Struct PageToken 

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

The engine’s own resume token: one plugin cursor per source stream, opaque to the caller exactly as a plugin’s cursor is opaque to the engine.

Rendered as lower-case hex, which is not obfuscation — the inside is not a secret — but the one property a token a person copies off a terminal has to have: it survives a shell. The document underneath holds a plugin’s own cursor, and a cursor may hold anything at all, so a token spelled as the raw JSON would carry quotes, braces and spaces straight into the next command line. Hex has no character a shell reads.

What a token is and is not checked for

Both ways in go through parse — including deserialising one — and what that establishes is structural: the string is hex, the bytes are this engine’s own resume document, and every state in it is well formed. It does not, and cannot, establish that this engine is the one that wrote it. A token is not a credential and carries nothing secret; forging one buys a caller nothing they could not have asked for outright, since every cursor inside is handed straight back to the source that issued it and is validated there.

What a forged token could do is name a stream this configuration has no source for, or resume further into a page than the engine ever pages. Both are refused where the token meets the query it is resuming, by Engine — see EngineError::Token — because only the engine knows which sources are configured and what page ceiling each declares.

Implementations

impl PageToken

pub fn parse(raw: impl Into<String>) -> Result<Self, SourceError>

Accept a token from a caller — a --page argument, or a deserialised response — refusing anything that is not this engine’s own resume document.

Structural only, deliberately: see the type’s own note for what this establishes and what Engine checks instead.

Errors

Returns SourceError::Malformed when raw is not hex, is not this engine’s document, or holds a state that is not well formed.

pub fn as_str(&self) -> &str

Borrow the underlying token.

Trait Implementations

impl Clone for PageToken

fn clone(&self) -> PageToken

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Debug for PageToken

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

Formats the value using the given formatter.

impl<'de> Deserialize<'de> for PageToken

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

where __D: Deserializer<'de>,

Deserialize this value from the given Serde deserializer.

impl Display for PageToken

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

The opaque string a caller passes back as --page.

impl Eq for PageToken

impl From<PageToken> for String

A token is its string, so serialising one is that string and nothing else — the checking all happens on the way in, where a caller’s input is.

fn from(value: PageToken) -> Self

Converts to this type from the input type.

impl Hash for PageToken

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 JsonSchema for PageToken

fn schema_name() -> Cow<'static, str>

The name of the generated JSON Schema.

fn schema_id() -> Cow<'static, str>

Returns a string that uniquely identifies the schema produced by this type.

fn json_schema(generator: &mut SchemaGenerator) -> Schema

Generates a JSON Schema for this type.

fn inline_schema() -> bool

Whether JSON Schemas generated for this type should be included directly in parent schemas, rather than being re-used where possible using the $ref keyword.

impl PartialEq for PageToken

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

Equality operator ==.

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

Inequality operator !=.

impl Serialize for PageToken

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 PageToken

impl TryFrom<String> for PageToken

Deserialising a token goes through PageToken::parse, so a response carrying a token this engine never issued is refused where it is read.

type Error = SourceError

The type returned in the event of a conversion error.

fn try_from(value: String) -> Result<Self, Self::Error>

Performs the conversion.