示例#1
0
文件: ctxutil.go 项目: oshimaya/go
func ctxDriverBegin(ctx context.Context, ci driver.Conn) (driver.Tx, error) {
	if ciCtx, is := ci.(driver.ConnBeginContext); is {
		return ciCtx.BeginContext(ctx)
	}

	if ctx.Done() == context.Background().Done() {
		return ci.Begin()
	}

	// Check the transaction level in ctx. If set and non-default
	// then return an error here as the BeginContext driver value is not supported.
	if level, ok := driver.IsolationFromContext(ctx); ok && level != driver.IsolationLevel(LevelDefault) {
		return nil, errors.New("sql: driver does not support non-default isolation level")
	}

	// Check for a read-only parameter in ctx. If a read-only transaction is
	// requested return an error as the BeginContext driver value is not supported.
	if ro := driver.ReadOnlyFromContext(ctx); ro {
		return nil, errors.New("sql: driver does not support read-only transactions")
	}

	txi, err := ci.Begin()
	if err == nil {
		select {
		default:
		case <-ctx.Done():
			txi.Rollback()
			return nil, ctx.Err()
		}
	}
	return txi, err
}
示例#2
0
文件: ctxutil.go 项目: Harvey-OS/go
func ctxDriverBegin(ctx context.Context, ci driver.Conn) (driver.Tx, error) {
	if ciCtx, is := ci.(driver.ConnBeginContext); is {
		return ciCtx.BeginContext(ctx)
	}

	if ctx.Done() == context.Background().Done() {
		return ci.Begin()
	}

	// Check the transaction level in ctx. If set and non-default
	// then return an error here as the BeginContext driver value is not supported.
	if level, ok := driver.IsolationFromContext(ctx); ok && level != driver.IsolationLevel(LevelDefault) {
		return nil, errors.New("sql: driver does not support non-default isolation level")
	}

	// Check for a read-only parameter in ctx. If a read-only transaction is
	// requested return an error as the BeginContext driver value is not supported.
	if ro := driver.ReadOnlyFromContext(ctx); ro {
		return nil, errors.New("sql: driver does not support read-only transactions")
	}

	type R struct {
		err   error
		panic interface{}
		txi   driver.Tx
	}
	rc := make(chan R, 1)
	go func() {
		r := R{}
		defer func() {
			if v := recover(); v != nil {
				r.panic = v
			}
			rc <- r
		}()
		r.txi, r.err = ci.Begin()
	}()
	select {
	case <-ctx.Done():
		go func() {
			<-rc
			close(rc)
		}()
		return nil, ctx.Err()
	case r := <-rc:
		if r.panic != nil {
			panic(r.panic)
		}
		return r.txi, r.err
	}
}