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|
use chrono::TimeDelta;
use futures::{
Stream, future,
stream::{self, StreamExt as _},
};
use sqlx::sqlite::SqlitePool;
use super::{
Broadcaster, Event as TokenEvent, Secret, Token, extract::Identity, repo::Provider as _,
};
use crate::{
clock::DateTime,
db,
db::NotFound as _,
error::failed::{Failed, ResultExt as _},
push::repo::Provider as _,
};
pub struct Tokens {
db: SqlitePool,
token_events: Broadcaster,
}
impl Tokens {
pub const fn new(db: SqlitePool, token_events: Broadcaster) -> Self {
Self { db, token_events }
}
pub async fn validate(
&self,
secret: &Secret,
used_at: &DateTime,
) -> Result<Identity, ValidateError> {
let mut tx = self.db.begin().await.fail(db::failed::BEGIN)?;
let (token, login) = tx
.tokens()
.validate(secret, used_at)
.await
.optional()
.fail("Failed to load token")?
.ok_or(ValidateError::InvalidToken)?;
tx.commit().await.fail(db::failed::COMMIT)?;
Ok(Identity { token, login })
}
pub async fn limit_stream<S, E>(
&self,
token: &Token,
events: S,
) -> Result<impl Stream<Item = E> + std::fmt::Debug + use<S, E>, ValidateError>
where
S: Stream<Item = E> + std::fmt::Debug,
E: std::fmt::Debug,
{
let token = token.id.clone();
// Subscribe, first.
let token_events = self.token_events.subscribe();
// Check that the token is valid at this point in time, second. If it is, then
// any future revocations will appear in the subscription. If not, bail now.
//
// It's possible, otherwise, to get to this point with a token that _was_ valid
// at the start of the request, but which was invalided _before_ the
// `subscribe()` call. In that case, the corresponding revocation event will
// simply be missed, since the `token_events` stream subscribed after the fact.
// This check cancels guarding the stream here.
//
// Yes, this is a weird niche edge case. Most things don't double-check, because
// they aren't expected to run long enough for the token's revocation to
// matter. Supervising a stream, on the other hand, will run for a
// _long_ time; if we miss the race here, we'll never actually carry out the
// supervision.
let mut tx = self.db.begin().await.fail(db::failed::BEGIN)?;
tx.tokens()
.require(&token)
.await
.optional()
.fail("Failed to load token")?
.ok_or(ValidateError::InvalidToken)?;
tx.commit().await.fail(db::failed::COMMIT)?;
// Then construct the guarded stream. First, project both streams into
// `GuardedEvent`.
let token_events = token_events
.filter(move |event| {
future::ready(matches!(event, TokenEvent::Revoked(id) if id == &token))
})
.map(|_| GuardedEvent::TokenRevoked);
let events = events.map(|event| GuardedEvent::Event(event));
// Merge the two streams, then unproject them, stopping at
// `GuardedEvent::TokenRevoked`.
let stream = stream::select(token_events, events).scan((), |(), event| {
future::ready(match event {
GuardedEvent::Event(event) => Some(event),
GuardedEvent::TokenRevoked => None,
})
});
Ok(stream)
}
pub async fn expire(&self, relative_to: &DateTime) -> Result<(), sqlx::Error> {
// Somewhat arbitrarily, expire after 7 days.
let expire_at = relative_to.to_owned() - TimeDelta::days(7);
let mut tx = self.db.begin().await?;
let tokens = tx.tokens().expire(&expire_at).await?;
tx.commit().await?;
tokens
.into_iter()
.map(TokenEvent::Revoked)
.for_each(|event| self.token_events.broadcast(event));
Ok(())
}
pub async fn logout(&self, token: &Token) -> Result<(), ValidateError> {
let mut tx = self.db.begin().await.fail(db::failed::BEGIN)?;
tx.push()
.unsubscribe_token(token)
.await
.fail("Failed to remove push subscriptions")?;
tx.tokens()
.revoke(token)
.await
.fail("Failed to revoke token")?;
tx.commit().await.fail(db::failed::COMMIT)?;
self.token_events
.broadcast(TokenEvent::Revoked(token.id.clone()));
Ok(())
}
}
#[derive(Debug, thiserror::Error)]
pub enum ValidateError {
#[error("invalid token")]
InvalidToken,
#[error(transparent)]
Failed(#[from] Failed),
}
#[derive(Debug)]
enum GuardedEvent<E> {
TokenRevoked,
Event(E),
}
|
