(key string)
| 710 | } |
| 711 | |
| 712 | func (c Client) listRotate(key string) (element ReturnValue, err error) { |
| 713 | var actions []dynamodb.TransactWriteItem |
| 714 | |
| 715 | rightEnd, ok, err := c.listFindEnd(key, Right) |
| 716 | |
| 717 | if err != nil || !ok { |
| 718 | return |
| 719 | } |
| 720 | |
| 721 | leftEnd, ok, err := c.listFindEnd(key, Left) |
| 722 | if err != nil || !ok { |
| 723 | return |
| 724 | } |
| 725 | |
| 726 | switch { |
| 727 | case rightEnd.address == leftEnd.address: |
| 728 | element = rightEnd.value |
| 729 | // no action to take |
| 730 | |
| 731 | case leftEnd.right == rightEnd.address: |
| 732 | actions = append(actions, leftEnd.updateBothSidesAction(rightEnd.address, listNull, c)) |
| 733 | actions = append(actions, rightEnd.updateBothSidesAction(listNull, leftEnd.address, c)) |
| 734 | element = rightEnd.value |
| 735 | |
| 736 | case leftEnd.right == rightEnd.left: |
| 737 | middle, ok, err := c.listGetByAddress(key, leftEnd.right) |
| 738 | if err != nil { |
| 739 | return element, err |
| 740 | } |
| 741 | |
| 742 | if !ok { |
| 743 | return element, errors.New("concurrent modification") |
| 744 | } |
| 745 | |
| 746 | actions = append(actions, leftEnd.updateBothSidesAction(rightEnd.address, middle.address, c)) |
| 747 | actions = append(actions, rightEnd.updateBothSidesAction(listNull, leftEnd.address, c)) |
| 748 | actions = append(actions, middle.updateBothSidesAction(leftEnd.address, listNull, c)) |
| 749 | element = rightEnd.value |
| 750 | |
| 751 | default: |
| 752 | penultimateRight, ok, err := c.listGetByAddress(key, rightEnd.left) |
| 753 | if err != nil { |
| 754 | return element, err |
| 755 | } |
| 756 | |
| 757 | if !ok { |
| 758 | return element, errors.New("concurrent modification") |
| 759 | } |
| 760 | |
| 761 | actions = append(actions, leftEnd.updateSideAction(Left, rightEnd.address, c)) |
| 762 | actions = append(actions, rightEnd.updateBothSidesAction(listNull, leftEnd.address, c)) |
| 763 | actions = append(actions, penultimateRight.updateSideAction(Right, listNull, c)) |
| 764 | element = rightEnd.value |
| 765 | } |
| 766 | |
| 767 | if len(actions) > 0 { |
| 768 | _, err = c.ddbClient.TransactWriteItemsRequest(&dynamodb.TransactWriteItemsInput{ |
| 769 | TransactItems: actions, |
no test coverage detected