worterbuch 1.5.0-alpha.2

A message broker / database hybrid.
Documentation
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use crate::{
    Config,
    auth::{JwtClaims, get_claims},
    server::common::{CloneableWbApi, SubscriptionInfo},
    worterbuch::PStateAggregator,
};
use serde_json::json;
use std::time::Duration;
use tokio::{spawn, sync::mpsc};
use tracing::{Level, debug, error, instrument, trace, warn};
use uuid::Uuid;
use worterbuch_common::{
    Ack, AuthCheck, AuthorizationRequest, ClientMessage as CM, Delete, Err, ErrorCode, Get, Ls,
    LsState, PDelete, PGet, PLs, PState, PStateEvent, PSubscribe, Privilege, Publish, SPub,
    SPubInit, ServerMessage, Set, State, StateEvent, Subscribe, SubscribeLs, SubscriptionId,
    TransactionId, Unsubscribe, UnsubscribeLs, WbApi,
    error::{Context, WorterbuchError, WorterbuchResult},
};

#[derive(Clone)]
pub struct V0 {
    pub client_id: Uuid,
    pub tx: mpsc::Sender<ServerMessage>,
    pub auth_required: bool,
    pub config: Config,
    pub worterbuch: CloneableWbApi,
}

impl V0 {
    #[instrument(level=Level::TRACE, skip(self), fields(protocol = "v0", client_id=%self.client_id))]
    pub async fn process_incoming_message(
        &self,
        msg: CM,
        authorized: &mut Option<JwtClaims>,
    ) -> WorterbuchResult<()> {
        match msg {
            CM::AuthorizationRequest(msg) => {
                if authorized.is_some() {
                    return Err(WorterbuchError::AlreadyAuthorized);
                }
                trace!("Authorizing client {} …", self.client_id);
                *authorized = Some(self.authorize(msg).await?);
                trace!("Authorizing client {} done.", self.client_id);
            }
            CM::Get(msg) => {
                if self
                    .check_auth(Privilege::Read, &msg.key, authorized, msg.transaction_id)
                    .await?
                {
                    trace!("Getting value for client {} …", self.client_id);
                    self.get(msg).await?;
                    trace!("Getting value for client {} done.", self.client_id);
                }
            }
            CM::PGet(msg) => {
                if self
                    .check_auth(
                        Privilege::Read,
                        &msg.request_pattern,
                        authorized,
                        msg.transaction_id,
                    )
                    .await?
                {
                    trace!("PGetting values for client {} …", self.client_id);
                    self.pget(msg).await?;
                    trace!("PGetting values for client {} done.", self.client_id);
                }
            }
            CM::Set(msg) => {
                if self
                    .check_auth(Privilege::Write, &msg.key, authorized, msg.transaction_id)
                    .await?
                {
                    trace!("Setting value for client {} …", self.client_id);
                    self.set(msg).await?;
                    trace!("Setting value for client {} done.", self.client_id);
                }
            }
            CM::SPubInit(msg) => {
                if self
                    .check_auth(Privilege::Write, &msg.key, authorized, msg.transaction_id)
                    .await?
                {
                    trace!(
                        "Mapping key to transaction ID for for client {} …",
                        self.client_id
                    );
                    self.spub_init(msg).await?;
                    trace!(
                        "Mapping key to transaction ID for client {} done.",
                        self.client_id
                    );
                }
            }
            CM::SPub(msg) => {
                trace!("Setting value for client {} …", self.client_id);
                self.spub(msg).await?;
                trace!("Setting value for client {} done.", self.client_id);
            }
            CM::Publish(msg) => {
                if self
                    .check_auth(Privilege::Write, &msg.key, authorized, msg.transaction_id)
                    .await?
                {
                    trace!("Publishing value for client {} …", self.client_id);
                    self.publish(msg).await?;
                    trace!("Publishing value for client {} done.", self.client_id);
                }
            }
            CM::Subscribe(msg) => {
                if self
                    .check_auth(Privilege::Read, &msg.key, authorized, msg.transaction_id)
                    .await?
                {
                    trace!("Making subscription for client {} …", self.client_id);
                    self.subscribe(msg).await?;
                    trace!("Making subscription for client {} done.", self.client_id);
                }
            }
            CM::PSubscribe(msg) => {
                if self
                    .check_auth(
                        Privilege::Read,
                        &msg.request_pattern,
                        authorized,
                        msg.transaction_id,
                    )
                    .await?
                {
                    trace!("Making psubscription for client {} …", self.client_id);
                    self.psubscribe(msg).await?;
                    trace!("Making psubscription for client {} done.", self.client_id);
                }
            }
            CM::Unsubscribe(msg) => self.unsubscribe(msg).await?,
            CM::Delete(msg) => {
                if self
                    .check_auth(Privilege::Delete, &msg.key, authorized, msg.transaction_id)
                    .await?
                {
                    trace!("Deleting value for client {} …", self.client_id);
                    self.delete(msg).await?;
                    trace!("Deleting value for client {} done.", self.client_id);
                }
            }
            CM::PDelete(msg) => {
                if self
                    .check_auth(
                        Privilege::Delete,
                        &msg.request_pattern,
                        authorized,
                        msg.transaction_id,
                    )
                    .await?
                {
                    trace!("PDeleting value for client {} …", self.client_id);
                    self.pdelete(msg).await?;
                    trace!("PDeleting value for client {} done.", self.client_id);
                }
            }
            CM::Ls(msg) => {
                let pattern = &msg
                    .parent
                    .as_ref()
                    .map(|it| format!("{it}/?"))
                    .unwrap_or("?".to_owned());
                if self
                    .check_auth(Privilege::Read, pattern, authorized, msg.transaction_id)
                    .await?
                {
                    trace!("Listing subkeys for client {} …", self.client_id);
                    self.ls(msg).await?;
                    trace!("Listing subkeys for client {} done.", self.client_id);
                }
            }
            CM::PLs(msg) => {
                let pattern = &msg
                    .parent_pattern
                    .as_ref()
                    .map(|it| format!("{it}/?"))
                    .unwrap_or("?".to_owned());
                if self
                    .check_auth(Privilege::Read, pattern, authorized, msg.transaction_id)
                    .await?
                {
                    trace!("Listing matching subkeys for client {} …", self.client_id);
                    self.pls(msg).await?;
                    trace!(
                        "Listing matching subkeys for client {} done.",
                        self.client_id
                    );
                }
            }
            CM::SubscribeLs(msg) => {
                let pattern = &msg
                    .parent
                    .as_ref()
                    .map(|it| format!("{it}/?"))
                    .unwrap_or("?".to_owned());
                if self
                    .check_auth(Privilege::Read, pattern, authorized, msg.transaction_id)
                    .await?
                {
                    trace!("Subscribing to subkeys for client {} …", self.client_id);
                    self.subscribe_ls(msg).await?;
                    trace!("Subscribing to subkeys for client {} done.", self.client_id);
                }
            }
            CM::UnsubscribeLs(msg) => {
                trace!("Unsubscribing from subkeys for client {} …", self.client_id);
                self.unsubscribe_ls(msg).await?;
                trace!(
                    "Unsubscribing from subkeys for client {} done.",
                    self.client_id
                );
            }

            CM::ProtocolSwitchRequest(_)
            | CM::CGet(_)
            | CM::CSet(_)
            | CM::Transform(_)
            | CM::Lock(_)
            | CM::AcquireLock(_)
            | CM::ReleaseLock(_) => {
                return Err(WorterbuchError::NotImplemented);
            }
        };
        Ok(())
    }

    pub async fn check_auth(
        &self,
        privilege: Privilege,
        pattern: &str,
        authorized: &Option<JwtClaims>,
        transaction_id: TransactionId,
    ) -> WorterbuchResult<bool> {
        if self.auth_required {
            match authorized {
                Some(claims) => {
                    if let Err(e) = claims.authorize(&privilege, AuthCheck::Pattern(pattern)) {
                        trace!("Client is not authorized, sending error …");
                        self.handle_store_error(
                            WorterbuchError::Unauthorized(e.clone()),
                            transaction_id,
                        )
                        .await?;
                        trace!("Client is not authorized, sending error done.");
                        return Ok(false);
                    }
                }
                None => return Err(WorterbuchError::AuthorizationRequired(privilege)),
            }
        }
        Ok(true)
    }

    pub async fn handle_store_error(
        &self,
        e: WorterbuchError,
        transaction_id: TransactionId,
    ) -> WorterbuchResult<()> {
        let error_code = ErrorCode::from(&e);
        let err_msg = format!("{e}");
        let err = Err {
            error_code,
            transaction_id,
            metadata: json!(err_msg).to_string(),
        };
        trace!("Error in store, queuing error message for client …");
        let res = self
            .tx
            .send(ServerMessage::Err(err))
            .await
            .context(|| "Error sending ERR message to client".to_owned());
        trace!("Error in store, queuing error message for client done");
        res
    }

    async fn authorize(&self, msg: AuthorizationRequest) -> WorterbuchResult<JwtClaims> {
        match get_claims(Some(&msg.auth_token), &self.config) {
            Ok(claims) => {
                self.tx
                    .send(ServerMessage::Authorized(Ack { transaction_id: 0 }))
                    .await
                    .context(|| "Error sending HANDSHAKE message".to_owned())?;
                Ok(claims)
            }
            Err(e) => {
                self.handle_store_error(WorterbuchError::Unauthorized(e.clone()), 0)
                    .await?;
                Err(WorterbuchError::Unauthorized(e))
            }
        }
    }

    pub async fn get(&self, msg: Get) -> WorterbuchResult<()> {
        let value = match self.worterbuch.get(msg.key).await {
            Ok(it) => it,
            Err(e) => {
                self.handle_store_error(e, msg.transaction_id).await?;
                return Ok(());
            }
        };

        let response = State {
            transaction_id: msg.transaction_id,
            event: StateEvent::Value(value),
        };

        self.tx
            .send(ServerMessage::State(response))
            .await
            .context(|| {
                format!(
                    "Error sending STATE message for transaction ID {}",
                    msg.transaction_id
                )
            })?;

        Ok(())
    }

    pub async fn pget(&self, msg: PGet) -> WorterbuchResult<()> {
        let values = match self.worterbuch.pget(msg.request_pattern.clone()).await {
            Ok(values) => values.into_iter().collect(),
            Err(e) => {
                self.handle_store_error(e, msg.transaction_id).await?;
                return Ok(());
            }
        };

        let response = PState {
            transaction_id: msg.transaction_id,
            request_pattern: msg.request_pattern,
            event: PStateEvent::KeyValuePairs(values),
        };

        self.tx
            .send(ServerMessage::PState(response))
            .await
            .context(|| {
                format!(
                    "Error sending PSTATE message for transaction ID {}",
                    msg.transaction_id
                )
            })?;

        Ok(())
    }

    #[instrument(level = Level::TRACE, skip(self), fields(client_id=%self.client_id) err)]
    pub async fn set(&self, msg: Set) -> WorterbuchResult<()> {
        if let Err(e) = self
            .worterbuch
            .set(msg.key, msg.value, self.client_id)
            .await
        {
            self.handle_store_error(e, msg.transaction_id).await?;
            return Ok(());
        }

        let response = Ack {
            transaction_id: msg.transaction_id,
        };

        trace!("Value set, queuing Ack …");
        let res = self.tx.send(ServerMessage::Ack(response)).await;
        trace!("Value set, queuing Ack done.");
        res.context(|| {
            format!(
                "Error sending ACK message for transaction ID {}",
                msg.transaction_id
            )
        })?;

        Ok(())
    }

    pub async fn spub_init(&self, msg: SPubInit) -> WorterbuchResult<()> {
        if let Err(e) = self
            .worterbuch
            .spub_init(msg.transaction_id, msg.key, self.client_id)
            .await
        {
            self.handle_store_error(e, msg.transaction_id).await?;
            return Ok(());
        }

        let response = Ack {
            transaction_id: msg.transaction_id,
        };

        trace!("Value set, queuing Ack …");
        let res = self.tx.send(ServerMessage::Ack(response)).await;
        trace!("Value set, queuing Ack done.");
        res.context(|| {
            format!(
                "Error sending ACK message for transaction ID {}",
                msg.transaction_id
            )
        })?;

        Ok(())
    }

    pub async fn spub(&self, msg: SPub) -> WorterbuchResult<()> {
        if let Err(e) = self
            .worterbuch
            .spub(msg.transaction_id, msg.value, self.client_id)
            .await
        {
            self.handle_store_error(e, msg.transaction_id).await?;
            return Ok(());
        }

        let response = Ack {
            transaction_id: msg.transaction_id,
        };

        trace!("Value set, queuing Ack …");
        let res = self.tx.send(ServerMessage::Ack(response)).await;
        trace!("Value set, queuing Ack done.");
        res.context(|| {
            format!(
                "Error sending ACK message for transaction ID {}",
                msg.transaction_id
            )
        })?;

        Ok(())
    }

    pub async fn publish(&self, msg: Publish) -> WorterbuchResult<()> {
        if let Err(e) = self.worterbuch.publish(msg.key, msg.value).await {
            self.handle_store_error(e, msg.transaction_id).await?;
            return Ok(());
        }

        let response = Ack {
            transaction_id: msg.transaction_id,
        };

        self.tx
            .send(ServerMessage::Ack(response))
            .await
            .context(|| {
                format!(
                    "Error sending ACK message for transaction ID {}",
                    msg.transaction_id
                )
            })?;

        Ok(())
    }

    pub async fn subscribe(&self, msg: Subscribe) -> WorterbuchResult<bool> {
        let (mut rx, subscription) = match self
            .worterbuch
            .subscribe(
                self.client_id,
                msg.transaction_id,
                msg.key.clone(),
                msg.unique,
                msg.live_only.unwrap_or(false),
            )
            .await
        {
            Ok(it) => it,
            Err(e) => {
                self.handle_store_error(e, msg.transaction_id).await?;
                return Ok(false);
            }
        };

        let response = Ack {
            transaction_id: msg.transaction_id,
        };

        self.tx
            .send(ServerMessage::Ack(response))
            .await
            .context(|| {
                format!(
                    "Error sending ACK message for transaction ID {}",
                    msg.transaction_id
                )
            })?;

        let transaction_id = msg.transaction_id;

        let wb_unsub = self.worterbuch.clone();
        let client_sub = self.tx.clone();
        let client_id = self.client_id;
        spawn(async move {
            debug!("Receiving events for subscription {subscription:?} …");
            while let Some(event) = rx.recv().await {
                let state = State {
                    transaction_id,
                    event,
                };
                if let Err(e) = client_sub.send(ServerMessage::State(state)).await {
                    error!("Error sending STATE message to client: {e}");
                    break;
                };
            }

            match wb_unsub.unsubscribe(client_id, transaction_id).await {
                Ok(()) => {
                    warn!("Subscription was not cleaned up properly!");
                }
                Err(WorterbuchError::NotSubscribed) => { /* this is expected */ }
                Err(e) => {
                    warn!("Error while unsubscribing: {e}");
                }
            }
        });

        Ok(true)
    }

    pub async fn psubscribe(&self, msg: PSubscribe) -> WorterbuchResult<bool> {
        let live_only = msg.live_only.unwrap_or(false);

        let (rx, subscription) = match self
            .worterbuch
            .psubscribe(
                self.client_id,
                msg.transaction_id,
                msg.request_pattern.clone(),
                msg.unique,
                live_only,
            )
            .await
        {
            Ok(rx) => rx,
            Err(e) => {
                self.handle_store_error(e, msg.transaction_id).await?;
                return Ok(false);
            }
        };

        let response = Ack {
            transaction_id: msg.transaction_id,
        };

        self.tx
            .send(ServerMessage::Ack(response))
            .await
            .context(|| {
                format!(
                    "Error sending ACK message for transaction ID {}",
                    msg.transaction_id
                )
            })?;

        let transaction_id = msg.transaction_id;
        let request_pattern = msg.request_pattern;

        let wb_unsub = self.worterbuch.clone();
        let client_sub = self.tx.clone();
        let client_id = self.client_id;

        let channel_buffer_size = self.worterbuch.config().channel_buffer_size;

        let aggregate_events = msg.aggregate_events.map(Duration::from_millis);
        if let Some(aggregate_duration) = aggregate_events {
            let subscription = SubscriptionInfo {
                aggregate_duration,
                channel_buffer_size,
                live_only,
                request_pattern,
                transaction_id,
            };
            spawn(async move {
                aggregate_loop(rx, subscription, client_sub, client_id).await;

                match wb_unsub.unsubscribe(client_id, transaction_id).await {
                    Ok(()) => {
                        warn!("Subscription was not cleaned up properly!");
                    }
                    Err(WorterbuchError::NotSubscribed) => { /* this is expected */ }
                    Err(e) => {
                        warn!("Error while unsubscribing: {e}");
                    }
                }
            });
        } else {
            spawn(async move {
                forward_loop(
                    rx,
                    transaction_id,
                    request_pattern,
                    subscription,
                    client_sub,
                )
                .await;

                match wb_unsub.unsubscribe(client_id, transaction_id).await {
                    Ok(()) => {
                        warn!("Subscription was not cleaned up properly!");
                    }
                    Err(WorterbuchError::NotSubscribed) => { /* this is expected */ }
                    Err(e) => {
                        warn!("Error while unsubscribing: {e}");
                    }
                }
            });
        }

        Ok(true)
    }

    pub async fn unsubscribe(&self, msg: Unsubscribe) -> WorterbuchResult<()> {
        if let Err(e) = self
            .worterbuch
            .unsubscribe(self.client_id, msg.transaction_id)
            .await
        {
            self.handle_store_error(e, msg.transaction_id).await?;
            return Ok(());
        };
        let response = Ack {
            transaction_id: msg.transaction_id,
        };

        self.tx
            .send(ServerMessage::Ack(response))
            .await
            .context(|| {
                format!(
                    "Error sending ACK message for transaction ID {}",
                    msg.transaction_id
                )
            })?;

        Ok(())
    }

    pub async fn delete(&self, msg: Delete) -> WorterbuchResult<()> {
        let value = match self.worterbuch.delete(msg.key, self.client_id).await {
            Ok(it) => it,
            Err(e) => {
                self.handle_store_error(e, msg.transaction_id).await?;
                return Ok(());
            }
        };

        let response = State {
            transaction_id: msg.transaction_id,
            event: StateEvent::Deleted(value),
        };

        self.tx
            .send(ServerMessage::State(response))
            .await
            .context(|| {
                format!(
                    "Error sending STATE message for transaction ID {}",
                    msg.transaction_id
                )
            })?;

        Ok(())
    }

    pub async fn pdelete(&self, msg: PDelete) -> WorterbuchResult<()> {
        let deleted = match self
            .worterbuch
            .pdelete(msg.request_pattern.clone(), self.client_id)
            .await
        {
            Ok(it) => it,
            Result::Err(e) => {
                self.handle_store_error(e, msg.transaction_id).await?;
                return Ok(());
            }
        };

        let response = PState {
            transaction_id: msg.transaction_id,
            request_pattern: msg.request_pattern,
            event: PStateEvent::Deleted(if msg.quiet.unwrap_or(false) {
                vec![]
            } else {
                deleted
            }),
        };

        self.tx
            .send(ServerMessage::PState(response))
            .await
            .context(|| {
                format!(
                    "Error sending PSTATE message for transaction ID {}",
                    msg.transaction_id
                )
            })?;

        Ok(())
    }

    pub async fn ls(&self, msg: Ls) -> WorterbuchResult<()> {
        let children = match self.worterbuch.ls(msg.parent).await {
            Ok(it) => it,
            Result::Err(e) => {
                self.handle_store_error(e, msg.transaction_id).await?;
                return Ok(());
            }
        };

        let response = LsState {
            transaction_id: msg.transaction_id,
            children,
        };

        self.tx
            .send(ServerMessage::LsState(response))
            .await
            .context(|| {
                format!(
                    "Error sending LSSTATE message for transaction ID {}",
                    msg.transaction_id
                )
            })?;

        Ok(())
    }

    pub async fn pls(&self, msg: PLs) -> WorterbuchResult<()> {
        let children = match self.worterbuch.pls(msg.parent_pattern).await {
            Ok(it) => it,
            Result::Err(e) => {
                self.handle_store_error(e, msg.transaction_id).await?;
                return Ok(());
            }
        };

        let response = LsState {
            transaction_id: msg.transaction_id,
            children,
        };

        self.tx
            .send(ServerMessage::LsState(response))
            .await
            .context(|| {
                format!(
                    "Error sending LSSTATE message for transaction ID {}",
                    msg.transaction_id
                )
            })?;

        Ok(())
    }

    pub async fn subscribe_ls(&self, msg: SubscribeLs) -> WorterbuchResult<bool> {
        let (mut rx, subscription) = match self
            .worterbuch
            .subscribe_ls(self.client_id, msg.transaction_id, msg.parent.clone())
            .await
        {
            Ok(it) => it,
            Err(e) => {
                self.handle_store_error(e, msg.transaction_id).await?;
                return Ok(false);
            }
        };

        let response = Ack {
            transaction_id: msg.transaction_id,
        };

        self.tx
            .send(ServerMessage::Ack(response))
            .await
            .context(|| {
                format!(
                    "Error sending ACK message for transaction ID {}",
                    msg.transaction_id
                )
            })?;

        let transaction_id = msg.transaction_id;

        let wb_unsub = self.worterbuch.clone();
        let client_sub = self.tx.clone();
        let client_id = self.client_id;

        spawn(async move {
            debug!("Receiving events for ls subscription {subscription:?} …");
            while let Some(children) = rx.recv().await {
                let state = LsState {
                    transaction_id,
                    children,
                };
                if let Err(e) = client_sub.send(ServerMessage::LsState(state)).await {
                    error!("Error sending STATE message to client: {e}");
                    break;
                };
            }

            match wb_unsub.unsubscribe_ls(client_id, transaction_id).await {
                Ok(()) => {
                    warn!("Ls Subscription was not cleaned up properly!");
                }
                Err(WorterbuchError::NotSubscribed) => { /* this is expected */ }
                Err(e) => {
                    warn!("Error while unsubscribing ls: {e}");
                }
            }
        });

        Ok(true)
    }

    pub async fn unsubscribe_ls(&self, msg: UnsubscribeLs) -> WorterbuchResult<()> {
        if let Err(e) = self
            .worterbuch
            .unsubscribe_ls(self.client_id, msg.transaction_id)
            .await
        {
            self.handle_store_error(e, msg.transaction_id).await?;
            return Ok(());
        }
        let response = Ack {
            transaction_id: msg.transaction_id,
        };

        self.tx
            .send(ServerMessage::Ack(response))
            .await
            .context(|| {
                format!(
                    "Error sending ACK message for transaction ID {}",
                    msg.transaction_id
                )
            })?;

        Ok(())
    }
}

async fn forward_loop(
    mut rx: mpsc::Receiver<PStateEvent>,
    transaction_id: TransactionId,
    request_pattern: String,
    subscription: SubscriptionId,
    client_sub: mpsc::Sender<ServerMessage>,
) {
    debug!("Receiving events for subscription {subscription:?} …");
    while let Some(event) = rx.recv().await {
        let event = PState {
            transaction_id,
            request_pattern: request_pattern.clone(),
            event,
        };
        if let Err(e) = client_sub.send(ServerMessage::PState(event)).await {
            error!("Error sending STATE message to client: {e}");
            break;
        }
    }
}

async fn aggregate_loop(
    mut rx: mpsc::Receiver<PStateEvent>,
    subscription: SubscriptionInfo,
    client_sub: mpsc::Sender<ServerMessage>,
    client_id: Uuid,
) {
    if !subscription.live_only {
        debug!("Immediately forwarding current state to new subscription {subscription:?} …");

        if let Some(event) = rx.recv().await {
            let event = PState {
                transaction_id: subscription.transaction_id,
                request_pattern: subscription.request_pattern.clone(),
                event,
            };

            if let Err(e) = client_sub.send(ServerMessage::PState(event)).await {
                error!("Error sending STATE message to client: {e}");
                return;
            }
        } else {
            return;
        }
    }

    debug!("Aggregating events for subscription {subscription:?} …");

    let aggregator = PStateAggregator::new(
        client_sub,
        subscription.request_pattern,
        subscription.aggregate_duration,
        subscription.transaction_id,
        subscription.channel_buffer_size,
        client_id,
    );

    while let Some(event) = rx.recv().await {
        if let Err(e) = aggregator.aggregate(event).await {
            error!("Error sending STATE message to client: {e}");
            break;
        }
    }
}