From 694d2890065b1555a01a81994cb80f106ca577ee Mon Sep 17 00:00:00 2001
From: Mikko Rasa <tdb@tdb.fi>
Date: Thu, 16 Aug 2018 01:08:46 +0300
Subject: [PATCH] Further merge conditions while flattening

---
 source/condition.cpp | 65 ++++++++++++++++++++++++++++++++++----------
 source/condition.h   |  3 ++
 2 files changed, 54 insertions(+), 14 deletions(-)

diff --git a/source/condition.cpp b/source/condition.cpp
index 42e9ee8..a8a5a90 100644
--- a/source/condition.cpp
+++ b/source/condition.cpp
@@ -91,6 +91,47 @@ Condition *CompoundCondition::dispatch_flatten(Condition *cond1, Condition *cond
 	throw logic_error("CompoundCondition::dispatch_flatten");
 }
 
+Condition *CompoundCondition::merge_two(Condition *cond1, Condition *cond2, bool del) const
+{
+	vector<Condition *> parts;
+	parts.reserve(2);
+	parts.push_back(cond1);
+	parts.push_back(cond2);
+	Condition *result = cond1->merge(parts, *this);
+	if(del)
+	{
+		delete cond1;
+		delete cond2;
+	}
+	return result;
+}
+
+Condition *CompoundCondition::add_merged_to(Condition *cond, CompoundCondition *target, bool del) const
+{
+	for(vector<Condition *>::iterator i=target->conditions.begin(); i!=target->conditions.end(); ++i)
+		if((*i)->can_merge(*cond, *target))
+		{
+			Condition *m = merge_two(cond, *i, false);
+			delete *i;
+			if(del)
+				delete cond;
+			*i = m;
+			return target;
+		}
+
+	target->add(del ? cond : cond->clone());
+	return target;
+}
+
+Condition *CompoundCondition::merge_contents_to(CompoundCondition *cond, CompoundCondition *target) const
+{
+	for(vector<Condition *>::iterator i=cond->conditions.begin(); i!=cond->conditions.end(); ++i)
+		add_merged_to(*i, target, false);
+
+	delete cond;
+	return target;
+}
+
 
 AndCondition *AndCondition::clone() const
 {
@@ -101,6 +142,9 @@ AndCondition *AndCondition::clone() const
 
 Condition *AndCondition::flatten(Condition *cond1, Condition *cond2) const
 {
+	if(cond1->can_merge(*cond2, *this))
+		return merge_two(cond1, cond2, true);
+
 	AndCondition *result = new AndCondition;
 	result->add(cond1);
 	result->add(cond2);
@@ -109,17 +153,12 @@ Condition *AndCondition::flatten(Condition *cond1, Condition *cond2) const
 
 Condition *AndCondition::flatten(AndCondition *cond1, Condition *cond2) const
 {
-	cond1->add(cond2);
-	return cond1;
+	return add_merged_to(cond2, cond1, true);
 }
 
 Condition *AndCondition::flatten(AndCondition *cond1, AndCondition *cond2) const
 {
-	unsigned count2 = cond2->count();
-	for(unsigned i=0; i<count2; ++i)
-		cond1->add(cond2->get(i)->clone());
-	delete cond2;
-	return cond1;
+	return merge_contents_to(cond2, cond1);
 }
 
 Condition *AndCondition::flatten(OrCondition *cond1, Condition *cond2) const
@@ -166,6 +205,9 @@ OrCondition *OrCondition::clone() const
 
 Condition *OrCondition::flatten(Condition *cond1, Condition *cond2) const
 {
+	if(cond1->can_merge(*cond2, *this))
+		return merge_two(cond1, cond2, true);
+
 	OrCondition *result = new OrCondition;
 	result->add(cond1);
 	result->add(cond2);
@@ -184,8 +226,7 @@ Condition *OrCondition::flatten(AndCondition *cond1, AndCondition *cond2) const
 
 Condition *OrCondition::flatten(OrCondition *cond1, Condition *cond2) const
 {
-	cond1->add(cond2);
-	return cond1;
+	return add_merged_to(cond2, cond1, true);
 }
 
 Condition *OrCondition::flatten(OrCondition *cond1, AndCondition *cond2) const
@@ -195,11 +236,7 @@ Condition *OrCondition::flatten(OrCondition *cond1, AndCondition *cond2) const
 
 Condition *OrCondition::flatten(OrCondition *cond1, OrCondition *cond2) const
 {
-	unsigned count2 = cond2->count();
-	for(unsigned i=0; i<count2; ++i)
-		cond1->add(cond2->get(i)->clone());
-	delete cond2;
-	return cond1;
+	return merge_contents_to(cond2, cond1);
 }
 
 void OrCondition::add_lines(list<FilterStatement> &st) const
diff --git a/source/condition.h b/source/condition.h
index 141e570..979f1e9 100644
--- a/source/condition.h
+++ b/source/condition.h
@@ -47,6 +47,9 @@ public:
 	virtual Condition *flatten() const;
 protected:
 	Condition *dispatch_flatten(Condition *, Condition *) const;
+	Condition *merge_two(Condition *, Condition *, bool) const;
+	Condition *add_merged_to(Condition *, CompoundCondition *, bool) const;
+	Condition *merge_contents_to(CompoundCondition *, CompoundCondition *) const;
 	virtual Condition *flatten(Condition *, Condition *) const = 0;
 	virtual Condition *flatten(AndCondition *, Condition *) const = 0;
 	virtual Condition *flatten(AndCondition *, AndCondition *) const = 0;
-- 
2.43.0