void join(Relation &lhs, Relation &rhs, vector<size_t> &vars, Relation &result) {
DEBUG("Joining", "");
DEBUG(" LHS size = ", lhs.size());
DEBUG(" RHS size = ", rhs.size());
Relation temp;
Order order(vars);
lhs.sort(order);
rhs.sort(order);
Relation::iterator lit = lhs.begin();
Relation::iterator rit = rhs.begin();
while (lit != lhs.end() && rit != rhs.end()) {
Tuple joined;
if (join(*lit, *rit, joined)) {
Relation::iterator it;
do {
temp.push_back(joined);
it = rit;
for (++it; it != rhs.end() && join(*lit, *it, joined); ++it) {
temp.push_back(joined);
}
++lit;
} while (lit != lhs.end() && join(*lit, *rit, joined));
rit = it;
} else if (order(*rit, *lit)) {
++rit;
} else {
++lit;
}
}
result.swap(temp);
DEBUG(" Result size = ", result.size());
}
void print_relations(const Relation& relations)
{
for (Relation::const_iterator rela_iter = relations.begin();
rela_iter != relations.end(); rela_iter++) {
copy(rela_iter->begin(), rela_iter->end(), ostream_iterator<int>(cout, " "));
cout << endl;
}
}
//! recreate html page if something changes
void MetadataItemPropertiesPanel::update()
{
Database* db = dynamic_cast<Database*>(objectM);
if (db && !db->isConnected())
{
objectM = 0;
if (MetadataItemPropertiesFrame* f = getParentFrame())
f->Close();
// MB: This code used to use:
//f->removePanel(this);
// which would allow us to mix property pages from different
// databases in the same Frame, but there are some mysterious
// reasons why it causes heap corruption with MSVC
return;
}
// if table or view columns change, we need to reattach
if (objectM->getType() == ntTable || objectM->getType() == ntView) // also observe columns
{
Relation* r = dynamic_cast<Relation*>(objectM);
if (!r)
return;
SubjectLocker locker(r);
r->ensureChildrenLoaded();
for (ColumnPtrs::iterator it = r->begin(); it != r->end(); ++it)
(*it)->attachObserver(this, false);
}
// if description of procedure params change, we need to reattach
if (objectM->getType() == ntProcedure)
{
Procedure* p = dynamic_cast<Procedure*>(objectM);
if (!p)
return;
SubjectLocker locker(p);
p->ensureChildrenLoaded();
for (ParameterPtrs::iterator it = p->begin(); it != p->end(); ++it)
(*it)->attachObserver(this, false);
}
// with this set to false updates to the same page do not show the
// "Please wait while the data is being loaded..." temporary page
// this results in less flicker, but may also seem less responsive
if (!htmlReloadRequestedM)
requestLoadPage(false);
}
void act(Atom &atom, Relation &results) {
DEBUG("Act: atom = ", atom);
Index &index = atoms[atom.predicate];
Relation::iterator result = results.begin();
size_t max = atom.arguments.end - atom.arguments.begin;
for (; result != results.end(); ++result) {
Tuple tuple(max);
size_t i;
for (i = 0; i < max; ++i) {
if (atom.arguments.begin[i].type == CONSTANT) {
tuple[i] = atom.arguments.begin[i].get.constant;
DEBUG("part ", tuple[i]);
} else if (atom.arguments.begin[i].type == VARIABLE) {
tuple[i] = result->at(atom.arguments.begin[i].get.variable);
DEBUG("part ", tuple[i]);
} else {
cerr << "[ERROR] Lists and/or function in target atom are not currently supported." << endl;
return;
}
}
DEBUG("inserting (ignore this ->", max);
index.insert(tuple);
}
}
bool special(Condition &condition, Relation &intermediate, Relation &filtered) {
if (condition.type != ATOMIC) {
return false;
}
switch (condition.get.atom.type) {
case ATOM:
case MEMBERSHIP:
case SUBCLASS:
case FRAME:
return false;
case EQUALITY: {
Term *lhs = &(condition.get.atom.get.sides[0]);
Term *rhs = &(condition.get.atom.get.sides[1]);
if (lhs->type == VARIABLE && rhs->type == CONSTANT) {
swap(lhs, rhs);
}
if (rhs->type == CONSTANT) {
if (lhs->get.constant != rhs->get.constant) {
Relation empty;
filtered.swap(empty);
} else {
filtered = intermediate;
}
} else if (lhs->type == CONSTANT) {
Relation result;
Relation::iterator it = intermediate.begin();
for (; it != intermediate.end(); ++it) {
if (it->size() <= rhs->get.variable) {
it->resize(rhs->get.variable + 1);
}
if (it->at(rhs->get.variable) == 0) {
result.push_back(*it);
Tuple &t = result.back();
t[rhs->get.variable] = lhs->get.constant;
} else if (it->at(rhs->get.variable) == lhs->get.constant) {
result.push_back(*it);
}
}
filtered.swap(result);
} else {
varint_t maxvar = max(lhs->get.variable, rhs->get.variable);
Relation result;
Relation::iterator it = intermediate.begin();
for (; it != intermediate.end(); ++it) {
if (it->size() <= maxvar) {
it->resize(maxvar + 1);
}
constint_t c1 = it->at(lhs->get.variable);
constint_t c2 = it->at(rhs->get.variable);
if (c1 == 0 && c2 == 0) {
cerr << "[ERROR] Please make sure equality statements occur to the right of atomic formulas that bind a variable." << endl;
return true;
}
if (c1 == 0) {
result.push_back(*it);
Tuple &t = result.back();
t[lhs->get.variable] = c2;
} else if (c2 == 0) {
result.push_back(*it);
Tuple &t = result.back();
t[rhs->get.variable] = c1;
} else if (c1 == c2) {
result.push_back(*it);
}
}
filtered.swap(result);
}
return true;
}
case EXTERNAL: {
break; // just handle outside the messy switch statement
}
default: {
cerr << "[ERROR] Unhandled case " << (int)condition.get.atom.type << " at line " << __LINE__ << endl;
return false;
}
}
///// HANDLE BUILTIN (EXTERNAL) /////
Builtin &builtin = condition.get.atom.get.builtin;
switch (builtin.predicate) {
case BUILTIN_PRED_LIST_CONTAINS: {
if (builtin.arguments.end - builtin.arguments.begin != 2) {
cerr << "[ERROR] Invalid use of list contains builtin, which should have exactly two arguments, but instead found " << builtin << endl;
return false;
}
Term *arg1 = builtin.arguments.begin;
Term *arg2 = arg1 + 1;
if (arg1->type != LIST) {
cerr << "[ERROR] First argument of list contains builtin must be a list, but instead found " << *arg1 << endl;
return false;
}
switch (arg2->type) {
case FUNCTION:
cerr << "[ERROR] Functions not supported." << endl;
return false;
case LIST:
cerr << "[ERROR] Currently not supporting nested lists." << endl;
return false;
case CONSTANT: {
Term *t = arg1->get.termlist.begin;
for (; t != arg1->get.termlist.end; ++t) {
if (t->type == CONSTANT && t->get.constant == arg2->get.constant) {
filtered = intermediate;
return true;
}
}
Relation empty;
filtered.swap(empty);
return true;
}
case VARIABLE:
break; // just handle outside messy switch statement
default:
cerr << "[ERROR] Unhandled case " << (int)builtin.predicate << " at line " << __LINE__ << endl;
return false;
}
Relation results;
Relation::iterator it = intermediate.begin();
for (; it != intermediate.end(); ++it) {
if (it->size() <= arg2->get.variable) {
it->resize(arg2->get.variable + 1);
}
constint_t c = it->at(arg2->get.variable);
if (c == 0) {
Term *t = arg1->get.termlist.begin;
for (; t != arg1->get.termlist.end; ++t) {
if (t->type == CONSTANT) {
results.push_back(*it);
results.back().at(arg2->get.variable) = t->get.constant;
}
}
} else {
Term *t = arg1->get.termlist.begin;
for (; t != arg1->get.termlist.end; ++t) {
if (t->type == CONSTANT && t->get.constant == c) {
results.push_back(*it);
break;
}
}
}
}
filtered.swap(results);
return true;
}
default: {
cerr << "[ERROR] Builtin predicate " << (int)builtin.predicate << " is unsupported." << endl;
return false;
}
}
}
void act(ActionBlock &action_block, Relation &results, Index &assertions, Index &retractions) {
if (action_block.action_variables.begin != action_block.action_variables.end) {
cerr << "[ERROR] Action variables are unsupported." << endl;
return;
}
Action *action = action_block.actions.begin;
for (; action != action_block.actions.end; ++action) {
switch (action->type) {
case ASSERT_FACT:
case RETRACT_FACT: {
if (action->get.atom.type == ATOM) {
if (action->type == RETRACT_FACT) {
cerr << "[ERROR] Retraction of atoms is currently unsupported." << endl;
return;
}
act(action->get.atom.get.atom, results);
continue;
}
if (action->get.atom.type != FRAME) {
cerr << "[ERROR] For now, supporting only assertion of frames/triples." << endl;
return;
}
Frame frame = action->get.atom.get.frame;
Tuple triple(3);
if (frame.object.type == LIST || frame.object.type == FUNCTION) {
cerr << "[ERROR] Not supporting lists or functions in action target." << endl;
return;
}
if (frame.object.type == CONSTANT) {
triple[0] = frame.object.get.constant;
}
pair<Term, Term> *slot = frame.slots.begin;
for (; slot != frame.slots.end; ++slot) {
if (slot->first.type == LIST || slot->first.type == FUNCTION ||
slot->second.type == LIST || slot->second.type == FUNCTION) {
cerr << "[ERROR] Not supporting lists or function in action target." << endl;
return;
}
if (slot->first.type == CONSTANT) {
triple[1] = slot->first.get.constant;
}
if (slot->second.type == CONSTANT) {
triple[2] = slot->second.get.constant;
}
if (!results.empty() && frame.object.type == CONSTANT && slot->first.type == CONSTANT && slot->second.type == CONSTANT) {
if (action->type == ASSERT_FACT) {
assertions.insert(triple);
} else {
retractions.insert(triple);
}
continue;
}
Relation::iterator tuple = results.begin();
for (; tuple != results.end(); ++tuple) {
if (frame.object.type == VARIABLE) {
triple[0] = tuple->at(frame.object.get.variable);
}
if (slot->first.type == VARIABLE) {
triple[1] = tuple->at(slot->first.get.variable);
}
if (slot->second.type == VARIABLE) {
triple[2] = tuple->at(slot->second.get.variable);
}
if (action->type == ASSERT_FACT) {
assertions.insert(triple);
} else {
retractions.insert(triple);
}
}
}
return;
}
default: {
cerr << "[ERROR] Currently supporting on ASSERT_FACT and RETRACT_FACT actions." << endl;
return;
}
}
}
}
void query(Condition &condition, set<varint_t> &allvars, Relation &results) {
deque<void*> negated;
Relation intermediate;
switch (condition.type) {
case ATOMIC: {
query(condition.get.atom, allvars, results);
return;
}
case CONJUNCTION: {
Condition *subformula = condition.get.subformulas.begin;
for (; subformula != condition.get.subformulas.end; ++subformula) {
if (subformula->type == NEGATION) {
negated.push_back((void*)subformula->get.subformulas.begin);
continue;
}
Relation subresult;
set<varint_t> newvars;
// TODO vvv this won't work right if a non-special query
// has not been performed first
if (special(*subformula, intermediate, subresult)) {
if (subformula == condition.get.subformulas.begin) {
cerr << "[ERROR] Must have non-special query at beginning of conjunction." << endl;
}
intermediate.swap(subresult);
continue;
}
query(*subformula, newvars, subresult);
if (subformula == condition.get.subformulas.begin) {
intermediate.swap(subresult);
} else {
vector<size_t> joinvars(allvars.size() + newvars.size());
vector<size_t>::iterator jit = set_intersection(allvars.begin(),
allvars.end(), newvars.begin(), newvars.end(), joinvars.begin());
joinvars.resize(jit - joinvars.begin());
join(intermediate, subresult, joinvars, intermediate);
}
allvars.insert(newvars.begin(), newvars.end());
}
break;
}
case DISJUNCTION: {
cerr << "[ERROR] Disjunction is not supported." << endl;
return;
}
case EXISTENTIAL: {
// assuming all quantified variables are uniquely named in the scope of the rule
Condition *subformula = condition.get.subformulas.begin;
for (; subformula != condition.get.subformulas.end; ++subformula) {
if (subformula->type == NEGATION) {
negated.push_back((void*)subformula->get.subformulas.begin);
}
Relation subresult;
query(*subformula, allvars, subresult);
intermediate.splice(intermediate.end(), subresult);
}
break;
}
case NEGATION: {
cerr << "[ERROR] This should never happen. query should not be called directly on negated formulas." << endl;
return;
}
default: {
cerr << "[ERROR] Unhandled case " << (int)condition.type << " on line " << __LINE__ << endl;
return;
}
}
// TODO deal with negation later, if at all
#if 1
deque<void*>::iterator it = negated.begin();
for (; !intermediate.empty() && it != negated.end(); ++it) {
Relation negresult;
Condition *cond = (Condition*) *it;
if (special(*cond, intermediate, negresult)) {
intermediate.sort();
negresult.sort();
Relation leftover(intermediate.size());
Relation::iterator iit = set_difference(intermediate.begin(),
intermediate.end(), negresult.begin(), negresult.end(),
leftover.begin());
Relation newinter;
newinter.splice(newinter.end(), leftover,
leftover.begin(), iit);
intermediate.swap(newinter);
continue;
}
query(*((Condition*)(*it)), allvars, negresult);
minusrel(intermediate, negresult, intermediate);
}
#endif
results.swap(intermediate);
}