package msc2836 import ( "bytes" "context" "database/sql" "encoding/base64" "encoding/json" "github.com/matrix-org/dendrite/internal/sqlutil" "github.com/matrix-org/dendrite/setup/base" "github.com/matrix-org/dendrite/setup/config" "github.com/matrix-org/gomatrixserverlib" "github.com/matrix-org/util" ) type eventInfo struct { EventID string OriginServerTS gomatrixserverlib.Timestamp RoomID string } type Database interface { // StoreRelation stores the parent->child and child->parent relationship for later querying. // Also stores the event metadata e.g timestamp StoreRelation(ctx context.Context, ev *gomatrixserverlib.HeaderedEvent) error // ChildrenForParent returns the events who have the given `eventID` as an m.relationship with the // provided `relType`. The returned slice is sorted by origin_server_ts according to whether // `recentFirst` is true or false. ChildrenForParent(ctx context.Context, eventID, relType string, recentFirst bool) ([]eventInfo, error) // ParentForChild returns the parent event for the given child `eventID`. The eventInfo should be nil if // there is no parent for this child event, with no error. The parent eventInfo can be missing the // timestamp if the event is not known to the server. ParentForChild(ctx context.Context, eventID, relType string) (*eventInfo, error) // UpdateChildMetadata persists the children_count and children_hash from this event if and only if // the count is greater than what was previously there. If the count is updated, the event will be // updated to be unexplored. UpdateChildMetadata(ctx context.Context, ev *gomatrixserverlib.HeaderedEvent) error // ChildMetadata returns the children_count and children_hash for the event ID in question. // Also returns the `explored` flag, which is set to true when MarkChildrenExplored is called and is set // back to `false` when a larger count is inserted via UpdateChildMetadata. // Returns nil error if the event ID does not exist. ChildMetadata(ctx context.Context, eventID string) (count int, hash []byte, explored bool, err error) // MarkChildrenExplored sets the 'explored' flag on this event to `true`. MarkChildrenExplored(ctx context.Context, eventID string) error } type DB struct { db *sql.DB writer sqlutil.Writer insertEdgeStmt *sql.Stmt insertNodeStmt *sql.Stmt selectChildrenForParentOldestFirstStmt *sql.Stmt selectChildrenForParentRecentFirstStmt *sql.Stmt selectParentForChildStmt *sql.Stmt updateChildMetadataStmt *sql.Stmt selectChildMetadataStmt *sql.Stmt updateChildMetadataExploredStmt *sql.Stmt } // NewDatabase loads the database for msc2836 func NewDatabase(base *base.BaseDendrite, dbOpts *config.DatabaseOptions) (Database, error) { if dbOpts.ConnectionString.IsPostgres() { return newPostgresDatabase(base, dbOpts) } return newSQLiteDatabase(base, dbOpts) } func newPostgresDatabase(base *base.BaseDendrite, dbOpts *config.DatabaseOptions) (Database, error) { d := DB{} var err error if d.db, d.writer, err = base.DatabaseConnection(dbOpts, sqlutil.NewDummyWriter()); err != nil { return nil, err } _, err = d.db.Exec(` CREATE TABLE IF NOT EXISTS msc2836_edges ( parent_event_id TEXT NOT NULL, child_event_id TEXT NOT NULL, rel_type TEXT NOT NULL, parent_room_id TEXT NOT NULL, parent_servers TEXT NOT NULL, CONSTRAINT msc2836_edges_uniq UNIQUE (parent_event_id, child_event_id, rel_type) ); CREATE TABLE IF NOT EXISTS msc2836_nodes ( event_id TEXT PRIMARY KEY NOT NULL, origin_server_ts BIGINT NOT NULL, room_id TEXT NOT NULL, unsigned_children_count BIGINT NOT NULL, unsigned_children_hash TEXT NOT NULL, explored SMALLINT NOT NULL ); `) if err != nil { return nil, err } if d.insertEdgeStmt, err = d.db.Prepare(` INSERT INTO msc2836_edges(parent_event_id, child_event_id, rel_type, parent_room_id, parent_servers) VALUES($1, $2, $3, $4, $5) ON CONFLICT DO NOTHING `); err != nil { return nil, err } if d.insertNodeStmt, err = d.db.Prepare(` INSERT INTO msc2836_nodes(event_id, origin_server_ts, room_id, unsigned_children_count, unsigned_children_hash, explored) VALUES($1, $2, $3, $4, $5, $6) ON CONFLICT DO NOTHING `); err != nil { return nil, err } selectChildrenQuery := ` SELECT child_event_id, origin_server_ts, room_id FROM msc2836_edges LEFT JOIN msc2836_nodes ON msc2836_edges.child_event_id = msc2836_nodes.event_id WHERE parent_event_id = $1 AND rel_type = $2 ORDER BY origin_server_ts ` if d.selectChildrenForParentOldestFirstStmt, err = d.db.Prepare(selectChildrenQuery + "ASC"); err != nil { return nil, err } if d.selectChildrenForParentRecentFirstStmt, err = d.db.Prepare(selectChildrenQuery + "DESC"); err != nil { return nil, err } if d.selectParentForChildStmt, err = d.db.Prepare(` SELECT parent_event_id, parent_room_id FROM msc2836_edges WHERE child_event_id = $1 AND rel_type = $2 `); err != nil { return nil, err } if d.updateChildMetadataStmt, err = d.db.Prepare(` UPDATE msc2836_nodes SET unsigned_children_count=$1, unsigned_children_hash=$2, explored=$3 WHERE event_id=$4 `); err != nil { return nil, err } if d.selectChildMetadataStmt, err = d.db.Prepare(` SELECT unsigned_children_count, unsigned_children_hash, explored FROM msc2836_nodes WHERE event_id=$1 `); err != nil { return nil, err } if d.updateChildMetadataExploredStmt, err = d.db.Prepare(` UPDATE msc2836_nodes SET explored=$1 WHERE event_id=$2 `); err != nil { return nil, err } return &d, err } func newSQLiteDatabase(base *base.BaseDendrite, dbOpts *config.DatabaseOptions) (Database, error) { d := DB{} var err error if d.db, d.writer, err = base.DatabaseConnection(dbOpts, sqlutil.NewExclusiveWriter()); err != nil { return nil, err } _, err = d.db.Exec(` CREATE TABLE IF NOT EXISTS msc2836_edges ( parent_event_id TEXT NOT NULL, child_event_id TEXT NOT NULL, rel_type TEXT NOT NULL, parent_room_id TEXT NOT NULL, parent_servers TEXT NOT NULL, UNIQUE (parent_event_id, child_event_id, rel_type) ); CREATE TABLE IF NOT EXISTS msc2836_nodes ( event_id TEXT PRIMARY KEY NOT NULL, origin_server_ts BIGINT NOT NULL, room_id TEXT NOT NULL, unsigned_children_count BIGINT NOT NULL, unsigned_children_hash TEXT NOT NULL, explored SMALLINT NOT NULL ); `) if err != nil { return nil, err } if d.insertEdgeStmt, err = d.db.Prepare(` INSERT INTO msc2836_edges(parent_event_id, child_event_id, rel_type, parent_room_id, parent_servers) VALUES($1, $2, $3, $4, $5) ON CONFLICT (parent_event_id, child_event_id, rel_type) DO NOTHING `); err != nil { return nil, err } if d.insertNodeStmt, err = d.db.Prepare(` INSERT INTO msc2836_nodes(event_id, origin_server_ts, room_id, unsigned_children_count, unsigned_children_hash, explored) VALUES($1, $2, $3, $4, $5, $6) ON CONFLICT DO NOTHING `); err != nil { return nil, err } selectChildrenQuery := ` SELECT child_event_id, origin_server_ts, room_id FROM msc2836_edges LEFT JOIN msc2836_nodes ON msc2836_edges.child_event_id = msc2836_nodes.event_id WHERE parent_event_id = $1 AND rel_type = $2 ORDER BY origin_server_ts ` if d.selectChildrenForParentOldestFirstStmt, err = d.db.Prepare(selectChildrenQuery + "ASC"); err != nil { return nil, err } if d.selectChildrenForParentRecentFirstStmt, err = d.db.Prepare(selectChildrenQuery + "DESC"); err != nil { return nil, err } if d.selectParentForChildStmt, err = d.db.Prepare(` SELECT parent_event_id, parent_room_id FROM msc2836_edges WHERE child_event_id = $1 AND rel_type = $2 `); err != nil { return nil, err } if d.updateChildMetadataStmt, err = d.db.Prepare(` UPDATE msc2836_nodes SET unsigned_children_count=$1, unsigned_children_hash=$2, explored=$3 WHERE event_id=$4 `); err != nil { return nil, err } if d.selectChildMetadataStmt, err = d.db.Prepare(` SELECT unsigned_children_count, unsigned_children_hash, explored FROM msc2836_nodes WHERE event_id=$1 `); err != nil { return nil, err } if d.updateChildMetadataExploredStmt, err = d.db.Prepare(` UPDATE msc2836_nodes SET explored=$1 WHERE event_id=$2 `); err != nil { return nil, err } return &d, nil } func (p *DB) StoreRelation(ctx context.Context, ev *gomatrixserverlib.HeaderedEvent) error { parent, child, relType := parentChildEventIDs(ev) if parent == "" || child == "" { return nil } relationRoomID, relationServers := roomIDAndServers(ev) relationServersJSON, err := json.Marshal(relationServers) if err != nil { return err } count, hash := extractChildMetadata(ev) return p.writer.Do(p.db, nil, func(txn *sql.Tx) error { _, err := txn.Stmt(p.insertEdgeStmt).ExecContext(ctx, parent, child, relType, relationRoomID, string(relationServersJSON)) if err != nil { return err } util.GetLogger(ctx).Infof("StoreRelation child=%s parent=%s rel_type=%s", child, parent, relType) _, err = txn.Stmt(p.insertNodeStmt).ExecContext(ctx, ev.EventID(), ev.OriginServerTS(), ev.RoomID(), count, base64.RawStdEncoding.EncodeToString(hash), 0) return err }) } func (p *DB) UpdateChildMetadata(ctx context.Context, ev *gomatrixserverlib.HeaderedEvent) error { eventCount, eventHash := extractChildMetadata(ev) if eventCount == 0 { return nil // nothing to update with } // extract current children count/hash, if they are less than the current event then update the columns and set to unexplored count, hash, _, err := p.ChildMetadata(ctx, ev.EventID()) if err != nil { return err } if eventCount > count || (eventCount == count && !bytes.Equal(hash, eventHash)) { _, err = p.updateChildMetadataStmt.ExecContext(ctx, eventCount, base64.RawStdEncoding.EncodeToString(eventHash), 0, ev.EventID()) return err } return nil } func (p *DB) ChildMetadata(ctx context.Context, eventID string) (count int, hash []byte, explored bool, err error) { var b64hash string var exploredInt int if err = p.selectChildMetadataStmt.QueryRowContext(ctx, eventID).Scan(&count, &b64hash, &exploredInt); err != nil { if err == sql.ErrNoRows { err = nil } return } hash, err = base64.RawStdEncoding.DecodeString(b64hash) explored = exploredInt > 0 return } func (p *DB) MarkChildrenExplored(ctx context.Context, eventID string) error { _, err := p.updateChildMetadataExploredStmt.ExecContext(ctx, 1, eventID) return err } func (p *DB) ChildrenForParent(ctx context.Context, eventID, relType string, recentFirst bool) ([]eventInfo, error) { var rows *sql.Rows var err error if recentFirst { rows, err = p.selectChildrenForParentRecentFirstStmt.QueryContext(ctx, eventID, relType) } else { rows, err = p.selectChildrenForParentOldestFirstStmt.QueryContext(ctx, eventID, relType) } if err != nil { return nil, err } defer rows.Close() // nolint: errcheck var children []eventInfo for rows.Next() { var evInfo eventInfo if err := rows.Scan(&evInfo.EventID, &evInfo.OriginServerTS, &evInfo.RoomID); err != nil { return nil, err } children = append(children, evInfo) } return children, nil } func (p *DB) ParentForChild(ctx context.Context, eventID, relType string) (*eventInfo, error) { var ei eventInfo err := p.selectParentForChildStmt.QueryRowContext(ctx, eventID, relType).Scan(&ei.EventID, &ei.RoomID) if err == sql.ErrNoRows { return nil, nil } else if err != nil { return nil, err } return &ei, nil } func parentChildEventIDs(ev *gomatrixserverlib.HeaderedEvent) (parent, child, relType string) { if ev == nil { return } body := struct { Relationship struct { RelType string `json:"rel_type"` EventID string `json:"event_id"` } `json:"m.relationship"` }{} if err := json.Unmarshal(ev.Content(), &body); err != nil { return } if body.Relationship.EventID == "" || body.Relationship.RelType == "" { return } return body.Relationship.EventID, ev.EventID(), body.Relationship.RelType } func roomIDAndServers(ev *gomatrixserverlib.HeaderedEvent) (roomID string, servers []string) { servers = []string{} if ev == nil { return } body := struct { RoomID string `json:"relationship_room_id"` Servers []string `json:"relationship_servers"` }{} if err := json.Unmarshal(ev.Unsigned(), &body); err != nil { return } return body.RoomID, body.Servers } func extractChildMetadata(ev *gomatrixserverlib.HeaderedEvent) (count int, hash []byte) { unsigned := struct { Counts map[string]int `json:"children"` Hash gomatrixserverlib.Base64Bytes `json:"children_hash"` }{} if err := json.Unmarshal(ev.Unsigned(), &unsigned); err != nil { // expected if there is no unsigned field at all return } for _, c := range unsigned.Counts { count += c } hash = unsigned.Hash return }