constant meaning this event names no connection, distinct from nobody is watching: the two would differ only in a build whose events nobody reads, so no caller decision turns on the difference — this workspace’s test for whether a distinction earns a name of its own. UNWATCHED names one of the two producers, and any spelling would name one or the other; read it as the ambient this event names no connection.

pub fn next() -> Self

The next id. Relaxed: this counter orders nothing, it only has to hand out distinct numbers.

It starts at 1, and that is load bearing rather than tidy: it is what makes UNWATCHED mean this event names no connection rather than this event names connection zero. crates/hclient-core/tests/shape.rs pins it.

pub fn get(self) -> u64

The number itself, for a log line.

Trait Implementations

impl Clone for ConnectionId

fn clone(&self) -> ConnectionId

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Copy for ConnectionId

impl Debug for ConnectionId

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

Formats the value using the given formatter.

impl Display for ConnectionId

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

Formats the value using the given formatter.

impl Eq for ConnectionId

impl Hash for ConnectionId

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

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 ConnectionId

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

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

Equality operator ==.

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

Inequality operator !=.

impl PartialOrd for ConnectionId

fn partial_cmp(&self, other: &ConnectionId) -> 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 StructuralPartialEq for ConnectionId