LibSQL: Fix BTree corruption in TreeNode::split

After splitting a node, the new node was written to the same pointer as
the current node - probably a copy / paste error. This new code requires
a `.pointer() -> u32` to exist on the object to be serialized,
preventing this issue from happening again.

Fixes SerenityOS#15844.

Tests/LibSQL/TestSqlStatementExecution.cpp

@@ -754,4 +754,23 @@ TEST_CASE(binary_operator_failure)
  expect_failure(move(result), '&');
 }
 
+TEST_CASE(describe_large_table_after_persist)
+{
+ ScopeGuard guard([]() { unlink(db_name); });
+ {
+ auto database = SQL::Database::construct(db_name);
+ EXPECT(!database->open().is_error());
+
+ auto result = execute(database, "CREATE TABLE Cookies ( name TEXT, value TEXT, same_site INTEGER, creation_time INTEGER, last_access_time INTEGER, expiry_time INTEGER, domain TEXT, path TEXT, secure INTEGER, http_only INTEGER, host_only INTEGER, persistent INTEGER );");
+ EXPECT_EQ(result.command(), SQL::SQLCommand::Create);
+ }
+ {
+ auto database = SQL::Database::construct(db_name);
+ EXPECT(!database->open().is_error());
+
+ auto result = execute(database, "DESCRIBE TABLE Cookies;");
+ EXPECT_EQ(result.size(), 12u);
+ }
+}
+
 }

Userland/Libraries/LibSQL/BTree.cpp

@@ -56,7 +56,7 @@ TreeNode* BTree::new_root()
 {
  set_pointer(new_record_pointer());
  m_root = make<TreeNode>(*this, nullptr, m_root.leak_ptr(), pointer());
- serializer().serialize_and_write(*m_root.ptr(), m_root->pointer());
+ serializer().serialize_and_write(*m_root.ptr());
  if (on_new_root)
  on_new_root();
  return m_root;

Userland/Libraries/LibSQL/BTreeIterator.cpp

@@ -232,7 +232,7 @@ bool BTreeIterator::update(Key const& new_value)
 
  // We are friend of BTree and TreeNode. Don't know how I feel about that.
  m_current->m_entries[m_index] = new_value;
- m_current->tree().serializer().serialize_and_write(*m_current, m_current->pointer());
+ m_current->tree().serializer().serialize_and_write(*m_current);
  return true;
 }
 

Userland/Libraries/LibSQL/Database.cpp

@@ -223,7 +223,7 @@ ErrorOr<void> Database::update(Row& tuple)
  VERIFY(m_table_cache.get(tuple.table()->key().hash()).has_value());
  // TODO Check constraints
  m_serializer.reset();
- m_serializer.serialize_and_write<Tuple>(tuple, tuple.pointer());
+ m_serializer.serialize_and_write<Tuple>(tuple);
 
  // TODO update indexes defined on table.
  return {};

Userland/Libraries/LibSQL/HashIndex.cpp

@@ -140,7 +140,7 @@ bool HashBucket::insert(Key const& key)
  return false;
  }
  m_entries.append(key);
- m_hash_index.serializer().serialize_and_write(*this, pointer());
+ m_hash_index.serializer().serialize_and_write(*this);
  return true;
 }
 
@@ -226,10 +226,10 @@ HashIndex::HashIndex(Serializer& serializer, NonnullRefPtr<TupleDescriptor> cons
  } else {
  auto bucket = append_bucket(0u, 1u, new_record_pointer());
  bucket->m_inflated = true;
- serializer.serialize_and_write(*bucket, bucket->pointer());
+ serializer.serialize_and_write(*bucket);
  bucket = append_bucket(1u, 1u, new_record_pointer());
  bucket->m_inflated = true;
- serializer.serialize_and_write(*bucket, bucket->pointer());
+ serializer.serialize_and_write(*bucket);
  m_nodes.append(first_node);
  write_directory_to_write_ahead_log();
  }
@@ -283,7 +283,7 @@ HashBucket* HashIndex::get_bucket_for_insert(Key const& key)
  }
  if (moved > 0) {
  dbgln_if(SQL_DEBUG, "Moved {} entries from bucket #{} to #{}", moved, base_index, ix);
- serializer().serialize_and_write(*sub_bucket, sub_bucket->pointer());
+ serializer().serialize_and_write(*sub_bucket);
  }
  total_moved += moved;
  }
@@ -292,7 +292,7 @@ HashBucket* HashIndex::get_bucket_for_insert(Key const& key)
  else
  dbgln_if(SQL_DEBUG, "Nothing redistributed from bucket #{}", base_index);
  bucket->set_local_depth(bucket->local_depth() + 1);
- serializer().serialize_and_write(*bucket, bucket->pointer());
+ serializer().serialize_and_write(*bucket);
  write_directory_to_write_ahead_log();
 
  auto bucket_after_redistribution = get_bucket(key_hash % size());
@@ -327,7 +327,7 @@ void HashIndex::write_directory_to_write_ahead_log()
  size_t num_node = 0u;
  while (offset < size()) {
  HashDirectoryNode node(*this, num_node, offset);
- serializer().serialize_and_write(node, node.pointer());
+ serializer().serialize_and_write(node);
  offset += node.number_of_pointers();
  }
 }

Userland/Libraries/LibSQL/Serializer.h

@@ -108,12 +108,12 @@ class Serializer {
  void serialize(String const&);
 
  template<typename T>
- bool serialize_and_write(T const& t, u32 pointer)
+ bool serialize_and_write(T const& t)
  {
  VERIFY(m_heap.ptr() != nullptr);
  reset();
  serialize<T>(t);
- m_heap->add_to_wal(pointer, m_buffer);
+ m_heap->add_to_wal(t.pointer(), m_buffer);
  return true;
  }
 

Userland/Libraries/LibSQL/TreeNode.cpp

@@ -172,7 +172,7 @@ bool TreeNode::update_key_pointer(Key const& key)
  if (m_entries[ix].pointer() != key.pointer()) {
  m_entries[ix].set_pointer(key.pointer());
  dump_if(SQL_DEBUG, "To WAL");
- tree().serializer().serialize_and_write<TreeNode>(*this, pointer());
+ tree().serializer().serialize_and_write<TreeNode>(*this);
  }
  return true;
  }
@@ -277,7 +277,7 @@ void TreeNode::just_insert(Key const& key, TreeNode* right)
  split();
  } else {
  dump_if(SQL_DEBUG, "To WAL");
- tree().serializer().serialize_and_write(*this, pointer());
+ tree().serializer().serialize_and_write(*this);
  }
  return;
  }
@@ -289,7 +289,7 @@ void TreeNode::just_insert(Key const& key, TreeNode* right)
  split();
  } else {
  dump_if(SQL_DEBUG, "To WAL");
- tree().serializer().serialize_and_write(*this, pointer());
+ tree().serializer().serialize_and_write(*this);
  }
 }
 
@@ -327,9 +327,9 @@ void TreeNode::split()
  auto median = m_entries.take_last();
 
  dump_if(SQL_DEBUG, "Split Left To WAL");
- tree().serializer().serialize_and_write(*this, pointer());
+ tree().serializer().serialize_and_write(*this);
  new_node->dump_if(SQL_DEBUG, "Split Right to WAL");
- tree().serializer().serialize_and_write(*new_node, pointer());
+ tree().serializer().serialize_and_write(*new_node);
 
  m_up->just_insert(median, new_node);
 }