void ExceptIntersectSetOperator::intersectTupleMaps(TupleMap& map_a, TupleMap& map_b) {
TupleMap::iterator it_a = map_a.begin();
while(it_a != map_a.end()) {
TupleMap::iterator it_b = map_b.find(it_a->first);
if (it_b == map_b.end()) {
it_a = map_a.erase(it_a);
} else {
it_a->second = std::min(it_a->second, it_b->second);
++it_a;
}
}
}
void ExceptIntersectSetOperator::exceptTupleMaps(TupleMap& map_a, TupleMap& map_b) {
TupleMap::iterator it_a = map_a.begin();
while(it_a != map_a.end()) {
TupleMap::iterator it_b = map_b.find(it_a->first);
if (it_b != map_b.end()) {
if (it_a->second > it_b->second) {
it_a->second -= it_b->second;
}
else {
it_a = map_a.erase(it_a);
continue;
}
}
++it_a;
}
}
// for debugging - may be unused
void SetOperator::printTupleMap(const char* nonce, TupleMap &tuples) {
printf("Printing TupleMap (%s): ", nonce);
for (TupleMap::const_iterator mapIt = tuples.begin(); mapIt != tuples.end(); ++mapIt) {
TableTuple tuple = mapIt->first;
printf("%s, ", tuple.debugNoHeader().c_str());
}
printf("\n");
fflush(stdout);
}
void ExceptIntersectSetOperator::collectTuples(Table& input_table, TupleMap& tuple_map) {
TableIterator iterator = input_table.iterator();
TableTuple tuple(input_table.schema());
while (iterator.next(tuple)) {
TupleMap::iterator mapIt = tuple_map.find(tuple);
if (mapIt == tuple_map.end()) {
tuple_map.insert(std::make_pair(tuple, 1));
} else if (m_is_all) {
++mapIt->second;
}
}
}
bool ExceptIntersectSetOperator::processTuples()
{
// Map to keep candidate tuples. The key is the tuple itself
// The value - tuple's repeat count in the final table.
TupleMap tuples;
assert( ! m_input_tables.empty());
size_t ii = m_input_tablerefs.size();
while (ii--) {
m_input_tables[ii] = m_input_tablerefs[ii].getTable();
}
if ( ! m_is_except) {
// For intersect we want to start with the smallest table
std::vector<Table*>::iterator minTableIt =
std::min_element(m_input_tables.begin(), m_input_tables.end(), TableSizeLess());
std::swap(m_input_tables[0], *minTableIt);
}
// Collect all tuples from the first set
Table* input_table = m_input_tables[0];
collectTuples(*input_table, tuples);
//
// For each remaining input table, collect its tuple into a separate map
// and substract/intersect it from/with the first one
//
TupleMap next_tuples;
for (size_t ctr = 1, cnt = m_input_tables.size(); ctr < cnt; ctr++) {
next_tuples.clear();
input_table = m_input_tables[ctr];
assert(input_table);
collectTuples(*input_table, next_tuples);
if (m_is_except) {
exceptTupleMaps(tuples, next_tuples);
} else {
intersectTupleMaps(tuples, next_tuples);
}
}
// Insert remaining tuples to the output table
for (TupleMap::const_iterator mapIt = tuples.begin(); mapIt != tuples.end(); ++mapIt) {
TableTuple tuple = mapIt->first;
for (size_t i = 0; i < mapIt->second; ++i) {
m_output_table->insertTempTuple(tuple);
}
}
return true;
}
bool ExceptIntersectSetOperator::processTuplesDo() {
// Map to keep candidate tuples. The key is the tuple itself
// The value - tuple's repeat count in the final table.
TupleMap tuples;
// Collect all tuples from the first set
assert(!m_input_tables.empty());
Table* input_table = m_input_tables[0];
collectTuples(*input_table, tuples);
//
// For each remaining input table, collect its tuple into a separate map
// and substract/intersect it from/with the first one
//
TupleMap next_tuples;
for (size_t ctr = 1, cnt = m_input_tables.size(); ctr < cnt; ctr++) {
next_tuples.clear();
Table* input_table = m_input_tables[ctr];
assert(input_table);
collectTuples(*input_table, next_tuples);
if (m_is_except) {
exceptTupleMaps(tuples, next_tuples);
} else {
intersectTupleMaps(tuples, next_tuples);
}
}
// Insert remaining tuples to our ouput table
for (TupleMap::const_iterator mapIt = tuples.begin(); mapIt != tuples.end(); ++mapIt) {
TableTuple tuple = mapIt->first;
for (size_t i = 0; i < mapIt->second; ++i) {
if (!m_output_table->insertTuple(tuple)) {
VOLT_ERROR("Failed to insert tuple from input table '%s' into"
" output table '%s'",
m_input_tables[0]->name().c_str(),
m_output_table->name().c_str());
return false;
}
}
}
return true;
}