dendrite/appservice/storage/sqlite3/txn_id_counter_table.go
Neil Alexander b24747b305
Transaction writer changes, move roomserver writers (#1285)
* Updated TransactionWriters, moved locks in roomserver, various other tweaks

* Fix redaction deadlocks

* Fix lint issue

* Rename SQLiteTransactionWriter to ExclusiveTransactionWriter

* Fix us not sending transactions through in latest events updater
2020-08-19 15:38:27 +01:00

69 lines
1.8 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"
"github.com/matrix-org/dendrite/internal/sqlutil"
)
const txnIDSchema = `
-- Keeps a count of the current transaction ID
CREATE TABLE IF NOT EXISTS appservice_counters (
name TEXT PRIMARY KEY NOT NULL,
last_id INTEGER DEFAULT 1
);
INSERT OR IGNORE INTO appservice_counters (name, last_id) VALUES('txn_id', 1);
`
const selectTxnIDSQL = `
SELECT last_id FROM appservice_counters WHERE name='txn_id';
UPDATE appservice_counters SET last_id=last_id+1 WHERE name='txn_id';
`
type txnStatements struct {
db *sql.DB
writer sqlutil.TransactionWriter
selectTxnIDStmt *sql.Stmt
}
func (s *txnStatements) prepare(db *sql.DB) (err error) {
s.db = db
s.writer = sqlutil.NewTransactionWriter()
_, err = db.Exec(txnIDSchema)
if err != nil {
return
}
if s.selectTxnIDStmt, err = db.Prepare(selectTxnIDSQL); err != nil {
return
}
return
}
// selectTxnID selects the latest ascending transaction ID
func (s *txnStatements) selectTxnID(
ctx context.Context,
) (txnID int, err error) {
err = s.writer.Do(s.db, nil, func(txn *sql.Tx) error {
err := s.selectTxnIDStmt.QueryRowContext(ctx).Scan(&txnID)
return err
})
return
}