StatusWith<ParsedDistinct> ParsedDistinct::parse(OperationContext* txn,
const NamespaceString& nss,
const BSONObj& cmdObj,
const ExtensionsCallback& extensionsCallback,
bool isExplain) {
// Extract the key field.
BSONElement keyElt;
auto statusKey = bsonExtractTypedField(cmdObj, kKeyField, BSONType::String, &keyElt);
if (!statusKey.isOK()) {
return {statusKey};
}
auto key = keyElt.valuestrsafe();
auto qr = stdx::make_unique<QueryRequest>(nss);
// Extract the query field. If the query field is nonexistent, an empty query is used.
if (BSONElement queryElt = cmdObj[kQueryField]) {
if (queryElt.type() == BSONType::Object) {
qr->setFilter(queryElt.embeddedObject());
} else if (queryElt.type() != BSONType::jstNULL) {
return Status(ErrorCodes::TypeMismatch,
str::stream() << "\"" << kQueryField << "\" had the wrong type. Expected "
<< typeName(BSONType::Object)
<< " or "
<< typeName(BSONType::jstNULL)
<< ", found "
<< typeName(queryElt.type()));
}
}
// Extract the collation field, if it exists.
if (BSONElement collationElt = cmdObj[kCollationField]) {
if (collationElt.type() != BSONType::Object) {
return Status(ErrorCodes::TypeMismatch,
str::stream() << "\"" << kCollationField
<< "\" had the wrong type. Expected "
<< typeName(BSONType::Object)
<< ", found "
<< typeName(collationElt.type()));
}
qr->setCollation(collationElt.embeddedObject());
}
qr->setExplain(isExplain);
auto cq = CanonicalQuery::canonicalize(txn, std::move(qr), extensionsCallback);
if (!cq.isOK()) {
return cq.getStatus();
}
return ParsedDistinct(std::move(cq.getValue()), std::move(key));
}
StatusWith<ParsedDistinct> ParsedDistinct::parse(OperationContext* opCtx,
const NamespaceString& nss,
const BSONObj& cmdObj,
const ExtensionsCallback& extensionsCallback,
bool isExplain,
const CollatorInterface* defaultCollator) {
IDLParserErrorContext ctx("distinct");
DistinctCommand parsedDistinct(nss);
try {
parsedDistinct = DistinctCommand::parse(ctx, cmdObj);
} catch (...) {
return exceptionToStatus();
}
auto qr = stdx::make_unique<QueryRequest>(nss);
if (parsedDistinct.getKey().find('\0') != std::string::npos) {
return Status(ErrorCodes::Error(31032), "Key field cannot contain an embedded null byte");
}
// Create a projection on the fields needed by the distinct command, so that the query planner
// will produce a covered plan if possible.
qr->setProj(getDistinctProjection(std::string(parsedDistinct.getKey())));
if (auto query = parsedDistinct.getQuery()) {
qr->setFilter(query.get());
}
if (auto collation = parsedDistinct.getCollation()) {
qr->setCollation(collation.get());
}
if (auto comment = parsedDistinct.getComment()) {
qr->setComment(comment.get().toString());
}
// The IDL parser above does not handle generic command arguments. Since the underlying query
// request requires the following options, manually parse and verify them here.
if (auto readConcernElt = cmdObj[repl::ReadConcernArgs::kReadConcernFieldName]) {
if (readConcernElt.type() != BSONType::Object) {
return Status(ErrorCodes::TypeMismatch,
str::stream() << "\"" << repl::ReadConcernArgs::kReadConcernFieldName
<< "\" had the wrong type. Expected "
<< typeName(BSONType::Object)
<< ", found "
<< typeName(readConcernElt.type()));
}
qr->setReadConcern(readConcernElt.embeddedObject());
}
if (auto queryOptionsElt = cmdObj[QueryRequest::kUnwrappedReadPrefField]) {
if (queryOptionsElt.type() != BSONType::Object) {
return Status(ErrorCodes::TypeMismatch,
str::stream() << "\"" << QueryRequest::kUnwrappedReadPrefField
<< "\" had the wrong type. Expected "
<< typeName(BSONType::Object)
<< ", found "
<< typeName(queryOptionsElt.type()));
}
qr->setUnwrappedReadPref(queryOptionsElt.embeddedObject());
}
if (auto maxTimeMSElt = cmdObj[QueryRequest::cmdOptionMaxTimeMS]) {
auto maxTimeMS = QueryRequest::parseMaxTimeMS(maxTimeMSElt);
if (!maxTimeMS.isOK()) {
return maxTimeMS.getStatus();
}
qr->setMaxTimeMS(static_cast<unsigned int>(maxTimeMS.getValue()));
}
qr->setExplain(isExplain);
const boost::intrusive_ptr<ExpressionContext> expCtx;
auto cq = CanonicalQuery::canonicalize(opCtx,
std::move(qr),
expCtx,
extensionsCallback,
MatchExpressionParser::kAllowAllSpecialFeatures);
if (!cq.isOK()) {
return cq.getStatus();
}
if (cq.getValue()->getQueryRequest().getCollation().isEmpty() && defaultCollator) {
cq.getValue()->setCollator(defaultCollator->clone());
}
return ParsedDistinct(std::move(cq.getValue()), parsedDistinct.getKey().toString());
}
