dendrite/syncapi/storage/postgres/output_room_events_topology_table.go

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// Copyright 2018 New Vector Ltd
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
// http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.
package postgres
import (
"context"
"database/sql"
"github.com/matrix-org/dendrite/internal"
"github.com/matrix-org/dendrite/syncapi/storage/tables"
"github.com/matrix-org/dendrite/syncapi/types"
"github.com/matrix-org/gomatrixserverlib"
)
const outputRoomEventsTopologySchema = `
-- Stores output room events received from the roomserver.
CREATE TABLE IF NOT EXISTS syncapi_output_room_events_topology (
-- The event ID for the event.
event_id TEXT PRIMARY KEY,
-- The place of the event in the room's topology. This can usually be determined
-- from the event's depth.
topological_position BIGINT NOT NULL,
stream_position BIGINT NOT NULL,
-- The 'room_id' key for the event.
room_id TEXT NOT NULL
);
-- The topological order will be used in events selection and ordering
CREATE UNIQUE INDEX IF NOT EXISTS syncapi_event_topological_position_idx ON syncapi_output_room_events_topology(topological_position, stream_position, room_id);
`
const insertEventInTopologySQL = "" +
"INSERT INTO syncapi_output_room_events_topology (event_id, topological_position, room_id, stream_position)" +
" VALUES ($1, $2, $3, $4)" +
" ON CONFLICT (topological_position, stream_position, room_id) DO UPDATE SET event_id = $1"
const selectEventIDsInRangeASCSQL = "" +
"SELECT event_id FROM syncapi_output_room_events_topology" +
" WHERE room_id = $1 AND (" +
"(topological_position > $2 AND topological_position < $3) OR" +
"(topological_position = $4 AND stream_position <= $5)" +
") ORDER BY topological_position ASC, stream_position ASC LIMIT $6"
const selectEventIDsInRangeDESCSQL = "" +
"SELECT event_id FROM syncapi_output_room_events_topology" +
" WHERE room_id = $1 AND (" +
"(topological_position > $2 AND topological_position < $3) OR" +
"(topological_position = $4 AND stream_position <= $5)" +
") ORDER BY topological_position DESC, stream_position DESC LIMIT $6"
const selectPositionInTopologySQL = "" +
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"SELECT topological_position, stream_position FROM syncapi_output_room_events_topology" +
" WHERE event_id = $1"
// Select the max topological position for the room, then sort by stream position and take the highest,
// returning both topological and stream positions.
const selectMaxPositionInTopologySQL = "" +
"SELECT topological_position, stream_position FROM syncapi_output_room_events_topology" +
" WHERE topological_position=(" +
"SELECT MAX(topological_position) FROM syncapi_output_room_events_topology WHERE room_id=$1" +
") ORDER BY stream_position DESC LIMIT 1"
type outputRoomEventsTopologyStatements struct {
insertEventInTopologyStmt *sql.Stmt
selectEventIDsInRangeASCStmt *sql.Stmt
selectEventIDsInRangeDESCStmt *sql.Stmt
selectPositionInTopologyStmt *sql.Stmt
selectMaxPositionInTopologyStmt *sql.Stmt
}
func NewPostgresTopologyTable(db *sql.DB) (tables.Topology, error) {
s := &outputRoomEventsTopologyStatements{}
_, err := db.Exec(outputRoomEventsTopologySchema)
if err != nil {
return nil, err
}
if s.insertEventInTopologyStmt, err = db.Prepare(insertEventInTopologySQL); err != nil {
return nil, err
}
if s.selectEventIDsInRangeASCStmt, err = db.Prepare(selectEventIDsInRangeASCSQL); err != nil {
return nil, err
}
if s.selectEventIDsInRangeDESCStmt, err = db.Prepare(selectEventIDsInRangeDESCSQL); err != nil {
return nil, err
}
if s.selectPositionInTopologyStmt, err = db.Prepare(selectPositionInTopologySQL); err != nil {
return nil, err
}
if s.selectMaxPositionInTopologyStmt, err = db.Prepare(selectMaxPositionInTopologySQL); err != nil {
return nil, err
}
return s, nil
}
// InsertEventInTopology inserts the given event in the room's topology, based
// on the event's depth.
func (s *outputRoomEventsTopologyStatements) InsertEventInTopology(
ctx context.Context, txn *sql.Tx, event *gomatrixserverlib.HeaderedEvent, pos types.StreamPosition,
) (err error) {
_, err = s.insertEventInTopologyStmt.ExecContext(
ctx, event.EventID(), event.Depth(), event.RoomID(), pos,
)
return
}
// SelectEventIDsInRange selects the IDs of events which positions are within a
// given range in a given room's topological order.
// Returns an empty slice if no events match the given range.
func (s *outputRoomEventsTopologyStatements) SelectEventIDsInRange(
ctx context.Context, txn *sql.Tx, roomID string, minDepth, maxDepth, maxStreamPos types.StreamPosition,
limit int, chronologicalOrder bool,
) (eventIDs []string, err error) {
// Decide on the selection's order according to whether chronological order
// is requested or not.
var stmt *sql.Stmt
if chronologicalOrder {
stmt = s.selectEventIDsInRangeASCStmt
} else {
stmt = s.selectEventIDsInRangeDESCStmt
}
// Query the event IDs.
rows, err := stmt.QueryContext(ctx, roomID, minDepth, maxDepth, maxDepth, maxStreamPos, limit)
if err == sql.ErrNoRows {
// If no event matched the request, return an empty slice.
return []string{}, nil
} else if err != nil {
return
}
defer internal.CloseAndLogIfError(ctx, rows, "selectEventIDsInRange: rows.close() failed")
// Return the IDs.
var eventID string
for rows.Next() {
if err = rows.Scan(&eventID); err != nil {
return
}
eventIDs = append(eventIDs, eventID)
}
return eventIDs, rows.Err()
}
// SelectPositionInTopology returns the position of a given event in the
// topology of the room it belongs to.
func (s *outputRoomEventsTopologyStatements) SelectPositionInTopology(
ctx context.Context, txn *sql.Tx, eventID string,
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) (pos, spos types.StreamPosition, err error) {
err = s.selectPositionInTopologyStmt.QueryRowContext(ctx, eventID).Scan(&pos, &spos)
return
}
func (s *outputRoomEventsTopologyStatements) SelectMaxPositionInTopology(
ctx context.Context, txn *sql.Tx, roomID string,
) (pos types.StreamPosition, spos types.StreamPosition, err error) {
err = s.selectMaxPositionInTopologyStmt.QueryRowContext(ctx, roomID).Scan(&pos, &spos)
return
}