110 lines
3.0 KiB
Go
110 lines
3.0 KiB
Go
// Copyright 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 sqlutil
|
|
|
|
import (
|
|
"database/sql"
|
|
"errors"
|
|
"fmt"
|
|
"runtime"
|
|
)
|
|
|
|
// ErrUserExists is returned if a username already exists in the database.
|
|
var ErrUserExists = errors.New("Username already exists")
|
|
|
|
// A Transaction is something that can be committed or rolledback.
|
|
type Transaction interface {
|
|
// Commit the transaction
|
|
Commit() error
|
|
// Rollback the transaction.
|
|
Rollback() error
|
|
}
|
|
|
|
// EndTransaction ends a transaction.
|
|
// If the transaction succeeded then it is committed, otherwise it is rolledback.
|
|
// You MUST check the error returned from this function to be sure that the transaction
|
|
// was applied correctly. For example, 'database is locked' errors in sqlite will happen here.
|
|
func EndTransaction(txn Transaction, succeeded *bool) error {
|
|
if *succeeded {
|
|
return txn.Commit() // nolint: errcheck
|
|
} else {
|
|
return txn.Rollback() // nolint: errcheck
|
|
}
|
|
}
|
|
|
|
// WithTransaction runs a block of code passing in an SQL transaction
|
|
// If the code returns an error or panics then the transactions is rolledback
|
|
// Otherwise the transaction is committed.
|
|
func WithTransaction(db *sql.DB, fn func(txn *sql.Tx) error) (err error) {
|
|
txn, err := db.Begin()
|
|
if err != nil {
|
|
return fmt.Errorf("sqlutil.WithTransaction.Begin: %w", err)
|
|
}
|
|
succeeded := false
|
|
defer func() {
|
|
err2 := EndTransaction(txn, &succeeded)
|
|
if err == nil && err2 != nil { // failed to commit/rollback
|
|
err = err2
|
|
}
|
|
}()
|
|
|
|
err = fn(txn)
|
|
if err != nil {
|
|
return
|
|
}
|
|
|
|
succeeded = true
|
|
return
|
|
}
|
|
|
|
// TxStmt wraps an SQL stmt inside an optional transaction.
|
|
// If the transaction is nil then it returns the original statement that will
|
|
// run outside of a transaction.
|
|
// Otherwise returns a copy of the statement that will run inside the transaction.
|
|
func TxStmt(transaction *sql.Tx, statement *sql.Stmt) *sql.Stmt {
|
|
if transaction != nil {
|
|
statement = transaction.Stmt(statement)
|
|
}
|
|
return statement
|
|
}
|
|
|
|
// Hack of the century
|
|
func QueryVariadic(count int) string {
|
|
return QueryVariadicOffset(count, 0)
|
|
}
|
|
|
|
func QueryVariadicOffset(count, offset int) string {
|
|
str := "("
|
|
for i := 0; i < count; i++ {
|
|
str += fmt.Sprintf("$%d", i+offset+1)
|
|
if i < (count - 1) {
|
|
str += ", "
|
|
}
|
|
}
|
|
str += ")"
|
|
return str
|
|
}
|
|
|
|
func SQLiteDriverName() string {
|
|
if runtime.GOOS == "js" {
|
|
return "sqlite3_js"
|
|
}
|
|
return "sqlite3"
|
|
}
|
|
|
|
type TransactionWriter interface {
|
|
Do(db *sql.DB, txn *sql.Tx, f func(txn *sql.Tx) error) error
|
|
}
|