mirror of
https://github.com/webx-top/echo
synced 2021-12-20 05:52:35 +00:00
118 lines
2.6 KiB
Go
118 lines
2.6 KiB
Go
/*
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Copyright 2019 Wenhui Shen <www.webx.top>
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Licensed under the Apache License, Version 2.0 (the "License");
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you may not use this file except in compliance with the License.
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You may obtain a copy of the License at
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http://www.apache.org/licenses/LICENSE-2.0
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Unless required by applicable law or agreed to in writing, software
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distributed under the License is distributed on an "AS IS" BASIS,
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WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
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See the License for the specific language governing permissions and
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limitations under the License.
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*/
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package echo
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import (
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"context"
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"fmt"
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"sync/atomic"
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)
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type Transaction interface {
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Begin(ctx context.Context) error
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Rollback(ctx context.Context) error
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Commit(ctx context.Context) error
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End(ctx context.Context, succeed bool) error
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}
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var (
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DefaultNopTransaction = NewTransaction(nil)
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DefaultDebugTransaction Transaction = &DebugTransaction{}
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)
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type DebugTransaction struct {
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}
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func (b *DebugTransaction) Begin(ctx context.Context) error {
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fmt.Println(`DebugTransaction: Begin`)
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return nil
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}
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func (b *DebugTransaction) Rollback(ctx context.Context) error {
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fmt.Println(`DebugTransaction: Rollback`)
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return nil
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}
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func (b *DebugTransaction) Commit(ctx context.Context) error {
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fmt.Println(`DebugTransaction: Commit`)
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return nil
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}
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func (b *DebugTransaction) End(ctx context.Context, succeed bool) error {
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if succeed {
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return b.Commit(ctx)
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}
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return b.Rollback(ctx)
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}
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func NewTransaction(trans Transaction) *BaseTransaction {
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return &BaseTransaction{Transaction: trans}
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}
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type BaseTransaction struct {
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i uint64
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Transaction
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}
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func (b *BaseTransaction) Begin(ctx context.Context) error {
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if b.Transaction == nil {
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return nil
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}
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newValue := atomic.LoadUint64(&b.i) + 1
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atomic.SwapUint64(&b.i, newValue)
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if newValue > 1 {
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return nil
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}
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return b.Transaction.Begin(ctx)
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}
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func (b *BaseTransaction) Rollback(ctx context.Context) error {
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if b.Transaction == nil {
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return nil
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}
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if atomic.LoadUint64(&b.i) == 0 {
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return nil
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}
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atomic.SwapUint64(&b.i, 0)
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return b.Transaction.Rollback(ctx)
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}
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func (b *BaseTransaction) Commit(ctx context.Context) error {
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if b.Transaction == nil {
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return nil
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}
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value := atomic.LoadUint64(&b.i)
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if value < 1 {
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panic(`transaction has already been committed or rolled back`)
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}
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value--
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atomic.SwapUint64(&b.i, value)
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if value > 0 {
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return nil
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}
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return b.Transaction.Commit(ctx)
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}
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func (b *BaseTransaction) End(ctx context.Context, succeed bool) error {
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if succeed {
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return b.Commit(ctx)
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}
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return b.Rollback(ctx)
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}
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