dendrite/appservice/storage/sqlite3/appservice_events_table.go

250 lines
7.4 KiB
Go

// Copyright 2018 New Vector Ltd
// Copyright 2019-2020 The Matrix.org Foundation C.I.C.
//
// 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 sqlite3
import (
"context"
"database/sql"
"encoding/json"
"time"
"github.com/matrix-org/gomatrixserverlib"
log "github.com/sirupsen/logrus"
)
const appserviceEventsSchema = `
-- Stores events to be sent to application services
CREATE TABLE IF NOT EXISTS appservice_events (
-- An auto-incrementing id unique to each event in the table
id INTEGER PRIMARY KEY AUTOINCREMENT,
-- The ID of the application service the event will be sent to
as_id TEXT NOT NULL,
-- JSON representation of the event
headered_event_json TEXT NOT NULL,
-- The ID of the transaction that this event is a part of
txn_id INTEGER NOT NULL
);
CREATE INDEX IF NOT EXISTS appservice_events_as_id ON appservice_events(as_id);
`
const selectEventsByApplicationServiceIDSQL = "" +
"SELECT id, headered_event_json, txn_id " +
"FROM appservice_events WHERE as_id = $1 ORDER BY txn_id DESC, id ASC"
const countEventsByApplicationServiceIDSQL = "" +
"SELECT COUNT(id) FROM appservice_events WHERE as_id = $1"
const insertEventSQL = "" +
"INSERT INTO appservice_events(as_id, headered_event_json, txn_id) " +
"VALUES ($1, $2, $3)"
const updateTxnIDForEventsSQL = "" +
"UPDATE appservice_events SET txn_id = $1 WHERE as_id = $2 AND id <= $3"
const deleteEventsBeforeAndIncludingIDSQL = "" +
"DELETE FROM appservice_events WHERE as_id = $1 AND id <= $2"
const (
// A transaction ID number that no transaction should ever have. Used for
// checking again the default value.
invalidTxnID = -2
)
type eventsStatements struct {
selectEventsByApplicationServiceIDStmt *sql.Stmt
countEventsByApplicationServiceIDStmt *sql.Stmt
insertEventStmt *sql.Stmt
updateTxnIDForEventsStmt *sql.Stmt
deleteEventsBeforeAndIncludingIDStmt *sql.Stmt
}
func (s *eventsStatements) prepare(db *sql.DB) (err error) {
_, err = db.Exec(appserviceEventsSchema)
if err != nil {
return
}
if s.selectEventsByApplicationServiceIDStmt, err = db.Prepare(selectEventsByApplicationServiceIDSQL); err != nil {
return
}
if s.countEventsByApplicationServiceIDStmt, err = db.Prepare(countEventsByApplicationServiceIDSQL); err != nil {
return
}
if s.insertEventStmt, err = db.Prepare(insertEventSQL); err != nil {
return
}
if s.updateTxnIDForEventsStmt, err = db.Prepare(updateTxnIDForEventsSQL); err != nil {
return
}
if s.deleteEventsBeforeAndIncludingIDStmt, err = db.Prepare(deleteEventsBeforeAndIncludingIDSQL); err != nil {
return
}
return
}
// selectEventsByApplicationServiceID takes in an application service ID and
// returns a slice of events that need to be sent to that application service,
// as well as an int later used to remove these same events from the database
// once successfully sent to an application service.
func (s *eventsStatements) selectEventsByApplicationServiceID(
ctx context.Context,
applicationServiceID string,
limit int,
) (
txnID, maxID int,
events []gomatrixserverlib.HeaderedEvent,
eventsRemaining bool,
err error,
) {
// Retrieve events from the database. Unsuccessfully sent events first
eventRows, err := s.selectEventsByApplicationServiceIDStmt.QueryContext(ctx, applicationServiceID)
if err != nil {
return
}
defer func() {
err = eventRows.Close()
if err != nil {
log.WithFields(log.Fields{
"appservice": applicationServiceID,
}).WithError(err).Fatalf("appservice unable to select new events to send")
}
}()
events, maxID, txnID, eventsRemaining, err = retrieveEvents(eventRows, limit)
if err != nil {
return
}
return
}
func retrieveEvents(eventRows *sql.Rows, limit int) (events []gomatrixserverlib.HeaderedEvent, maxID, txnID int, eventsRemaining bool, err error) {
// Get current time for use in calculating event age
nowMilli := time.Now().UnixNano() / int64(time.Millisecond)
// Iterate through each row and store event contents
// If txn_id changes dramatically, we've switched from collecting old events to
// new ones. Send back those events first.
lastTxnID := invalidTxnID
for eventsProcessed := 0; eventRows.Next(); {
var event gomatrixserverlib.HeaderedEvent
var eventJSON []byte
var id int
err = eventRows.Scan(
&id,
&eventJSON,
&txnID,
)
if err != nil {
return nil, 0, 0, false, err
}
// Unmarshal eventJSON
if err = json.Unmarshal(eventJSON, &event); err != nil {
return nil, 0, 0, false, err
}
// If txnID has changed on this event from the previous event, then we've
// reached the end of a transaction's events. Return only those events.
if lastTxnID > invalidTxnID && lastTxnID != txnID {
return events, maxID, lastTxnID, true, nil
}
lastTxnID = txnID
// Limit events that aren't part of an old transaction
if txnID == -1 {
// Return if we've hit the limit
if eventsProcessed++; eventsProcessed > limit {
return events, maxID, lastTxnID, true, nil
}
}
if id > maxID {
maxID = id
}
// Portion of the event that is unsigned due to rapid change
// TODO: Consider removing age as not many app services use it
if err = event.SetUnsignedField("age", nowMilli-int64(event.OriginServerTS())); err != nil {
return nil, 0, 0, false, err
}
events = append(events, event)
}
return
}
// countEventsByApplicationServiceID inserts an event mapped to its corresponding application service
// IDs into the db.
func (s *eventsStatements) countEventsByApplicationServiceID(
ctx context.Context,
appServiceID string,
) (int, error) {
var count int
err := s.countEventsByApplicationServiceIDStmt.QueryRowContext(ctx, appServiceID).Scan(&count)
if err != nil && err != sql.ErrNoRows {
return 0, err
}
return count, nil
}
// insertEvent inserts an event mapped to its corresponding application service
// IDs into the db.
func (s *eventsStatements) insertEvent(
ctx context.Context,
appServiceID string,
event *gomatrixserverlib.HeaderedEvent,
) (err error) {
// Convert event to JSON before inserting
eventJSON, err := json.Marshal(event)
if err != nil {
return err
}
_, err = s.insertEventStmt.ExecContext(
ctx,
appServiceID,
eventJSON,
-1, // No transaction ID yet
)
return
}
// updateTxnIDForEvents sets the transactionID for a collection of events. Done
// before sending them to an AppService. Referenced before sending to make sure
// we aren't constructing multiple transactions with the same events.
func (s *eventsStatements) updateTxnIDForEvents(
ctx context.Context,
appserviceID string,
maxID, txnID int,
) (err error) {
_, err = s.updateTxnIDForEventsStmt.ExecContext(ctx, txnID, appserviceID, maxID)
return
}
// deleteEventsBeforeAndIncludingID removes events matching given IDs from the database.
func (s *eventsStatements) deleteEventsBeforeAndIncludingID(
ctx context.Context,
appserviceID string,
eventTableID int,
) (err error) {
_, err = s.deleteEventsBeforeAndIncludingIDStmt.ExecContext(ctx, appserviceID, eventTableID)
return
}