Struct Answer 

#[non_exhaustive]
pub struct Answer {

    pub outcome: AnswerOutcome,
    pub receipt: Option<Receipt>,
    pub trust: Option<TrustLabel>,
    pub age_seconds: Option<u64>,
    pub superseded_by: Option<String>,
    pub reason: Option<String>,
    pub quote: Option<Quote>,
    pub retry_after_seconds: Option<u64>,
    pub error: Option<ErrorCode>,
    pub fault: Option<Fault>,
    pub detail: Option<ForeignDetail>,
    pub fn_hash: Option<String>,
    pub pending: Option<Pending>,
    pub page: Option<SlicePage>,
    /* private fields */
}

An envelope of spec-0.4.2 (5.5), checked or to be written: every outcome, trust label and member, with a slice page (5.6) for the ok answer of the slice endpoint; since 0.3.7 (spec-0.4.3) also E_FOREIGN_UNAVAILABLE with its detail (Answer::foreign_unavailable). As a builder: one constructor per outcome, with_* for the optional members, Answer::to_json for the body and Answer::status for the HTTP status; check the body back with check_answer (or check_slice_answer) to hold it to every rule.

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.

outcome: AnswerOutcome

The outcome.

receipt: Option<Receipt>

The receipt (ok, stale; not a slice page’s).

trust: Option<TrustLabel>

The trust label (ok, stale).

age_seconds: Option<u64>

Seconds since the mesh last confirmed the receipt (stale).

superseded_by: Option<String>

Hash of a newer receipt for the same cell.

reason: Option<String>

Why the receipt was superseded.

quote: Option<Quote>

The quote (payment_required).

retry_after_seconds: Option<u64>

Seconds to wait (rate_limited).

error: Option<ErrorCode>

The code (bad_request, error, and E_NAME_UNBOUND in not_covered).

fault: Option<Fault>

The formula evaluation fault (not_covered).

detail: Option<ForeignDetail>

What failed in reaching a foreign mesh: with E_FOREIGN_UNAVAILABLE only, and always with it (error, 502; spec-0.4.3).

fn_hash: Option<String>

The function the answer is of: a pin’s echo, or the hash the name resolved to.

pending: Option<Pending>

The pending envelope’s members.

page: Option<SlicePage>

The slice page (ok at the slice endpoint).

Implementations

impl Answer

pub fn ok(receipt: Receipt, trust: TrustLabel) -> Answer

ok (200): receipt, served with trust.

pub fn stale(receipt: Receipt, trust: TrustLabel, age_seconds: u64) -> Answer

stale (200): the last receipt known, last confirmed age_seconds ago.

pub fn not_covered() -> Answer

not_covered (404).

pub fn unlicensed() -> Answer

unlicensed (403).

pub fn payment_required(quote: Quote) -> Answer

payment_required (402) with its quote.

pub fn rate_limited(retry_after_seconds: u64) -> Answer

rate_limited (429): retry after this many seconds.

pub fn bad_request(code: ErrorCode) -> Result<Answer>

bad_request (400) with a code it can carry (5.5: a parse code, E_CANON_HEX, E_SLICE_AT_CELL, or E_JOB_UNKNOWN at a job URL); E_ENVELOPE otherwise.

pub fn error(code: ErrorCode) -> Result<Answer>

error (500; see Answer::with_status) with a code it can carry (any of 10.2 but E_ENVELOPE, E_JOB_UNKNOWN, E_SLICE_AT_CELL and E_NAME_UNBOUND). E_FOREIGN_UNAVAILABLE needs a detail and HTTP 502: build it with Answer::foreign_unavailable (here it is E_ENVELOPE).

pub fn foreign_unavailable(detail: ForeignDetail) -> Answer

error with E_FOREIGN_UNAVAILABLE and detail (5.5, spec-0.4.3), HTTP 502: the cell belongs to another mesh, which could not be reached. Answered by a resolver, or by a mesh fetching across meshes, when no HTTP response came back from the foreign host. Its status must stay 502 (Answer::with_status to another fails check_answer).

pub fn pending(p: Pending) -> Answer

pending (202).

pub fn page(page: SlicePage) -> Answer

The ok answer of the slice endpoint (5.6).

pub fn with_fn_hash(self, fn_hash: &str) -> Result<Answer>

With the fn_hash echo (64 lowercase hex digits; not on pending); E_ENVELOPE otherwise.

pub fn with_fault(self, fault: Fault) -> Answer

A not_covered answer with a formula evaluation fault. Not checked here: a fault with error, or on another outcome, fails check_answer.

pub fn with_error(self, code: ErrorCode) -> Result<Answer>

A not_covered answer with error (only E_NAME_UNBOUND, and not with a fault); E_ENVELOPE otherwise.

pub fn with_superseded( self, superseded_by: &str, reason: Option<&str>, ) -> Answer

An ok or stale answer pointing to a newer receipt, with an optional reason.

pub fn with_status(self, status: u16) -> Answer

The HTTP status to send, for an error within 500-599 (other outcomes have one status).

pub fn status(&self) -> u16

The HTTP status: the outcome’s, or for a checked answer the one received.

pub fn to_value(&self) -> Value

The JSON form of the envelope.

pub fn to_json(&self) -> Vec<u8>

The envelope’s body: its canonical JSON text (JCS).

Trait Implementations

impl Clone for Answer

fn clone(&self) -> Self

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Debug for Answer

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

Formats the value using the given formatter.

impl Eq for Answer

impl PartialEq for Answer

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

Equality operator ==.

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

Inequality operator !=.

impl StructuralPartialEq for Answer