Revert to checking the upper bound on a per-key basis in BlockBasedTableIterator (#5428)

Summary:
PR #5111 reduced the number of key comparisons when iterating with
upper/lower bounds; however, this caused a regression for MyRocks.
Reverting to the previous behavior in BlockBasedTableIterator as a hotfix.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/5428

Differential Revision: D15721038

Pulled By: ltamasi

fbshipit-source-id: 5450106442f1763bccd17f6cfd648697f2ae8b6c
This commit is contained in:
Levi Tamasi 2019-06-07 15:13:43 -07:00 committed by Facebook Github Bot
parent ad52626cf4
commit 0f48e56f96
2 changed files with 13 additions and 2 deletions

View file

@ -467,6 +467,8 @@ inline bool DBIter::FindNextUserEntryInternal(bool skipping, bool prefix_check)
is_key_seqnum_zero_ = (ikey_.sequence == 0);
assert(iterate_upper_bound_ == nullptr || iter_.MayBeOutOfUpperBound() ||
user_comparator_.Compare(ikey_.user_key, *iterate_upper_bound_) < 0);
if (iterate_upper_bound_ != nullptr && iter_.MayBeOutOfUpperBound() &&
user_comparator_.Compare(ikey_.user_key, *iterate_upper_bound_) >= 0) {
break;
@ -859,6 +861,9 @@ void DBIter::PrevInternal() {
return;
}
assert(iterate_lower_bound_ == nullptr || iter_.MayBeOutOfLowerBound() ||
user_comparator_.Compare(saved_key_.GetUserKey(),
*iterate_lower_bound_) >= 0);
if (iterate_lower_bound_ != nullptr && iter_.MayBeOutOfLowerBound() &&
user_comparator_.Compare(saved_key_.GetUserKey(),
*iterate_lower_bound_) < 0) {

View file

@ -2597,9 +2597,15 @@ void BlockBasedTableIterator<TBlockIter, TValue>::FindBlockForward() {
return;
}
// Whether next data block is out of upper bound, if there is one.
bool next_block_is_out_of_bound =
// TODO: we should be able to use !data_block_within_upper_bound_ here
// instead of performing the comparison; however, the flag can apparently
// be out of sync with the comparison in some cases. This should be
// investigated.
const bool next_block_is_out_of_bound =
read_options_.iterate_upper_bound != nullptr &&
block_iter_points_to_real_block_ && !data_block_within_upper_bound_;
block_iter_points_to_real_block_ &&
(user_comparator_.Compare(*read_options_.iterate_upper_bound,
index_iter_->user_key()) <= 0);
ResetDataIter();
index_iter_->Next();
if (next_block_is_out_of_bound) {