Struct activitypub_federation::fetch::object_id::ObjectId

pub struct ObjectId<Kind>(/* private fields */)
where
    Kind: Object,
    for<'de2> <Kind as Object>::Kind: Deserialize<'de2>;

Typed wrapper for Activitypub Object ID which helps with dereferencing and caching.

It provides convenient methods for fetching the object from remote server or local database. Objects are automatically cached locally, so they don’t have to be fetched every time. Much of the crate functionality relies on this wrapper.

Every time an object is fetched via HTTP, [RequestData.request_counter] is incremented by one. If the value exceeds [FederationSettings.http_fetch_limit], the request is aborted with Error::RequestLimit. This prevents denial of service attacks where an attack triggers infinite, recursive fetching of data.

let config = FederationConfig::builder()
    .domain("example.com")
    .app_data(db_connection)
    .build().await?;
let request_data = config.to_request_data();
let object_id = ObjectId::<DbUser>::parse("https://lemmy.ml/u/nutomic")?;
// Attempt to fetch object from local database or fall back to remote server
let user = object_id.dereference(&request_data).await;
assert!(user.is_ok());
// Now you can also read the object from local database without network requests
let user = object_id.dereference_local(&request_data).await;
assert!(user.is_ok());

Implementations

impl<Kind> ObjectId<Kind>

where Kind: Object + Send + Debug + 'static, for<'de2> <Kind as Object>::Kind: Deserialize<'de2>,

pub fn parse(url: &str) -> Result<Self, ParseError>

Construct a new objectid instance

pub fn inner(&self) -> &Url

Returns a reference to the wrapped URL value

pub fn into_inner(self) -> Url

Returns the wrapped URL value

pub async fn dereference( &self, data: &Data<<Kind as Object>::DataType> ) -> Result<Kind, <Kind as Object>::Error>

where <Kind as Object>::Error: From<Error>,

Fetches an activitypub object, either from local database (if possible), or over http.

pub async fn dereference_forced( &self, data: &Data<<Kind as Object>::DataType> ) -> Result<Kind, <Kind as Object>::Error>

where <Kind as Object>::Error: From<Error>,

If this is a remote object, fetch it from origin instance unconditionally to get the latest version, regardless of refresh interval.

pub async fn dereference_local( &self, data: &Data<<Kind as Object>::DataType> ) -> Result<Kind, <Kind as Object>::Error>

where <Kind as Object>::Error: From<Error>,

Fetch an object from the local db. Instead of falling back to http, this throws an error if the object is not found in the database.

pub fn is_local(&self, data: &Data<<Kind as Object>::DataType>) -> bool

Returns true if the object’s domain matches the one defined in [[FederationConfig.domain]].

Trait Implementations

impl<Kind> Clone for ObjectId<Kind>

where Kind: Object, for<'de2> <Kind as Object>::Kind: Deserialize<'de2>,

Need to implement clone manually, to avoid requiring Kind to be Clone

fn clone(&self) -> Self

Returns a copy of the value.

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

Performs copy-assignment from source.

impl<Kind> Debug for ObjectId<Kind>

where Kind: Object, for<'de2> <Kind as Object>::Kind: Deserialize<'de2>,

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

Formats the value using the given formatter.

impl<'de, Kind> Deserialize<'de> for ObjectId<Kind>

where Kind: Object, for<'de2> <Kind as Object>::Kind: Deserialize<'de2>,

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

where __D: Deserializer<'de>,

Deserialize this value from the given Serde deserializer.

impl<Kind> Display for ObjectId<Kind>

where Kind: Object, for<'de2> <Kind as Object>::Kind: Deserialize<'de2>,

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

Formats the value using the given formatter.

impl<Kind> From<ObjectId<Kind>> for Url

where Kind: Object, for<'de2> <Kind as Object>::Kind: Deserialize<'de2>,

fn from(id: ObjectId<Kind>) -> Self

Converts to this type from the input type.

impl<Kind> From<Url> for ObjectId<Kind>

where Kind: Object + Send + 'static, for<'de2> <Kind as Object>::Kind: Deserialize<'de2>,

fn from(url: Url) -> Self

Converts to this type from the input type.

impl<T> FromStr for ObjectId<T>

where T: Object + Send + Debug + 'static, for<'de2> <T as Object>::Kind: Deserialize<'de2>,

type Err = ParseError

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<Kind> PartialEq for ObjectId<Kind>

where Kind: Object, for<'de2> <Kind as Object>::Kind: Deserialize<'de2>,

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

This method tests for self and other values to be equal, and is used by ==.

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

This method tests for !=. The default implementation is almost always sufficient, and should not be overridden without very good reason.

impl<Kind> Serialize for ObjectId<Kind>

where Kind: Object, for<'de2> <Kind as Object>::Kind: Deserialize<'de2>,

fn serialize<__S>(&self, __serializer: __S) -> Result<__S::Ok, __S::Error>

where __S: Serializer,

Serialize this value into the given Serde serializer.