Struct Region 

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

A region code that has already passed is_valid_region, stored in the normalized (uppercase, untrimmed-of-nothing) form.

The point of the type is that the normalization is done ONCE, at the parse boundary, instead of at every comparison site. A raw String carrying “an ISO 3166-1 alpha-2 code” by doc comment alone leaves each consumer to re-derive that: decdn-client’s candidate ranking was trimming and case-folding on every comparison because one side came normalized from config and the other raw from the chain, and structural Eq on the containing type was wrong as a result — " us " and "US" compared unequal (#1348).

Two bytes, Copy, and bounded by construction — which also caps what an operator-submitted regionHint can cost on a deserialize path, where the on-chain source permits any string up to 16 bytes.

Serializes as the plain 2-character string, so persisted forms stay human-readable and a Region field is wire-compatible with the String it replaces in the serialize direction.

Implementations

impl Region

pub fn parse(raw: &str) -> Option<Self>

Parse raw into a Region, or None if it is not an accepted code.

Surrounding whitespace is trimmed and the code is uppercased before the allowlist check, because both sources this reads from are operator-submitted: a config file and an on-chain regionHint the contract does not constrain beyond a length cap.

None rather than an error type: for the advisory uses (locality-aware node ranking) an unrecognized code means “no locality information”, not “reject this node”. Callers that need it to be fatal — config resolution — say so at their own layer.

pub fn as_str(&self) -> &str

The normalized code.

Trait Implementations

impl AsRef<str> for Region

fn as_ref(&self) -> &str

Converts this type into a shared reference of the (usually inferred) input type.

impl Clone for Region

fn clone(&self) -> Self

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Copy for Region

impl Debug for Region

Hand-written so the code renders as text, not as its bytes. A derived Debug over the [u8; 2] payload prints Region([85, 83]), and this type IS formatted with {:?} on an operator-facing path — decdn get’s “discovered node … (region {:?})” line — as well as into tracing fields and anyhow context. The derive turned that line’s output from "US" into Some(Region([85, 83])).

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

Formats the value using the given formatter.

impl<'de> Deserialize<'de> for Region

Deserializing re-runs the allowlist, so the invariant holds for values that arrive from a file or the wire rather than through Region::parse — a derived impl over the byte array would let any two bytes in.

Deserializes an owned String rather than a borrowed &str so this works against non-borrowing formats too (a serde_json reader, postcard over a streamed buffer); the allocation is bounded by the caller’s own input and dropped immediately.

fn deserialize<D: Deserializer<'de>>(d: D) -> Result<Self, D::Error>

Deserialize this value from the given Serde deserializer.

impl Display for Region

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

Formats the value using the given formatter.

impl Eq for Region

impl FromStr for Region

Rejects with the same allowlist Region::parse applies. The error carries no input — a region code reaches log fields and metric labels, and this type exists partly to keep unvalidated bytes out of them. The Deserialize impl below upholds the same property, so it holds for every fallible construction path, not just this one.

type Err = InvalidRegion

The associated error which can be returned from parsing.

fn from_str(s: &str) -> Result<Self, Self::Err>

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

impl Hash for Region

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 Region

fn cmp(&self, other: &Self) -> 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.

fn clamp_to<R>(self, range: R) -> Self

where Self: Sized, R: ClampBounds<Self>,

🔬This is a nightly-only experimental API. (clamp_to)

Restrict a value to a certain range.

impl PartialEq for Region

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

Equality operator ==.

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

Inequality operator !=.

impl PartialOrd for Region

fn partial_cmp(&self, other: &Self) -> 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 Region

fn serialize<S: Serializer>(&self, s: S) -> Result<S::Ok, S::Error>

Serialize this value into the given Serde serializer.

impl StructuralPartialEq for Region