Store outlier room events. (#3)

* Storage functions for event types
* Consume outlier room events

src/github.com/matrix-org/dendrite/roomserver/api/input.go

@@ -23,6 +23,7 @@ const (
 )
 
 // InputRoomEvent is a matrix room event to add to the room server database.
+// TODO: Implement UnmarshalJSON/MarshalJSON in a way that does something sensible with the event JSON.
 type InputRoomEvent struct {
 	// Whether this event is new, backfilled or an outlier.
 	// This controls how the event is processed.

src/github.com/matrix-org/dendrite/roomserver/input/consumer.go

@@ -2,12 +2,15 @@
 package input
 
 import (
+	"encoding/json"
+	"github.com/matrix-org/dendrite/roomserver/api"
 	"github.com/matrix-org/dendrite/roomserver/types"
 	sarama "gopkg.in/Shopify/sarama.v1"
 )
 
 // A ConsumerDatabase has the storage APIs needed by the consumer.
 type ConsumerDatabase interface {
+	RoomEventDatabase
 	// PartitionOffsets returns the offsets the consumer has reached for each partition.
 	PartitionOffsets(topic string) ([]types.PartitionOffset, error)
 	// SetPartitionOffset records where the consumer has reached for a partition.
@@ -87,7 +90,21 @@ func (c *Consumer) Start() error {
 func (c *Consumer) consumePartition(pc sarama.PartitionConsumer) {
 	defer pc.Close()
 	for message := range pc.Messages() {
-		// TODO: Do stuff with message.
+		var input api.InputRoomEvent
+		if err := json.Unmarshal(message.Value, &input); err != nil {
+			// If the message is invalid then log it and move onto the next message in the stream.
+			c.logError(message, err)
+		} else {
+			if err := processRoomEvent(c.DB, input); err != nil {
+				// If there was an error processing the message then log it and
+				// move onto the next message in the stream.
+				// TODO: If the error was due to a problem talking to the database
+				// then we shouldn't move onto the next message and we should either
+				// retry processing the message, or panic and kill ourselves.
+				c.logError(message, err)
+			}
+		}
+		// Advance our position in the stream so that we will start at the right position after a restart.
 		if err := c.DB.SetPartitionOffset(c.RoomEventTopic, message.Partition, message.Offset); err != nil {
 			c.logError(message, err)
 		}

src/github.com/matrix-org/dendrite/roomserver/input/events.go

@@ -0,0 +1,46 @@
+package input
+
+import (
+	"github.com/matrix-org/dendrite/roomserver/api"
+	"github.com/matrix-org/gomatrixserverlib"
+)
+
+// A RoomEventDatabase has the storage APIs needed to store a room event.
+type RoomEventDatabase interface {
+	StoreEvent(event gomatrixserverlib.Event) error
+}
+
+func processRoomEvent(db RoomEventDatabase, input api.InputRoomEvent) error {
+	// Parse and validate the event JSON
+	event, err := gomatrixserverlib.NewEventFromUntrustedJSON(input.Event)
+	if err != nil {
+		return err
+	}
+
+	if err := db.StoreEvent(event); err != nil {
+		return err
+	}
+
+	// TODO:
+	//  * Check that the event passes authentication checks.
+
+	if input.Kind == api.KindOutlier {
+		// For outliers we can stop after we've stored the event itself as it
+		// doesn't have any associated state to store and we don't need to
+		// notify anyone about it.
+		return nil
+	}
+
+	// TODO:
+	//  * Calcuate the state at the event if necessary.
+	//  * Store the state at the event.
+	//  * Update the extremities of the event graph for the room
+	//  * Caculate the new current state for the room if the forward extremities have changed.
+	//  * Work out the delta between the new current state and the previous current state.
+	//  * Work out the visibility of the event.
+	//  * Write a message to the output logs containing:
+	//      - The event itself
+	//      - The visiblity of the event, i.e. who is allowed to see the event.
+	//      - The changes to the current state of the room.
+	panic("Not implemented")
+}

src/github.com/matrix-org/dendrite/roomserver/storage/sql.go

@@ -8,35 +8,70 @@ import (
 type statements struct {
 	selectPartitionOffsetsStmt *sql.Stmt
 	upsertPartitionOffsetStmt  *sql.Stmt
+	insertEventTypeNIDStmt     *sql.Stmt
+	selectEventTypeNIDStmt     *sql.Stmt
+	insertEventStateKeyNIDStmt *sql.Stmt
+	selectEventStateKeyNIDStmt *sql.Stmt
+	insertRoomNIDStmt          *sql.Stmt
+	selectRoomNIDStmt          *sql.Stmt
+	insertEventStmt            *sql.Stmt
+	insertEventJSONStmt        *sql.Stmt
 }
 
 func (s *statements) prepare(db *sql.DB) error {
 	var err error
 
-	_, err = db.Exec(partitionOffsetsSchema)
-	if err != nil {
+	if err = s.preparePartitionOffsets(db); err != nil {
 		return err
 	}
 
-	if s.selectPartitionOffsetsStmt, err = db.Prepare(selectPartitionOffsetsSQL); err != nil {
+	if err = s.prepareEventTypes(db); err != nil {
 		return err
 	}
+
+	if err = s.prepareEventStateKeys(db); err != nil {
+		return err
+	}
+
+	if err = s.prepareRooms(db); err != nil {
+		return err
+	}
+
+	if err = s.prepareEvents(db); err != nil {
+		return err
+	}
+
+	if err = s.prepareEventJSON(db); err != nil {
+		return err
+	}
+
+	return nil
+}
+
+func (s *statements) preparePartitionOffsets(db *sql.DB) (err error) {
+	_, err = db.Exec(partitionOffsetsSchema)
+	if err != nil {
+		return
+	}
+	if s.selectPartitionOffsetsStmt, err = db.Prepare(selectPartitionOffsetsSQL); err != nil {
+		return
+	}
 	if s.upsertPartitionOffsetStmt, err = db.Prepare(upsertPartitionOffsetsSQL); err != nil {
-		return err
+		return
 	}
-	return nil
+	return
 }
 
 const partitionOffsetsSchema = `
 -- The offsets that the server has processed up to.
 CREATE TABLE IF NOT EXISTS partition_offsets (
-	-- The name of the topic.
-	topic TEXT NOT NULL,
-	-- The 32-bit partition ID
-	partition INTEGER NOT NULL,
-	-- The 64-bit offset.
-	partition_offset BIGINT NOT NULL,
-	CONSTRAINT topic_partition_unique UNIQUE (topic, partition)
+    -- The name of the topic.
+    topic TEXT NOT NULL,
+    -- The 32-bit partition ID
+    partition INTEGER NOT NULL,
+    -- The 64-bit offset.
+    partition_offset BIGINT NOT NULL,
+    CONSTRAINT topic_partition_unique UNIQUE (topic, partition)
 );
 `
 
@@ -68,3 +103,276 @@ func (s *statements) upsertPartitionOffset(topic string, partition int32, offset
 	_, err := s.upsertPartitionOffsetStmt.Exec(topic, partition, offset)
 	return err
 }
+
+func (s *statements) prepareEventTypes(db *sql.DB) (err error) {
+	_, err = db.Exec(eventTypesSchema)
+	if err != nil {
+		return
+	}
+	if s.insertEventTypeNIDStmt, err = db.Prepare(insertEventTypeNIDSQL); err != nil {
+		return
+	}
+	if s.selectEventTypeNIDStmt, err = db.Prepare(selectEventTypeNIDSQL); err != nil {
+		return
+	}
+	return
+}
+
+const eventTypesSchema = `
+-- Numeric versions of the event "type"s. Event types tend to be taken from a
+-- small common pool. Assigning each a numeric ID should reduce the amount of
+-- data that needs to be stored and fetched from the database.
+-- It also means that many operations can work with int64 arrays rather than
+-- string arrays which may help reduce GC pressure.
+-- Well known event types are pre-assigned numeric IDs:
+--   1 -> m.room.create
+--   2 -> m.room.power_levels
+--   3 -> m.room.join_rules
+--   4 -> m.room.third_party_invite
+--   5 -> m.room.member
+--   6 -> m.room.redaction
+--   7 -> m.room.history_visibility
+-- Picking well-known numeric IDs for the events types that require special
+-- attention during state conflict resolution means that we write that code
+-- using numeric constants.
+-- It also means that the numeric IDs for common event types should be
+-- consistent between different instances which might make ad-hoc debugging
+-- easier.
+-- Other event types are automatically assigned numeric IDs starting from 2**16.
+-- This leaves room to add more pre-assigned numeric IDs and clearly separates
+-- the automatically assigned IDs from the pre-assigned IDs.
+CREATE SEQUENCE IF NOT EXISTS event_type_nid_seq START 65536;
+CREATE TABLE IF NOT EXISTS event_types (
+    -- Local numeric ID for the event type.
+    event_type_nid BIGINT PRIMARY KEY DEFAULT nextval('event_type_nid_seq'),
+    -- The string event_type.
+    event_type TEXT NOT NULL CONSTRAINT event_type_unique UNIQUE
+);
+INSERT INTO event_types (event_type_nid, event_type) VALUES
+    (1, 'm.room.create'),
+    (2, 'm.room.power_levels'),
+    (3, 'm.room.join_rules'),
+    (4, 'm.room.third_party_invite'),
+    (5, 'm.room.member'),
+    (6, 'm.room.redaction'),
+    (7, 'm.room.history_visibility') ON CONFLICT DO NOTHING;
+`
+
+// Assign a new numeric event type ID.
+// The usual case is that the event type is not in the database.
+// In that case the ID will be assigned using the next value from the sequence.
+// We use `RETURNING` to tell postgres to return the assigned ID.
+// But it's possible that the type was added in a query that raced with us.
+// This will result in a conflict on the event_type_unique constraint.
+// We peform a update that does nothing rather that doing nothing at all because
+// postgres won't return anything unless we touch a row in the table.
+const insertEventTypeNIDSQL = "" +
+	"INSERT INTO event_types (event_type) VALUES ($1)" +
+	" ON CONFLICT ON CONSTRAINT event_type_unique" +
+	" DO UPDATE SET event_type = $1" +
+	" RETURNING (event_type_nid)"
+
+const selectEventTypeNIDSQL = "" +
+	"SELECT event_type_nid FROM event_types WHERE event_type = $1"
+
+func (s *statements) insertEventTypeNID(eventType string) (eventTypeNID int64, err error) {
+	err = s.insertEventTypeNIDStmt.QueryRow(eventType).Scan(&eventTypeNID)
+	return
+}
+
+func (s *statements) selectEventTypeNID(eventType string) (eventTypeNID int64, err error) {
+	err = s.selectEventTypeNIDStmt.QueryRow(eventType).Scan(&eventTypeNID)
+	return
+}
+
+func (s *statements) prepareEventStateKeys(db *sql.DB) (err error) {
+	_, err = db.Exec(eventStateKeysSchema)
+	if err != nil {
+		return
+	}
+	if s.insertEventStateKeyNIDStmt, err = db.Prepare(insertEventStateKeyNIDSQL); err != nil {
+		return
+	}
+	if s.selectEventStateKeyNIDStmt, err = db.Prepare(selectEventStateKeyNIDSQL); err != nil {
+		return
+	}
+	return
+}
+
+const eventStateKeysSchema = `
+-- Numeric versions of the event "state_key"s. State keys tend to be reused so
+-- assigning each string a numeric ID should reduce the amount of data that
+-- needs to be stored and fetched from the database.
+-- It also means that many operations can work with int64 arrays rather than
+-- string arrays which may help reduce GC pressure.
+-- Well known state keys are pre-assigned numeric IDs:
+--   1 -> "" (the empty string)
+-- Other state keys are automatically assigned numeric IDs starting from 2**16.
+-- This leaves room to add more pre-assigned numeric IDs and clearly separates
+-- the automatically assigned IDs from the pre-assigned IDs.
+CREATE SEQUENCE IF NOT EXISTS event_state_key_nid_seq START 65536;
+CREATE TABLE IF NOT EXISTS event_state_keys (
+    -- Local numeric ID for the state key.
+    event_state_key_nid BIGINT PRIMARY KEY DEFAULT nextval('event_state_key_nid_seq'),
+    event_state_key TEXT NOT NULL CONSTRAINT event_state_key_unique UNIQUE
+);
+INSERT INTO event_state_keys (event_state_key_nid, event_state_key) VALUES
+    (1, '') ON CONFLICT DO NOTHING;
+`
+
+// Same as insertEventTypeNIDSQL
+const insertEventStateKeyNIDSQL = "" +
+	"INSERT INTO event_state_keys (event_state_key) VALUES ($1)" +
+	" ON CONFLICT ON CONSTRAINT event_state_key_unique" +
+	" DO UPDATE SET event_state_key = $1" +
+	" RETURNING (event_state_key_nid)"
+
+const selectEventStateKeyNIDSQL = "" +
+	"SELECT event_state_key_nid FROM event_state_keys WHERE event_state_key = $1"
+
+func (s *statements) insertEventStateKeyNID(eventStateKey string) (eventStateKeyNID int64, err error) {
+	err = s.insertEventStateKeyNIDStmt.QueryRow(eventStateKey).Scan(&eventStateKeyNID)
+	return
+}
+
+func (s *statements) selectEventStateKeyNID(eventStateKey string) (eventStateKeyNID int64, err error) {
+	err = s.selectEventStateKeyNIDStmt.QueryRow(eventStateKey).Scan(&eventStateKeyNID)
+	return
+}
+
+func (s *statements) prepareRooms(db *sql.DB) (err error) {
+	_, err = db.Exec(roomsSchema)
+	if err != nil {
+		return
+	}
+	if s.insertRoomNIDStmt, err = db.Prepare(insertRoomNIDSQL); err != nil {
+		return
+	}
+	if s.selectRoomNIDStmt, err = db.Prepare(selectRoomNIDSQL); err != nil {
+		return
+	}
+	return
+}
+
+const roomsSchema = `
+CREATE SEQUENCE IF NOT EXISTS room_nid_seq;
+CREATE TABLE IF NOT EXISTS rooms (
+    -- Local numeric ID for the room.
+    room_nid BIGINT PRIMARY KEY DEFAULT nextval('room_nid_seq'),
+    -- Textual ID for the room.
+    room_id TEXT NOT NULL CONSTRAINT room_id_unique UNIQUE
+);
+`
+
+// Same as insertEventTypeNIDSQL
+const insertRoomNIDSQL = "" +
+	"INSERT INTO rooms (room_id) VALUES ($1)" +
+	" ON CONFLICT ON CONSTRAINT room_id_unique" +
+	" DO UPDATE SET room_id = $1" +
+	" RETURNING (room_nid)"
+
+const selectRoomNIDSQL = "" +
+	"SELECT room_nid FROM rooms WHERE room_id = $1"
+
+func (s *statements) insertRoomNID(roomID string) (roomNID int64, err error) {
+	err = s.insertRoomNIDStmt.QueryRow(roomID).Scan(&roomNID)
+	return
+}
+
+func (s *statements) selectRoomNID(roomID string) (roomNID int64, err error) {
+	err = s.selectRoomNIDStmt.QueryRow(roomID).Scan(&roomNID)
+	return
+}
+
+const eventsSchema = `
+-- The events table holds metadata for each event, the actual JSON is stored
+-- separately to keep the size of the rows small.
+CREATE SEQUENCE IF NOT EXISTS event_nid_seq;
+CREATE TABLE IF NOT EXISTS events (
+    -- Local numeric ID for the event.
+    event_nid BIGINT PRIMARY KEY DEFAULT nextval('event_nid_seq'),
+    -- Local numeric ID for the room the event is in.
+    -- This is never 0.
+    room_nid BIGINT NOT NULL,
+    -- Local numeric ID for the type of the event.
+    -- This is never 0.
+    event_type_nid BIGINT NOT NULL,
+    -- Local numeric ID for the state_key of the event
+    -- This is 0 if the event is not a state event.
+    event_state_key_nid BIGINT NOT NULL,
+    -- The textual event id.
+    -- Used to lookup the numeric ID when processing requests.
+    -- Needed for state resolution.
+    -- An event may only appear in this table once.
+    event_id TEXT NOT NULL CONSTRAINT event_id_unique UNIQUE,
+    -- The sha256 reference hash for the event.
+    -- Needed for setting reference hashes when sending new events.
+    reference_sha256 BYTEA NOT NULL
+);
+`
+
+const insertEventSQL = "" +
+	"INSERT INTO events (room_nid, event_type_nid, event_state_key_nid, event_id, reference_sha256)" +
+	" VALUES ($1, $2, $3, $4, $5)" +
+	" ON CONFLICT ON CONSTRAINT event_id_unique" +
+	" DO UPDATE SET event_id = $1" +
+	" RETURNING event_nid"
+
+func (s *statements) prepareEvents(db *sql.DB) (err error) {
+	_, err = db.Exec(eventsSchema)
+	if err != nil {
+		return
+	}
+	if s.insertEventStmt, err = db.Prepare(insertEventSQL); err != nil {
+		return
+	}
+	return
+}
+
+func (s *statements) insertEvent(
+	roomNID, eventTypeNID, eventStateKeyNID int64,
+	eventID string,
+	referenceSHA256 []byte,
+) (eventNID int64, err error) {
+	err = s.insertEventStmt.QueryRow(
+		roomNID, eventTypeNID, eventStateKeyNID, eventID, referenceSHA256,
+	).Scan(&eventNID)
+	return
+}
+
+func (s *statements) prepareEventJSON(db *sql.DB) (err error) {
+	_, err = db.Exec(eventJSONSchema)
+	if err != nil {
+		return
+	}
+	if s.insertEventJSONStmt, err = db.Prepare(insertEventJSONSQL); err != nil {
+		return
+	}
+	return
+}
+
+const eventJSONSchema = `
+-- Stores the JSON for each event. This kept separate from the main events
+-- table to keep the rows in the main events table small.
+CREATE TABLE IF NOT EXISTS event_json (
+    -- Local numeric ID for the event.
+    event_nid BIGINT NOT NULL PRIMARY KEY,
+    -- The JSON for the event.
+    -- Stored as TEXT because this should be valid UTF-8.
+    -- Not stored as a JSONB because we always just pull the entire event
+    -- so there is no point in postgres parsing it.
+    -- Not stored as JSON because we already validate the JSON in the server
+    -- so there is no point in postgres validating it.
+    -- TODO: Should we be compressing the events with Snappy or DEFLATE?
+    event_json TEXT NOT NULL
+);
+`
+
+const insertEventJSONSQL = "" +
+	"INSERT INTO event_json (event_nid, event_json) VALUES ($1, $2)" +
+	" ON CONFLICT DO NOTHING"
+
+func (s *statements) insertEventJSON(eventNID int64, eventJSON []byte) error {
+	_, err := s.insertEventJSONStmt.Exec(eventNID, eventJSON)
+	return err
+}

src/github.com/matrix-org/dendrite/roomserver/storage/storage.go

@@ -5,6 +5,7 @@ import (
 	// Import the postgres database driver.
 	_ "github.com/lib/pq"
 	"github.com/matrix-org/dendrite/roomserver/types"
+	"github.com/matrix-org/gomatrixserverlib"
 )
 
 // A Database is used to store room events and stream offsets.
@@ -35,3 +36,82 @@ func (d *Database) PartitionOffsets(topic string) ([]types.PartitionOffset, erro
 func (d *Database) SetPartitionOffset(topic string, partition int32, offset int64) error {
 	return d.statements.upsertPartitionOffset(topic, partition, offset)
 }
+
+// StoreEvent implements input.EventDatabase
+func (d *Database) StoreEvent(event gomatrixserverlib.Event) error {
+	var (
+		roomNID          int64
+		eventTypeNID     int64
+		eventStateKeyNID int64
+		eventNID         int64
+		err              error
+	)
+
+	if roomNID, err = d.assignRoomNID(event.RoomID()); err != nil {
+		return err
+	}
+
+	if eventTypeNID, err = d.assignEventTypeNID(event.Type()); err != nil {
+		return err
+	}
+
+	eventStateKey := event.StateKey()
+	// Assigned a numeric ID for the state_key if there is one present.
+	// Otherwise set the numeric ID for the state_key to 0.
+	if eventStateKey != nil {
+		if eventStateKeyNID, err = d.assignStateKeyNID(*eventStateKey); err != nil {
+			return err
+		}
+	}
+
+	if eventNID, err = d.statements.insertEvent(
+		roomNID,
+		eventTypeNID,
+		eventStateKeyNID,
+		event.EventID(),
+		event.EventReference().EventSHA256,
+	); err != nil {
+		return err
+	}
+
+	return d.statements.insertEventJSON(eventNID, event.JSON())
+}
+
+func (d *Database) assignRoomNID(roomID string) (int64, error) {
+	// Check if we already have a numeric ID in the database.
+	roomNID, err := d.statements.selectRoomNID(roomID)
+	if err == sql.ErrNoRows {
+		// We don't have a numeric ID so insert one into the database.
+		return d.statements.insertRoomNID(roomID)
+	}
+	if err != nil {
+		return 0, err
+	}
+	return roomNID, nil
+}
+
+func (d *Database) assignEventTypeNID(eventType string) (int64, error) {
+	// Check if we already have a numeric ID in the database.
+	eventTypeNID, err := d.statements.selectEventTypeNID(eventType)
+	if err == sql.ErrNoRows {
+		// We don't have a numeric ID so insert one into the database.
+		return d.statements.insertEventTypeNID(eventType)
+	}
+	if err != nil {
+		return 0, err
+	}
+	return eventTypeNID, nil
+}
+
+func (d *Database) assignStateKeyNID(eventStateKey string) (int64, error) {
+	// Check if we already have a numeric ID in the database.
+	eventStateKeyNID, err := d.statements.selectEventStateKeyNID(eventStateKey)
+	if err == sql.ErrNoRows {
+		// We don't have a numeric ID so insert one into the database.
+		return d.statements.insertEventStateKeyNID(eventStateKey)
+	}
+	if err != nil {
+		return 0, err
+	}
+	return eventStateKeyNID, nil
+}