remove big gap tag of btree and fix memory leak of macro block meta

Co-authored-by: Nsimonjoylet <simonjoylet@gmail.com>

src/storage/ddl/ob_tablet_ddl_kv.cpp

@@ -158,6 +158,12 @@ void ObBlockMetaTree::destroy()
   macro_blocks_.reset();
   block_tree_.destroy();
   data_desc_.reset();
+  for (int64_t i = 0; i < sorted_rowkeys_.count(); ++i) {
+    const ObDataMacroBlockMeta *cur_meta = sorted_rowkeys_.at(i).block_meta_;
+    if (OB_NOT_NULL(cur_meta)) {
+      cur_meta->~ObDataMacroBlockMeta();
+    }
+  }
   sorted_rowkeys_.reset();
   tree_allocator_.reset();
   arena_.reset();
@@ -216,6 +222,9 @@ int ObBlockMetaTree::build_sorted_rowkeys()
       } else if (OB_ISNULL(block_meta)) {
         ret = OB_ERR_UNEXPECTED;
         LOG_WARN("block_meta is null", K(ret), KP(block_meta));
+      } else if (((uint64_t)(block_meta) & 7ULL) != 0) {
+        ret = OB_ERR_UNEXPECTED;
+        LOG_ERROR("invalid btree value", K(ret), KP(block_meta));
       } else {
         IndexItem cur_item(rowkey_wrapper.rowkey_, block_meta);
         cur_item.header_.version_ = ObIndexBlockRowHeader::INDEX_BLOCK_HEADER_V1;

src/storage/memtable/mvcc/ob_keybtree.cpp

@@ -341,9 +341,6 @@ int ScanHandle<BtreeKey, BtreeVal>::get(BtreeKey &key, BtreeVal &val, bool is_ba
     key = leaf->get_key(pos, index);
     val = leaf->get_val_with_tag(pos, version_, index);
     last_key = is_backward? &leaf->get_key(0, index): &leaf->get_key(leaf->size(index) - 1, index);
-    if (maybe_big_gap(is_backward)) {
-      val = (BtreeVal)((uint64_t)val | 2UL);
-    }
   }
   return ret;
 }
@@ -457,30 +454,6 @@ int ScanHandle<BtreeKey, BtreeVal>::find_path(BtreeNode *root, BtreeKey key, int
   return ret;
 }
 
-template<typename BtreeKey, typename BtreeVal>
-bool ScanHandle<BtreeKey, BtreeVal>::maybe_big_gap(bool is_backward) {
-  bool ret = false;
-  BtreeNode* node = nullptr;
-  int pos = 0;
-  MultibitSet *index = &this->index_;
-  if (0 == path_.top_k(3, node, pos)) {
-    if (is_backward) {
-      if (--pos >= 0) {
-        ret = node->get_tag(pos, index);
-      } else {
-        ret = true;
-      }
-    } else {
-      if (++pos < node->size(index)) {
-        ret = node->get_tag(pos, index);
-      } else {
-        ret = true;
-      }
-    }
-  }
-  return ret;
-}
-
 template<typename BtreeKey, typename BtreeVal>
 int ScanHandle<BtreeKey, BtreeVal>::scan_forward(const int64_t level) {
   int ret = OB_SUCCESS;

src/storage/memtable/mvcc/ob_keybtree_deps.h

@@ -447,7 +447,6 @@ public:
       BtreeKey*& last_key, int64_t &gap_size);
   int pop_level_node(const int64_t level);
   int find_path(BtreeNode *root, BtreeKey key, int64_t version);
-  bool maybe_big_gap(bool is_backward);
   int scan_forward(const int64_t level);
   int scan_backward(const int64_t level);
   int scan_forward(bool skip_inactive=false, int64_t* skip_cnt=NULL);

src/storage/memtable/mvcc/ob_query_engine.h

@@ -89,10 +89,9 @@ public:
           TRANS_LOG(WARN, "get_next from keybtree fail", "ret", ret, "value", value_);
         }
       } else {
-        // IN_GAP & BIG_GAP_HINT
         key_.encode(key_wrapper.get_rowkey());
-        iter_flag_ = (uint8_t)((uint64_t)value_ & 3UL);
-        value_ = (ObMvccRow*)((uint64_t)value_ & ~3UL);
+        BTREE_ASSERT(((uint64_t)value_ & 7ULL) == 0);
+        iter_flag_ = 0;
         if (OB_ISNULL(value_)) {
           ret = common::OB_ITER_END;
         } else {