AqlValue Expression::executeSimpleExpression (AstNode const* node,
TRI_document_collection_t const** collection,
triagens::arango::AqlTransaction* trx,
AqlItemBlock const* argv,
size_t startPos,
std::vector<Variable const*> const& vars,
std::vector<RegisterId> const& regs,
bool doCopy) {
if (node->type == NODE_TYPE_ATTRIBUTE_ACCESS) {
// object lookup, e.g. users.name
TRI_ASSERT_EXPENSIVE(node->numMembers() == 1);
auto member = node->getMemberUnchecked(0);
auto name = static_cast<char const*>(node->getData());
TRI_document_collection_t const* myCollection = nullptr;
AqlValue result = executeSimpleExpression(member, &myCollection, trx, argv, startPos, vars, regs, false);
auto j = result.extractObjectMember(trx, myCollection, name, true, _buffer);
result.destroy();
return AqlValue(new Json(TRI_UNKNOWN_MEM_ZONE, j.steal()));
}
else if (node->type == NODE_TYPE_INDEXED_ACCESS) {
// array lookup, e.g. users[0]
// note: it depends on the type of the value whether an array lookup or an object lookup is performed
// for example, if the value is an object, then its elements might be accessed like this:
// users['name'] or even users['0'] (as '0' is a valid attribute name, too)
// if the value is an array, then string indexes might also be used and will be converted to integers, e.g.
// users['0'] is the same as users[0], users['-2'] is the same as users[-2] etc.
TRI_ASSERT(node->numMembers() == 2);
auto member = node->getMember(0);
auto index = node->getMember(1);
TRI_document_collection_t const* myCollection = nullptr;
AqlValue result = executeSimpleExpression(member, &myCollection, trx, argv, startPos, vars, regs, false);
if (result.isArray()) {
TRI_document_collection_t const* myCollection2 = nullptr;
AqlValue indexResult = executeSimpleExpression(index, &myCollection2, trx, argv, startPos, vars, regs, false);
if (indexResult.isNumber()) {
auto j = result.extractArrayMember(trx, myCollection, indexResult.toInt64(), true);
indexResult.destroy();
result.destroy();
return AqlValue(new Json(TRI_UNKNOWN_MEM_ZONE, j.steal()));
}
else if (indexResult.isString()) {
auto&& value = indexResult.toString();
indexResult.destroy();
try {
// stoll() might throw an exception if the string is not a number
int64_t position = static_cast<int64_t>(std::stoll(value.c_str()));
auto j = result.extractArrayMember(trx, myCollection, position, true);
result.destroy();
return AqlValue(new Json(TRI_UNKNOWN_MEM_ZONE, j.steal()));
}
catch (...) {
// no number found.
}
}
else {
indexResult.destroy();
}
// fall-through to returning null
}
else if (result.isObject()) {
TRI_document_collection_t const* myCollection2 = nullptr;
AqlValue indexResult = executeSimpleExpression(index, &myCollection2, trx, argv, startPos, vars, regs, false);
if (indexResult.isNumber()) {
auto&& indexString = std::to_string(indexResult.toInt64());
auto j = result.extractObjectMember(trx, myCollection, indexString.c_str(), true, _buffer);
indexResult.destroy();
result.destroy();
return AqlValue(new Json(TRI_UNKNOWN_MEM_ZONE, j.steal()));
}
else if (indexResult.isString()) {
auto&& value = indexResult.toString();
indexResult.destroy();
auto j = result.extractObjectMember(trx, myCollection, value.c_str(), true, _buffer);
result.destroy();
return AqlValue(new Json(TRI_UNKNOWN_MEM_ZONE, j.steal()));
}
else {
indexResult.destroy();
}
// fall-through to returning null
}
result.destroy();
return AqlValue(new Json(TRI_UNKNOWN_MEM_ZONE, &NullJson, Json::NOFREE));
}
else if (node->type == NODE_TYPE_ARRAY) {
if (node->isConstant()) {
auto json = node->computeJson();
if (json == nullptr) {
THROW_ARANGO_EXCEPTION(TRI_ERROR_OUT_OF_MEMORY);
}
// we do not own the JSON but the node does!
return AqlValue(new Json(TRI_UNKNOWN_MEM_ZONE, json, Json::NOFREE));
}
size_t const n = node->numMembers();
std::unique_ptr<Json> array(new Json(Json::Array, n));
for (size_t i = 0; i < n; ++i) {
auto member = node->getMemberUnchecked(i);
TRI_document_collection_t const* myCollection = nullptr;
AqlValue result = executeSimpleExpression(member, &myCollection, trx, argv, startPos, vars, regs, false);
array->add(result.toJson(trx, myCollection, true));
result.destroy();
}
return AqlValue(array.release());
}
else if (node->type == NODE_TYPE_OBJECT) {
if (node->isConstant()) {
auto json = node->computeJson();
if (json == nullptr) {
THROW_ARANGO_EXCEPTION(TRI_ERROR_OUT_OF_MEMORY);
}
// we do not own the JSON but the node does!
return AqlValue(new Json(TRI_UNKNOWN_MEM_ZONE, json, Json::NOFREE));
}
size_t const n = node->numMembers();
std::unique_ptr<Json> object(new Json(Json::Object, n));
for (size_t i = 0; i < n; ++i) {
auto member = node->getMemberUnchecked(i);
TRI_document_collection_t const* myCollection = nullptr;
TRI_ASSERT(member->type == NODE_TYPE_OBJECT_ELEMENT);
auto key = member->getStringValue();
member = member->getMember(0);
AqlValue result = executeSimpleExpression(member, &myCollection, trx, argv, startPos, vars, regs, false);
object->set(key, result.toJson(trx, myCollection, true));
result.destroy();
}
return AqlValue(object.release());
}
else if (node->type == NODE_TYPE_VALUE) {
auto json = node->computeJson();
if (json == nullptr) {
THROW_ARANGO_EXCEPTION(TRI_ERROR_OUT_OF_MEMORY);
}
// we do not own the JSON but the node does!
return AqlValue(new Json(TRI_UNKNOWN_MEM_ZONE, json, Json::NOFREE));
}
else if (node->type == NODE_TYPE_REFERENCE) {
auto v = static_cast<Variable const*>(node->getData());
{
auto it = _variables.find(v);
if (it != _variables.end()) {
*collection = nullptr;
return AqlValue(new Json(TRI_UNKNOWN_MEM_ZONE, TRI_CopyJson(TRI_UNKNOWN_MEM_ZONE, (*it).second))); //, Json::NOFREE));
}
}
size_t i = 0;
for (auto it = vars.begin(); it != vars.end(); ++it, ++i) {
if ((*it)->name == v->name) {
TRI_ASSERT(collection != nullptr);
// save the collection info
*collection = argv->getDocumentCollection(regs[i]);
if (doCopy) {
return argv->getValueReference(startPos, regs[i]).clone();
}
// AqlValue.destroy() will be called for the returned value soon,
// so we must not return the original AqlValue from the AqlItemBlock here
return argv->getValueReference(startPos, regs[i]).shallowClone();
}
}
// fall-through to exception
}
else if (node->type == NODE_TYPE_FCALL) {
// some functions have C++ handlers
// check if the called function has one
auto func = static_cast<Function*>(node->getData());
TRI_ASSERT(func->implementation != nullptr);
auto member = node->getMemberUnchecked(0);
TRI_ASSERT(member->type == NODE_TYPE_ARRAY);
size_t const n = member->numMembers();
FunctionParameters parameters;
parameters.reserve(n);
try {
for (size_t i = 0; i < n; ++i) {
TRI_document_collection_t const* myCollection = nullptr;
auto arg = member->getMemberUnchecked(i);
if (arg->type == NODE_TYPE_COLLECTION) {
parameters.emplace_back(AqlValue(new Json(TRI_UNKNOWN_MEM_ZONE, arg->getStringValue(), arg->getStringLength())), nullptr);
}
else {
auto value = executeSimpleExpression(arg, &myCollection, trx, argv, startPos, vars, regs, false);
parameters.emplace_back(value, myCollection);
}
}
auto res2 = func->implementation(_ast->query(), trx, parameters);
for (auto& it : parameters) {
it.first.destroy();
}
return res2;
}
catch (...) {
// prevent leak and rethrow error
for (auto& it : parameters) {
it.first.destroy();
}
throw;
}
}
else if (node->type == NODE_TYPE_RANGE) {
TRI_document_collection_t const* leftCollection = nullptr;
TRI_document_collection_t const* rightCollection = nullptr;
auto low = node->getMember(0);
auto high = node->getMember(1);
AqlValue resultLow = executeSimpleExpression(low, &leftCollection, trx, argv, startPos, vars, regs, false);
AqlValue resultHigh = executeSimpleExpression(high, &rightCollection, trx, argv, startPos, vars, regs, false);
AqlValue res = AqlValue(resultLow.toInt64(), resultHigh.toInt64());
resultLow.destroy();
resultHigh.destroy();
return res;
}
else if (node->type == NODE_TYPE_OPERATOR_UNARY_NOT) {
TRI_document_collection_t const* myCollection = nullptr;
AqlValue operand = executeSimpleExpression(node->getMember(0), &myCollection, trx, argv, startPos, vars, regs, false);
bool const operandIsTrue = operand.isTrue();
operand.destroy();
return AqlValue(new Json(TRI_UNKNOWN_MEM_ZONE, operandIsTrue ? &FalseJson : &TrueJson, Json::NOFREE));
}
else if (node->type == NODE_TYPE_OPERATOR_BINARY_AND ||
node->type == NODE_TYPE_OPERATOR_BINARY_OR) {
TRI_document_collection_t const* leftCollection = nullptr;
AqlValue left = executeSimpleExpression(node->getMember(0), &leftCollection, trx, argv, startPos, vars, regs, true);
TRI_document_collection_t const* rightCollection = nullptr;
AqlValue right = executeSimpleExpression(node->getMember(1), &rightCollection, trx, argv, startPos, vars, regs, true);
if (node->type == NODE_TYPE_OPERATOR_BINARY_AND) {
// AND
if (left.isTrue()) {
// left is true => return right
left.destroy();
return right;
}
// left is false, return left
right.destroy();
return left;
}
else {
// OR
if (left.isTrue()) {
// left is true => return left
right.destroy();
return left;
}
// left is false => return right
left.destroy();
return right;
}
}
else if (node->type == NODE_TYPE_OPERATOR_BINARY_EQ ||
node->type == NODE_TYPE_OPERATOR_BINARY_NE ||
node->type == NODE_TYPE_OPERATOR_BINARY_LT ||
node->type == NODE_TYPE_OPERATOR_BINARY_LE ||
node->type == NODE_TYPE_OPERATOR_BINARY_GT ||
node->type == NODE_TYPE_OPERATOR_BINARY_GE ||
node->type == NODE_TYPE_OPERATOR_BINARY_IN ||
node->type == NODE_TYPE_OPERATOR_BINARY_NIN) {
TRI_document_collection_t const* leftCollection = nullptr;
AqlValue left = executeSimpleExpression(node->getMember(0), &leftCollection, trx, argv, startPos, vars, regs, false);
TRI_document_collection_t const* rightCollection = nullptr;
AqlValue right = executeSimpleExpression(node->getMember(1), &rightCollection, trx, argv, startPos, vars, regs, false);
if (node->type == NODE_TYPE_OPERATOR_BINARY_IN ||
node->type == NODE_TYPE_OPERATOR_BINARY_NIN) {
// IN and NOT IN
if (! right.isArray()) {
// right operand must be a list, otherwise we return false
left.destroy();
right.destroy();
// do not throw, but return "false" instead
return AqlValue(new Json(TRI_UNKNOWN_MEM_ZONE, &FalseJson, Json::NOFREE));
}
bool result = findInArray(left, right, leftCollection, rightCollection, trx, node);
if (node->type == NODE_TYPE_OPERATOR_BINARY_NIN) {
// revert the result in case of a NOT IN
result = ! result;
}
left.destroy();
right.destroy();
return AqlValue(new triagens::basics::Json(result));
}
// all other comparison operators...
// for equality and non-equality we can use a binary comparison
bool compareUtf8 = (node->type != NODE_TYPE_OPERATOR_BINARY_EQ && node->type != NODE_TYPE_OPERATOR_BINARY_NE);
int compareResult = AqlValue::Compare(trx, left, leftCollection, right, rightCollection, compareUtf8);
left.destroy();
right.destroy();
if (node->type == NODE_TYPE_OPERATOR_BINARY_EQ) {
return AqlValue(new Json(TRI_UNKNOWN_MEM_ZONE, (compareResult == 0) ? &TrueJson : &FalseJson, Json::NOFREE));
}
else if (node->type == NODE_TYPE_OPERATOR_BINARY_NE) {
return AqlValue(new Json(TRI_UNKNOWN_MEM_ZONE, (compareResult != 0) ? &TrueJson : &FalseJson, Json::NOFREE));
}
else if (node->type == NODE_TYPE_OPERATOR_BINARY_LT) {
return AqlValue(new Json(TRI_UNKNOWN_MEM_ZONE, (compareResult < 0) ? &TrueJson : &FalseJson, Json::NOFREE));
}
else if (node->type == NODE_TYPE_OPERATOR_BINARY_LE) {
return AqlValue(new Json(TRI_UNKNOWN_MEM_ZONE, (compareResult <= 0) ? &TrueJson : &FalseJson, Json::NOFREE));
}
else if (node->type == NODE_TYPE_OPERATOR_BINARY_GT) {
return AqlValue(new Json(TRI_UNKNOWN_MEM_ZONE, (compareResult > 0) ? &TrueJson : &FalseJson, Json::NOFREE));
}
else if (node->type == NODE_TYPE_OPERATOR_BINARY_GE) {
return AqlValue(new Json(TRI_UNKNOWN_MEM_ZONE, (compareResult >= 0) ? &TrueJson : &FalseJson, Json::NOFREE));
}
// fall-through intentional
}
else if (node->type == NODE_TYPE_OPERATOR_TERNARY) {
TRI_document_collection_t const* myCollection = nullptr;
AqlValue condition = executeSimpleExpression(node->getMember(0), &myCollection, trx, argv, startPos, vars, regs, false);
bool const isTrue = condition.isTrue();
condition.destroy();
if (isTrue) {
// return true part
return executeSimpleExpression(node->getMember(1), &myCollection, trx, argv, startPos, vars, regs, true);
}
// return false part
return executeSimpleExpression(node->getMember(2), &myCollection, trx, argv, startPos, vars, regs, true);
}
else if (node->type == NODE_TYPE_EXPANSION) {
TRI_ASSERT(node->numMembers() == 5);
// LIMIT
int64_t offset = 0;
int64_t count = INT64_MAX;
auto limitNode = node->getMember(3);
if (limitNode->type != NODE_TYPE_NOP) {
TRI_document_collection_t const* subCollection = nullptr;
AqlValue sub = executeSimpleExpression(limitNode->getMember(0), &subCollection, trx, argv, startPos, vars, regs, false);
offset = sub.toInt64();
sub.destroy();
subCollection = nullptr;
sub = executeSimpleExpression(limitNode->getMember(1), &subCollection, trx, argv, startPos, vars, regs, false);
count = sub.toInt64();
sub.destroy();
}
if (offset < 0 || count <= 0) {
// no items to return... can already stop here
return AqlValue(new triagens::basics::Json(triagens::basics::Json::Array));
}
// FILTER
AstNode const* filterNode = node->getMember(2);
if (filterNode->type == NODE_TYPE_NOP) {
filterNode = nullptr;
}
else if (filterNode->isConstant()) {
if (filterNode->isTrue()) {
// filter expression is always true
filterNode = nullptr;
}
else {
// filter expression is always false
return AqlValue(new triagens::basics::Json(triagens::basics::Json::Array));
}
}
auto iterator = node->getMember(0);
auto variable = static_cast<Variable*>(iterator->getMember(0)->getData());
auto levels = node->getIntValue(true);
AqlValue value;
if (levels > 1) {
// flatten value...
// generate a new temporary for the flattened array
std::unique_ptr<Json> flattened(new Json(Json::Array));
TRI_document_collection_t const* myCollection = nullptr;
value = executeSimpleExpression(node->getMember(0), &myCollection, trx, argv, startPos, vars, regs, false);
if (! value.isArray()) {
// must cast value to array first
FunctionParameters parameters{ std::make_pair(value, myCollection) };
auto res = Functions::ToArray(_ast->query(), trx, parameters);
// destroy old value and swap with function call result
value.destroy();
value = res;
}
std::function<void(TRI_json_t const*, int64_t)> flatten = [&] (TRI_json_t const* json, int64_t level) {
if (! TRI_IsArrayJson(json)) {
return;
}
size_t const n = TRI_LengthArrayJson(json);
for (size_t i = 0; i < n; ++i) {
auto item = static_cast<TRI_json_t const*>(TRI_AtVector(&json->_value._objects, i));
bool const isArray = TRI_IsArrayJson(item);
if (! isArray || level == levels) {
flattened->add(TRI_CopyJson(TRI_UNKNOWN_MEM_ZONE, item));
}
else if (isArray && level < levels) {
flatten(item, level + 1);
}
}
};
auto subJson = value.toJson(trx, myCollection, false);
flatten(subJson.json(), 1);
value.destroy();
value = AqlValue(flattened.release());
}
else {
TRI_document_collection_t const* myCollection = nullptr;
value = executeSimpleExpression(node->getMember(0), &myCollection, trx, argv, startPos, vars, regs, false);
if (! value.isArray()) {
// must cast value to array first
FunctionParameters parameters{ std::make_pair(value, myCollection) };
auto res = Functions::ToArray(_ast->query(), trx, parameters);
// destroy old value and swap with function call result
value.destroy();
value = res;
}
}
// RETURN
// the default is to return array member unmodified
AstNode const* projectionNode = node->getMember(1);
if (node->getMember(4)->type != NODE_TYPE_NOP) {
// return projection
projectionNode = node->getMember(4);
}
size_t const n = value.arraySize();
std::unique_ptr<Json> array(new Json(Json::Array, n));
for (size_t i = 0; i < n; ++i) {
// TODO: check why we must copy the array member. will crash without copying!
TRI_document_collection_t const* myCollection = nullptr;
auto arrayItem = value.extractArrayMember(trx, myCollection, i, true);
setVariable(variable, arrayItem.json());
bool takeItem = true;
if (filterNode != nullptr) {
// have a filter
TRI_document_collection_t const* subCollection = nullptr;
AqlValue sub = executeSimpleExpression(filterNode, &subCollection, trx, argv, startPos, vars, regs, false);
takeItem = sub.isTrue();
sub.destroy();
}
if (takeItem && offset > 0) {
// there is an offset in place
--offset;
takeItem = false;
}
if (takeItem) {
TRI_document_collection_t const* subCollection = nullptr;
AqlValue sub = executeSimpleExpression(projectionNode, &subCollection, trx, argv, startPos, vars, regs, true);
array->add(sub.toJson(trx, subCollection, true));
sub.destroy();
}
clearVariable(variable);
arrayItem.destroy();
if (takeItem && count > 0) {
// number of items to pick was restricted
if (--count == 0) {
// done
break;
}
}
}
value.destroy();
return AqlValue(array.release());
}
else if (node->type == NODE_TYPE_ITERATOR) {
TRI_ASSERT(node != nullptr);
TRI_ASSERT(node->numMembers() == 2);
// intentionally do not stringify node 0
TRI_document_collection_t const* myCollection = nullptr;
AqlValue value = executeSimpleExpression(node->getMember(1), &myCollection, trx, argv, startPos, vars, regs, true);
return value;
}
std::string msg("unhandled type '");
msg.append(node->getTypeString());
msg.append("' in executeSimpleExpression()");
THROW_ARANGO_EXCEPTION_MESSAGE(TRI_ERROR_INTERNAL, msg.c_str());
}
bool Expression::findInArray (AqlValue const& left,
AqlValue const& right,
TRI_document_collection_t const* leftCollection,
TRI_document_collection_t const* rightCollection,
triagens::arango::AqlTransaction* trx,
AstNode const* node) const {
TRI_ASSERT_EXPENSIVE(right.isArray());
size_t const n = right.arraySize();
if (node->getMember(1)->isSorted()) {
// node values are sorted. can use binary search
size_t l = 0;
size_t r = n - 1;
while (true) {
// determine midpoint
size_t m = l + ((r - l) / 2);
auto arrayItem = right.extractArrayMember(trx, rightCollection, m, false);
AqlValue arrayItemValue(&arrayItem);
int compareResult = AqlValue::Compare(trx, left, leftCollection, arrayItemValue, nullptr, false);
if (compareResult == 0) {
// item found in the list
return true;
}
if (compareResult < 0) {
if (m == 0) {
// not found
return false;
}
r = m - 1;
}
else {
l = m + 1;
}
if (r < l) {
return false;
}
}
}
else {
// use linear search
for (size_t i = 0; i < n; ++i) {
// do not copy the list element we're looking at
auto arrayItem = right.extractArrayMember(trx, rightCollection, i, false);
AqlValue arrayItemValue(&arrayItem);
int compareResult = AqlValue::Compare(trx, left, leftCollection, arrayItemValue, nullptr, false);
if (compareResult == 0) {
// item found in the list
return true;
}
}
return false;
}
}