Query history from history server

sable_history/Cargo.toml

@@ -11,6 +11,7 @@ built = { version = "0.5", features = [ "git2" ] }
 sable_network = { path = "../sable_network" }
 sable_server = { path = "../sable_server" }
 
+futures = "0.3"
 tokio = { version = "1.14", features = [ "full" ] }
 serde = { version = "1", features = [ "derive" ] }
 serde_with = "1.11"

sable_history/diesel.toml

@@ -4,6 +4,7 @@
 [print_schema]
 file = "src/schema.rs"
 custom_type_derives = ["diesel::query_builder::QueryId", "Clone"]
+import_types = ["crate::type::*"]
 
 [migrations_directory]
 dir = "migrations"

sable_history/migrations/2024-10-27-125826_reproducible_messages/down.sql

@@ -0,0 +1,7 @@
+DROP INDEX messages_by_timestamp;
+
+ALTER TABLE
+    DROP COLUMN message_type,
+    DROP COLUMN timestamp;
+
+DROP TYPE "MessageType";

sable_history/migrations/2024-10-27-125826_reproducible_messages/up.sql

@@ -0,0 +1,8 @@
+CREATE TYPE "Message_Type" AS ENUM ('privmsg', 'notice');
+
+ALTER TABLE messages
+    ADD COLUMN message_type "Message_Type" NOT NULL,
+    ADD COLUMN timestamp TIMESTAMP NOT NULL;
+
+CREATE INDEX messages_by_timestamp ON messages USING BRIN (timestamp, id);
+COMMENT ON INDEX messages_by_timestamp IS 'Includes the id in order to be a consistent total order across requests';

sable_history/src/lib.rs

@@ -1,5 +1,8 @@
+mod pg_history_service;
+pub use pg_history_service::PgHistoryService;
 mod server;
 pub use server::*;
 
 mod models;
 mod schema;
+mod types;

sable_history/src/models/message.rs

@@ -5,9 +5,19 @@ use super::*;
 #[diesel(check_for_backend(diesel::pg::Pg))]
 #[diesel(belongs_to(Channel, foreign_key = target_channel))]
 #[diesel(belongs_to(HistoricUser, foreign_key = source_user))]
+#[derive(Debug)]
 pub struct Message {
     pub id: Uuid,
     pub source_user: i32,
     pub target_channel: i64,
     pub text: String,
+    pub message_type: crate::types::MessageType,
+    /// Timestamp of the *update* introducing the message.
+    ///
+    /// This is usually the same second as the one in [`id`] (a UUIDv7), but is
+    /// occasionally 1 second later, because the message id is created before being
+    /// pushed to the log.
+    /// It can also before significantly different, because both are based on the
+    /// system clock, which can change arbitrarily.
+    pub timestamp: chrono::NaiveDateTime,
 }

sable_history/src/pg_history_service.rs

@@ -0,0 +1,326 @@
+use std::collections::HashMap;
+
+use anyhow::{bail, Result};
+use chrono::{DateTime, NaiveDateTime, Utc};
+use diesel::dsl::sql;
+use diesel::prelude::*;
+use diesel_async::{AsyncPgConnection, RunQueryDsl};
+use futures::stream::{StreamExt, TryStreamExt};
+use tokio::sync::Mutex;
+use uuid::Uuid;
+
+use sable_network::prelude::*;
+
+use crate::schema::{channels, historic_users, messages};
+
+/// Implementation of [`HistoryService`] backed PostgreSQL
+pub struct PgHistoryService<'a> {
+    database_connection: &'a Mutex<AsyncPgConnection>,
+}
+
+impl<'a> PgHistoryService<'a> {
+    pub fn new(database_connection: &'a Mutex<AsyncPgConnection>) -> Self {
+        Self {
+            database_connection,
+        }
+    }
+}
+
+impl<'a> HistoryService for PgHistoryService<'a> {
+    async fn list_targets(
+        &self,
+        _user: UserId,
+        _after_ts: Option<i64>,
+        _before_ts: Option<i64>,
+        _limit: Option<usize>,
+    ) -> HashMap<TargetId, i64> {
+        // TODO: access control
+        // TODO: after_ts, before_ts, limit
+        match channels::dsl::channels
+            .select((
+                channels::dsl::id,
+                sql::<diesel::pg::sql_types::Uuid>(
+                    "SELECT MAX(id) FROM messages WHERE target_channel=channels.id",
+                ),
+            ))
+            .load_stream(&mut *self.database_connection.lock().await)
+            .await
+        {
+            Err(e) => {
+                tracing::error!("Could not get history channels: {e}");
+                return HashMap::new();
+            }
+            Ok(rows) => rows
+                .map(|row| -> Result<(TargetId, i64)> {
+                    let (channel_id, max_message_id): (i64, Uuid) = row?;
+                    let channel =
+                        TargetId::Channel(ChannelId::from(Snowflake::from(channel_id as u64)));
+
+                    let Some(ts) = max_message_id.get_timestamp() else {
+                        bail!("messages.id should be a UUID7, not {max_message_id}");
+                    };
+                    let (seconds, _) = ts.to_unix();
+                    let Ok(seconds) = seconds.try_into() else {
+                        bail!("message {max_message_id}'s UNIX timestamp is negative");
+                    };
+                    Ok((channel, seconds))
+                })
+                .try_collect()
+                .await
+                .unwrap_or_else(|e| {
+                    tracing::error!("Could not read rows: {e}");
+                    HashMap::new()
+                }),
+        }
+    }
+
+    async fn get_entries(
+        &self,
+        _user: UserId,
+        target: TargetId,
+        request: HistoryRequest,
+    ) -> Result<impl IntoIterator<Item = HistoricalEvent>, HistoryError> {
+        // TODO: access control
+        let TargetId::Channel(channel_id) = target else {
+            // TODO: PMs
+            return Err(HistoryError::InvalidTarget(target));
+        };
+
+        let mut connection_lock = self.database_connection.lock().await;
+
+        let db_channel_id = channel_id.as_u64() as i64;
+        let channel = match channels::dsl::channels
+            .find(db_channel_id)
+            .select(crate::models::Channel::as_select())
+            .first(&mut *connection_lock)
+            .await
+            .optional()
+        {
+            Ok(Some(channel)) => channel,
+            Ok(None) => return Err(HistoryError::InvalidTarget(target)),
+            Err(e) => {
+                tracing::error!("Could not check if channel exists: {e}");
+                return Err(HistoryError::InternalError(
+                    "Could not check if channel exists".to_string(),
+                ));
+            }
+        };
+
+        let base_query = messages::dsl::messages
+            .inner_join(historic_users::dsl::historic_users)
+            .select((
+                messages::dsl::id,
+                messages::dsl::timestamp,
+                messages::dsl::message_type,
+                messages::dsl::text,
+                historic_users::dsl::nick,
+                historic_users::dsl::ident,
+                historic_users::dsl::vhost,
+                historic_users::dsl::account_name,
+            ))
+            .filter(messages::dsl::target_channel.eq(db_channel_id));
+        match request {
+            HistoryRequest::Latest { to_ts, limit } => {
+                let limit = i64::min(10000, i64::try_from(limit).unwrap_or(i64::MAX));
+                match to_ts {
+                    Some(to_ts) => {
+                        let to_ts = DateTime::from_timestamp(to_ts, 999_999)
+                            .unwrap_or(DateTime::<Utc>::MIN_UTC)
+                            .naive_utc();
+                        collect_query(
+                            connection_lock,
+                            &channel,
+                            true, // reverse
+                            base_query
+                                .filter(messages::dsl::timestamp.gt(to_ts))
+                                // total order, consistent across requests
+                                .order((messages::dsl::timestamp.desc(), messages::dsl::id.desc()))
+                                .limit(limit),
+                        )
+                        .await
+                    }
+                    None => {
+                        collect_query(
+                            connection_lock,
+                            &channel,
+                            true, // reverse
+                            base_query
+                                // total order, consistent across requests
+                                .order((messages::dsl::timestamp.desc(), messages::dsl::id.desc()))
+                                .limit(limit),
+                        )
+                        .await
+                    }
+                }
+            }
+            HistoryRequest::Before { from_ts, limit } => {
+                let limit = i64::min(10000, i64::try_from(limit).unwrap_or(i64::MAX));
+                let from_ts = DateTime::from_timestamp(from_ts, 0)
+                    .unwrap_or(DateTime::<Utc>::MAX_UTC)
+                    .naive_utc();
+                collect_query(
+                    connection_lock,
+                    &channel,
+                    true, // reverse
+                    base_query
+                        .filter(messages::dsl::timestamp.lt(from_ts))
+                        // total order, consistent across requests
+                        .order((messages::dsl::timestamp.desc(), messages::dsl::id.desc()))
+                        .limit(limit),
+                )
+                .await
+            }
+            HistoryRequest::After { start_ts, limit } => {
+                let limit = i64::min(10000, i64::try_from(limit).unwrap_or(i64::MAX));
+                let start_ts = DateTime::from_timestamp(start_ts, 999_999)
+                    .unwrap_or(DateTime::<Utc>::MIN_UTC)
+                    .naive_utc();
+                collect_query(
+                    connection_lock,
+                    &channel,
+                    false, // don't reverse
+                    base_query
+                        .filter(messages::dsl::timestamp.gt(start_ts))
+                        // total order, consistent across requests
+                        .order((messages::dsl::timestamp, messages::dsl::id))
+                        .limit(limit),
+                )
+                .await
+            }
+            HistoryRequest::Around { around_ts, limit } => {
+                let limit = i64::min(10000, i64::try_from(limit).unwrap_or(i64::MAX));
+                let around_ts = DateTime::from_timestamp(around_ts, 0)
+                    .unwrap_or(DateTime::<Utc>::MIN_UTC)
+                    .naive_utc();
+                collect_query(
+                    connection_lock,
+                    &channel,
+                    false, // don't reverse
+                    CombineDsl::union(
+                        base_query
+                            .filter(messages::dsl::timestamp.le(around_ts))
+                            // total order, consistent across requests
+                            .order((messages::dsl::timestamp.desc(), messages::dsl::id.desc()))
+                            .limit(limit),
+                        base_query
+                            .filter(messages::dsl::timestamp.gt(around_ts))
+                            // total order, consistent across requests
+                            .order((messages::dsl::timestamp, messages::dsl::id))
+                            .limit(limit),
+                    ),
+                )
+                .await
+                .map(|mut events| {
+                    // TODO: make postgresql sort it, it may be able to do it directly from
+                    // the index scan instead of sorting after the union
+                    events.sort_unstable_by_key(|event| match event {
+                        HistoricalEvent::Message { id, timestamp, .. } => (*timestamp, *id),
+                    });
+                    events
+                })
+            }
+            HistoryRequest::Between {
+                start_ts,
+                end_ts,
+                limit,
+            } => {
+                if start_ts <= end_ts {
+                    let start_ts = DateTime::from_timestamp(start_ts, 999_999)
+                        .unwrap_or(DateTime::<Utc>::MIN_UTC)
+                        .naive_utc();
+                    let end_ts = DateTime::from_timestamp(end_ts, 0)
+                        .unwrap_or(DateTime::<Utc>::MAX_UTC)
+                        .naive_utc();
+                    let limit = i64::min(10000, i64::try_from(limit).unwrap_or(i64::MAX));
+                    collect_query(
+                        connection_lock,
+                        &channel,
+                        false, // don't reverse
+                        base_query
+                            .filter(messages::dsl::timestamp.gt(start_ts))
+                            .filter(messages::dsl::timestamp.lt(end_ts))
+                            // total order, consistent across requests
+                            .order((messages::dsl::timestamp, messages::dsl::id))
+                            .limit(limit),
+                    )
+                    .await
+                } else {
+                    let start_ts = DateTime::from_timestamp(start_ts, 0)
+                        .unwrap_or(DateTime::<Utc>::MAX_UTC)
+                        .naive_utc();
+                    let end_ts = DateTime::from_timestamp(end_ts, 999_999)
+                        .unwrap_or(DateTime::<Utc>::MIN_UTC)
+                        .naive_utc();
+                    let limit = i64::min(10000, i64::try_from(limit).unwrap_or(i64::MAX));
+                    collect_query(
+                        connection_lock,
+                        &channel,
+                        true, // reverse
+                        base_query
+                            .filter(messages::dsl::timestamp.gt(end_ts))
+                            .filter(messages::dsl::timestamp.lt(start_ts))
+                            // total order, consistent across requests
+                            .order((messages::dsl::timestamp.desc(), messages::dsl::id.desc()))
+                            .limit(limit),
+                    )
+                    .await
+                }
+            }
+        }
+    }
+}
+
+type JoinedMessageRow = (
+    uuid::Uuid,
+    NaiveDateTime,
+    crate::types::MessageType,
+    String,
+    String,
+    String,
+    String,
+    Option<String>,
+);
+
+async fn collect_query<'query>(
+    mut connection: tokio::sync::MutexGuard<'_, AsyncPgConnection>,
+    channel: &crate::models::Channel,
+    reverse: bool,
+    query: impl diesel_async::RunQueryDsl<AsyncPgConnection>
+        + diesel_async::methods::LoadQuery<'query, AsyncPgConnection, JoinedMessageRow>
+        + 'query,
+) -> Result<Vec<HistoricalEvent>, HistoryError> {
+    let events = query
+        .load_stream(&mut *connection)
+        .await
+        .map_err(|e| {
+            tracing::error!("Could not query messages: {e}");
+            HistoryError::InternalError("Could not query messages".to_string())
+        })?
+        .map_ok(|row| make_historical_event(channel, row))
+        .try_collect::<Vec<_>>()
+        .await
+        .map_err(|e| {
+            tracing::error!("Could not parse messages: {e}");
+            HistoryError::InternalError("Could not parse message".to_string())
+        })?;
+    Ok(if reverse {
+        events.into_iter().rev().collect()
+    } else {
+        events
+    })
+}
+
+fn make_historical_event(
+    channel: &crate::models::Channel,
+    (id, timestamp, message_type, text, source_nick, source_ident, source_vhost, source_account): JoinedMessageRow,
+) -> HistoricalEvent {
+    HistoricalEvent::Message {
+        id: MessageId::new(id.try_into().expect("Message id is a non-v7 UUID")),
+        timestamp: timestamp.and_utc().timestamp(),
+        source: format!("{}!{}@{}", source_nick, source_ident, source_vhost),
+        source_account,
+        message_type: message_type.into(),
+        target: channel.name.clone(), // assume it's the same
+        text,
+    }
+}