ruwuma/src/lib.rs
2019-10-19 02:31:54 +02:00

986 lines
33 KiB
Rust

//! Crate `ruma_events` contains serializable types for the events in the [Matrix](https://matrix.org)
//! specification that can be shared by client and server code.
//!
//! All data exchanged over Matrix is expressed as an event.
//! Different event types represent different actions, such as joining a room or sending a message.
//! Events are stored and transmitted as simple JSON structures.
//! While anyone can create a new event type for their own purposes, the Matrix specification
//! defines a number of event types which are considered core to the protocol, and Matrix clients
//! and servers must understand their semantics.
//! ruma-events contains Rust types for each of the event types defined by the specification and
//! facilities for extending the event system for custom event types.
//!
//! # Event types
//!
//! ruma-events includes a Rust enum called `EventType`, which provides a simple enumeration of
//! all the event types defined by the Matrix specification. Matrix event types are serialized to
//! JSON strings in [reverse domain name
//! notation](https://en.wikipedia.org/wiki/Reverse_domain_name_notation), although the core event
//! types all use the special "m" TLD, e.g. *m.room.message*.
//! `EventType` also includes a variant called `Custom`, which is a catch-all that stores a string
//! containing the name of any event type that isn't part of the specification.
//! `EventType` is used throughout ruma-events to identify and differentiate between events of
//! different types.
//!
//! # Event kinds
//!
//! Matrix defines three "kinds" of events:
//!
//! 1. **Events**, which are arbitrary JSON structures that have two required keys:
//! * `type`, which specifies the event's type
//! * `content`, which is a JSON object containing the "payload" of the event
//! 2. **Room events**, which are a superset of events and represent actions that occurred within
//! the context of a Matrix room.
//! They have at least the following additional keys:
//! * `event_id`, which is a unique identifier for the event
//! * `room_id`, which is a unique identifier for the room in which the event occurred
//! * `sender`, which is the unique identifier of the Matrix user who created the event
//! * Optionally, `unsigned`, which is a JSON object containing arbitrary additional metadata
//! that is not digitally signed by Matrix homeservers.
//! 3. **State events**, which are a superset of room events and represent persistent state
//! specific to a room, such as the room's member list or topic.
//! Within a single room, state events of the same type and with the same "state key" will
//! effectively "replace" the previous one, updating the room's state.
//! They have at least the following additional keys:
//! * `state_key`, a string which serves as a sort of "sub-type."
//! The state key allows a room to persist multiple state events of the same type.
//! You can think of a room's state events as being a `HashMap` where the keys are the tuple
//! `(event_type, state_key)`.
//! * Optionally, `prev_content`, a JSON object containing the `content` object from the
//! previous event of the given `(event_type, state_key)` tuple in the given room.
//!
//! ruma-events represents these three event kinds as traits, allowing any Rust type to serve as a
//! Matrix event so long as it upholds the contract expected of its kind.
//!
//! # Core event types
//!
//! ruma-events includes Rust types for every one of the event types in the Matrix specification.
//! To better organize the crate, these types live in separate modules with a hierarchy that
//! matches the reverse domain name notation of the event type.
//! For example, the *m.room.message* event lives at `ruma_events::room::message::MessageEvent`.
//! Each type's module also contains a Rust type for that event type's `content` field, and any
//! other supporting types required by the event's other fields.
//!
//! # Custom event types
//!
//! Although any Rust type that implements `Event`, `RoomEvent`, or `StateEvent` can serve as a
//! Matrix event type, ruma-events also includes a few convenience types for representing events
//! that are not covered by the spec and not otherwise known by the application.
//! `CustomEvent`, `CustomRoomEvent`, and `CustomStateEvent` are simple implementations of their
//! respective event traits whose `content` field is simply a `serde_json::Value` value, which
//! represents arbitrary JSON.
//!
//! # Serialization and deserialization
//!
//! All concrete event types in ruma-events can be serialized via the `Serialize` trait from
//! [serde](https://serde.rs/) and can be deserialized from a `&str` of JSON data via the `FromStr`
//! trait from the standard library. (`TryFrom<&str>` is also implemented and can be used in place
//! of `FromStr` if preferred.) Supporting types for each event generally implement serde's
//! `Deserialize` trait directly. In order to handle incoming data that may not conform to
//! ruma-events's strict definitions of event structures, deserializing from JSON will return an
//! `InvalidEvent` on error. This error covers both invalid JSON data as well as valid JSON that
//! doesn't match the structure expected by ruma-events's event types. In the latter case, the error
//! exposes the deserialized `serde_json::Value` so that developers can still work with the received
//! event data. This also makes it possible to deserialize a collection of events without the entire
//! collection failing to deserialize due to a single invalid event. The "content" type for each
//! event also implements `Serialize` and either `FromStr` (for dedicated content types) or
//! `Deserialize` (when the content is a type alias), allowing content to be converted to and from
//! JSON indepedently of the surrounding event structure, if needed.
//!
//! # Collections
//!
//! With the trait-based approach to events, it's easy to write generic collection types like
//! `Vec<Box<R: RoomEvent>>`.
//! However, there are APIs in the Matrix specification that involve heterogeneous collections of
//! events, i.e. a list of events of different event types.
//! Because Rust does not have a facility for arrays, vectors, or slices containing multiple
//! concrete types, ruma-events provides special collection types for this purpose.
//! The collection types are enums which effectively "wrap" each possible event type of a
//! particular event "kind."
//!
//! Because of the hierarchical nature of event kinds in Matrix, these collection types are divied
//! into two modules, `ruma_events::collections::all` and `ruma_events::collections::only`.
//! The "all" versions include every event type that implements the relevant event trait as well as
//! more specific event traits.
//! The "only" versions include only the event types that implement "at most" the relevant event
//! trait.
//!
//! For example, the `ruma_events::collections::all::Event` enum includes *m.room.message*, because
//! that event type is both an event and a room event.
//! However, the `ruma_events::collections::only::Event` enum does *not* include *m.room.message*,
//! because *m.room.message* implements a *more specific* event trait than `Event`.
#![deny(missing_debug_implementations)]
#![deny(missing_docs)]
#![deny(warnings)]
use std::{
convert::Infallible,
error::Error,
fmt::{Debug, Display, Error as FmtError, Formatter, Result as FmtResult},
};
use js_int::UInt;
use ruma_identifiers::{EventId, RoomId, UserId};
use serde::{
de::{DeserializeOwned, Error as SerdeError, IntoDeserializer, MapAccess, Visitor},
ser::SerializeMap,
Deserialize, Deserializer, Serialize, Serializer,
};
use serde_json::Value;
pub use custom::CustomEvent;
pub use custom_room::CustomRoomEvent;
pub use custom_state::CustomStateEvent;
#[macro_use]
mod macros;
mod util;
pub mod call;
/// Enums for heterogeneous collections of events.
pub mod collections {
pub mod all;
pub mod only;
mod raw {
pub mod all;
pub mod only;
}
}
pub mod direct;
pub mod dummy;
pub mod forwarded_room_key;
pub mod fully_read;
pub mod ignored_user_list;
pub mod key;
pub mod presence;
pub mod push_rules;
pub mod receipt;
pub mod room;
pub mod room_key;
pub mod room_key_request;
pub mod sticker;
pub mod stripped;
pub mod tag;
pub mod typing;
/// An event that is malformed or otherwise invalid.
///
/// When attempting to create an event from a string of JSON data, an error in the input data may
/// cause deserialization to fail, or the JSON structure may not corresponded to ruma-events's
/// strict definition of the event's schema. If deserialization completely fails, this type will
/// provide a message with details about the deserialization error. If deserialization succeeds but
/// the event is otherwise invalid, a similar message will be provided, as well as a
/// `serde_json::Value` containing the raw JSON data as it was deserialized.
#[derive(Clone, Debug)]
pub struct InvalidEvent<T>(InnerInvalidEvent<T>);
impl<T> InvalidEvent<T> {
/// A message describing why the event is invalid.
pub fn message(&self) -> String {
match self.0 {
InnerInvalidEvent::Deserialization { ref error, .. } => error.to_string(),
InnerInvalidEvent::Validation { ref message, .. } => message.to_string(),
}
}
/// The raw event data, if deserialization succeeded but validation failed.
pub fn raw_data(&self) -> Option<&T> {
match self.0 {
InnerInvalidEvent::Validation { ref raw_data, .. } => Some(raw_data),
_ => None,
}
}
/// The `serde_json::Value` representation of the invalid event, if deserialization failed.
pub fn json(&self) -> Option<&Value> {
match self.0 {
InnerInvalidEvent::Deserialization { ref json, .. } => Some(json),
_ => None,
}
}
}
impl<T> Display for InvalidEvent<T> {
fn fmt(&self, f: &mut Formatter) -> FmtResult {
write!(f, "{}", self.message())
}
}
impl<T: Debug> Error for InvalidEvent<T> {}
/// An event that is malformed or otherwise invalid.
#[derive(Clone, Debug)]
enum InnerInvalidEvent<T> {
/// An event that failed to deserialize from JSON.
Deserialization {
/// The raw `serde_json::Value` representation of the invalid event.
json: Value,
/// The deserialization error returned by serde.
error: String,
},
/// An event that deserialized but failed validation.
Validation {
/// The event data that failed validation.
raw_data: T,
/// A message describing why the event was invalid.
message: String,
},
}
/// An error returned when attempting to create an event with data that would make it invalid.
///
/// This type is similar to `InvalidEvent`, but used during the construction of a new event, as
/// opposed to deserialization of an existing event from JSON.
#[derive(Clone, Debug, PartialEq)]
pub struct InvalidInput(String);
impl Display for InvalidInput {
fn fmt(&self, f: &mut Formatter) -> FmtResult {
write!(f, "{}", self.0)
}
}
impl Error for InvalidInput {}
/// See `TryFromRaw`. This trait is merely a convenience that can be implemented instead of
/// `TryFromRaw` to get a `TryFromRaw` implementation with slightly less code if the conversion
/// can't fail, that is, the raw type and `Self` are identical in definition.
pub trait FromRaw: Sized {
/// The raw type.
type Raw: DeserializeOwned;
/// Converts the raw type to `Self`.
fn from_raw(_: Self::Raw) -> Self;
}
/// Types corresponding to some item in the matrix spec. Types that implement this trait need to
/// have a corresponding 'raw' type, a potentially invalid representation that can be converted to
/// `Self`.
pub trait TryFromRaw: Sized {
/// The raw type.
type Raw: DeserializeOwned;
/// The error type returned if conversion fails.
type Err: Display;
/// Tries to convert the raw type to `Self`.
fn try_from_raw(_: Self::Raw) -> Result<Self, (Self::Err, Self::Raw)>;
}
impl<T: FromRaw> TryFromRaw for T {
type Raw = <T as FromRaw>::Raw;
type Err = Infallible;
fn try_from_raw(raw: Self::Raw) -> Result<Self, (Self::Err, Self::Raw)> {
Ok(Self::from_raw(raw))
}
}
/// The result of deserializing an event, which may or may not be valid.
///
/// When data is successfully deserialized and validated, this structure will contain the
/// deserialized value `T`. When deserialization succeeds, but the event is invalid for any reason,
/// this structure will contain an `InvalidEvent`. See the documentation for `InvalidEvent` for
/// more details.
#[derive(Clone, Debug)]
pub enum EventResult<T: TryFromRaw> {
/// `T` deserialized and validated successfully.
Ok(T),
/// `T` failed either deserialization or validation.
///
/// `InvalidEvent` contains the error message and the raw data.
Err(InvalidEvent<T::Raw>),
}
impl<T: TryFromRaw> EventResult<T> {
/// Convert `EventResult<T>` into the equivalent `std::result::Result<T, InvalidEvent>`.
pub fn into_result(self) -> Result<T, InvalidEvent<T::Raw>> {
match self {
EventResult::Ok(t) => Ok(t),
EventResult::Err(invalid_event) => Err(invalid_event),
}
}
}
impl<'de, T> Deserialize<'de> for EventResult<T>
where
T: TryFromRaw,
{
fn deserialize<D>(deserializer: D) -> Result<Self, D::Error>
where
D: Deserializer<'de>,
{
let json = serde_json::Value::deserialize(deserializer)?;
let raw_data: T::Raw = match serde_json::from_value(json.clone()) {
Ok(raw) => raw,
Err(error) => {
return Ok(EventResult::Err(InvalidEvent(
InnerInvalidEvent::Deserialization {
json,
error: error.to_string(),
},
)));
}
};
match T::try_from_raw(raw_data) {
Ok(value) => Ok(EventResult::Ok(value)),
Err((err, raw_data)) => Ok(EventResult::Err(InvalidEvent(
InnerInvalidEvent::Validation {
message: err.to_string(),
raw_data,
},
))),
}
}
}
/// An error when attempting to create a value from a string via the `FromStr` trait.
///
/// This error type is only used for simple enums with unit variants. Event deserialization through
/// the `FromStr` trait returns an `InvalidEvent` on error.
#[derive(Clone, Copy, Eq, Debug, Hash, PartialEq)]
pub struct FromStrError;
impl Display for FromStrError {
fn fmt(&self, f: &mut Formatter) -> FmtResult {
write!(f, "failed to parse type from string")
}
}
impl Error for FromStrError {}
/// A meaningless value that serializes to an empty JSON object.
///
/// This type is used in a few places where the Matrix specification requires an empty JSON object,
/// but it's wasteful to represent it as a `HashMap` in Rust code.
#[derive(Clone, Debug, PartialEq)]
pub struct Empty;
impl Serialize for Empty {
fn serialize<S>(&self, serializer: S) -> Result<S::Ok, S::Error>
where
S: Serializer,
{
serializer.serialize_map(Some(0))?.end()
}
}
impl<'de> Deserialize<'de> for Empty {
fn deserialize<D>(deserializer: D) -> Result<Self, D::Error>
where
D: Deserializer<'de>,
{
struct EmptyMapVisitor;
impl<'de> Visitor<'de> for EmptyMapVisitor {
type Value = Empty;
fn expecting(&self, f: &mut Formatter) -> FmtResult {
write!(f, "an object/map")
}
fn visit_map<A>(self, _map: A) -> Result<Self::Value, A::Error>
where
A: MapAccess<'de>,
{
Ok(Empty)
}
}
deserializer.deserialize_map(EmptyMapVisitor)
}
}
/// The type of an event.
#[derive(Clone, Debug, Eq, Hash, PartialEq)]
pub enum EventType {
/// m.call.answer
CallAnswer,
/// m.call.candidates
CallCandidates,
/// m.call.hangup
CallHangup,
/// m.call.invite
CallInvite,
/// m.direct
Direct,
/// m.dummy
Dummy,
/// m.forwarded_room_key
ForwardedRoomKey,
/// m.fully_read
FullyRead,
/// m.key.verification.accept
KeyVerificationAccept,
/// m.key.verification.cancel
KeyVerificationCancel,
/// m.key.verification.key
KeyVerificationKey,
/// m.key.verification.mac
KeyVerificationMac,
/// m.key.verification.request
KeyVerificationRequest,
/// m.key.verification.start
KeyVerificationStart,
/// m.ignored_user_list
IgnoredUserList,
/// m.presence
Presence,
/// m.push_rules
PushRules,
/// m.receipt
Receipt,
/// m.room.aliases
RoomAliases,
/// m.room.avatar
RoomAvatar,
/// m.room.canonical_alias
RoomCanonicalAlias,
/// m.room.create
RoomCreate,
/// m.room.encrypted
RoomEncrypted,
/// m.room.encryption
RoomEncryption,
/// m.room.guest_access
RoomGuestAccess,
/// m.room.history_visibility
RoomHistoryVisibility,
/// m.room.join_rules
RoomJoinRules,
/// m.room.member
RoomMember,
/// m.room.message
RoomMessage,
/// m.room.message.feedback
RoomMessageFeedback,
/// m.room.name
RoomName,
/// m.room.pinned_events
RoomPinnedEvents,
/// m.room.power_levels
RoomPowerLevels,
/// m.room.redaction
RoomRedaction,
/// m.room.server_acl
RoomServerAcl,
/// m.room.third_party_invite
RoomThirdPartyInvite,
/// m.room.tombstone
RoomTombstone,
/// m.room.topic
RoomTopic,
/// m.room_key
RoomKey,
/// m.room_key_request
RoomKeyRequest,
/// m.sticker
Sticker,
/// m.tag
Tag,
/// m.typing
Typing,
/// Any event that is not part of the specification.
Custom(String),
/// Additional variants may be added in the future and will not be considered breaking changes
/// to ruma-events.
#[doc(hidden)]
__Nonexhaustive,
}
/// A basic event.
pub trait Event: Debug + Serialize + Sized + TryFromRaw {
/// The type of this event's `content` field.
type Content: Debug + Serialize;
/// The event's content.
fn content(&self) -> &Self::Content;
/// The type of the event.
fn event_type(&self) -> EventType;
}
/// An event within the context of a room.
pub trait RoomEvent: Event {
/// The unique identifier for the event.
fn event_id(&self) -> &EventId;
/// Timestamp (milliseconds since the UNIX epoch) on originating homeserver when this event was
/// sent.
fn origin_server_ts(&self) -> UInt;
/// The unique identifier for the room associated with this event.
///
/// This can be `None` if the event came from a context where there is
/// no ambiguity which room it belongs to, like a `/sync` response for example.
fn room_id(&self) -> Option<&RoomId>;
/// The unique identifier for the user who sent this event.
fn sender(&self) -> &UserId;
/// Additional key-value pairs not signed by the homeserver.
fn unsigned(&self) -> Option<&Value>;
}
/// An event that describes persistent state about a room.
pub trait StateEvent: RoomEvent {
/// The previous content for this state key, if any.
fn prev_content(&self) -> Option<&Self::Content>;
/// A key that determines which piece of room state the event represents.
fn state_key(&self) -> &str;
}
mod custom {
use ruma_events_macros::ruma_event;
use serde_json::Value;
ruma_event! {
/// A custom basic event not covered by the Matrix specification.
CustomEvent {
kind: Event,
event_type: Custom,
content_type_alias: {
/// The payload for `CustomEvent`.
Value
},
}
}
}
mod custom_room {
use ruma_events_macros::ruma_event;
use serde_json::Value;
ruma_event! {
/// A custom room event not covered by the Matrix specification.
CustomRoomEvent {
kind: RoomEvent,
event_type: Custom,
content_type_alias: {
/// The payload for `CustomRoomEvent`.
Value
},
}
}
}
mod custom_state {
use ruma_events_macros::ruma_event;
use serde_json::Value;
ruma_event! {
/// A custom state event not covered by the Matrix specification.
CustomStateEvent {
kind: StateEvent,
event_type: Custom,
content_type_alias: {
/// The payload for `CustomStateEvent`.
Value
},
}
}
}
impl Display for EventType {
fn fmt(&self, f: &mut Formatter<'_>) -> Result<(), FmtError> {
let event_type_str = match *self {
EventType::CallAnswer => "m.call.answer",
EventType::CallCandidates => "m.call.candidates",
EventType::CallHangup => "m.call.hangup",
EventType::CallInvite => "m.call.invite",
EventType::Direct => "m.direct",
EventType::Dummy => "m.dummy",
EventType::ForwardedRoomKey => "m.forwarded_room_key",
EventType::FullyRead => "m.fully_read",
EventType::KeyVerificationAccept => "m.key.verification.accept",
EventType::KeyVerificationCancel => "m.key.verification.cancel",
EventType::KeyVerificationKey => "m.key.verification.key",
EventType::KeyVerificationMac => "m.key.verification.mac",
EventType::KeyVerificationRequest => "m.key.verification.request",
EventType::KeyVerificationStart => "m.key.verification.start",
EventType::IgnoredUserList => "m.ignored_user_list",
EventType::Presence => "m.presence",
EventType::PushRules => "m.push_rules",
EventType::Receipt => "m.receipt",
EventType::RoomAliases => "m.room.aliases",
EventType::RoomAvatar => "m.room.avatar",
EventType::RoomCanonicalAlias => "m.room.canonical_alias",
EventType::RoomCreate => "m.room.create",
EventType::RoomEncrypted => "m.room.encrypted",
EventType::RoomEncryption => "m.room.encryption",
EventType::RoomGuestAccess => "m.room.guest_access",
EventType::RoomHistoryVisibility => "m.room.history_visibility",
EventType::RoomJoinRules => "m.room.join_rules",
EventType::RoomMember => "m.room.member",
EventType::RoomMessage => "m.room.message",
EventType::RoomMessageFeedback => "m.room.message.feedback",
EventType::RoomName => "m.room.name",
EventType::RoomPinnedEvents => "m.room.pinned_events",
EventType::RoomPowerLevels => "m.room.power_levels",
EventType::RoomRedaction => "m.room.redaction",
EventType::RoomServerAcl => "m.room.server_acl",
EventType::RoomThirdPartyInvite => "m.room.third_party_invite",
EventType::RoomTombstone => "m.room.tombstone",
EventType::RoomTopic => "m.room.topic",
EventType::RoomKey => "m.room_key",
EventType::RoomKeyRequest => "m.room_key_request",
EventType::Sticker => "m.sticker",
EventType::Tag => "m.tag",
EventType::Typing => "m.typing",
EventType::Custom(ref event_type) => event_type,
EventType::__Nonexhaustive => {
panic!("__Nonexhaustive enum variant is not intended for use.")
}
};
write!(f, "{}", event_type_str)
}
}
impl<'a> From<&'a str> for EventType {
fn from(s: &'a str) -> EventType {
match s {
"m.call.answer" => EventType::CallAnswer,
"m.call.candidates" => EventType::CallCandidates,
"m.call.hangup" => EventType::CallHangup,
"m.call.invite" => EventType::CallInvite,
"m.direct" => EventType::Direct,
"m.dummy" => EventType::Dummy,
"m.forwarded_room_key" => EventType::ForwardedRoomKey,
"m.fully_read" => EventType::FullyRead,
"m.key.verification.accept" => EventType::KeyVerificationAccept,
"m.key.verification.cancel" => EventType::KeyVerificationCancel,
"m.key.verification.key" => EventType::KeyVerificationKey,
"m.key.verification.mac" => EventType::KeyVerificationMac,
"m.key.verification.request" => EventType::KeyVerificationRequest,
"m.key.verification.start" => EventType::KeyVerificationStart,
"m.ignored_user_list" => EventType::IgnoredUserList,
"m.presence" => EventType::Presence,
"m.push_rules" => EventType::PushRules,
"m.receipt" => EventType::Receipt,
"m.room.aliases" => EventType::RoomAliases,
"m.room.avatar" => EventType::RoomAvatar,
"m.room.canonical_alias" => EventType::RoomCanonicalAlias,
"m.room.create" => EventType::RoomCreate,
"m.room.encrypted" => EventType::RoomEncrypted,
"m.room.encryption" => EventType::RoomEncryption,
"m.room.guest_access" => EventType::RoomGuestAccess,
"m.room.history_visibility" => EventType::RoomHistoryVisibility,
"m.room.join_rules" => EventType::RoomJoinRules,
"m.room.member" => EventType::RoomMember,
"m.room.message" => EventType::RoomMessage,
"m.room.message.feedback" => EventType::RoomMessageFeedback,
"m.room.name" => EventType::RoomName,
"m.room.pinned_events" => EventType::RoomPinnedEvents,
"m.room.power_levels" => EventType::RoomPowerLevels,
"m.room.redaction" => EventType::RoomRedaction,
"m.room.server_acl" => EventType::RoomServerAcl,
"m.room.third_party_invite" => EventType::RoomThirdPartyInvite,
"m.room.tombstone" => EventType::RoomTombstone,
"m.room.topic" => EventType::RoomTopic,
"m.room_key" => EventType::RoomKey,
"m.room_key_request" => EventType::RoomKeyRequest,
"m.sticker" => EventType::Sticker,
"m.tag" => EventType::Tag,
"m.typing" => EventType::Typing,
event_type => EventType::Custom(event_type.to_string()),
}
}
}
impl Serialize for EventType {
fn serialize<S>(&self, serializer: S) -> Result<S::Ok, S::Error>
where
S: Serializer,
{
serializer.serialize_str(&self.to_string())
}
}
impl<'de> Deserialize<'de> for EventType {
fn deserialize<D>(deserializer: D) -> Result<Self, D::Error>
where
D: Deserializer<'de>,
{
struct EventTypeVisitor;
impl<'de> Visitor<'de> for EventTypeVisitor {
type Value = EventType;
fn expecting(&self, formatter: &mut Formatter<'_>) -> FmtResult {
write!(formatter, "a Matrix event type as a string")
}
fn visit_str<E>(self, v: &str) -> Result<Self::Value, E>
where
E: SerdeError,
{
Ok(EventType::from(v))
}
}
deserializer.deserialize_str(EventTypeVisitor)
}
}
/// An encryption algorithm to be used to encrypt messages sent to a room.
#[derive(Clone, Debug, PartialEq)]
pub enum Algorithm {
/// Olm version 1 using Curve25519, AES-256, and SHA-256.
OlmV1Curve25519AesSha2,
/// Megolm version 1 using AES-256 and SHA-256.
MegolmV1AesSha2,
/// Any algorithm that is not part of the specification.
Custom(String),
/// Additional variants may be added in the future and will not be considered breaking changes
/// to `ruma-events`.
#[doc(hidden)]
__Nonexhaustive,
}
impl Display for Algorithm {
fn fmt(&self, f: &mut Formatter<'_>) -> FmtResult {
let algorithm_str = match *self {
Algorithm::OlmV1Curve25519AesSha2 => "m.olm.v1.curve25519-aes-sha2",
Algorithm::MegolmV1AesSha2 => "m.megolm.v1.aes-sha2",
Algorithm::Custom(ref algorithm) => algorithm,
Algorithm::__Nonexhaustive => {
panic!("__Nonexhaustive enum variant is not intended for use.")
}
};
write!(f, "{}", algorithm_str)
}
}
impl<'a> From<&'a str> for Algorithm {
fn from(s: &'a str) -> Algorithm {
match s {
"m.olm.v1.curve25519-aes-sha2" => Algorithm::OlmV1Curve25519AesSha2,
"m.megolm.v1.aes-sha2" => Algorithm::MegolmV1AesSha2,
algorithm => Algorithm::Custom(algorithm.to_string()),
}
}
}
impl Serialize for Algorithm {
fn serialize<S>(&self, serializer: S) -> Result<S::Ok, S::Error>
where
S: Serializer,
{
serializer.serialize_str(&self.to_string())
}
}
impl<'de> Deserialize<'de> for Algorithm {
fn deserialize<D>(deserializer: D) -> Result<Self, D::Error>
where
D: Deserializer<'de>,
{
struct CancelCodeVisitor;
impl<'de> Visitor<'de> for CancelCodeVisitor {
type Value = Algorithm;
fn expecting(&self, formatter: &mut Formatter<'_>) -> FmtResult {
write!(formatter, "an encryption algorithm code as a string")
}
fn visit_str<E>(self, v: &str) -> Result<Self::Value, E>
where
E: SerdeError,
{
Ok(Algorithm::from(v))
}
}
deserializer.deserialize_str(CancelCodeVisitor)
}
}
/// Serde deserialization decorator to map empty Strings to None,
/// and forward non-empty Strings to the Deserialize implementation for T.
/// Useful for the typical
/// "A room with an X event with an absent, null, or empty Y field
/// should be treated the same as a room with no such event."
/// formulation in the spec.
///
/// To be used like this:
/// `#[serde(deserialize_with = "empty_string_as_none"]`
/// Relevant serde issue: https://github.com/serde-rs/serde/issues/1425
fn empty_string_as_none<'de, D, T>(de: D) -> Result<Option<T>, D::Error>
where
D: serde::Deserializer<'de>,
T: serde::Deserialize<'de>,
{
let opt = Option::<String>::deserialize(de)?;
let opt = opt.as_ref().map(String::as_str);
match opt {
None | Some("") => Ok(None),
// If T = String, like in m.room.name, the second deserialize is actually superfluous.
// TODO: optimize that somehow?
Some(s) => T::deserialize(s.into_deserializer()).map(Some),
}
}
/// Serde serialization and deserialization functions that map a `Vec<T>` to a `HashMap<T, Empty>`.
///
/// To be used as `#[serde(with = "vec_as_map_of_empty")]`
mod vec_as_map_of_empty {
use super::Empty;
use serde::{Deserialize, Deserializer, Serialize, Serializer};
use std::{collections::HashMap, hash::Hash};
#[allow(clippy::ptr_arg)]
pub fn serialize<S, T>(vec: &Vec<T>, serializer: S) -> Result<S::Ok, S::Error>
where
S: Serializer,
T: Serialize + Hash + Eq,
{
vec.iter()
.map(|v| (v, Empty))
.collect::<HashMap<_, _>>()
.serialize(serializer)
}
pub fn deserialize<'de, D, T>(deserializer: D) -> Result<Vec<T>, D::Error>
where
D: Deserializer<'de>,
T: Deserialize<'de> + Hash + Eq,
{
HashMap::<T, Empty>::deserialize(deserializer)
.map(|hashmap| hashmap.into_iter().map(|(k, _)| k).collect())
}
}
/// Used to default the `bool` fields to `true` during deserialization.
fn default_true() -> bool {
true
}
#[cfg(test)]
mod tests {
use serde_json::{from_str, to_string};
use super::{Algorithm, EventType};
#[test]
fn event_types_serialize_to_display_form() {
assert_eq!(
to_string(&EventType::RoomCreate).unwrap(),
r#""m.room.create""#
);
}
#[test]
fn custom_event_types_serialize_to_display_form() {
assert_eq!(
to_string(&EventType::Custom("io.ruma.test".to_string())).unwrap(),
r#""io.ruma.test""#
);
}
#[test]
fn event_types_deserialize_from_display_form() {
assert_eq!(
from_str::<EventType>(r#""m.room.create""#).unwrap(),
EventType::RoomCreate
);
}
#[test]
fn custom_event_types_deserialize_from_display_form() {
assert_eq!(
from_str::<EventType>(r#""io.ruma.test""#).unwrap(),
EventType::Custom("io.ruma.test".to_string())
)
}
#[test]
fn algorithms_serialize_to_display_form() {
assert_eq!(
to_string(&Algorithm::MegolmV1AesSha2).unwrap(),
r#""m.megolm.v1.aes-sha2""#
);
}
#[test]
fn custom_algorithms_serialize_to_display_form() {
assert_eq!(
to_string(&Algorithm::Custom("io.ruma.test".to_string())).unwrap(),
r#""io.ruma.test""#
);
}
#[test]
fn algorithms_deserialize_from_display_form() {
assert_eq!(
from_str::<Algorithm>(r#""m.megolm.v1.aes-sha2""#).unwrap(),
Algorithm::MegolmV1AesSha2
);
}
#[test]
fn custom_algorithms_deserialize_from_display_form() {
assert_eq!(
from_str::<Algorithm>(r#""io.ruma.test""#).unwrap(),
Algorithm::Custom("io.ruma.test".to_string())
)
}
}