| /* |
| * Licensed to the Apache Software Foundation (ASF) under one or more |
| * contributor license agreements. See the NOTICE file distributed with |
| * this work for additional information regarding copyright ownership. |
| * The ASF licenses this file to You 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 store |
| |
| import ( |
| "context" |
| ) |
| |
| import ( |
| "github.com/pkg/errors" |
| |
| "go.uber.org/multierr" |
| ) |
| |
| type txCtx struct{} |
| |
| func CtxWithTx(ctx context.Context, tx Transaction) context.Context { |
| return context.WithValue(ctx, txCtx{}, tx) |
| } |
| |
| func TxFromCtx(ctx context.Context) (Transaction, bool) { |
| if value, ok := ctx.Value(txCtx{}).(Transaction); ok { |
| return value, true |
| } |
| return nil, false |
| } |
| |
| type Transaction interface { |
| Commit(ctx context.Context) error |
| Rollback(ctx context.Context) error |
| } |
| |
| // Transactions is a producer of transactions if a resource store support transactions. |
| // Transactions are never required for consistency in dubbo, because there are ResourceStores that does not support transactions. |
| // However, in a couple of cases executing queries in transaction can improve the performance. |
| // |
| // In case of Postgres, you may set hooks when retrieve and release connections for the connection pool. |
| // In this case, if you create multiple resources, you need to acquire connection and execute hooks for each create. |
| // If you create transaction for it, you execute hooks once and you hold the connection. |
| // |
| // Transaction is propagated implicitly through Context. |
| type Transactions interface { |
| Begin(ctx context.Context) (Transaction, error) |
| } |
| |
| func InTx(ctx context.Context, transactions Transactions, fn func(ctx context.Context) error) error { |
| tx, err := transactions.Begin(ctx) |
| if err != nil { |
| return err |
| } |
| if err := fn(CtxWithTx(ctx, tx)); err != nil { |
| if rollbackErr := tx.Rollback(ctx); rollbackErr != nil { |
| return multierr.Append(errors.Wrap(rollbackErr, "could not rollback transaction"), err) |
| } |
| return err |
| } |
| return tx.Commit(ctx) |
| } |
| |
| type NoopTransaction struct{} |
| |
| func (n NoopTransaction) Commit(context.Context) error { |
| return nil |
| } |
| |
| func (n NoopTransaction) Rollback(context.Context) error { |
| return nil |
| } |
| |
| var _ Transaction = &NoopTransaction{} |
| |
| type NoTransactions struct{} |
| |
| func (n NoTransactions) Begin(context.Context) (Transaction, error) { |
| return NoopTransaction{}, nil |
| } |
| |
| var _ Transactions = &NoTransactions{} |