mirror of
https://github.com/ClickHouse/ClickHouse.git
synced 2024-11-24 16:42:05 +00:00
471 lines
13 KiB
C++
471 lines
13 KiB
C++
#include <Interpreters/TreeCNFConverter.h>
|
|
#include <Parsers/IAST.h>
|
|
#include <Parsers/ASTFunction.h>
|
|
#include <Parsers/ASTIdentifier.h>
|
|
#include <Common/checkStackSize.h>
|
|
#include <IO/Operators.h>
|
|
|
|
|
|
namespace DB
|
|
{
|
|
|
|
namespace ErrorCodes
|
|
{
|
|
extern const int LOGICAL_ERROR;
|
|
extern const int INCORRECT_QUERY;
|
|
extern const int TOO_MANY_TEMPORARY_COLUMNS;
|
|
}
|
|
|
|
namespace
|
|
{
|
|
|
|
bool isLogicalFunction(const ASTFunction & func)
|
|
{
|
|
return func.name == "and" || func.name == "or" || func.name == "not";
|
|
}
|
|
|
|
size_t countAtoms(const ASTPtr & node)
|
|
{
|
|
checkStackSize();
|
|
if (node->as<ASTIdentifier>() || node->as<ASTLiteral>())
|
|
return 1;
|
|
|
|
const auto * func = node->as<ASTFunction>();
|
|
if (func && !isLogicalFunction(*func))
|
|
return 1;
|
|
|
|
size_t num_atoms = 0;
|
|
for (const auto & child : node->children)
|
|
num_atoms += countAtoms(child);
|
|
return num_atoms;
|
|
}
|
|
|
|
/// Splits AND(a, b, c) to AND(a, AND(b, c)) for AND/OR
|
|
void splitMultiLogic(ASTPtr & node)
|
|
{
|
|
checkStackSize();
|
|
auto * func = node->as<ASTFunction>();
|
|
|
|
if (func && (func->name == "and" || func->name == "or"))
|
|
{
|
|
if (func->arguments->children.size() < 2)
|
|
throw Exception("Bad AND or OR function. Expected at least 2 arguments", ErrorCodes::INCORRECT_QUERY);
|
|
|
|
if (func->arguments->children.size() > 2)
|
|
{
|
|
ASTPtr res = func->arguments->children[0]->clone();
|
|
for (size_t i = 1; i < func->arguments->children.size(); ++i)
|
|
res = makeASTFunction(func->name, res, func->arguments->children[i]->clone());
|
|
|
|
node = res;
|
|
}
|
|
|
|
auto * new_func = node->as<ASTFunction>();
|
|
for (auto & child : new_func->arguments->children)
|
|
splitMultiLogic(child);
|
|
}
|
|
else if (func && func->name == "not")
|
|
{
|
|
for (auto & child : func->arguments->children)
|
|
splitMultiLogic(child);
|
|
}
|
|
}
|
|
|
|
/// Push NOT to leafs, remove NOT NOT ...
|
|
void traversePushNot(ASTPtr & node, bool add_negation)
|
|
{
|
|
checkStackSize();
|
|
auto * func = node->as<ASTFunction>();
|
|
|
|
if (func && (func->name == "and" || func->name == "or"))
|
|
{
|
|
if (add_negation)
|
|
{
|
|
if (func->arguments->children.size() != 2)
|
|
throw Exception("Bad AND or OR function. Expected at least 2 arguments", ErrorCodes::LOGICAL_ERROR);
|
|
|
|
/// apply De Morgan's Law
|
|
node = makeASTFunction(
|
|
(func->name == "and" ? "or" : "and"),
|
|
func->arguments->children[0]->clone(),
|
|
func->arguments->children[1]->clone());
|
|
}
|
|
|
|
auto * new_func = node->as<ASTFunction>();
|
|
for (auto & child : new_func->arguments->children)
|
|
traversePushNot(child, add_negation);
|
|
}
|
|
else if (func && func->name == "not")
|
|
{
|
|
if (func->arguments->children.size() != 1)
|
|
throw Exception("Bad NOT function. Expected 1 argument", ErrorCodes::INCORRECT_QUERY);
|
|
/// delete NOT
|
|
node = func->arguments->children[0]->clone();
|
|
|
|
traversePushNot(node, !add_negation);
|
|
}
|
|
else
|
|
{
|
|
if (add_negation)
|
|
node = makeASTFunction("not", node->clone());
|
|
}
|
|
}
|
|
|
|
/// Push Or inside And (actually pull AND to top)
|
|
bool traversePushOr(ASTPtr & node, size_t num_atoms, size_t max_atoms)
|
|
{
|
|
if (max_atoms && num_atoms > max_atoms)
|
|
return false;
|
|
|
|
checkStackSize();
|
|
auto * func = node->as<ASTFunction>();
|
|
|
|
if (func && (func->name == "or" || func->name == "and"))
|
|
{
|
|
for (auto & child : func->arguments->children)
|
|
if (!traversePushOr(child, num_atoms, max_atoms))
|
|
return false;
|
|
}
|
|
|
|
if (func && func->name == "or")
|
|
{
|
|
assert(func->arguments->children.size() == 2);
|
|
size_t and_node_id = func->arguments->children.size();
|
|
for (size_t i = 0; i < func->arguments->children.size(); ++i)
|
|
{
|
|
auto & child = func->arguments->children[i];
|
|
auto * and_func = child->as<ASTFunction>();
|
|
if (and_func && and_func->name == "and")
|
|
and_node_id = i;
|
|
}
|
|
|
|
if (and_node_id == func->arguments->children.size())
|
|
return true;
|
|
|
|
const size_t other_node_id = 1 - and_node_id;
|
|
const auto * and_func = func->arguments->children[and_node_id]->as<ASTFunction>();
|
|
|
|
auto a = func->arguments->children[other_node_id];
|
|
auto b = and_func->arguments->children[0];
|
|
auto c = and_func->arguments->children[1];
|
|
|
|
/// apply the distributive law ( a or (b and c) -> (a or b) and (a or c) )
|
|
node = makeASTFunction(
|
|
"and",
|
|
makeASTFunction("or", a->clone(), b),
|
|
makeASTFunction("or", a, c));
|
|
|
|
/// Count all atoms from 'a', because it was cloned.
|
|
num_atoms += countAtoms(a);
|
|
return traversePushOr(node, num_atoms, max_atoms);
|
|
}
|
|
|
|
return true;
|
|
}
|
|
|
|
/// transform ast into cnf groups
|
|
void traverseCNF(const ASTPtr & node, CNFQuery::AndGroup & and_group, CNFQuery::OrGroup & or_group)
|
|
{
|
|
checkStackSize();
|
|
|
|
auto * func = node->as<ASTFunction>();
|
|
if (func && func->name == "and")
|
|
{
|
|
for (auto & child : func->arguments->children)
|
|
{
|
|
CNFQuery::OrGroup group;
|
|
traverseCNF(child, and_group, group);
|
|
if (!group.empty())
|
|
and_group.insert(std::move(group));
|
|
}
|
|
}
|
|
else if (func && func->name == "or")
|
|
{
|
|
for (auto & child : func->arguments->children)
|
|
{
|
|
traverseCNF(child, and_group, or_group);
|
|
}
|
|
}
|
|
else if (func && func->name == "not")
|
|
{
|
|
if (func->arguments->children.size() != 1)
|
|
throw Exception("Bad NOT function. Expected 1 argument", ErrorCodes::INCORRECT_QUERY);
|
|
or_group.insert(CNFQuery::AtomicFormula{true, func->arguments->children.front()});
|
|
}
|
|
else
|
|
{
|
|
or_group.insert(CNFQuery::AtomicFormula{false, node});
|
|
}
|
|
}
|
|
|
|
void traverseCNF(const ASTPtr & node, CNFQuery::AndGroup & result)
|
|
{
|
|
CNFQuery::OrGroup or_group;
|
|
traverseCNF(node, result, or_group);
|
|
if (!or_group.empty())
|
|
result.insert(or_group);
|
|
}
|
|
|
|
}
|
|
|
|
std::optional<CNFQuery> TreeCNFConverter::tryConvertToCNF(
|
|
const ASTPtr & query, size_t max_growth_multiplier)
|
|
{
|
|
auto cnf = query->clone();
|
|
size_t num_atoms = countAtoms(cnf);
|
|
|
|
splitMultiLogic(cnf);
|
|
traversePushNot(cnf, false);
|
|
|
|
size_t max_atoms = max_growth_multiplier
|
|
? std::max(MAX_ATOMS_WITHOUT_CHECK, num_atoms * max_growth_multiplier)
|
|
: 0;
|
|
|
|
if (!traversePushOr(cnf, num_atoms, max_atoms))
|
|
return {};
|
|
|
|
CNFQuery::AndGroup and_group;
|
|
traverseCNF(cnf, and_group);
|
|
|
|
CNFQuery result{std::move(and_group)};
|
|
|
|
return result;
|
|
}
|
|
|
|
CNFQuery TreeCNFConverter::toCNF(
|
|
const ASTPtr & query, size_t max_growth_multiplier)
|
|
{
|
|
auto cnf = tryConvertToCNF(query, max_growth_multiplier);
|
|
if (!cnf)
|
|
throw Exception(ErrorCodes::TOO_MANY_TEMPORARY_COLUMNS,
|
|
"Cannot convert expression '{}' to CNF, because it produces to many clauses."
|
|
"Size of boolean formula in CNF can be exponential of size of source formula.");
|
|
|
|
return *cnf;
|
|
}
|
|
|
|
ASTPtr TreeCNFConverter::fromCNF(const CNFQuery & cnf)
|
|
{
|
|
const auto & groups = cnf.getStatements();
|
|
if (groups.empty())
|
|
return nullptr;
|
|
|
|
ASTs or_groups;
|
|
for (const auto & group : groups)
|
|
{
|
|
if (group.size() == 1)
|
|
{
|
|
if ((*group.begin()).negative)
|
|
or_groups.push_back(makeASTFunction("not", (*group.begin()).ast->clone()));
|
|
else
|
|
or_groups.push_back((*group.begin()).ast->clone());
|
|
}
|
|
else if (group.size() > 1)
|
|
{
|
|
or_groups.push_back(makeASTFunction("or"));
|
|
auto * func = or_groups.back()->as<ASTFunction>();
|
|
for (const auto & atom : group)
|
|
{
|
|
if (atom.negative)
|
|
func->arguments->children.push_back(makeASTFunction("not", atom.ast->clone()));
|
|
else
|
|
func->arguments->children.push_back(atom.ast->clone());
|
|
}
|
|
}
|
|
}
|
|
|
|
if (or_groups.size() == 1)
|
|
return or_groups.front();
|
|
|
|
ASTPtr res = makeASTFunction("and");
|
|
auto * func = res->as<ASTFunction>();
|
|
for (const auto & group : or_groups)
|
|
func->arguments->children.push_back(group);
|
|
|
|
return res;
|
|
}
|
|
|
|
static void pushPullNotInAtom(CNFQuery::AtomicFormula & atom, const std::unordered_map<std::string, std::string> & inverse_relations)
|
|
{
|
|
auto * func = atom.ast->as<ASTFunction>();
|
|
if (!func)
|
|
return;
|
|
if (auto it = inverse_relations.find(func->name); it != std::end(inverse_relations))
|
|
{
|
|
/// inverse func
|
|
atom.ast = atom.ast->clone();
|
|
auto * new_func = atom.ast->as<ASTFunction>();
|
|
new_func->name = it->second;
|
|
/// add not
|
|
atom.negative = !atom.negative;
|
|
}
|
|
}
|
|
|
|
static void pullNotOut(CNFQuery::AtomicFormula & atom)
|
|
{
|
|
static const std::unordered_map<std::string, std::string> inverse_relations = {
|
|
{"notEquals", "equals"},
|
|
{"greaterOrEquals", "less"},
|
|
{"greater", "lessOrEquals"},
|
|
{"notIn", "in"},
|
|
{"notLike", "like"},
|
|
{"notEmpty", "empty"},
|
|
};
|
|
|
|
pushPullNotInAtom(atom, inverse_relations);
|
|
}
|
|
|
|
void pushNotIn(CNFQuery::AtomicFormula & atom)
|
|
{
|
|
if (!atom.negative)
|
|
return;
|
|
|
|
static const std::unordered_map<std::string, std::string> inverse_relations = {
|
|
{"equals", "notEquals"},
|
|
{"less", "greaterOrEquals"},
|
|
{"lessOrEquals", "greater"},
|
|
{"in", "notIn"},
|
|
{"like", "notLike"},
|
|
{"empty", "notEmpty"},
|
|
{"notEquals", "equals"},
|
|
{"greaterOrEquals", "less"},
|
|
{"greater", "lessOrEquals"},
|
|
{"notIn", "in"},
|
|
{"notLike", "like"},
|
|
{"notEmpty", "empty"},
|
|
};
|
|
|
|
pushPullNotInAtom(atom, inverse_relations);
|
|
}
|
|
|
|
CNFQuery & CNFQuery::pullNotOutFunctions()
|
|
{
|
|
transformAtoms([](const AtomicFormula & atom) -> AtomicFormula
|
|
{
|
|
AtomicFormula result{atom.negative, atom.ast->clone()};
|
|
pullNotOut(result);
|
|
return result;
|
|
});
|
|
return *this;
|
|
}
|
|
|
|
CNFQuery & CNFQuery::pushNotInFunctions()
|
|
{
|
|
transformAtoms([](const AtomicFormula & atom) -> AtomicFormula
|
|
{
|
|
AtomicFormula result{atom.negative, atom.ast->clone()};
|
|
pushNotIn(result);
|
|
return result;
|
|
});
|
|
return *this;
|
|
}
|
|
|
|
namespace
|
|
{
|
|
CNFQuery::AndGroup reduceOnce(const CNFQuery::AndGroup & groups)
|
|
{
|
|
CNFQuery::AndGroup result;
|
|
for (const CNFQuery::OrGroup & group : groups)
|
|
{
|
|
CNFQuery::OrGroup copy(group);
|
|
bool inserted = false;
|
|
for (const CNFQuery::AtomicFormula & atom : group)
|
|
{
|
|
copy.erase(atom);
|
|
CNFQuery::AtomicFormula negative_atom(atom);
|
|
negative_atom.negative = !atom.negative;
|
|
copy.insert(negative_atom);
|
|
|
|
if (groups.contains(copy))
|
|
{
|
|
copy.erase(negative_atom);
|
|
result.insert(copy);
|
|
inserted = true;
|
|
break;
|
|
}
|
|
|
|
copy.erase(negative_atom);
|
|
copy.insert(atom);
|
|
}
|
|
if (!inserted)
|
|
result.insert(group);
|
|
}
|
|
return result;
|
|
}
|
|
|
|
bool isSubset(const CNFQuery::OrGroup & left, const CNFQuery::OrGroup & right)
|
|
{
|
|
if (left.size() > right.size())
|
|
return false;
|
|
for (const auto & elem : left)
|
|
if (!right.contains(elem))
|
|
return false;
|
|
return true;
|
|
}
|
|
|
|
CNFQuery::AndGroup filterSubsets(const CNFQuery::AndGroup & groups)
|
|
{
|
|
CNFQuery::AndGroup result;
|
|
for (const CNFQuery::OrGroup & group : groups)
|
|
{
|
|
bool insert = true;
|
|
|
|
for (const CNFQuery::OrGroup & other_group : groups)
|
|
{
|
|
if (isSubset(other_group, group) && group != other_group)
|
|
{
|
|
insert = false;
|
|
break;
|
|
}
|
|
}
|
|
|
|
if (insert)
|
|
result.insert(group);
|
|
}
|
|
return result;
|
|
}
|
|
}
|
|
|
|
CNFQuery & CNFQuery::reduce()
|
|
{
|
|
while (true)
|
|
{
|
|
AndGroup new_statements = reduceOnce(statements);
|
|
if (statements == new_statements)
|
|
{
|
|
statements = filterSubsets(statements);
|
|
return *this;
|
|
}
|
|
else
|
|
statements = new_statements;
|
|
}
|
|
}
|
|
|
|
std::string CNFQuery::dump() const
|
|
{
|
|
WriteBufferFromOwnString res;
|
|
bool first = true;
|
|
for (const auto & group : statements)
|
|
{
|
|
if (!first)
|
|
res << " AND ";
|
|
first = false;
|
|
res << "(";
|
|
bool first_in_group = true;
|
|
for (const auto & atom : group)
|
|
{
|
|
if (!first_in_group)
|
|
res << " OR ";
|
|
first_in_group = false;
|
|
if (atom.negative)
|
|
res << " NOT ";
|
|
res << atom.ast->getColumnName();
|
|
}
|
|
res << ")";
|
|
}
|
|
|
|
return res.str();
|
|
}
|
|
|
|
}
|