diff options
Diffstat (limited to 'src/third_party/wiredtiger/src/history/hs.c')
| -rw-r--r-- | src/third_party/wiredtiger/src/history/hs.c | 47 |
1 files changed, 39 insertions, 8 deletions
diff --git a/src/third_party/wiredtiger/src/history/hs.c b/src/third_party/wiredtiger/src/history/hs.c index 5c6d2a1f30d..15f86d5c69e 100644 --- a/src/third_party/wiredtiger/src/history/hs.c +++ b/src/third_party/wiredtiger/src/history/hs.c @@ -574,14 +574,15 @@ __wt_hs_insert_updates(WT_SESSION_IMPL *session, WT_PAGE *page, WT_MULTI *multi) WT_MODIFY entries[MAX_REVERSE_MODIFY_NUM]; WT_MODIFY_VECTOR modifies; WT_SAVE_UPD *list; - WT_UPDATE *prev_upd, *upd; + WT_UPDATE *prev_upd, *second_older_than_prepare, *upd; WT_HS_TIME_POINT stop_time_point; wt_off_t hs_size; uint64_t insert_cnt, max_hs_size; uint32_t i; uint8_t *p; int nentries; - bool squashed; + bool squashed, track_prepare; + uint8_t upd_count; btree = S2BT(session); cursor = session->hs_cursor; @@ -634,6 +635,9 @@ __wt_hs_insert_updates(WT_SESSION_IMPL *session, WT_PAGE *page, WT_MULTI *multi) session, btree, upd = __wt_update_obsolete_check(session, page, list->onpage_upd, true)); __wt_free_update_list(session, &upd); upd = list->onpage_upd; + second_older_than_prepare = NULL; + track_prepare = false; + upd_count = 0; /* * The algorithm assumes the oldest update on the update chain in memory is either a full @@ -666,6 +670,32 @@ __wt_hs_insert_updates(WT_SESSION_IMPL *session, WT_PAGE *page, WT_MULTI *multi) if (upd->txnid == WT_TXN_ABORTED) continue; WT_ERR(__wt_modify_vector_push(&modifies, upd)); + + /* + * If the update is the second update older than the prepared update and we haven't seen + * a tombstone. Mark the update. + */ + if (upd->prepare_state == WT_PREPARE_INPROGRESS) { + /* + * No normal update between prepared updates and the first prepared update cannot be + * a tombstone. + */ + WT_ASSERT(session, (track_prepare && upd_count == 0) || + (!track_prepare && upd->type != WT_UPDATE_TOMBSTONE)); + track_prepare = true; + } else if (track_prepare) { + if (upd->type == WT_UPDATE_TOMBSTONE) { + upd_count = 0; + track_prepare = false; + } else if (upd_count == 0) + ++upd_count; + else { + second_older_than_prepare = upd; + upd_count = 0; + track_prepare = false; + } + } + /* * If we've reached a full update and its in the history store we don't need to continue * as anything beyond this point won't help with calculating deltas. @@ -763,13 +793,16 @@ __wt_hs_insert_updates(WT_SESSION_IMPL *session, WT_PAGE *page, WT_MULTI *multi) * It is not correct to check prev_upd == list->onpage_upd as we may have aborted * updates in the middle. * - * We can't calculate reverse modify based on an uncommitted prepared update because - * it may be aborted. + * We must insert the first and second updates after a prepared update as full + * values because if the prepared update is aborted, we will remove the first update + * after it from the history store to the update chain. Readers reading the older + * values need a full update as the base value for constructing reverse modifies. */ nentries = MAX_REVERSE_MODIFY_NUM; if (!F_ISSET(upd, WT_UPDATE_HS)) { if (upd->type == WT_UPDATE_MODIFY && prev_upd->prepare_state != WT_PREPARE_INPROGRESS && + (second_older_than_prepare == NULL || upd != second_older_than_prepare) && __wt_calc_modify(session, prev_full_value, full_value, prev_full_value->size / 10, entries, &nentries) == 0) { WT_ERR(__wt_modify_pack(cursor, entries, nentries, &modify_value)); @@ -1049,11 +1082,9 @@ __wt_find_hs_upd(WT_SESSION_IMPL *session, WT_ITEM *key, const char *value_forma */ WT_ERR(__wt_buf_set(session, &upd_value->buf, hs_value->data, hs_value->size)); skip_buf: - upd_value->durable_ts = durable_timestamp; - upd_value->txnid = WT_TXN_NONE; + upd_value->tw.durable_start_ts = durable_timestamp; + upd_value->tw.start_txn = WT_TXN_NONE; upd_value->type = upd_type; - upd_value->prepare_state = - (hs_start_ts == durable_timestamp) ? WT_PREPARE_INIT : WT_PREPARE_RESOLVED; done: err: |