[#9162] Fix stack overflow in filtering iterator

Summary:
Filtering iterator could make a call to Next/Prev while checking filter.
But those methods also would check filter.
So, iterating over one skipped entry results in adding two more stack frames, one for Next() or Prev() and one more for ApplyFilter(), and the stack grows proportionally to the number of skipped entries, resulting in a potential stack overflow.

Actually we should call Next/Prev of the underlying iterator in this case, as done in this diff. This approach would only utilize a constant amount of space on the stack and not linear space based on the number of skipped entries.

Test Plan: ybd debug --gtest_filter BackupTxnTest.PointInTimeBigSkipRestore

Reviewers: bogdan, mbautin

Reviewed By: mbautin

Subscribers: ybase

Differential Revision: https://phabricator.dev.yugabyte.com/D12143

src/yb/client/backup-txn-test.cc

@@ -205,6 +205,38 @@ TEST_F(BackupTxnTest, PointInTimeRestore) {
   ASSERT_NO_FATALS(VerifyData(/* num_transactions=*/ 1, WriteOpType::INSERT));
 }
 
+TEST_F(BackupTxnTest, PointInTimeBigSkipRestore) {
+  constexpr int kNumWrites = RegularBuildVsSanitizers(100000, 100);
+  constexpr int kKey = 123;
+
+  std::vector<std::future<FlushStatus>> futures;
+  auto session = CreateSession();
+  ASSERT_OK(WriteRow(session, kKey, 0));
+  auto hybrid_time = cluster_->mini_tablet_server(0)->server()->Clock()->Now();
+  for (size_t r = 1; r <= kNumWrites; ++r) {
+    ASSERT_OK(WriteRow(session, kKey, r, WriteOpType::INSERT, client::Flush::kFalse));
+    futures.push_back(session->FlushFuture());
+  }
+
+  int good = 0;
+  for (auto& future : futures) {
+    if (future.get().status.ok()) {
+      ++good;
+    }
+  }
+
+  LOG(INFO) << "Total good: " << good;
+
+  auto snapshot_id = ASSERT_RESULT(CreateSnapshot());
+  ASSERT_OK(VerifySnapshot(snapshot_id, SysSnapshotEntryPB::COMPLETE));
+
+  ASSERT_OK(RestoreSnapshot(snapshot_id, hybrid_time));
+
+  auto value = ASSERT_RESULT(SelectRow(session, kKey));
+  ASSERT_EQ(value, 0);
+}
+
+
 TEST_F(BackupTxnTest, Persistence) {
   LOG(INFO) << "Write data";
 

src/yb/rocksdb/table/filtering_iterator.h

@@ -103,9 +103,9 @@ class FilteringIterator : public InternalIterator {
         break;
       }
       if (!backward) {
-        Next();
+        iterator_->Next();
       } else {
-        Prev();
+        iterator_->Prev();
       }
     }
   }