Struct CanonicalRef 

#[non_exhaustive]
pub struct CanonicalRef {
    pub source_type: SourceType,
    pub source_id: String,
    pub resolver_profile: String,
    pub version: Option<String>,
}

Four-tuple audit identity of a fetched paper (ADR-0021 §1).

Two fetches of the same DOI through different resolvers (e.g. Crossref vs. Unpaywall) produce two distinct CanonicalRef values and therefore two distinct CanonicalRef::digest outputs. This is the resolver-distinction the audit log uses to separate “fetched via Crossref” from “fetched via Unpaywall” without changing the on-disk filename derivation (which remains keyed on Ref via crate::Safekey).

Marked #[non_exhaustive] per docs/PUBLIC_API.md §6 — adding new fields in a future minor bump is non-breaking. External callers construct values via Ref::promote or CanonicalRef::new, not by struct-literal.

Fields (Non-exhaustive)

Non-exhaustive structs could have additional fields added in future. Therefore, non-exhaustive structs cannot be constructed in external crates using the traditional Struct { .. } syntax; cannot be matched against without a wildcard ..; and struct update syntax will not work.

source_type: SourceType

Identifier class (DOI / arXiv / future).

source_id: String

Validated identifier string ("10.1234/foo", "2401.12345").

resolver_profile: String

Resolver key that produced this audit identity. One of the existing resolver keys ("crossref", "unpaywall", "arxiv", "oa-publisher") plus future ones ("openalex", "s2", …).

version: Option<String>

Optional version (arXiv "v2", Crossref-snapshot date). When None, the digest treats this field as the empty byte sequence (ADR-0021 §1 Slice 2 clarification — no sentinel).

Implementations

impl CanonicalRef

pub fn new( source_type: SourceType, source_id: impl Into<String>, resolver_profile: impl Into<String>, version: Option<String>, ) -> Self

Construct a new CanonicalRef from its four fields.

The struct is #[non_exhaustive]; external code MUST use this constructor (or Ref::promote) rather than a struct literal.

pub fn digest(&self) -> [u8; 32]

Compute the canonical-digest per ADR-0021 §1.

SHA256( source_type | 0x00 | source_id | 0x00
      | resolver_profile | 0x00 | version_or_empty )

version_or_empty is the empty byte sequence when Self::version is None (ADR-0021 §1 NORMATIVE clarification — no "null" / "none" / "-" sentinel).

pub fn digest_hex(&self) -> String

Hex-encoded Self::digest — 64 lowercase ASCII hex chars.

Trait Implementations

impl Clone for CanonicalRef

fn clone(&self) -> CanonicalRef

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Debug for CanonicalRef

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

Formats the value using the given formatter.

impl<'de> Deserialize<'de> for CanonicalRef

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

where __D: Deserializer<'de>,

Deserialize this value from the given Serde deserializer.

impl Hash for CanonicalRef

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 PartialEq for CanonicalRef

fn eq(&self, other: &CanonicalRef) -> 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 CanonicalRef

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 CanonicalRef

impl StructuralPartialEq for CanonicalRef