Delete one element represented by 'entry' * * 'entry' stores enough metadata to delete the proper position in * the correct ziplist in the correct quicklist node. */
| 656 | * 'entry' stores enough metadata to delete the proper position in |
| 657 | * the correct ziplist in the correct quicklist node. */ |
| 658 | void quicklistDelEntry(quicklistIter *iter, quicklistEntry *entry) { |
| 659 | quicklistNode *prev = entry->node->prev; |
| 660 | quicklistNode *next = entry->node->next; |
| 661 | int deleted_node = quicklistDelIndex((quicklist *)entry->quicklist, |
| 662 | entry->node, &entry->zi); |
| 663 | |
| 664 | /* after delete, the zi is now invalid for any future usage. */ |
| 665 | iter->zi = NULL; |
| 666 | |
| 667 | /* If current node is deleted, we must update iterator node and offset. */ |
| 668 | if (deleted_node) { |
| 669 | if (iter->direction == AL_START_HEAD) { |
| 670 | iter->current = next; |
| 671 | iter->offset = 0; |
| 672 | } else if (iter->direction == AL_START_TAIL) { |
| 673 | iter->current = prev; |
| 674 | iter->offset = -1; |
| 675 | } |
| 676 | } |
| 677 | /* else if (!deleted_node), no changes needed. |
| 678 | * we already reset iter->zi above, and the existing iter->offset |
| 679 | * doesn't move again because: |
| 680 | * - [1, 2, 3] => delete offset 1 => [1, 3]: next element still offset 1 |
| 681 | * - [1, 2, 3] => delete offset 0 => [2, 3]: next element still offset 0 |
| 682 | * if we deleted the last element at offet N and now |
| 683 | * length of this ziplist is N-1, the next call into |
| 684 | * quicklistNext() will jump to the next node. */ |
| 685 | } |
| 686 | |
| 687 | /* Replace quicklist entry at offset 'index' by 'data' with length 'sz'. |
| 688 | * |
no test coverage detected