Optimize creation of expression and partial indices (#7559)

* Refactor index condition/expression evaluation into classes. Speed up (appr. 10x) creation and validation time for conditional indices.

* Simplified NULL handling when index keys are composed

* Refactor index key creation (from record). Optimize evaluation of index expressions.

* Adjustments after Vlad's review

* Remove redundant variables

Author: dyemanov

src/jrd/btr.cpp

@@ -327,6 +327,108 @@ class IndexErrorContext
 	bool isLocationDefined;
 };
 
+// Helper classes to allow efficient evaluation of index conditions/expressions
+
+class IndexCondition
+{
+public:
+	IndexCondition(thread_db* tdbb, index_desc* idx);
+	~IndexCondition();
+
+	bool evaluate(Record* record) const;
+
+private:
+	thread_db* const m_tdbb;
+	BoolExprNode* m_condition = nullptr;
+	Request* m_request = nullptr;
+};
+
+class IndexExpression
+{
+public:
+	IndexExpression(thread_db* tdbb, index_desc* idx);
+	~IndexExpression();
+
+	dsc* evaluate(Record* record) const;
+
+private:
+	thread_db* const m_tdbb;
+	ValueExprNode* m_expression = nullptr;
+	Request* m_request = nullptr;
+};
+
+// Index key wrapper
+
+class IndexKey
+{
+public:
+	IndexKey(thread_db* tdbb, jrd_rel* relation, index_desc* idx)
+		: m_tdbb(tdbb), m_relation(relation), m_index(idx),
+		  m_keyType((idx->idx_flags & idx_unique) ? INTL_KEY_UNIQUE : INTL_KEY_SORT),
+		  m_segments(idx->idx_count), m_expression(tdbb, idx)
+	{}
+
+	IndexKey(thread_db* tdbb, jrd_rel* relation, index_desc* idx,
+			 USHORT keyType, USHORT segments)
+		: m_tdbb(tdbb), m_relation(relation), m_index(idx),
+		  m_keyType(keyType), m_segments(segments), m_expression(tdbb, idx)
+	{
+		fb_assert(m_segments && m_segments <= idx->idx_count);
+	}
+
+	idx_e compose(Record* record);
+
+	operator temporary_key*()
+	{
+		return &m_key;
+	}
+
+	temporary_key* operator->()
+	{
+		return &m_key;
+	}
+
+	bool operator==(const IndexKey& other) const
+	{
+		if (m_key.key_length != other.m_key.key_length)
+			return false;
+
+		return !memcmp(m_key.key_data, other.m_key.key_data, m_key.key_length);
+	}
+
+	bool operator!=(const IndexKey& other) const
+	{
+		if (m_key.key_length != other.m_key.key_length)
+			return true;
+
+		return memcmp(m_key.key_data, other.m_key.key_data, m_key.key_length);
+	}
+
+	// Return ordinal number of the first NULL segment
+	USHORT getNullSegment() const
+	{
+		USHORT nulls = m_key.key_nulls;
+
+		for (USHORT i = 0; nulls; i++)
+		{
+			if (nulls & 1)
+				return i;
+
+			nulls >>= 1;
+		}
+
+		return MAX_USHORT;
+	}
+
+private:
+	thread_db* const m_tdbb;
+	jrd_rel* const m_relation;
+	index_desc* const m_index;
+	const USHORT m_keyType;
+	const USHORT m_segments;
+	temporary_key m_key;
+	IndexExpression m_expression;
+};
 
 } //namespace Jrd
 

src/jrd/btr.h

@@ -35,14 +35,12 @@ void	BTR_create(Jrd::thread_db*, Jrd::IndexCreation&, Jrd::SelectivityList&);
 bool	BTR_delete_index(Jrd::thread_db*, Jrd::win*, USHORT);
 bool	BTR_description(Jrd::thread_db*, Jrd::jrd_rel*, Ods::index_root_page*, Jrd::index_desc*, USHORT);
 bool	BTR_check_condition(Jrd::thread_db*, Jrd::index_desc*, Jrd::Record*);
-DSC*	BTR_eval_expression(Jrd::thread_db*, Jrd::index_desc*, Jrd::Record*, bool&);
+dsc*	BTR_eval_expression(Jrd::thread_db*, Jrd::index_desc*, Jrd::Record*);
 void	BTR_evaluate(Jrd::thread_db*, const Jrd::IndexRetrieval*, Jrd::RecordBitmap**, Jrd::RecordBitmap*);
 UCHAR*	BTR_find_leaf(Ods::btree_page*, Jrd::temporary_key*, UCHAR*, USHORT*, bool, int);
 Ods::btree_page*	BTR_find_page(Jrd::thread_db*, const Jrd::IndexRetrieval*, Jrd::win*, Jrd::index_desc*,
 								 Jrd::temporary_key*, Jrd::temporary_key*, bool = true);
 void	BTR_insert(Jrd::thread_db*, Jrd::win*, Jrd::index_insertion*);
-Jrd::idx_e	BTR_key(Jrd::thread_db*, Jrd::jrd_rel*, Jrd::Record*, Jrd::index_desc*, Jrd::temporary_key*,
-					const USHORT, USHORT = 0);
 USHORT	BTR_key_length(Jrd::thread_db*, Jrd::jrd_rel*, Jrd::index_desc*);
 Ods::btree_page*	BTR_left_handoff(Jrd::thread_db*, Jrd::win*, Ods::btree_page*, SSHORT);
 bool	BTR_lookup(Jrd::thread_db*, Jrd::jrd_rel*, USHORT, Jrd::index_desc*, Jrd::RelationPages*);